Adiabatic Invariants

linking unknown work to known

2011-11-14T04:55:00.000-08:00

The job I need to do right now is to implement Radia kick maps in AT. Its something that's been done before in other codes, and probably even in AT before. I have a supervisor who knows enough about it to help me with it, and is interested that I do it. So why do I go so slowly?
One of the problems is that I see this as an obscure topic that only a few people understand. Further its already been done before, so I am not breaking new ground. So its hard to gather motivation, since there will be few people who can benefit from this and some people who know that its not even new.

What would be valuable about it, is if it allows the code to be easier to use in the process and connects the topic both conceptually and software-wise to a larger community. So, to get myself to do it, I sit in a place which is more well-known and approach the problem with pedagogic bent. Initially, I came to the problem from the beam dynamics side. From here, one is naturally led to the questions of dynamic aperture and lifetime. But the kick maps come from insertion devices which are there for the purpose of creating the x-rays. So now I learn the Radia code, and try to sit on that side. Somehow in the piecing together of these two perspectives, I hope to make it a little more useful or at least understandable, and hopefully not take the rest of my life to do it. (really its not so hard, and perhaps one could say I'm just lazy and procrastinating writing such posts as this)

physics of photons and needs of SR experiments

2011-11-03T01:54:00.000-07:00

On the topic of #3 from my last post, I try to learn a bit of how to understand photons. I posted a question on Stack Exchange here. I referenced a paper by KJ Kim on the Wigner function approach to synchrotron radiation, and asked the question:

When one represents radiation via a Wigner function, is this really quantum mechanics?

I got some links to papers about Wigner functions and about photons. I think that quantum optics has a lot to say on this topic, but unfortunately I seem to have lost my copy of Mandel and Wolf. I was referred to papers on the wave function of a photon, such as this by Iwo Bialynicki-Birula. The wave function defined by Bialynicki-Birula is referenced here in a 2011 New Journal of Physics article by Saldanha and Monken. In this article, they extend the photon wave function approach to "to include the interaction of photons with non-absorptive continuous media."

I was interested in this question because I wanted to understand undulator radiation better. The question is what one should calculate? How should one represent the radiation such that it covers the properties used by the experiments with synchrotron radiation? In "Undulators, Wigglers and Their Applications", edited by Elleaume and Onuki, the brilliance is identified with the Wigner function and is computed for undulators, wigglers and bending magnets. Its a dense book, but contains an up-do-date perspective on these topics. Regarding codes, the synchrotron radiation may be computed in the near field with SRW. But this just computes different components of the Electric field for a given electron beam source and undulator construction. What to do with the output, and are there still open foundational questions?

Once one knows the radiation fields, one can propagate them, and probably ray optics is sufficient for most purposes. The Shadow code may be used for this purpose, and allows one to enter lenses, mirrors and other optical components in the x-ray beamline.

So, this is sort of the the landscape, as far as books, theoretical frameworks, and software for synchrotron radiation. Certainly I'm biased to that used at my institute, but I think it covers a good amount.

For some practical questions, I think one can look at how some different electron beam parameters affect the photon beam. For example, the electron beam energy spread, or the tilt angle of the electron beam. Next, the question is, for the experiments one does with the radiation, what are really the important parameters. Brightness is important, but it seems to be a stand-in for a more detailed case by case examination. Does one need large numbers of photons (flux?), does one want a round beam? Are the coherence properties of the x-rays important? In the latter case, it appears that the Wigner function does not tell all, but in faction one needs to compute the mutual intensity (the argument of the integral in the definition of the Wigner function).

research topics/work to do.

2011-10-25T13:31:00.000-07:00

I've been continuing with this effort of finding links between beam dynamics and other areas. I met with some theorists to try to explain what are some of the problems here, and see if I could find stuff in common. In general, I've been trying to find other areas of physics that could have things in common with beam dynamics and synchrotron radiation physics. But in order to do this, I need to identify what areas of beam dynamics are really research topics that could use developing. So here is my attempt to point out what I think are still somewhat hard, but maybe tractable problems to be worked on.

Single particle dynamics :Given a one turn map- find the long behavior. What is the stable region ? What happens when damping is added ? Can we find the right parameters from the one-turn map that effect the long term behavior ? Has this problem been solved in chaotic map literature?
Collective effects: Distribution with diffusion, damping, feedback. Instability due to one effect may be limited by other effects. Is there a theory in this range ?
Want to know emittance growth, non-Gaussain distributions.
Analysis of Fokker-Planck. Maybe more terms as in Master equation is needed sometimes?
Radiation from electron beam:Interface between electron beam and photons. Definition of Wigner function. Sometimes negative. Not fully understood.
Need to define photon beam operationally based on how the photons will interact, be focussed by optics, etc.
Radiation from spin-polarized electrons?

Now, there's certainly been work done on each of these. For the first, we have the whole theory of normal form. For the second, we have all the stuff about mode frequencies and instabilities, and covers the basics of equilibrium distributions. And the third is the basic way things are computed, but there's still some confusion. But it would be nice to point these a little more directly towards the applications in biology, chemistry and solid state physics.
On the software end, there's work to be done on the electron side and on the code side. On the electron side, we have many codes. Personally I think AT is good to develop, since its in Matlab and easier to add to. Elegant is also nice, though open and extendable in the same way. On the radiation side, we have SRW to compute the radiation in the near field, right out of the bending magnets or undulators. Then there's Shadow which tracks the radiation further down the beam line. There may be some work underway to combine these together in some way.

For myself, I just like to see this big picture. Of course I can only work on a very small amount of this. But I'd at least like to work on something within a bigger picture that makes sense to me.

electron properties (AT) and x-ray properties

2011-10-18T16:48:00.000-07:00

Well, the talk went pretty well. People told me they understood stuff and hadn't heard a comprehensive talk on this topic before. I have a few new contacts.

Now, I need to figure out what to do next. Basically, I see two areas. One is to start to really learn about radiation in undulators and keep in mind the question of whether the details of the electron distribution may yield something potentially interesting. The second is to be able to use AT better and make it better. Perhaps try to encourage and help write a non-linear dynamics optimization package? But this is still the ugly topic. Maybe this can be a foundation to do it better? We might as well at least implement some of the stuff that is known to work. And probably people already have. There's also the kick maps for tracking. Do I really recapitulate this history and keep going with the power series maps?

Hard to get motivated with this again, but I feel like its necessary (at least once more? probably multiple times...) When this problem gets too small, I completely lose interest. Need to remember some of the big questions, and think about clean implementations.
Overview:
1)Radiation brightness and beam size, 2) physics of one electron, 3) electron beam emittance, size and shape, 4)beam lifetime

The other issue here is the return to "work". I have to get back to concrete work with respect to understanding how the machine works, where the files are, and how to model it using AT. Expansion of networks and joining with other areas is important, but there has to be something there to join with. What is useful to model and understand? Can one be in some way comprehensive and systematic, or is this hopeless?

talk

2011-09-26T23:01:00.000-07:00

I'm preparing a talk for this Friday. Its been a long time coming, but somehow my preparation is not where it should be. Its ok.

I will talk about the physics of electron beams in a synchrotron. The goal is to explain the origin of the equilibrium beam sizes and the beam lifetime. What I'd like to say is that these are two basic things everyone should understand if you want to know where your photon beam comes from. From a web perspective, I think these topics are not well covered. Here is beam emittance on wikipedia. The fact that an equilibrium emittance exists for an electron ring, independent of the initial distribution isn't mentioned. The perspective is entirely from non-radiating (or not much) hadron storage rings.

The first question is how do you store an electron. Basically, you create a 6-D harmonic oscillator. Transversely this comes from quadrupole magnets. Longitudinally, this comes from an RF cavity. Using quadrupoles to create a stable quadradatic potential was not discovered immediately. It is referred to as the concept of Strong Focusing, and was found by Courant and Snyder and by Cristofolis independently. The problem is that a quadrupolar magnet field focuses in one direction, but is defocusing in the perpendicular direction. However, by creating a system of several quadrupoles of alternating polarity, one can create a net focusing effect.

So, we have a stable bucket both transversely and longitudinally. Now what? Throw an electron in there! Next, we observe that the energy loss through radiation depends on the energy in such a way that a higher energy electron loses more, and a lower energy electron loses less. Thus we have a damping effect where the electron will head towards a fixed value. This damping effect also comes into the transverse dimensions, and thus overall a bunch of electrons wants to spiral down to a single point in phase space.

What stops the spiraling process? What comes into play to limit the beam size. First, one may imagine it is the coulomb repulsion. However this turns out to be extremely small for a relativistic beam. Basically, the electric repulsion is cancelled (reduced by gamma squared) by the magnetic attraction.

The effect that does set the beam size is the quantum nature of the radiation. The radiation is emitted in photons, and indeed a rather small number of them. This causes a randomness in the energy change that results in a diffusion process. This diffusion, together with the radiation damping effect mentioned cause the equilibrium beam sizes.

The interaction between the electrons is important however. The typical interactions are quite small, but the less frequent short range scattering causes large energy changes which may result in an electron being lost. This is the source of the beam lifetime (actually there's also a part from scattering off the gas in the chamber.).

That's the basic story I want to get across.

Becoming comfortable with

2011-08-29T05:04:00.000-07:00

Both of my parents have moved to remote places, with unique communities, and are rather isolated in some ways. Had I grown up in either of these places, I think I would have wanted to escape in some way. I might have longed for something different and looked at how to get out, geographically, socially, and regarding lifestyle and mentality.

At this point in my life, I am only a visitor in these places. But arriving in each one, I get the feeling of being pulled into a black hole, with little communication to the rest of my life, and not sure how to connect the experience to who I am. At the same time, I am adaptable, and arriving, and within the experience, it has an integrity and a quality to it that is quite nice. But the boundaries are difficult. I can't think my way into it from outside, or out of it from inside.

So I have slowly worked on the problem over the years by looking carefully at the boundaries. In the remote town in California where my father lives, for example, I look to see whether there are surrounding communities that might have some life to them. I try to find things in common to other places regarding environment and landscape. I plan trips there with an exit strategy, and friends and other family flanking it. Certainly this is also quite personal, and relates to my own experience of family and who I am there, and who I am seen as. I am starting to try the same strategy with my mother's house in Iowa. There, the boundaries are physical, but there is also a strong ideological barrier that is uncomfortable to me. Is there something within that I can relate to? I find pieces of interest to that community that I might interpret in a different way, but still find interesting.

Is such an elaborate process necessary? Maybe I will reach a point where it will seem smaller and less important, but somehow this work is necessary. The other option is to say that visiting my family is too difficult, and no common ground can be found, but I don't want to do that.

On the Petrolia side, there is the natural environment. The trees, the river, the ocean.
On the MUM/Fairfield side, there is the nearby Mississippi river. There are coffee shops in Fairfield. Ideologically, MUM is more challenging. The Maharishi is a figure that I just have a very hard time appreciating. And the closed mentality fosters an inside/outside split that is hard to overcome. One of the Maharishi's main texts he interpretted and based his power around has been the Baghavad Gita. I think this is something I could become interested in.

Back to the mess

2011-08-28T23:45:00.000-07:00

I have to finish a paper for a conference by Wednesday night. It is on the measurements relating to Touschek lifetime and momentum acceptance. There's an analysis of data to be done, and general writing and preparation of the paper. I really don't want to work on it.

Why don't I want to do it? Its late, I know. A paper needs to be written, and doing an analysis at the last minute can derail me from the process of fixing figures, adding references, and putting a clear narrative together. But its also that I've gotten myself out of thinking of this topic, and am wary of going back. It was my compromise. I will not leave accelerator physics entirely. I will do some work in this field, but move outward at the same time. But the topic is a mess for me. It is a personal mess in that my own files and documents and the relevant equations are not in such clear order. And a general historical mess in that it relates to the topic of dynamic aperture and sextupole optimization which is an unsolved problem. That question of dynamic aperture and stability has been the piece that I have slowly worked on, and tried to lay out a personal groundwork, so I don't feel so lost working in that area. Maybe this is a reflection of the fact that I didn't really finish this process.

So, my own angle on Touschek lifetime and measurement that I would like to get across is that the measurements are a diagnostic for the various lattice optimizations. There is both vertical emittance reduction goals, and increase of momentum acceptance via sextupole optimization. Stating clearly what these mean, and having measurements to ground discussion and results puts this other more nebulous "accelerator physics" activity onto a ground that relates to the goal of the machine- production of stable, long lived synchrotron radiation.

online

2011-08-18T03:00:00.000-07:00

Can we get beyond talking about people "living online"?
Along the lines of this post from Crooked Timber, I think the metaphor has gone too far.
Yes, the modes of communication have expanded, and there things that we do that are interacting directly with software (and perhaps with others in a delayed way, such as blogging!), rather than directly with people, but we are not living online.
What does the question "are you online?" mean these days? Yes, we may be available or not to communicate via a variety of channels, but no "we" are not online. I'm still here, in this room, breathing, as usual.
Perhaps "living online" is used in the sense of "living in one's head", which is generally not though of as such a good thing to do.
I guess, as a general topic, and as a source for personal time and space and energy management, I want to limit the extent to which one says "we" are online. Things like Facebook have an almost avatar like quality to them, where a certain amount of our information is packaged and available to others even when we are not available. It sort of represents us. How this fits in is something to continue to struggle with, but I just need to remind myself at times, that I am here, and these are modes of communication. We do say that google can be like extended memory, but I just don't want to go down that path. Perhaps people of the future will have some kind of choice like this to make, but for myself, I am who I am, not changed so much, but with a few more communication and knowledge access tools.

What Technology Wants

2011-08-10T08:50:00.001-07:00

I recently read Kevin Kelly's "What Technology Wants". I think my biggest complaint is the lack of humility when it comes to the big ideas, particularly with respect to the ill-defined "technium". The claims are grand and vague on the one hand, and at the same time it is stated that it is expected that these concepts will go through a number of iterations and changes over time. Stephen Wolfram's "A New Kind of Science" had a similar grandiosity to it. It allows the author some maneuver room later to claim further developments under his/her rubric.

I think one can classify this book under the category of books where the author holds two divergent view points and tries to build some kind of narrative that encompasses the two. In this case, Kelly seems to have some kind of Christian God viewpoint that he is seeking to capture in the "Technium", and at the same time has the computer science and general science background that is perhaps less able to make statements about overall meaning or goal orientation in the universe. I think this dissonance can occur in scientists who also have religious commitments. John Hagelin's writings connecting Transcendental Meditation to Unified field theories is one example. Frank Tipler's "Physics of Immortality" is another. Fritjof Capra's "The Tau of Physics" is another example, but I think less difficult to swallow. (Actually these first two struck me as so strange that I doubted the honesty of the authors, whereas with Capra, and here with Kelly, one feels a fervency that doesn't seem so forced, even if the logic is flawed. Perhaps the real dishonesty simply comes in with the claiming that such an integration has been achieved, and this could indeed relate to high levels of self-deception.) In all of these works, it would be nice to see a section evaluating how well the author believes such a synthesis has worked. But perhaps the existence of such a section would have a rhetorical effect of diminishing the power of the hoped for unification.

I did really appreciate Kelly's discussion of the Amish, and in general about ways of thinking about adoption of technology and the imperative that one (individually and collectively) have the option of saying no sometimes. And his discussion of the "Technium" did make me want to seek out a more precise definition of some collection of human created artifacts and tools including some ideas, culture, and laws perhaps, that might usefully be viewed as having a sort of unity to it. The identification of this not well articulated entity with a biological entity did not seem to be so well founded. Clearly it is the recent widespread adoption and development of some internet communication technologies that provides the ground for such speculations and theorizing. In any case, it seems to be the same kind of thinking in conspiracy theories where agency is ascribed to some larger entity that may contain people as elements. Certainly one can find some truth out of this kind of thinking, but it seems to often lead to more errors and less clarity than it illuminates.

(Update... here is an interview of K.K. on his explicit religious views about the "technium")

Thinking a little further, I think that what we should celebrate (and engage with) in this book, is the fact that Kelly is articulating a system of values here. In particular, he is willing to say and argue as why technology is intrinsically "good". I'll have to track down the relevant quote, but the basic point he makes is that each technology has a possibility to be used in both positive and negative ways. However, the very existence of this choice is what tips it to the positive. Do I believe this? Its not obviously wrong. And in fact it may be part of what motivates me to contribute to the world of ideas and technology. Its hard to say that its always true, though. Can we stomach it for guns, say? A gun allows you the new choice to either defend yourself, or to injure/kill someone else. There are certainly some who would argue that this choice is not a net benefit for society. For the case of the Amish, Kelly wants to say that their choices to reject a given technology are appropriate for them, but not necessarily overall. So his encouragement of this practice doesn't invalidate his larger point. What about the bigger, more questionable technologies (genetic engineering, nanotechnology, and nuclear). I think he wants to say that even here, more choice is better, even if those choices seem pretty odd. (With nuclear weapons, one has the new choice to blow up this city, or that city. Ok, maybe one can conceive of positive options, but it seems likely that as a whole, the options created are not really a net gain.)
Anyway, it seems to be a somewhat slim blanket justification, but it is better than a complete lack of engagement in ethics, which is the norm for technologists.

Qualifying this somewhat... I guess, the main point (or guess, or suggestion) Kelly makes is that technology is slightly more "good" than "bad". So even if sometimes the creation of more options isn't "good", if the options produced by most technologies are on the whole "good", then it could still come out ahead. The question then might become, what is this unified thing that is slightly more good than bad? Is it really one thing, or have the good things just somehow been selected. Are repugnant political philosophies that yield great harm on humanity considered part of the technium? Or does he really just have something like the current manifestation of the internet and the associated technologies that are required to create a sort of closure surrounding that?

time

2011-04-14T00:42:00.000-07:00

There is a rhythm to my life in France that seems to involve patience in new ways than I have experienced previously. It seems to require that I put faith into systems and processes that move slower than I am accustomed to working with. And at the same time, these processes seem hidden, and my instinct is to doubt and wonder whether they are in fact real, even though time and again they show progress and stability. It is something like observing the process of growth of a plant from a seed. There is a logic and robustness to the process, and unless one has watched this particular kind of seed grow before, one can't really look at the current state and figure out where it will go. Instead, one just continues to water, continues to protect, and has faith that something with come of all this.

Back to Cartwright

2011-03-14T07:49:00.000-07:00

I seem to keep coming back to reading "How the Laws of Physics Lie" and "The Dappled World".
I think the reason is that I don't usually get very far. I get bogged down, skip ahead, and feel annoyed. I get a little out of it, but its dense, and the meaning of an essay is often not what I thought it was going to be. I didn't realize that the examples such as the BCS theory of superconductivity, and some laser physics (Also the measurement problem and the relations between classical and quantum systems) were gone into in such detail. The exposition is actually pretty clear, but you don't often know so much detail is on its way.

Anyway, I've finally been getting to the end and actually understanding more of it. In the end, it is more inspirational for a practicing physicist than I thought. The essay on the Quantum measurement problem in HLPL ends with stating that one should take the formalism of quantum statistical mechanics seriously which treats mixtures and superpositions on the same footing. This leaves physicists with the job of figuring out which cases have unitary evolution and which don't. And I think this is in line with the way one analyzes a new phenomena. Take a look at it. Use what we already know. Make some guesses. Test them. Refine them. An approach to learning about new things that involves actually studying those things.

And the discussion about capacities, vs. laws, is not so radical in the end. Perhaps from a philosophy perspective it is. But thinking of electric charge and gravitational mass as imbuing capacities on electrons rather than laying out laws of motion is just the way one thinks about these things. We learn about certain aspects of things, and then we may try to isolate it such that just that one property comes into play. This is what fundamental experiments are about. And we do learn some real about these things. The question may arise as to whether the same effect occurs in different environments, or exactly how the forces or whatever other properties combine when acting in concert. And this way of looking at physical knowledge puts it in the same box as other knowledge we have. There still may be questions of reduction or relationships between different kinds of knowledge, but the starting point seems good.

I must say I'm still not sure I get what she means by nomological machine. She makes a "strong claim" in "The Dappled World" that behind every regularity in the world is a nomological machine. Let's say we are in Switzerland where trains are highly reliable. The matching of the trains to the schedule is a nomological machine? I suppose it is. And the fact that my car (usually) works is a nomological machine. And atoms are nomological machines. And proteins are nomological machines. And a market is a nomological machine. And a beam of light is a nomological machine.

Anyway, just to remind that getting into certain details can be demotivating if one gets stuck in them, but if a topic actually relates to the world and the way things really work, then understanding it will lead to more tools and more clarity in the end. Which is to say that previously, reading this made me shut down certain ways of thinking, but now I find it mainly adds.

Apparently Philip Anderson may have had some trouble following "Dappled World" as well.

I just read Anderson's review (see here). Wow, that's pretty intense. He refers a lot to the feeling he gets about it. "One gets the feeling" he states a lot, without actually quoting many passages, or covering arguments. I must admit, that I sometimes had these same "feelings". But reading more closely, I often found that Cartwright was saying something more precise and more interesting than I initially thought.

Here are other reviews of The Dappled World.

Finally, once one digests some of the seemingly right arguments, one would like to see engagement of other authors. Here's some essays doing this. In particular, I'd like to understand this one by Carl Hoefer in defense of "fundamentalism". He concludes with

To engineers and experimentalists, I commend Cartwright’s philosophy of science wholeheartedly. But I hope to have made space for theoreticians and philosophers of physics to keep their faith in a world with fundamental physical laws.

As a quick summary of Hoefer's article, he says that one can keep the fundamentalist approach but deny that some kinds of reductionism may be possible. What I wonder then is about the terminology of laws. Cartwright already says that we learn about capacities. I'd assume that the hydrogen atom in the dewar and the hydrogen atom in the hallway and the hydrogren atom in a distant galaxy all have the same capacities. (It does seem a bit odd to say that a hydrogen atom has the capacity to form the states specified by the Shroedinger equation with the central force potential term in its Hamiltonian, but maybe this is just what one must say.) I guess the question to address is how to relate such facts to programs in which we take electrodynamics, quantum mechanics, fluid mechanics, thermal physics, statistical mechanics, etc. and try to say that in some sense these theories "govern" matter.

Another way to get at the question is to take this fact about hydrogen seriously and see how much it says. Using the capacity language, we say that we know the capacities of hydrogen atoms, and also that we find hydrogen atoms all of the place. And less us take it a step further, and say we know the capacities of molecules, and that we also find these things all over the place. Is physics the domain that is responsible for such knowledge? Its certainly a good part of it, but I think its reasonable to say that the methods and ideas of chemistry are also involved in this knowledge. So I'd need to understand a little better what is meant by a law in the expression "fundamental law" to see if it captures the knowledge we have about the atomic and molecular basis of matter.

information vs. story/meaning

2011-01-18T07:56:00.001-08:00

Ok, another post to motivate myself to get back to some work I should be doing.

First about information in general: I was just realizing that in some sense, I never really got my head around what this actually means. We are saying that information is key. And we develop information technologies, etc. But what is information? There is the physics definition in terms of entropy, but what is the more practical definition? I suppose it would have to do with a representation of something existing in the real world? So why are these representations so important? I guess because some things are set up such that once one has such a representation, one can impact the thing itself? A person has a set of information associated with them that is deemed important. And this information represents certain aspects of that person. And with this information, the person can be affected. If one has information about a country, then one may affect that country in certain ways.

On another end of this topic, I've been realizing that I've had this concept of work where I just need to collect together the appropriate information associated with some topic, and then I feel that my job is mostly done. Now I need to put together a report on beam lifetime, and I'm realizing that there's a lot to be done even though in some sense most of what I thought of as the work, is already done. I need to put the report together which means presenting the plots in certain ways, labelling stuff, etc. I think that other people would keep such a report, or a paper, or some other final product more in mind as they do the work of assembling the information. Then it gets put into the proper form along the way. I suppose there's a balance. Collecting stuff with such a clear final goal in mind may also skew the results and make them less robust. But it may also be more understandable, and have more impact. I could learn to direct my work a bit more towards goals, and would probably save myself some work, and get more done. Pure information is not so useful if you can't do something with it.

Do these two different queries/angles on information inform each other? I will have to think further on this.
(Incidentally, this question about the nature of information was partially prompted by reading stuff by Jared Lanier. I've been finding a lot of his writing a nice anecdote to some of what scares me online these days. Thinking more clearly about ideology and about our opinions on "information" seems useful. Perhaps more later.)

optics and light representation

2011-01-11T03:28:00.001-08:00

Well, in accordance with this blog title, I move slowly, and as I noted recently, have been moving into the radiation end of things. Its somewhat of a shock to go from such a specialized literature of accelerator physics and beam physics to the extremely vast literature of optics and light.
On the other hand, accelerator physics was never such a well defined concept. It is well defined from the sense that it is a collection of all the physics one may need in analyzing, building, designing or improving a particle accelerator. But its a rather mixed bag of classical mechanics, relativity, electricity and magnetism, and material science.

On to radiation, one has Maxwell's equations describing the evolution of electric and magnetic fields. However, one often represents light via a complex scalar field, or via a Wigner function, when coherence properties are required. Currently I'm trying to understand all this terminology related to Fourier Optics. One has a point spread function. One has an optical transfer function. One has an amplitude transfer function. Does one gain something new with these different representations? With the Wigner function, there's a partial interpretation in terms of the distribution of photons. But, being sometimes negative, its not such a clear interpretation. There are operator representations for quantum optics. One has the coherent states and the squeezed states. Is all of this unified, or in each domain of application does one in some sense use a different representation and mapping between the the real physical system and our calculational tools?

light source physics

2010-12-19T10:55:00.000-08:00

I've been writing about some frustration with the field of accelerator physics and where I fit into it recently. I came up with something of a tentative solution to this long standing problem, which I want to say a little about here. It may look like just words, but it does represent a change of orientation, and perhaps will lead to a better fit between what I am interested in and can do well, and what I am doing and asked to be doing for my job/career.

Outside of the question of how well research is supported, there has been an additional problem.
My thesis work was on electron storage rings and equilibrium electron distributions. But to actually continue on with that sort of topic is typically defined as accelerator physics, or beam physics, or even machine physics. The problem is that none of these really excites me that much. I was basically interested in the classical mechanics, or the non-linear dynamics, or the statistical mechanics. But not in making particles go as fast as possible. Beam physics is more interesting to me, but if it is defined so narrowly and with such little research support, its still not great. Machine physics also seems like a somewhat derogatory way of describing the topic. It doesn't describe what the physics is about, but only where it takes place. It is the stuff back there, beyond where the real science is happening, inside that big machine.

So I decided to define my own field of work/research as light source physics. This is meant to both exclude and include. One can say that light source physics (for synchrotron light sources, anyway) relies on accelerator physics and beam physics. But one could also say there is some overlap with accelerator physics and beam physics. First of all, one needs to get the beam there in the first place. That's the accelerator physics (but of course, its much more. Its engineering, its control systems, its infrastructure...) Then one needs to know about general behavior of relativistic beams of charged particles. This would be beam physics. Light source physics implies that the purpose of this electron beam is the radiation it produces. And furthermore, the dynamics of this beam is only half the story. The other half is the light that is produced. The electrons produce electromagnetic fields, or perhaps photons, or perhaps a distribution of light. I'd say that until this light exits the front end and heads down the beamline, we are in the realm of light source physics. The source of the light.
Thus both accelerator physics and other applications of beams are excluded. Colliding beams are used for particle physics. There are also medical purposes for beams. There is electron microscopy using electron beams.

Finally, whereas beam physics is shared between synchrotron light sources and colliders, on the radiation end, we could say its shared with xray optics particularly, and optics more generally. So flashlights and LED's and the sun, and fluorescent molecules are also light sources. And its within the realm of these topics that the definitions of brightness, brilliance, flux, and all that has been developed. So its not cheating to say that they are part of the field.

As for its need, one can look to a site such as Lightsources.org and one finds all about the applications, but not too much about synchrotron radiation and even less about the electron beam. So, though unorthodox, it seems to me a gap that could use development, but with different emphasis and theory than comes to mind with accelerator physics or beam physics or machine physics. In particular, both single pass and multipass is included. FEL's can be included... for now, just my own personal definition. But I think it makes sense. Talman's "Accelerator X-Ray Sources" is I think a good reference to orient some of this.

Just briefly, so, the picture is going from an electron beam to a photon beam. The electron beam may be described with Twiss parameters, and more general coupling formalism. I believe one can describe the photon beam in the same way.

Anyway, this blog has been somewhat a strange mix of personal and professional stuff. Since I hope to see how well I can do as a light source physicist, I decided to create a separate blog called Light Source Physics. The present blog will stay a bit more personal, and amateurish, venturing briefly into topics I know little about, but find interesting. Perhaps the other will develop more substantially. Or perhaps by splitting into two, I'll lose interest in blogging on either one... we shall see...

Another idea is to focus more on the philosophical aspects of things here, and more technical on the other one. Light may be described with a Wigner function for example. I'm curious what it means. Its supposed to be the closest to a representation of the distribution of photons. But it can go negative. Its interpretation is also difficult in quantum mechanics. So I'm curious about it with light. Is it a quantum mechanics issue? Is light transport a good context for thinking about basic non-relativisitic quantum mechanics? Is symplecticity an important concept in light transport?

The other thing to do with this blog is to continue with the mess I've been working on and describing related to accelerator physics, and beam physics. But hopefully continuing in a positive direction. Oriented towards getting a good code, and a reasonable set of references to help understand these things. It is a part of light source physics, after all.

slow

2010-11-18T05:16:00.000-08:00

Today I feel frustrated. There's a sense of crystalization. Job splits into two parts- a work part and a research part. Not exactly, and its still a little vague, but it feels like its heading towards this.
You create something- a possibility?- and then you live with it. But in the process you don't pursue other options, and I find a heaviness in taking on the option that I've created. I was talking to my dad a few days ago, and describing some of my thoughts and efforts at cleaning up old messes and turning my field into something I can work with. He recommended a book he was reading about two brothers who can't throw anything away, that live in an apartment with everything they have ever collected.

Is this what I do? Just simply refuse to move on? Keep on working with an unworkable situation? In the language of the mess- is the mess simply too big? And even if its not, will there be anything interesting left after the mess is clean?

I feel like its all come to a stop. I reached a point of unstable equilibrium and just sit there, but its a very gradual slope away from this point. There are things I can work on; they are somewhat useful but not urgent. There are half-way interesting research-like questions. But this is my own internal process. Does it match expectations, and categorizations for achievement?

All this digital life continues to bother me (though I participate, such as with this blog). I continue to hear from the computer scientists about optimization and automated search and categorization. And one's activities on social networks become discrete. "So and so did this." "Now they did this." "Oh?" "Yes, they did do that." "Now so and so did this." "Really. That's great! So glad that you told me." Someone tells me about classification of human actions. They describe the "atoms" of action. Tom Waits smoking a cigarette and drinking coffee from a mug, the motion of hand away from mouth, "atomic".

work

2010-11-10T06:54:00.000-08:00

Back to this theme of work vs. research, I guess I want to put a good word in for the difficulty of work. (Previously I said researchers may work harder.)

I'm trying to calculate something for a bunch of stored measurements. The formula is known, and its programmed into a matlab code. I really just have to get the parameters and plug them into the formula. What can be so hard about this?

Well, first, there is a fair amount of uncertainty in some of the parameters. It takes some work to cross check with various sources to get the parameter values reasonable. Then I need to learn how to access the data and to manage transfer of data and programs I write across a varied computing landscape. Finally, I need to choose which data to actually analyze such that the results will hopefully tell some kind of story out of which we can learn something.

A lot of these steps are the same in research. But, even though there is a lot of uncertainty, in some ways there is more certainty, because there is a research program. A set of questions to be answered. In the case of almost research, where the job is to understand something and keep it going and maybe make a few improvements, it may be even more open ended than research. Not to say I can't define some research projects within this, but there is a lot to be done that is really about gathering together data from disparate sources to understand and diagnose problems. And I wouldn't call this aspect research per se.

models

2010-11-09T10:54:00.000-08:00

I enjoyed reading this paper today by Ronald Giere called "Representing with Physical Models".
Its an interesting thought that one can consider a graph or other representation of data like a 3-d image as a model in a similar sense that one has legos for a model car, or lincoln logs for a model house.

In the process of working through some problem, I often want feedback at an early stage, and so I produce some kind of plot that may partially get at what I want to say, or where I want to go, and I show it to a supervisor, or someone else. Its always an interesting process to have someone else look at your plot and take it as it is. For me, it is a termporary representation of some data I've been playing around with, but for someone else, it becomes an object contained within itself. They look at its boundary, ask about its imperfections, and describe the picture that it paints.

In the article, Giere describes representation via theoretical, physical, and computational models. His example of a theoretical model is a harmonic oscillator, his physical model example is Watson and Crick's colored balls representing DNA, and for a computational model, it is a 3-D image picture of a protein based on theoretical calculations and some protein data. He wants to say that these are all basically doing the same thing. That together with a person to do the interpreting, each of these can be acted on in various ways to learn something about the real system.

I guess this makes some sense to me. The nice thing about a toy model of something is you can play with it, get some feeling for it. You know harmonic oscillators have a fixed frequency, you can picture them oscillating in your mind, and you can even imagine the force they push against you as you try to compress the spring. Similarly with the real balls representing DNA and the 3-D image, you can play with them and relate them to things you know in the world. So with a plot you produce. Its limits and its potentialities may come alive in the viewers mind. It doesn't tell all, but it gives something concrete to hang on to to start building a picture of a given something or other you're trying to understand.

In my last post I said that physics gives us a bunch of models which have been used to describe electron storage rings (the example I focus on because I work on this, and want to clarify certain messy aspects of it). I think maybe some of the difficulty in this field is that computational approaches were developed, but somehow the last step of using them to make models didn't happen so well. One has a picture of a map with a resonance, but there's no good software to really turn this into a model where one can play with it and get a feel for it. (I suppose frequency map analysis software may qualify in this sense. One gets colorful pictures in which the resonances show up in the tune diagrams.) The concepts are there, and the software has been written (e.g. FPP) but not many people know how to use it, or how it relates to the phenomena of storage ring maps. In this context, model has usually meant the elements going into the computer code, and I suppose that's the theoretical model. But with the incoming model being very complex (so its hard to play around with in one's mind), and the software not being easy to use and visualize and relate to familiar things, one is left without good conceptual tools to understand some of these phenomena.

system, environment

2010-11-08T23:19:00.000-08:00

So physics provides us with interpretive models. We have ways of translating things into mathematical structures. Let's take this example of the electron storage ring.
We have magnets. These are big, heavy metallic objects with current running through them, shaped in ways to produce magnetic fields. So we line these up and put them in some configuration. Now, there's a certain region of space that maps out a doughnut-type shape inside all these magnets. Physics gives us the model of a magnetic field at all places inside this doughnut.
We have devices that mesh well with this picture. They measure the field and we basically assume that at a given time, the field has some value everywhere, and one can repeat measurements and get the same value. Then, to this, we throw some matter in there. We interpret that matter in terms of point charges with various masses and charges, such as electrons or air molecules.

The magnets and magnetic field is the environment or the background. The charges now move in this background. Now, depending on the needs, one can use different descriptions of the dynamics of the electrons. One can use classical electrodynamics to describe the motion of the charges, and the electric and magnetic fields they produce that may then also act back on those charges. I'm not entirely sure the status of the self-force and consistency within classical E&M. But I think its basically understood how to deal with it.

But actually, we need a little more than classical E&M. We need a bit of quantum mechanics. The radiation the electrons give off comes in lumps, and the lumpiness actually has an important effect that we can't ignore. Without the quantum lumpiness, for an appropriately set-up storage ring, the electrons would all end up at the center of the potential. Classical E&M says there is a damping mechanism that causes this to happen. Now, the interaction between electrons would limit the size of the resulting beam to a very small, finite size. But it turns out that the quantum lumpiness causes the beam to be much larger, and together with the damping mechanism, sets the size of the electron beam.

How do we treat the lumpiness? We use quantum mechanics (is it really full-blown QED? Or some semiclassical approximation given the emission spectrum of the electron?) to provide the diffusion coefficient. This turns the Lorentz equation into a stochastic differential equation. In the case of linear dynamics and constant damping and diffusion, the result is a Gaussian probability distribution, which when considered for an ensemble of electrons results in an actual Gaussian charge distribution.

Once the magnetic field has been set, and one is considering charged particles, there are other formulations for describing the classical dynamics besides the Lorentz force law. In particular one can use Lagrangian or Hamiltonian mechanics. Let us take the lead of Michelotti in describing this framework. He begins with the pendulum to introduce model systems that have the properties we need that the maps around the storage ring will have. He emphasizes with the pendulum that the phase space may not be R^n, but is a manifold. In chapter two he introduces linear and nonlinear models. He discusses the Hopf map and the Henon map, and gives the ideas of ergodicity and some other probability concepts such as partitions. So in general, we are actually in the realm of dynamical systems. And where does Michelotti end up? By chapter 5, he is discussing perturabtion theories for Hamiltonian dynamics and tries to give description of the Forest, Berz, Irwin normal form algorithm, which may contain isolated resonances.

So this is a long path stretching away from the magnets we see and the measured fields. It provides tools. A path to walk on. But there has to be a pulling from the other end. We have to know where we want to go. I would say that one usually wants to go to questions of stability. One wants to know whether a given bunch of electrons moving through this doughnut will last very long or not. And unfortunately, the elaborate normal form perturbation theories don't tell us this. And the same goes for the numerical implementation of these perturbation theories. One can compute resonance strengths and tune shift with amplitude to arbitrary order, for a machine with all the appropriate misallignments and field errors, and the full Hamiltonian, and one still doesn't answer the stability question by the perturbation theories.

But these are nice paths. And the tools are good tools. But without some pulling from the other side, the use of these tools gets lost. One doesn't know that sometimes one needs to develop new tools, or maybe give up on full understanding and just track the particles and see what happens.
Between the end point of injection efficiency and Touschek lifetime (momentum aperture), and the beginning or magnets leading to particular paths through classical mechanics with brief borrowings/harvestings from the quantum, one will simply get lost on these paths.

hot topics

2010-11-05T16:58:00.000-07:00

I commented again (29) at Cosmic Variance on a post about "Physicalist Anti-Reductionism" which included a debate between John Dupré and Alex Rosenberg. Sean seems to minimize the importance of the topic, finding it "the most boring argument in all of philosophy of science."
To me, it gets back to this kind of split I experienced when reading Nancy Cartwright. I found it hard to do physics when I didn't have this grand picture of it in mind, and instead having a skeptical approach. Can one be critical of something and excited about it at the same time?

But actually, to me, reading more skeptical philosophy of science is kind of like finding an honest way back to appreciating some of the stuff that originally excited me.
Maybe I'm just trying to justify choosing a not so "hot" topic in physics. Condensed matter theory, or particle theory or cosmology might have been sexier in some ways. Maybe I chose a purposefully boring topic because I thought it would be more honest.

Anyway, I was just realizing that this sense that a kind of reductionism is wrong has made me just not think very much about the components of things. Yes, there's a real sense in which we're made of molecules. And they are pretty cool. And there's a lot of them. And people make pretty pictures of them. And understanding a mechanism is pretty exciting.

The basic problem I have with accelerator physics is that try as I may, I can't put it in the same bag of exciting stuff as I've seen a lot of other topics before. Thinking about protein structure, or photosynthesis, or quantum mechanics is fun for me. But thinking about dispersion functions and chromaticity and tune shift with amplitude and momentum compaction factors... is just hard to get excited about. There were topics that originally seemed exciting. There's basically a new approach to classical mechanics that is developed in the early accelerator theory- a Lie algebra approach. Then there's the stuff with power series, whose early advocate describes in terms of differential algebras with connection to non-standard analysis. But in some sense, these mathematical abstractions are a bit overblown (particularly the latter). The reason I say they are overblown is that the problem has not even been solved. The real non-linear dynamics problem is that of the dynamic aperture (the stable region of a non-linear map) and as far as I know, this isn't really a solved problem. So going out so far into a given formalism when that formalism doesn't even solve the main problem seems a little too much.

Anyway, I'm not giving up. I like the classical mechanics. Synchrotron radiation is something I can put in the bag of exciting stuff. And the awful messy code situation may be able to slowly improve. So that's sort of the package. We've got some kind of nice classical mechanics. A bunch of somewhat useful definitions of things that are measured. A bit of a computer code and sociological infrastructure difficulty, and then some cool stuff with synchrotron radiation. Its a topic. It may be more fun to think about ecology or species of mosses, or the definition and validity of reductionism. But at least the topic is becoming less awful. Less ugly. Back away from all the extremists with their unfinished pyramids to build, and one has a topic in need of some sprucing up and simplification, but honorable nonetheless.

advanced light sensing

2010-11-03T01:51:00.000-07:00

A funny quote from p. 5 of the book "Elements of Synchrotron Light" by G. Margaritondo:

As new-born babies, we begin to learn by 'seeing' things with light, which consists of electromagnetic waves. As we grow up and become more sophisticated, we can use different types of electromagnetic waves to explore different properties of the world around us: for example infrared light to study atomic-level vibrations or X-rays to study the atomic structure of molecules.

Now, I'm always looking for how to "tell the story" of synchrotron light sources. But this is an odd angle! We start our lives by seeing with visible light, and then after we become more mature (as a synchrotron light experimenter), then we add infrared and X-rays to the spectra of usable light to learn about the world!!

some generality of science

2010-10-30T11:39:00.000-07:00

I've been on a critical direction for awhile, and looking to find a more constructive direction.
I'd like to get back to some of the excitement I've had for science. And it really covers a lot of good stuff.

So what are some of the important things we know? I think Feynman said that he thought the most astonishing and important knowledge was about atoms. Here is something like a universal knowledge. We can take anything we find, anywhere, and if we break it down in a variety of ways, we find that there are atoms that made it up. Maybe often you get molecules instead of atoms. But this idea of breaking material apart and always getting something of a fixed set of elements. This does seem to be pretty significant knowledge, and to always be true. Does this mean that atoms are the "underlying story" of everything? Maybe.

So this seems to be a kind of reductionism defined operationally. Stuff can always be broken down into atoms. (How to make it more precise? Step 1. Find something. Step 2. break off a little piece. Step 3. break off a little piece of that. Step 4. heat it up? explode it? ...)

What else do we have? We have light. There are radio waves, and visible light, and ultraviolet waves, and xrays. You can't really talk about light in the same way you talk about matter. You don't break stuff apart and find light at the bottom. Stuff goes through some transitions, and light is emitted- it makes other stuff go through transitions.

I really don't want to end up with a network here, with nodes and messages being passed between the nodes. Yuck. I'm sick of networks.

Anyway, yeah, there's stuff, and there's light.

What about a beautiful forest- an intricate ecosystem? Stuff and light? Does that get us very far in understanding and appreciating it? More work for another day.

research infrastructrure

2010-10-27T13:20:00.000-07:00

In some ways, people doing research may do more work than others. You take the problem with you all the time, and you really put a lot of yourself into solving it. The benefit to this may be that you have freedom to pursue something that really interests you, and your work and passion may be aligned.

There's a danger when a field does not have a strong research culture, but still has a research component. If most of the work to be done really isn't research, then what is and isn't research may be confused. A person programming for a company doesn't think of themself as doing research, but rather as problem solving. The difference is that much of the framework is predetermined.

In a field without a strong research infrastructure, one is expected to make the framework oneself, but one will never really do something new, because the information is just badly managed. The problems have already been solved long before. If one is supposed to be doing research, but is really just catching up to where others have already been, or cleaning up old messes, this is not very healthy. Instead, this component should simply be called work, a set of objectives should be set up, and the work divided amongst those doing it.
(added...)
Summary: if its work and not research, then there need to be very clear goals and it should be finished, even if imperfectly. Depth and creativity and perfection is not well spent on something that cannot support real innovation. Real innovation will look bad at first, and will take awhile to get somewhere and perhaps other people to finish things at a later time. I need to learn to separate research from work. I seem to never quite learn this lesson, and it gets me again and again.

beam distribution, lifetime, synchrotron radiation

2010-10-10T07:58:00.000-07:00

Ok, closer to what I should actually be working on...
We have an electron beam with a variety of interactions. At high energy in a storage ring, mainly you get a Gaussian due to damping and diffusion processes from synchrotron radiation. The self interaction mainly manifests as a beam lifetime- scattered particles are lost in what's known as the Touschek lifetime. Also, if there's an aperture close enough to this Gaussian, then particles are lost through this diffusion process in what's known as the Quantum lifetime.

Suppose we have a non-Gaussian beam. How did it get this way? What does this say about the lifetime?

We can treat the synchrotron radiation effect on the distribution via the Fokker-Planck equation. Can other noise processes on the beam also be treated via the FP equation? What would a non-Gaussian distribution do to the emitted synchrotron radiation?

Finally, does anyone care? We use this radiation for all sorts of experiments. Which experiments care about lifetime? Which care about beam size? Which care about the coherence of the radiation?

phil sci, dirac

2010-10-10T03:47:00.000-07:00

From Taking up Spacetime is a link to the philosophy of science preprint server, here.
I've been browsing a bit and enjoying reading some papers. I found this paper on interpretations of the Dirac equation here (M. Valenti, 2008) which I've skimmed a bit. He talks about using QED to describe the Hydrogen atom, which I'd be interested to understand better. It does seem that mostly QFT calculates S-matrix type stuff, and bound states are more foreign. If NR QM and the Dirac equation really come out of QED, then it should be able to deal with bound states. I vaguely remember something about "resonances" (related to the complex poles) of the S-matrix being the bound states...
Maybe too hard to understand right now, but interesting stuff anyway.

(added... Ok, here's an interesting quote related to this reductionism, model building stuff:

In this way we are not restricted by Haag’s theorem – and so we can retain the concept of quanta in the description of interactions – because, from a physical point of view, the Lagrangian of quantum electrodynamics does not provide us (contrary to what from a mathematical abstract point of view might appear) with the possibility of describing a system of (undifferentiated) interacting Dirac and Maxwell fields, but with a way of developing models that describe in a limited way the interaction between the fields.

Valenti, p. 14)

inner space

2010-10-08T08:51:00.000-07:00

I was complaining a little while ago that with all this network stuff, blogs, hypertext, RSS, info overload etc. that the challenging thing may be to relearn to read. I certainly noticed that I haven't been reading novels in depth in awhile, but this probably has multiple causes.

Anyway, it seems that in order to be able to really take something in, we need to spend time on it, and not be distracted. And we need to have the space for it. We need to be relaxed and not overloaded. This sounds like conventional wisdom, but it can be easy to forget. We can see the effects of reading more, but sometimes forget the value of reading less, more carefully. Allowing the words, sentences, ideas to sit there for awhile, to connect up to each other, to try to see what bigger picture the author was constructing, and to relate the text to our own experience and ideas. This is an internal process that can't be sped up by skimming, or by reading more background information, researching every last connection. I know some people who analyze texts by doing these word clouds, and finding out which words, or phrases are the most prevalent, and want to try to extract understanding from such an approach. I imagine you can get more sophisticated and start writing programs to understand things for you, and just give you some kind of summary.

It reminds me of tools in math in physics such as calculators or programming languages, compilers, etc. Here we let the machine do the work for us. Is there a benefit to doing the work ourself? I know that I learned calculus by doing many, many integrals, on paper, and learning the ins and outs of various tricks. Doing this builds up intuition and a whole workshop that connects to your other thoughts. You get a lot more out of it, than just the ability to solve a specific problem. I think in addition, you get the possibility to have a sense of which problems might be solvable, and ways in which definitions might be shifted to get useful results.
You become richer, and its more fun.

Anyway, since language and ideas are important to me and the source of lots of enjoyment, its sad to see ways in which some kinds of thought may be bypassed. My general approach is to try to make sure I can do something by myself before I get a tool that can do it better and faster.
I do use Mathematica to test out whether an integral may have an analytical solution, but I feel good that I can (or at least used to be able to!) do it myself. (Here's a page of an accelerator physicist with some quotes on this topic.)

I want to be able to read in depth, think in depth, and calculate in depth, and to take my time with it, even if someone or thing can reach the same conclusions faster or more reliably. The inner world involved, and the benefit to me as a person to this seems incalculably valuable.

positive

2010-10-06T00:43:00.000-07:00

Still reading Nancy Cartwright sometimes, and my tendency is towards criticism and thinking about why things are not as big a deal as people say they are.
But this isn't so great a way to do things/live life at some point. Actually she writes in one of her books that people tell her that her project is not very inspiring. But she does have a positive project I think, along with the criticism.
Anyway, for me, I do like physics a lot. Better to find some real questions to work on and try to make progress. The critical approach can always be there, but if its all there is, its not so productive, and probably leads to mistakes also...

seriously, completely understood

2010-09-29T16:14:00.000-07:00

Sean presses forward with "Seriously, the Laws Underlying the Physics
of Everyday Life Really Are Completely Understood"

I would put an emphasis on the word physics here. I think there's an
interesting question about the definition of physics. People who
think of themselves as physicists would of course like to define it so
that it is as powerful as possible. Reading Lubos a while back, (finally it got to be too much, and I found reading him, and the few attempts to engage with comments just too upsetting) one
could see this activity at play in the realm of string theory. String
theory was to be the best, most powerful theory out there. It didn't
matter that it wasn't well defined or maybe covered a variety of topics. Future work would go into its definition and elaboration. What was important was that it was known
ahead of time that it was all powerful.

Clearly the standard model and general relativity are powerful frameworks that are extremely fruitful for building models to describe and predict the world. And there do seem to be some facts about how we can take anything we find and break it apart and find the same underlying stuff. And if we put that stuff into an accelerator or in various
configurations, we can predict what it does.

But if the real point here is to emphasize the power and generality of the standard model and general relativity, then why talk about the "physics" of everyday life? This is the fundamentalism that Nancy Cartwright fights against. An effort to put disparate activities and types of argumentation together into one whole and say that it somehow covers everything.

Of course, I'm also sympathetic to this view of physics (or perhaps one can generalize to science, as well) as a unified extremely powerful discipline, and it was the faith that pulled me through graduate school. One thing for me that was discouraging (to continue a thread from Wimsatt's description of finding out how important "jerk" was) was when learning about quantum field theory and renormalization. QFT was presented as a generalization of the non-relativistic quantum mechanics we'd learned. But then it was shown that one actually got wrong answers and had to patch things up with this method called renormalization. If this was the fundamental theory, and it still required this much tinkering to get results for particle physics experiments, it seemed plausible that it might require different tinkering to apply it to correctly to limiting cases such as a helium atom. In some sense I hope I'm wrong about this, but it certainly was never presented in a coherent way. Foundations of QFT don't really seem to be too popular though, or seen as really open topics.

update... now the final (?) installment: one last stab.
I added a comment about how the reduction of helium to the standard model isn't usually done in a chemistry class, and it actually seems pretty hard. We're still trying to get protons out of QCD, with lattice QCD. I just wonder how much theories change as they pass from one discipline to another.

All figured out

2010-09-23T14:33:00.001-07:00

Here is Sean at Cosmic Variance patting ourselves on the back for having all the physics underlying our every day life figured out. I know what he means, and in some sense its a good point. I've tried to make this point to people before. That the laws of physics that we know, explain everything. Everything. Its a good point to not nitpick about the mass of the Higgs or the existence of sypersymmetry, or an accurate framework for quantum gravity.

At the same time, here is the reductionist mentality writ large. I'd like to see more debate and clarification on this point. Is there a way to make this point that is not so arrogant and overblown? Its certainly an accomplishment, and there's certainly a precise statement to be made, but how to make it without claiming too much, or minimizing the work and value and richness involved in "the playing out" of these laws?

organization

2010-09-15T00:22:00.000-07:00

I've never been very good at organizing my life systematically. Somehow things seem to work, but I am also always left with a feeling that there are so many loose ends. Part of me wants to keep pushing to find a system, and part of me says- "look, what you are doing seems to work, so don't worry about it." I've heard the French described in this way, and I've seen it myself. There is a big mess of redundancy, it looks like a disaster, but somehow when you really need something, it tends to actually be there and work, somehow.

For example, should I make a To Do list? Where do I put it? Do I write it on a piece of paper and carry this everywhere? Or put it up on my wall? If I carry it, then I may always be worried about what I have to do, and never relax. If I leave it at home, I may not have it when I most need it. Do I write it in a file or using a program on my laptop? Then, when my laptop fails, all may be lost. Do I use some networked site like google or some other service to manage my data? Firstly I need to learn their system. Secondly I am then dependent on a large company that may not have my interests at heart. And these companies are getting too powerful, anyway. Do I really want to be a part of that system? Of course I use their services sometimes, but do I really want to make this the sole point of contact and system for my data?

So what about a more varied system? Where the same information is written on paper, in my email box, on my laptop calendar program, and perhaps sometimes in a google calendar or some other network type application. Having a system like this takes some work, and I think needs to grow organically in some sense. It needs to be robust. (Yes, still processing some of Wimsatt's concepts.) I think somehow I never developed such a system, and any attempt to produce one too quickly runs into some of the problems I've mentioned. When life is too busy, any flaws in my system are made worse. I try to write things down, and the proliferation of paper is worse than the organizational benefit from doing it.

Maybe it really is time to buy one of these organizer things.

what we are afraid of

2010-08-18T10:43:00.000-07:00

So I've been reading W. Wimsatt's "Re-Engineering Philosophy for Limited Beings: Piecewise Approximations to Reality". It has a lot of material on reductionism, which is quite wonderful, since its always been a topic that fascinates me and scares me. He provides tools to get around the various overly crude reductionisms- the "nothing but"isms. One challenge is that its rather focused on philosophy of biology, and I don't know this literature so well. But I'm still appreciating it quite a bit. In particular, Dawkins' reduction of all natural selection to the level of the gene ("the selfish gene") is something that scared me when I read it, and would like to find more articulated criticisms within the group selection literature.

It occurred to me that extreme reductions may be behind a variety of fears we have. We are afraid of being too machine-like. We are afraid of being too computer-like. We are afraid of being too tool-like. We are afraid of being too money focused. We somehow know that to view all as "mechanism", or all as "computation" or "communication" or "economics" is a kind of simplification that will make many things we value rather hard to articulate. (A friend was recently telling me about his "all is optimization" theory of life, which of course is the very same type of beast.) So the fear is perhaps our reminder to ourselves not to take the (maybe useful) ideology too seriously- a nagging suspicion that everything we value is being defined out of existence.

This occurred to me as I was thinking about my own life and how to form patterns that are positive (a self-help/therapeutic approach to life). I was realizing that I have a deep antipathy to planning things too much. "It makes me into a machine." I say. Or perhaps, "it makes me into a computer."

To say much more, I'd either have to be more explicit about myself, or try to be more precise about these philosophical arguments and societal forces. But I'll stay in this gray zone where hopefully I've still said something useful. (I know its a bad habit of staying in this gray zone, and I ought to start moving out.)

language

2010-07-13T00:04:00.000-07:00

To have a nicely working system, people should know the names of things. And computers and programs make this even more difficult since they are so inflexible when it comes to names.
So put oneself in a multi-lingual environment with disparate computer codes, and naming of things becomes a difficult job.
I'm trying to get my own mess sorted out. I have directories with names that classify.
I have files with different extensions implying the programs that can read them.
And I have different projects I am working on. I keep redefining the projects, so I keep renaming them, and there is overlap between the different projects. And I seem to have multiple copies of the same files in different locations.
Basically, there are settings for devices, there is a corresponding parameter in a model, and then there are measured and calculated quantities for these different settings.
Sometimes settings are named based on the day they were used to link them together with other parameters for those days. Sometimes they are named with something like the word 'nominal' to try to push these into standard settings.
Now, I might think I am obsessive about this sort of thing except for the fact that I really have not yet created a working system. So its really just unfinished work that I'm having trouble moving forward on.

A final point about this kind of work. There are two aspects to this kind of work. First there is this clarification work. Work to try to make language that works well for the different people involved. Then there is actually getting stuff done. For the latter purpose, there will inevitable be arbitrary choices made. The area is complicated enough that its not always clear what the right thing to do is. The point is that you should know what you did. So if someone asks you, you can tell, and they can repeat (or you can!) if necessary. So you need to know what you did. And depending on the kinds of people you are working with, you may also need to have answers ready to defend the arbitrary choices you made- or at least a strategy so that you could easily try something else if you can't defend a choice.

There is a conflict between doing something definite and coming up with an appropriate language to describe what you are doing. Doing something definite will often make you make choices about language before you are ready to do so. Walking the line between these two things is the key to move forward but also bring others along with you so that it can help the total understanding and group good as well.

tolerance

2010-06-24T02:31:00.000-07:00

I'm trying to do some detailed work. I have to create a bunch of files with settings of currents and magnet strengths, and then load these values into a model of the machine and calculate quantities based on tracking particles through the machine.
I'm realizing that I have an approach where I assume that everything I do I might make some mistakes. If I focus really hard, I can make fewer mistakes, but this is exhausting, and its hard to think creatively while doing this. So I try to set up my systems so that they are tolerant to making mistakes. This means that there are checks later on, and reviews where I can catch the mistakes I make.
I think that other people don't work this way with this kind of work. They are more careful, they don't make many mistakes, and once things are checked, they leave things as is for fear of messing it up.

This to me is another aspect of "the mess". Its an area, where in order to turn something not into a mess, I have to work much harder than I normally would. If it were not a mess, and I had no problems with the systems in place, then I could just work in my concentrated mode, not make mistakes (or very rarely), and get a lot more done. Since I allow myself to make mistakes, then I have to change the system itself in order to accommodate this, or else face the consequences of making mistakes and looking bad as a result.

relearning to read

2010-05-18T01:20:00.000-07:00

The institute for the future of the book blog discusses a slow viewing of a Herzog film
and states

The problem of availability is something that seems increasingly to have been solved. To view or to read well is another kind of problem. In the past, when there was an economy based on scarcity, this might not have been as much of an issue: whatever was available was watched or read. Now we need to think about how we want to watch: we need to become better readers.

I've been chewing on this for awhile. This morning it struck me that perhaps this is a much harder task than we may think. And perhaps the technical challenges associated with bringing about the new mode of availability are trivial compared to the human and social challenges of reclaiming the same depth we had and perhaps developing it in new directions. I, for one, have certainly become worse at in depth reading in recent years. Perhaps there will be long term benefits. But I'm most often struck by a sense of loss.

To me, there are two separate questions. The first is about the nature of hyper text, and what such a literature might mean. My gut feeling is to reject it, and somehow it feels like this is related to the integrity of personal identity, and the linearity of time... (problem much simpler reasons are available)... were there ever choose your own adventure stories that reached the level of high literature?

The second question is about how to read single texts. Do we take notes? Do we spend hours at a time, or minutes? Do we always read linearly, or sometimes skip ahead? I don't know why these questions should even be asked, except that with internet reading I've taken to all these habits, and perhaps they should be clarified if not rejected on an individual basis. I think for the most part, these are bad habits, akin to seeking out cliff notes for a book and not actually reading it. The danger of mistaking the map for the territory?

One final point is that there's a small flaw in the claim that the availability problem has been solved. What this means is that digitally, texts are more and more easily available. However, at this point, I really don't feel like e-readers are good enough. Maybe I just haven't given them a chance. But in any case, the truth is that if one prefers to read a printed text in a convenient book form, then the digital existence on one's devices is not the same. And independent book stores provide a filtering process that forms a community and provides these books for immediate purchase. I see the new system as an alternative, but calling it the "availability" problem hides the changes that have already taken place and will continue to take place with respect to what books mean, how they get to us, and the connection to the author.

I guess I just really like libraries and bookstores, and wonder what will happen to these institutions and how the social role will develop. Probably much has been written on this, but I think its easy to think that somehow the technical part of digitally distributing text has somehow done away with a large amount of preexisting objects, culture and ways of thinking about things.

messes

2010-03-21T13:40:00.000-07:00

How do we deal with being stuck in a messy situation?

The nature of a mess is that you put energy into fixing it and it is still a mess. Perhaps one can slowly turn a mess into not a mess, but during the process it will be a mess. The key is to not look for completion, and to make sure one has other resources and interests. Some kinds of life projects give regular rewards, and have regular moments of clarity and transformation. A mess on the other hand, is a constant drain. Again, the work may still be valuable, and in the end, something good may come of it, but for large amounts of time, no such rewards are there, and not being draining may be the best possible scenario.

When one is involved in such a project, it is rather frustrating because one is often asked if one is passionate about it, and if one loves it. But really, all one can say is that one is trying to improve a mess. One can barely even talk intelligibly about it because the nature of the mess is that it cannot be clearly defined, and in fact incoherent approaches to characterization of the issues may abound. Thus, not talking about it may be the clearest and most honest approach available, but this leaves oneself in a state of mystery where one is exhausted, but cannot say why. Historical and psychological analyses of those involved may also help, but without the grounding in other healthier areas (such that its essentially just an approach of humor/compassion), one may again be led to increasing the problem, rather than improving it.

Living through a mess is difficult because one's faster/more direct analytical facilities are led astray. The one thing that one may do is to constantly remind oneself that one is involved in a mess, think to somewhat more healthy situations, and not push too hard. Put energy into it, notice that it is still a mess, and then recover from that effort, having hopefully pushed things along incrementally such that they will be a bit better then next time you return.

slow processes

2010-03-12T01:58:00.000-08:00

I think that watching computer technology develop sometimes is disheartening for us humans.
We watch things go faster and faster, and see any process which once took an hour and a person to help with it, now take a single function call in a high level interpreted programming language, and a few seconds of processor time.

Seeing this, and looking at ourselves, and our own development, its hard not to feel impatient with ourselves. Some things take years, and lots of work, and the progress is still only partial. Things like developing friendships, coming to terms with our past, and finding an appropriate way of life, profession, etc. How do we keep our dignity and allow ourselves our slowness when many things seem to be faster and faster? I think there is some flaw in thinking that devalues something for its slowness. When we have a beautiful tree in the yard providing shade for years, do we put this tree down because it took so long to grow? No, in some sense the time it took to grow adds to its value.

So what is the difference between a tree and a Fourier transform algorithm? I don't think many people would wish that their basic programming tools could run a little slower. We like responsiveness.

How do we defend slowness? Perhaps the point is again back to the question of dominant natural and technological language. This computer age asks us to put all things in terms of algorithms and processes. But our own lives are mysteries in some ways. When we translate this into computer language, we have inevitably left things of value out. In the same way that when we translate into economics language, we also leave things out. Its certainly worth the effort to try to understand why some things are slow, and all of the different things that are involved in the process from an algorithmic perspective, but one should also just accept that the translation is only partial, and slow things of great value exist.

separation of duties

2010-03-11T18:17:00.001-08:00

There have been various times in my life when I've felt "smart". Sometimes this goes along with some context in which others think I understand what is going on. When I realize that in some context I am considered "smart", my usual response is one of something of the sort: "wow, but I am so confused! I know so little!" Now, one might put this down as modesty, and say, no, in fact I know quite a bit and such and such. But to me this dynamic seems to expose something of the structure of knowledge in society (as I have encountered it). There are people who feel they are not so smart and that others have most things figured out, and there are those who realize they don't know very much, but somehow represent structured knowledge to the others. To me this feels like a hoax that doesn't serve either person very well.

Now, this is a caricature, and I wouldn't want to say that it says much about the actual validity of knowledge. I only point out that this is a dynamic that may complicate things when evaluating how much ground a particular area of study actually covers. Consider perhaps a set of different areas of study, each overlapping with the other in some way, and as a whole covering a large amount of ground. Suppose further that the people studying each area take the subject matter in the surrounding areas to be more solid than those actually studying them do themselves (though they may be less forthright about this aspect than they should be). How do we evaluate the total ground covered by the overlap of these different disciplines? I suppose, we need to try to gain a bit of expertise in each of the areas and ignore some of the sociology and build up our own picture of the total ground covered.

distributed consciousness

2010-02-26T11:41:00.001-08:00

Ok, I was getting worried before about the internet and distributed consciousness.
Nice to read from Crispin about collective consciousness. Here and here.
Yes, I like to think that if there are thoughts, that those thoughts belong to someone.
In any case, I am here. I interact with many others through this funny medium, but my consciousness is associated with me body, here and now.

commucations theory

2010-02-16T22:48:00.000-08:00

I recently read this article by William Deresiewicz on the history of friendship, and how social networking is changing the definition. I guess its about ideas from one area of technology, development coming into another. In this case, communications theory is being applied to human interaction. So we have nodes that are sending messages to other nodes through channels. Those channels have various properties, such as (?) latency and bandwidth. Thus, we can communicate with each other over the phone, through email, through Facebook, Twitter, Skype and other messaging services. Now, from our perspective, we are living our lives, and these are modes of communicating with others. From the system designer's perspective, we are nodes trying to communicate with each other. Face to face contact through light and sound that travel through the air becomes another channel. It is prized for its "high bandwidth".

Like each such system, the difficult part from a human perspective is that one is put on the defensive. One may be required to put ones values into this new language in order to defend them. I was complaining about Facebook recently and how many of your actions become publicly available. The response of the person I was speaking to was "don't you know about privacy settings?" There was a dismissive attitude to this. It was my job to understand the way in which Facebook had designed the system, and to address my concerns within that system. Rather than keeping things as they are, Facebook allowed more information to be shared publicly than was previously being done, and then put the burden on the user to figure out its system to reinstate those values. Its a similar situation with environmental concerns and economics. Within the domain of economics, those who don't think that species should be wiped out, or forests destroyed, or rivers polluted must phrase these goods within the language of economics.

Let me add one more point. In his article Deresiewicz discusses a Facebook friend who tells everyone that they are at Central park, and Deresiewicz asks why this person felt the need to share this. The thing about these new technologies is that they make this sharing just incredibly easy. The amount of effort to share such a thought is minimal. So, if in the end, one decides that such sharing is actually detrimental to one's relationships, then one must see these technologies as rather dangerous. Or, at least, something that requires a new kind of thought and understanding. A new kind of ledge one may fall off if one isn't careful. The new tools encourage us to externalize our internal worlds. This has much potential, and can improve self expression. But one can also give away important things, and not get much back in return. So, I note the dangers. And hopefully use this as a reminder to those developing this technology to use humility and don't expect everyone to fit into your system.

Computer science is the new physics?

2010-02-15T10:51:00.000-08:00

I've been meeting a lot of people doing research in various topics in either computer science, machine learning, or various areas of somewhat related applied math topics. I was discussing pure vs. applied research with someone, and they were telling me that it was a very good time to be doing relatively abstract research in computer science. It was perceived that any kind of results, no matter how abstract can have practical benefit in a relatively short amount of time.

This reminds me of how I imagine it to have been for physics following the creation of the atomic bomb. The physicists were seen as miracle workers. Give these guys some money, and they will do magic with it. It seems to me like we are coming to the end of this. Physics has lost some its sway on the popular imagination. Observing the public perception of the LHC, for example, its hard not to see the last gasps of this former power. I don't think the physicists have no culpability in the impression that the LHC may create black holes to swallow up the world. Although not actively pushed, I think that it is also not actively discouraged. The problem with this, and I think the whole unification of everything via string theory falls along the same lines, is that no real result can live up to this hype. No matter what happens, it will be a let down to the public.

On the computer science front, I suppose there may be fruitful years of research ahead. What personally scares me about this is that the research is about our own imaginations, and not about the world. (But then, maybe this is just my bias, from not being very involved in it.) I do hope that this research doesn't get too far ahead of itself, and leave the world, and people behind. I suppose that physics has its control aspect as well.

A friend/colleague of mine forwarded me this link to these lectures by Hal Abelson and Gerald Jay Sussman about computer programming based around Lisp. One can only hope that some of this kind of spirit survives in the discipline of computer science. It is a joy of discovery and appreciation of simplicity and clarity that has a kindness and humanity behind it.

For me, I prefer to stick with the science. I prefer to try to understand what's already here, rather than create infrastructure to dramatically change things. And on the creation front, I prefer more modest modes of expression.

Looking back, I'm glad we have found quantum mechanics, and it is said that CERN produced the internet. I'm sorry that it has to be at the cost of a certain group of people presenting themselves as magicians.

A final comment I'd add, is that even though I phrased this in terms of "popular imagination", I think there is more to the story than this. I think that it is accurate to say that there isn't much chance that elementary particle physics will produce practical/technological benefits at this point. Certainly its possible, and one never knows the results of research. But it certainly doesn't appear that the Higgs Boson has any practical benefit, nor do the superparticles for that matter. And I don't think many particle physicists think this either. I think they just believe very strongly in reductionism, and this is the main argument as to why particle physics research should continue. I have to admit, I'm sympathetic to this line of reasoning. But I also think something has gone wrong with this approach- it has gone too far- and it will be very interesting to see what the effects of LHC research are, whatever the results!

philosophy of science

2010-01-23T11:14:00.000-08:00

Hmm, so my interest in Nancy Cartwright isn't so idiosyncratic after all perhaps.

wreckage?

2010-01-21T07:09:00.000-08:00

I look around accelerator physics and see that there are so many tried and aborted projects.
I think of this process of working on an open source project, and I see its been tried before with the UAL framework. Every idea one has has already been tried and failed.

Perhaps I should try to put a more positive spin on this, and list the open source beam physics projects. We have Zgoubi, and the previously mentioned UAL. Then there is XAL, which is an offshoot of UAL developed for the SNS. Each of these is rather project related, I believe.
UAL is an attempt at generality, but from a physics perspective seems to be more about absorbing existing codes, than developing new algorithms. It is used in the RHIC online model.

Also, I think beam physics should look to other fields such as HEP, with GEANT, and on the synchrotron optics side with codes such as shadow.

cyber

2009-12-22T22:56:00.000-08:00

I came across this piece of writing called iGooglesque by E. Sartwell, who is actually a cousin of mine (second cousin, once removed?). It was satisfying to see some analysis of what a large amount of time interacting with a web browser might mean, and what it says about personal choice and identity.

It left me with a desire to better understand these things, and led to a flurry of web searches and wikipedia reading on cyborgs. Particularly disturbing was the idea of distributed consciousness. I read something about this, and it opens up a new concept that then pushes me away from the path I've been following. To me, the concept of grounding oneself, of being very much in touch with one's surroundings, and of consolidating experience, and slowing down; all these things are very important and I would like to do them more often and be better at this. But reading about the idea of a distributed consciousness left me wondering if there wasn't a short cut to all of this. This left me with the same uneasiness I used to feel when contemplating the concept of determinism, after reading Richard Dawkins, for example.

beam optics codes

2009-12-17T16:49:00.000-08:00

So I'm continuing on with my conversion of the Excel optics code into Open Office Calc. I've been calling the code Open Optics. I've almost finished the part where a lattice is copied together with the appropriate formulas for calculating some uncoupled parameters by adding them up around the ring. Hard to keep up momentum on this project, because I think that no one will really use it.
But its really not that hard of a job to do, so I can keep moving forward slowly.

For a second project, I have two different possibilities. One is working on the idea of developing a TPSA library to work with Accelerator Toolbox (AT), so that the one turn map can be computed and used to optimize various quantities.

Secondly, there is the need for more collaboration on Accelerator Toolbox. Many different people use it at different labs and they are repeating the work. I can try to put the code in a central repository so that people can work together on it. This is probably the first thing to do before working on the TPSA project. Once more people are working together, it may be easier to use existing code and get more ideas about the right way to combine AT with TPSA. Of course, then, something like a normal form algorithm should be written- or at least something to find tune shift with amplitude.

For the moment, I need to learn better how to use Sourceforge and SVN. I did this with the Tracy code, but my collaborator knew more about it than me. I should set it up myself, and figure out how to do it from behind the firewall, etc.

Finally, there is MAD-X and PTC. This is the existing rich TPSA, normal form code. But its not used that much for light sources, and the tracking routines are somewhat obscure- buried in the PTC Fortran 90. Getting this physics (well, sort of- symplectic integration) out in the open, would be part of the point of collaborating on AT. The tracking routines are very easy to find and read there.

mumbling

2009-12-07T02:59:00.001-08:00

And one day we woke up, and everyone we ever knew was there.
The familiar smiles, the wry comments, each distinctive approach.
But there was a strange slowness and vagueness to each individual. Focus as you will, you couldn't quite grasp them. Small pieces came through, but not the whole. There was a kaleidoscope of moments, a flooding of halting attempts to communicate.
"This is who I am!", Alan said. "Ok, we believe you." But he had spoken too loudly. His mumbling had been mistaken for clarity. His words parsed, the structure analyzed, but his face was foggy, and the impressions he received were not coming through.

direction

2009-12-04T01:47:00.000-08:00

One can choose direction in many aspects of life.
I guess on this blog I have mostly dealt with my work and attitude towards online stuff.
Can analysis help? We may try to think about who we are communicating with, how we are doing it, and what we hope to gain from this. In a blog, you mainly put stuff out there and don't get a lot back. It can be valuable for the purpose of collecting thoughts and recording moments, but as far as interaction, its rather minimal. I suppose this is not set in stone. Some blogs may cultivate communities in which the relationship is quite different. Perhaps blog is just not a very good word, or its meaning is not specific enough.
Anyway, if one is to be serious about online communication and work this into one's life as a positive thing, and not always an experimental, rather unconscious hope that it will be therapeutic in some form, maybe a little more clarity and direction is required.
This is just to note here that I would like to do this. Either fade this aspect of my life out, or clarify it. The one to anonymous connection doesn't feel like a long term healthy solution. It is too murky, and though perhaps part of development, should be clarified.

works too well

2009-11-25T06:12:00.000-08:00

There are some things that work just too well.
Like google search, whatever you put in, you get something back, as if you meant it.

I was going to try to run a program I am writing, and realized that I hadn't written everything that I need to yet. I was thinking, could the code somehow be smart enough to guess what I wanted to do, and then just run? Why do I have to take the time to put all these explicit instructions in there? Of course the reason is that it is based on rules that I understand, so I have a certain measure of control in the situation. If the code could decide itself what it thought that I wanted to do, then its no longer a situation based on rules that I can understand to whatever degree I want.

I'm not saying I think Google should crash on badly phrased searches, but having hidden rules with a goal of never failing and always trying to guess what you want takes the control away from the people using the code and puts it into those writing it.

Again

2009-11-17T08:56:00.000-08:00

Just because something has been done many times before, doesn't mean it shouldn't be done again. Yes, the awareness is helpful to some extent. But you will always bring something new.

I'm thinking of my project of writing an accelerator optics code in Calc. What can I do differently? Can I document it better than MAD? Can I make it easier to use?
This area has such a heavy history. Too many codes already. Yes, I'm writing another one. But maybe I can bring something good to the process, and even the result?

harmonizing

2009-10-26T14:09:00.000-07:00

Realizing that there have been a number of situations in my life, where try as I may, I just can't put it all together, and can't find a nice picture. Ah well. No reason not to try to harmonize in other contexts, perhaps on a smaller scale.

computers as tools

2009-10-06T11:30:00.000-07:00

I came across this article (seems to be badly formatted- should be run through some wiki software?- I cut and pasted it into emacs to get the line breaks...) by Chris Dent at University of Indiana.

He says that there are two different views we have of computers. One is as "interactive artifacts", and the other is as tools. He suggests that the view as being interactive is flawed and the source of computers resulting in much less increase in efficiency than you might expect. He says that basically it is a flawed metaphor. We think of the computer as like a person, able to interact with us. However, for the forseeable future, computer programs are still rule based within a given domain, not able to form their own categories and make connections between domains. Thus, we have overly high expectations for how easy the interaction will be (the computer can understand what I want!), and also too low expectations for how that experience actually goes (I guess I just don't know how to talk like a computer :( )

He says that the two main ways in which computers are tools are in terms of automating tasks that are now or were previously done by people, and by acting as tools to augment ourselves.
I must say that I get a little uncomfortable thinking of augmentation. But I really like this idea of thinking of computers as tools. It throws away the fiction that we are somehow creating beings, or entities, or some kind of abstract existence out there. Instead we are using tools. These tools may store, represent, and manipulate information. And much more. But turning it back into tools, gives us the responsibility. What tools do we want? How effective are they? What do we want them for?

living with networks

2009-09-30T02:03:00.000-07:00

Whenever I hear that something is "on the internet", or to "buy it on the net", or search "the net", a little feeling of hopelessness creeps in. I guess the reason is that this view of the internet as an undifferentiated ocean out there, serves a role as a panacea. Or maybe the problem is the identification of the internet as a place, which to me seems to inevitably devalue our physical world. Now there have been video games and virtual reality games of varying degrees of simulation and imagination since when, the '80s?
This is the view of the internet as "cyberspace".

The problem is that to the extent that it makes sense that we exist in this space, we certainly have to change, and this change sometimes feels forceful, like its not recognized the level of discomfort resulting from these changes, and not dealt with in a delicate way.
Of course we can revisit the philosophical questions of life, and what it is, and of consciousness and what it is. And like all technologies, they can actually give new perspective on old philosophical questions. In the sense that one doesn't have to work as hard in "what if" statements.

I recently read Vannevar Bush's rather prescient article from 1945 Atlantic (available here, -- I found this thanks to John Jowett again). He describes the ways in which various technologies pushed forward will link us together, and make examining "the record" more powerful. It is somehow satisfying to see "the internet", or something like it, described at a much earlier date. It gives a new head space in which to think about it, not seeing its current incarnation as inevitable.

few thoughts

2009-09-28T00:50:00.000-07:00

A little more on the previous topic.
First, Jodi Dean discusses the UC strike, in a rather abstract way.
Here, she says that the crisis in universities is that universities are a part of the capitalist system, designed to create whatever type of labor capital needs. But supposedly "capital doesn't need us anymore". Is this really true? Does she mean that computerized systems can do everything that people can, and perhaps better? I think this goes too far, and is a mistake in some way, but I may also misunderstand what she's saying. Not that I really want "capital" to want me so badly, or even that I quite know what "capital" is. (Oh, looking at this more, I see that she is actually critiquing that view of the university... I should read this more carefully...)

I've been trying to create systems for myself, and then follow through on them. Every time I start following a linear procedure, something in me tells me that this is dehumanizing, and I ought not to be doing this. I know there's something wrong with this. The most healthy of people have working systems they are a part of, and being a part of that system will certainly involve following linear procedures.

On this topic, I should quote from Karl Popper (stolen from here)

As I wrote many years ago at the very beginning of the debate about computers, a computer is just a glorified pencil. Einstein once said "my pencil is cleverer than I". What he meant could perhaps be put thus: armed with a pencil, we can be more than twice as clever as we are without. Armed with a computer (a typical World 3 object), we can perhaps be more than a hundred times as clever as we are without; and with improving computers there need not be an upper limit to this.

Karl Popper, The Self and Its Brain, p. 208

The French seem to really like bureaucracy. But it also seems to me to be a functional bureaucracy- one that really involves people. Something about this is reminding me of how Americans sometimes see nature, in terms of something totally separate, totally wild. This idea of not separating ourselves from our systems quite so much is also hitting me in terms of how I've seen Europe. I've seen it as a place of history. Its tempting, as in the case of nature, to see contrast civilization with the wild. Likewise, we can contrast living, modern places, with places steeped in history. But Europe, with longer experience of dealing both with nature and a longer history, maybe has developed a different, more interactive approach here.

People and computers

2009-09-24T10:15:00.000-07:00

Sometimes it feels like we are designing/(haphazardly pushing forward) a world in which we have no part. Its moving faster and faster, and one wonders whether a different creature- perhaps some digital descendant of ours is better fit to survive here.
We can think of previous revolutions such as mechanical and chemical. In the end we still found a role for ourselves. We found ways in which to buffer ourselves and take advantage of the power of these new technologies. We created cars and airplanes to travel fast and still be in relative comfort. And we don't have to use these fast technologies.
Here's an interview with Ray Kurzweil. Actually he kind of pisses me off. Notice at around 2:30, he is asked the question of what we can do to prepare for the change. He doesn't answer the question, instead, he seems to revel in the predictions of how fast things are changing.
For him, the human brain is something to copy, source material for something else. That's ok, but why do we want to do this? Why just build and build and build. Ok, there's a certain inevitability to some of it. But what's more interesting to me, is people and how they interact with these changes. There's a cheapening effect. Where's the depth? Sure, he might say that the power is there for even more depth. But shouldn't we start with the depth that we have and try to increase that? Where is literature and art and experience of nature in this kind of vision? Its just faster and faster and faster? I guess this is just another kind of conversation to have.
But for me, the thing to remember is that there's no reason why things have to be worse. We don't need to just try to get faster stuff for its own sake.

work vs. research

2009-09-10T19:06:00.000-07:00

My new project involves developing a beam optics code based around a spreadsheet. The job is basically to convert this program from Microsoft Excel and Visual Basic to something based on Open Office Calc. Now, despite the fact that open source is nice, and open office seems to be pretty quality stuff, there is something decidedly unsexy about spreadsheets. They suggest doing a large number of small, not particularly interesting calculations. An emphasis on detail, an office setting, and a sense of the mundane come to mind.

But this area of beam optics and particle tracking is a mess. There are multiple codes with lousy interface and difficult interconnection. People become experts at particular codes, and this is what accelerator physicists do. The expertise, however, is often more in the technicalities of the mess- the bureaucracy of the multiple organizations and the history of the field, if you like. Its called research, or physics, or dynamics, or something exciting, just to motivate people to do this rather boring work.

Thus, to me, developing an optics code based on a spreadsheet is confronting this fact about this field honestly. We are managers of many small formulae, doing rather well-known things.
The point is that perhaps this project will allow one to more easily separate what is well known from what is a bit more difficult. In other words, we can train people to do those parts of this work that are already figured out. The operators in the control room should be able to change the quadrupoles to reduce the emittance, or affect a change in the optics to reduce the beta function, or play around with the weights on the non-linear dynamics properties. This isn't research, but it still takes effort, care, and can be done well with pride.

So I see this project less as a research project, and more as providing a tool that will separate out the known from the unknown- give people a tool with which the known aspects of this field can used, in the same sense that knowledge in finance, medicine, or nutrition might be utilized.
At the same time, in order for a field to be healthy, there must be this transition of knowledge into the arena of easily available, well known information. I think this is the value and nature of science, as described in "Laboratory Life" by Latour and Woolgar for example.

I don't want to say that there is no research to be done in this field, but just that there is a lot of known stuff, and it should be made easily available. It may not be popular with those who would rather keep the mess of obscurity. But I think its necessary if there is to be development.

moving and the symplectic camel

2009-08-31T19:30:00.000-07:00

Yeah, yeah, more about this tedious moving process, whereby I reduce my digital, physical and mental footprint, so that I can cross the sea and find peace in a new land.
A recent paper someone forwarded to me:
"Symplectic capacities and the geometry of uncertainty: The irruption of symplectic topology in classical and quantum mechanics"
One of the main points is the story of the symplectic camel, that sad creature who could not pass through the eye of the needle. It is in fact a relatively recent rigorous result (Gromov's non-squeezing theorem) about symplectic geometry.
Basically it says that whatever your initial projection onto the different phase planes, a canonical transformation will never decrease, only increase them.
So, yes, I suppose this means that I should get rid of stuff. The connection is obvious, right?

On a different, not really related subject, I just finished reading Alan Watts' "The Book on the Taboo Against Knowing Who You Are".
Some parts really resonated with me, though at times it put me in that kind of trance where he could say just about anything, and I'd nod slowly with a blank stare. No, actually, it did that remarkably little. The image of self as the universe playing hide and seek with itself is an interesting one.

frequency amplitude dependence

2009-08-25T19:08:00.000-07:00

So, consider a dynamical system that has an elliptical fixed point. The eigenvalues of the map linearized about the fixed point gives the frequency associated with rotation about that fixed point. Move away from the fixed point and the frequency changes. This is one definition of a non-linear system. A pendulum, for example, has this property; and this changing frequency explains why it doesn't make a perfect clock.

This simple property is what I am trying to get to the bottom of. It becomes less simple when one wants to think of this continuum of frequencies as the spectrum of some operator. So the operator has become rather more complicated from the simple matrix expanded about the fixed point. Suddenly it has taken on an infinity of eigenvalues! Once we say this, however, we are left with the question of what the eigenvectors mean. Are they functions that are basically delta functions except where the orbit is? This is a rather messy singular quantity. How about the eigenvectors of the adjoint operator? These are the quantities we've been looking at, but they seem to be rather strange.
This is the line thinking I've been following lately. I'm hoping I can find a simple reference that explains all this. But I can't seem to.

trimming books

2009-07-27T05:42:00.000-07:00

I'm trying to get rid of books. The problem is that many are unfinished. I start too many that I don't finish- then they sit there as reminders of work I should still do.
I need to figure out how to keep track of what I wanted from a given book, even if I don't keep it.

Item: "Flim Flam: Psychics, ESP, Unicorns and Other Delusion" by James Randi.
If I start to give a postmodern open to everything, relativistic view of science too much clout, then a book like this is an antidote- confident, documented. But really the value of this is that it is one of the places where the Maharishi (Mahesh Sharma?) is described in a skeptical light. Anyway, it has now been recorded, and I can get rid of it.

forming a working web: vague thoughts

2009-07-03T15:32:00.000-07:00

What does it mean that the center doesn't hold in a dysfunctional situation? It means that there is nothing one can say that is constructive that doesn't piss someone off. So the situation is just constantly exhausting. But as long as one continues a certain level respect for all people involved, then one can just continue talking, continue communicating, until maybe, just maybe, the resentments get smaller. This ability to pick away at a difficult situation and not give up, and never fully lose respect for the elements (people, concepts, etc. ) involved; perhaps this is something I am good at. I think that its not necessarily a recipe for reconciliation. Perhaps its just a recipe for personal survival within a difficult situation. If one chooses to stay, instead of leave, perhaps this is one way to not be totally consumed.

Social media have been dominating lately. I don't know whether I have an unhealthy dependence. I think that they allow new possibilities. They extend your social life in new directions perhaps. But they certainly don't replace the need to develop meaningful deep relationships. Perhaps that depth can contain some elements of these new digital communications, but it seems that they can easily distort and make shallow appear deep.

Workwise, and socially, I am scattered, but using electronic media to make something more solid of this web. I've been trying to say no and yes at the same time. No to certain sustained commitments (because one can only make so many of these), and yes to a more loose form of electronic collaboration. Whether this latter turns out to be an illusion or not remains to be seen. But the saying no part has been hard. Painful and sad, and requires every ounce of my energy.

map analysis

2009-06-20T20:09:00.000-07:00

In a circular accelerator, if you look at a single beam position monitor (BPM), or say, a couple of them, to give you phase space, you essentially looking at the properties of the one and many turn behavior of electrons. The value of the Hamiltonian -free description, the map description, is that it treats the machine as a whole, without necessarily thinking of how that map comes about.
This is analogous to solid state physics and scattering analysis. You define various quantities of the material that can be probed via scattering stuff off it. You don't need to know the position of every atom in the material in order to define these quantities.

Why has this approach not developed further in accelerator physics? Because there aren't enough accelerators. Each one has its own peculiarities, and so people think more about how to change those peculiarities and effect certain global behaviors rather than be more creative in defining the global behaviors. It would be like analyzing ten space ships, each of which was rather different from the other. One would probably not extract a general theory of space ships out of this.

Tower of Babel

2009-06-20T13:13:00.000-07:00

At some time, I'd like to try to lay out the genealogy of particle tracking codes in accelerator physics. Looking about the CERN site for MADX, we find a presentation on the Universal Accelerator Parser for the Accelerator Markup Language. Here, we see the status of accelerator codes described by Sagan as a "Tower of Babel". But, to be honest, at this point, I would not say that this accelerator markup language has caught on that widely.

I don't know why, but I keep trying to construct some kind of epic narrative about this topic. If the field of particle tracking codes is the tower of Babel, then we might refer to the shutdown of the SSC as the "hand of God" coming in and crushing the unified human effort to pierce Heaven for the glorification of Man.

Yes... dangerous waters. There is already far too much implicit religious metaphor pervading this field.

In any case, let us hope that something like the UAP/AML can help put the pieces back together again.

I should also mention another effort in this direction, the UAL, Unified Accelerator Library. I don't know the best link for this, since the BNL site seems to not be online anymore. Here's a paper, or here for a SPIRES search.

mathematical methods of accelerator physics?

2009-06-19T10:36:00.000-07:00

There is a post by Mark at Cosmic Variance requesting ideas for topics for a course on mathematical physics. I added a comment suggesting non-linear dynamics for storage rings could make a good topic.
Thinking it through a bit more, perhaps this would be tough. I myself am in the process of trying to understand this field better and pick out what is and isn't essential. So maybe its not ready for someone to pick up outside the field.
The references I mentioned were to Dragt's online book and to the book by L. Michelotti called “Intermediate Classical Dynamics with Applications to Beam Physics”. The wikibook might still be a good place to sort this out.
Perhaps if one is talking about Lie Algebras or Lie Groups, this is nice to know that they are not just used in particle physics, but in classical mechanics as well. And classical mechanics is such a broad subject. It is almost the same as mathematical methods of classical systems.

I also mentioned that the maps with their resonance islands and separatrices and chaotic and non-chaotic regions had made their way into atomic and molecular physics through the quantum accelerator modes. Here is a link, first from google, but I haven't looked into the field enough to judge it yet... A topic for more investigation. I do know that the name of Shmuel Fishman comes up a lot with respect to this research area.

(Added comment: This topic did make it into several articles in Journal of Mathematical Physics. For example, see an article by Forest here.)

machines

2009-06-08T13:32:00.000-07:00

We accelerator physicists are the builders and caretakers of machines. We build machines that bring charged particles to very high energies, small sizes, strong currents. These flows of charge smash into each other, produce light, smash into targets and produce neutrons, are guided with great precision to be measured with great precision. We seek to control the flow, the identity, the environment of our charged armies. We build electronic systems, and software control, we protect, clean, and raise money for, and mourn the death of our machines. We are machine physicists. We create families of quadrupoles and sextupoles. We analyze power consumption, and ground vibrations. We deliver our beams shining and controlled, coherent and stable. We talk to the users of these beams- the scientists, the doctors, the patients, the companies. They want our beams- bright, stable, and on time. But we know that we need our machines to accomplish this.

facebook and tmfree

2009-06-06T12:19:00.000-07:00

Will MUM become a more open place?

bottom up/top down organization

2009-06-04T14:41:00.000-07:00

I recently read "Here Comes Everybody: The Power of Organizing Without Organizations " by Clay Shirky. It was a very refreshing book that made me feel like I got a bit of perspective on the changes we're encountering as we become more used to internet communications. He gave several examples of ways in which new things are possible in self organization with internet tools- basically, group forming and communication becomes easier, and because the technology to form these groups is essentially part of the web infrastructure, there is minimal cost associated with their formation.

As I've been thinking about jobs and where to go with my career, I've been seeing that there is a tension between the organizations that may want to hire me, and the connections I have and projects I can see to work on that cross organizational boundaries. I see the field of accelerator physics and how fragmented it is, and think that the internet could really facilitate some formation of commonality. At the same time, the reason the field exists is to build and operate accelerators that serve specific purposes or user communities. The building and running of such a facility is a rather expensive operation, and though there are new challenges for any project, many of the methods and technologies are already developed. So, from the facility perspective, a large amount of rather well-defined work needs to be done. This perhaps can only be done with the help of a more traditional top-down organization.

So I'm trying to understand how these two types of organization can work together- bottom up, spontaneous, informal, and multifacility on the one hand, and top-down single purpose, long term planned on the other hand.

anchors across the sea

2009-05-14T23:05:00.000-07:00

Trying to make a home, or at least imagine a home while working at BNL is challenging.
Firstly, there is Long Island itself, which is not an easy place to live for a Californian.
Some of it seems cultural, some is the landscape, some simply the lack of time and the feedback loop of too much work and lack of engagement.
Another aspect is the transiency of the people I meet in similar situations as me. The graduate students and postdocs are often only there for a few years and either plan to go back to where they came from, or on to somewhere else beyond BNL. Many are from across the Atlantic. This is a difficult situation. Its not that I don't want to travel to Europe, and can imagine living in Europe, but there is still a gap. If I were to live in Europe, it would be a jump. And my approach seems to be to continue moving in some direction. I feel like I need to consolidate rather than expand. So I make friends with those with anchors elsewhere, and I'm pulled. At the same time I search for grounding in this sandy land, and it seems rather inhospitable. And somehow, I feel that there is still something to learn, connections to be made before moving on.

commissioning a machine

2009-05-13T22:09:00.001-07:00

For complex machinery such as a synchrotron light source, one of the major considerations is the commissioning process. This is the process where all of the diagnostics need to be turned on and calibrated and the machine is tested component by component. This is what the LHC is going through right now, and what its recent problems relate to.
I keep trying to avoid some realities about this field I am in. One is the size and complexity of the machines. In order to come to terms with this, I have to come to terms with the commissioning process. I suppose the basic idea is to do it step by step. First you commission the linac and get the electrons looking good there. Then you inject into the booster and see if you can ramp it up to high enough energy. Then you inject into the storage ring, turning on your BPM's and trying to get a good orbit.
Somehow this seems so engineering oriented, I want to run away from the whole thing. I guess the problem for me is the stress level involved. I worry that there aren't enough people, and it will just turn into a mess. It also sounds like the end of research for me. The process also seems backwards, in that I'm building something without really knowing how it works first.
For practice, looks like I may be able to be involved with/observe the PETRA III commissioning.

blogging at work

2009-05-11T09:53:00.000-07:00

My friend Josh's blog no dna control.

Conference goals

2009-05-06T14:12:00.000-07:00

1) get papers in proceedings and present posters
2) find out directions that field is going
3) get myself some job offers or leads on jobs
4) meet other theorists in this field and see what they are doing and
how they make it.
5) See what universities hire accelerator physicists and what the
options are.
6) Find out whether anyone has done the same thing on this non-linear dynamics problem.
Explain it to people.
7) Tell people who I am- get to be better known in this field.
8) Talk about wiki and openness in field.

science is for people!

2009-04-27T14:08:00.000-07:00

As I try to write up work and look at the plots I create and the documents, I realize that these are for reading. A good part of the work was making files that could be passed back and forth between computer programs. I also realize that there are perhaps different styles and I was working with someone more on the autistic end of things.
So I'm finally looking at this work and trying to view it as natural language and as images.
What an odd path I have been through.
Have I been trying to turn dysfunction into function? Or simply a system I didn't understand into one I did?
I'm still not there, and even writing this is perhaps a form of procrastination. But being able to speak, think and look clearly about my work has been missing, so this is just a piece of the process that will or will not finish on time...

work

2009-04-17T10:39:00.000-07:00

Sometimes I get the feeling that I'm not supposed to be a human being at work.
I feel like only the technical work is valued and the collaborative work and work at helping others understand things is left implicit. Its true that a certain minimal level of expressiveness and clarity is required in documenting. I sometimes find that if I really take the technical work seriously, I'm left without enough energy left to pull it together and explain it properly. I then appear to have done very little work.
I guess the point is that these abilities to pull things together and put them in a reasonable context require you to be a more complete human being. And this isn't nurtured in this environment. The time I need to feel like a more normal person just isn't allowed.
So this means I should change jobs?
Or just keep at it, and hope that I can straddle both worlds?
Regardless, it only makes sense to sacrafice being a full person for so long... and one hopes that by the time you remember to stop sacraficing so much, there is still enough of you left.

Day as theorist

2009-04-04T16:05:00.000-07:00

Theory is a rather lonely profession.
And what is my approach?
I want to contribute to non-linear dynamics.
I approach it from this funny corner of technology/history/discipline called accelerator physics.
There is a body of insight here that is stuck and is a mess. If straightened out, it may be some important results can come from this.
Or perhaps it is just a cult-like curiosity?
I wonder if those who leave cults have a similar experience of trying to relate what they learned within the cult and bring it to a larger audience?
This is my basic question: am I actually doing something interesting, or is my main achievement simply survival within a difficult insular group?

papers

2009-04-01T21:27:00.000-07:00

Papers continue.
Slow progress. Somehow, out of disfunction and unfinished work, something more solid seems to form. I call this field unscientific. I complain a lot.
Maybe this is just how it goes.

I apply for jobs. I head towards staying where I am. I try to gather enough perspective, to see clearly enough that the choice feels like my own. Progress comes during the dark times, reveals itself after the difficulty.

I keep trying to find words and clarity. I keep feeling trapped and not wanting to trap others. I see every limitation and weakness in others as a potential cult. I question science, don't want to be managed. I look at this and it seems to point to a questioning of the notion of progress, of the value of any organization. I know that I go too far, here, and so I just float from day to day. My papers are like a mantra in a meditation. I put my attention on them, only to find my mind veer off. But what is satisfying is the fact that they don't go away. They are there to return to.

mess

2009-03-11T19:07:00.001-07:00

I am trying to finish a paper.
In fact, I don't know how far along I am.

Let me be self-indulgent. I would like to say that the mess I find on my computer as I try to make improvements and clarifications is not entirely my own.

I try to find the text files describing the data I used in my sometimes blurry plots. What I find is a maze of changed directions, desperation. I think back over this time and how I've responded to the challenges. I sought outside resources and survived. But it is a story of trauma rather than excellence. Survival rather than triumph. At the same time, it is not entirely my own story. I confuse parts of others with myself. There is lack of clarity here.

So, how do I make progress amidst my own mess which I accept to be partly the mess of the community I have involved myself with? Taking it easy on myself seems to be a good part of this. I have tried to have high standards amidst a decaying science. I have mined the labyrinths of the minds who have contorted themselves in this history.

So, I keep starting over, each time having a higher standard for clarity, and hope, and hope for progress.

physics from control theory

2009-03-09T09:52:00.000-07:00

One of the challenges I have been dealing with in my current position is trying to remain true to my scientist interests while working in a largely engineering environment. See e.g. here for some of my thoughts/struggles with science vs. engineering. Specifically, I had the feeling that a control theory methodology was killing the science outlook in my group.

Recently a colleague recommended an article on control theory in Review of Modern Physics:
(sorry, you need a subscription..) entitled "Feedback for physicists: a tutorial essay on control".
The author John Bechhoefer covers quite broad ground in this review article. I've just read a little so far, but a paragraph in the conclusion caught my eye:

What is perhaps most interesting to a physicist is the way new kinds of behavior arise from the structure of control loops. The tracking property of integral feedback comes from the structure of the feedback loop, not the nature of the individual elements. In this sense, it is a kind of "emergent phenomenon", but one that differs from the ones familiar in physics such as the soft modes and phase rigidity that accompany symmetry breaking phase transitions. Thus, engineering provides an alternate set of archetypes for emergent phenomena... (p. 832)

What Bechhoefer is pointing out is a way to go beyond control theory as purely an attempt to control, but instead to look for examples of control mechanisms in nature. He gives biology examples, and even suggests some quantum mechanics examples. Here is engineering giving back to science, at a conceptual level. Looks like the start of a more healthy collaboration!

wikibook

2009-02-21T05:34:00.001-08:00

Collaborating on a wikibook on non-linear dynamics in accelerator physics:
Guide to non-linear dynamics in accelerator physics
Nice to just start getting some of this material out there.

working with focussed people

2009-02-16T09:33:00.000-08:00

Scientists are often people with very narrow focus. They like for a problem to be defined for them externally, and then within those contexts, use all their energy and creativity to find a solution.
This can go wrong when there is no clear direction to go in. People are so anxious to get to work. They want to create big things and just go go go. But it may be that the center doesn't hold in all this. That hard work just creates heat. And sometimes organizations and environments perpetuate this by rewarding hard work in itself. This is the case if the organization doesn't have a good grasp on what it is trying to do, or if it underestimates the difficulty or misunderstands the foundations of some of the work being done. Then people rise to power by simply making a lot of noise, pointing out flaws in others and making very confident sounding statements.

deceleration

2009-02-07T09:08:00.000-08:00

I sometimes feel stuck in accelerator physics. I am running computer codes, reading papers and thinking about particles in storage rings that have been accelerated up to high energies. The machine I am working on for example, has electrons with energies of 3 GeV. This corresponds to a relativistic factor gamma of around 6000. Its a strange phenomenon to work at these extremes. Its not very grounded. There is not a feeling that you really understand things.
One of the aspects I've studied have been off-momentum dynamics. Whether particles with slightly different energies or momenta will still stay stable. Particles scattering for example causes a change in their energy and this can cause the particles to be lost.
As I finally start thinking about the relevant equations for off-energy particles, I imagine the deceleration process, the returning of these electrons to rest.
Even electrons themselves are hard to picture, and the whole field has an air of unreality to it.
I guess it says I've been too much of a theorist.

value of analysis

2009-02-04T12:26:00.000-08:00

What is the value of finding simple formulas to explain things?
Our minds, in the midst of this computerized landscape, sometimes seem small and insignificant.
If a program exists to simulate a system, what is the value of searching for simple ways of looking at it? One answer is that it cuts down on the number of cases one needs to simulate. Getting at the important parameters limits and sharpens the questions and makes on more effective at using the simulation. But what if one can somehow ask the computer to do this? To write such a nice interface to the code that new structures are created based on results from running the code.

The research topic I'm involved in has a funny history with computation. I think that some of the people involved in the early days had something against mathematical reasoning, and the slow process of analysis. One can try to guess at the reasons. Perhaps they'd observed too many mathematicians or theorists making grand statements on practical problems where the methods were simply inadequate and did not actually solve the problem. Or maybe they were not great analysts themselves and just trying to keep the power in their own hands. Regardless, the closing of the SSC precipitated a battle that is still going today between computation and analysis. There is excess on both sides. The theoretical structures one sees are overly grandiose. There are lie algebras and differential algebras and non-standard analysis and geometrical concepts such as tensors and fiber bundles. These are spoken of both with reverence and spite. Those who invoke such concepts either are trying to appease those theorists who they admire or prevent people from thinking critically and trap them into a self-serving view. Some of the original theorists had good motivations and indeed a broader set of questions they were looking at where such abstraction may have been helpful. On the computing side, one sees object oriented computing concepts such as polymorphism, linked lists, discrete algorithmic type approaches, control theory, optimization, SVD, model theory.
Viewing physics from an information theory, algorithmic approach. It sounds modern and laudable in some sense, but behind it is a desire to kill analysis.

This snake's nest of buggy concepts and software in the end often solves the problems good enough to get by. But one sacrafices understandability in entering this field. One speaks of minimizing terms and higher order calculations where exactly what kinds of objects these terms are members of and sometimes even what is meant by order is typically murky. It resembles a religious cult or a radical political group more than solid physics. But the rhetoric is getting old.
So I've gotten a bit specific here. I meant to try to explore the value of analysis. I feel that clear analysis is the only way out of this mess, but just what that means and whether it is adequate is not always clear.

slogans

2009-01-26T18:19:00.000-08:00

"Tensors make me tense"
"Resonance driving terms drive me crazy"

normal form

2009-01-26T04:16:00.000-08:00

A cross-roads. A meeting of the old and new.
I see other people's lives and I want to jump into them. I don't know if I can finish what I started.
My own work seems dark, slow, difficult.
But its because I always look elsewhere. If I look back on my own experience, I see my room at my dad's house, the oak tree outside, the hill with the curving gravel road leading steeply through forest to the small cabin. Behind it was the field which led to further paths with madrone berries, bay laurel leaves, blackberries. I would look down through a clearing and see the surface of evergreen trees covering the hills, and I wanted to fly down the mountain. I could almost taste it all, it was almost edible: the sights, the experiences, the possibilities.
And today I read through papers that describe procedures and equations and survival strategies. And I see strength and weakness and unfulfilled potential. And I try to do something with all of this, to put it into my own terms, to make each piece come alive. I reread the same difficult papers and try not to lose my balance. I follow the paths that lead to cruel tricks and powerful constrained mysteries. And I try not to get too lost, to always keep the common ground in mind, or at least the attempt to build common ground.

arnold diffusion

2009-01-21T22:21:00.000-08:00

Definition by Mathworld:
The nonconservation of adiabatic invariants which arises in systems with three or more degrees of freedom.

Yes, another dynamical systems topic.
Yes, it seeps into my life.
Near the origin of phase space, in enough dimensions, the tori do not hold.
The particles slip and slide out, in between.
And so, even when I try to be as normal as possible, as regular and elliptical as possible, I still escape. The regularity presses against me. It tries to constrain me, but I am one of many.
And don't even get me started on the homoclinic tangle...

KAM

2009-01-15T05:25:00.000-08:00

Its snowing outside.
I try to read a bit about the KAM theorem.
But those clever people switch it to KAM theory. Like string theory, its not so definite. It becomes an attitude, a community attached to solving some problems, not a solution.
What once seemed like a set of problems to be solved dissolves into history and definitions.
And perhaps all I've been doing is trying to find the calmest places amidst all of this, to navigate without being pushed over.

keep going

2008-12-29T09:11:00.000-08:00

How does one do something new in a contentious area?
How do you contribute when your words are being scrutinized for their relevance to long-going battles?
One option is to stay out of the fray. You simply don't follow the daily fights. You withdraw, and build up your own form. You design your own notation, and find as much as you can with that notation.
The danger of this approach is either irrelevance, or prolongation of the battle. There may well be much that is rich and interesting that has not been formalized, but is assumed by one side or another. It may well be that the outsider doesn't get far enough. On the other hand, if there is much that is assumed, but is wrong, if the whole edifice is mud and cotton, then a solid arrow may simply pierce through and head off in a new direction, leaving the participants simply more injured than before leading to more fighting and misery.
The other approach is to move very slowly. To take in a few contentious issues at a time, and one by one connect them to more solid ground. Develop a few new colorful pebbles, but make sure these pebbles lie on solid shores and sparkle brightly enough to capture the attention and content of battlers.

academic

2008-12-08T04:19:00.000-08:00

Wikipedia on Academia:

Academia is sometimes contrasted pejoratively with "practice", such as daily living, employment, and business. Critics of academia say that academic theory is insulated from the 'real world', and thus does not have to take into account the real effects, results, and risks of actually performing the actions which academics study. Academic insularity is sometimes referred to as the ivory tower. This often leads to a real or perceived tension between academics and practitioners in many fields of knowledge, particularly when an academic is critical of the actions of a practitioner. Depending on the degree of criticism, the practitioner's critique of academia could also be seen as anti-intellectualism. The balance to the view from the practitioner is that even if academia is insulated from practice in the real world, that does not mean academic study is valueless. In fact it is often seen that many academic developments turn out only much later to have great practical results. However, given that among practitioners there is a perception of academic insularity, it may increase the value and impact of the academician's studies and or opinion if they take that insularity into account when discussing or offering criticism of a practitioner or a practice in general.

I've been struggling with this question of the value of academia within an intensely practical fast-paced development environment. There are two aspects in which one's work may be judged overly academic. First, the topic itself may be perceived as useless. Secondly, too much emphasis on clear writing may be seen as a waste. The main issue here is time. Both of these things take too much time compared to the immediate needs.

From this perspective, however, an academic approach can be seen as a long term approach. On the one hand, tools are developed that may not be immediately necessary, but will provide fuel and resources for years to come. Secondly, communication without a delineation of context is also short-termed. It assumes a shared understanding that is rather fragile. People reading at a later time may well misunderstand.

Its this second goal that I've been most reluctant to give up, and I question the split. I don't want to give up clear writing, both for its practical benefit and for its personal benefit. Writing poorly takes the power away from the person writing. The truth is that there is a personal story here related to the group I am working in. I'd like sometime to try to write this out more clearly, but its probably better not to give too many details.

As a thread to follow up on, one of the books I read in high school that was influential was Herman Hesse's "Glass Bead Game". I've been meaning to come back to this book. I felt like Hesse had read my academic dreams and then put them into a larger context together with a warning to not become overly isolated.

Great first line to a technical paper

2008-12-06T06:26:00.000-08:00

In the last few years, our vision of the dynamics of the Solar System has notably changed, and the picture of the planets moving around the Sun in a regular quasi-periodic motion has suffered many outrages.

J. Laskar, ICARUS 88, 266-291 (1990)
"The Chaotic Motion of the Solar System: A Numerical Estimate of
the Size of the Chaotic Zones"

finishing things

2008-11-28T17:41:00.000-08:00

I've been trying to do things more quickly. To just get things done, even if they're not great.
This involves knowing that I put, say, an hour into something, and what I came up with is reasonable for an hour's work.
Some things I just take forever on. I was trying to understand why. I have this image of certain important things that are very fragile and complicated. I picture a many armed Hindu God carrying many plates, each with a crucial element that needs to eventually be combined with something else. But this God is on rather shaky footing, and must hop continually in order to avoid dropping one of the plates. Anything that touches on this domain must be treated very carefully, because it won't be a top priority. It needs to make sure it doesn't break anything, and the very process of doing it may involve helping to combine together some of the plates.
I don't think there's anything to be done accept to realize when something can be done independently of this blue creature. Then it can just be finished in its usual partial messy way, but not cause so much damage.

correspondence

2008-11-21T17:43:00.000-08:00

When to write?
This evening, I am tired. I have made progress on big messy things that are not very satisfying. I have moved forward two steps through oatmeal and piles of string.
I tell myself, just take it easy. Don't bring in more stimulus, and the passage of time will bring new views. So I am deciding that my thoughts are not important for the next 10 hours.
And where do I find myself 1/2 hour later? Writing to people long overdue emails, and putting my disowned thoughts down on this blog.

chapters

2008-11-18T17:56:00.000-08:00

What always shocks me about language is how obvious and powerful some words can be.
And when I think back to the time when my mind was in a knot, I imagine these words and what they would have meant to me then.
"I just can't believe how valuable people are."
This thought has such richness, and wonder how I could possibly maintain the tightness in its presence. But such a thought was unthinkable. All words were gray. All passed over piles of theorems and jagged bits of past and little jabs.

Paperless

2008-11-06T03:35:00.000-08:00

I spend a lot of time on my laptop. Many documents are available there, and many transactions can be performed. At the same time, I feel like there are hidden problems.
My laptop even replaces watching TV sometimes. Last night, instead of watching a DVD on my TV, I watched the Simpsons on my laptop. The difference was that I can put the screen anywhere I want. On the one hand, TV has sentimental value to me. But further, the idea of a screen that is watched for certain purposes being located in one place has its role. Its like organizing our space. What happens when we open up the possibility of continually changing spaces?
How do we live? We are creatures of habbit.
This is something I have a problem with. I tend to get myself into continually changing environments. Yet there is a good part of me that this doesn't work for. How can something grow, when its environment is always shifting? I grew up with two houses, going back and forth between my father's and mother's, transferring twice a week until high school. Each place was different, with different rules and expectations, positive and negative aspects. I trace a lot of my scattered approach to life back to a coping mechanism for this lifestyle. My parents tell me that it was what everyone was recommending at the time for divorced parents with kids. However, the opinion later changed. A topic for future research/discussion.
Back to paperless. Despite all the benefits and time that I do indeed use digital media, it scares me. There's an underlying fear that the bottom has fallen out. That Borges' image of the infinite library is at hand. At the heart of this is perhaps the requirement for new skills at maintaining ourselves and new dangers to recognize. But for myself, I try to recognize the same patterns that I see in my approach to people, research, and organizing my life in my digital/paper approach.
Here is a random document I found in my search for the term "paperless office" (a review of a study called "The Paperless Office" by Abigail J. Sellen and Richard H. R. Harper). In the conclusion of the review, this line caught my eye:

Second, the digital alternatives to paper need to be better designed. Until that happens, until paper is used as an analytical resource for the design of technologies, paper will almost certainly continue to be the medium of choice.

It just reminded me to be wary of the hidden costs of using digital media. Paper hasn't been around for ever, and our current digital technology and metaphors won't be around forever, but technology shouldn't be quite as powerful in its role as dictating what questions we ask and what kinds of collaborations we pursue.

Sorry for rambling. Let me again blame the medium. Or more precisely, this medium seems to make this kind of shallow jumping around easy to do.
Finally, let me just add, as a "direction for further research", that perhaps where digital media fall short is in their very lack of physicality. We have a lot of intuition about our three dimensional world. To quote from my undergraduate thesis (on adiabatic invariants!) "We are largely concerned with getting ourselves from here to there and moving other things from here to there." The computer desktop metaphor is just that, a metaphor, not a reality. It is still largely a two dimensional model, with links between different chunks of 2-D space. You may argue that a book is also largely two dimensional. But the links between the different pages occur truly in space. The flipping of pages and the locating of later pages deeper in the book than earlier pages, is something that screen reading does not fully replicate.
Its surprising, but I find myself having to mount a defense for our poor 3 dimensional world!!

standards

2008-10-30T08:05:00.000-07:00

I was recently told that I should lower my standards. That I take too long to get things done because I want perfection. There's some truth to this, but I think really I need to aim lower. Shoot for smaller things. If the project is too big then if you fail, you fail spectacularly. It is just totally useless, the work you put into it. There's a point when something is clearly pretty good: most of the pieces are in place and it basically is what it claims to be. Now, by lowering my standards, I certainly don't want to not achieve that level. Standards should come in at the final stage: how well to polish.

The problem is that I tend to end up with lots of partial results that each require a lot of work to even get to the "pretty good" stage. Its confusing because I look and see lots of work that I've done, but none of it seems to amount to much. There's a temptation when the time comes to account for what you've done, to paste together all these partial results and try to pretend that its one grand whole. Doing this would indeed be lowering my standards, but I don't think that this is the right thing to do. It doesn't leave you with much, unless you spend half your time tricking people and confusing them and convincing them that any holes in your argument are due to their lack of reasoning ability.

santayana

2008-10-26T16:08:00.000-07:00

I've been finding audio lately.
Here's chapter 3 of George Santayana's "Some Turns of Thought in Modern Philosophy".
I haven't absorbed it all yet, but the first part on separation of duties between experts and scientists (thinkers?) is right along the lines of what I have been thinking about and dealing with.
Later he concludes that relativity is a welcome, acceptable revolution in science, but with it must come humility. I'd like to understand better what he's saying here.

knot

2008-10-21T20:27:00.000-07:00

I'm always drawn to traumatic history.
The topic I'm involved in is one part physics, three parts scattered remnants of trauma. The question is whether there is anything left of me before this knot dissolves. The poison infects everything eventually. Now my current collaboration is getting sucked into the old mess. The same issues of credit, hurt egos, unfulfilled dreams rear their heads. But perhaps this time they occur in a vacuum where they don't actually have effects. And after playing themselves out, sadness can be felt and people can move on. But again, this really doesn't seem to be the normal role for people in physics, and I wonder how much reality there is to this crazy quest.

today

2008-09-27T19:59:00.000-07:00

I have been pushing hard lately. Just get things done. But nothing very specific. Many small things that set the stage for other things. Too abstract.
Today my dad told me that he thought I am a bit lost. That he's never before seen me without a clear path forward. But has my path ever really been clear? It has certainly not seemed that way.
Today I was at Barnes and Nobles for awhile. I saw people from within my isolation and didn't talk to them. But I feel like some processes are playing themselves out that have been hidden and pushed below. I think some of this is good. I was actually looking at this feeling of isolation, and deciding not to fight it in that moment. One thing I have come to realize about myself is that I am basically an introvert. I've learned to be an extrovert, but its not always so natural to me.
I picked up a book called "Loneliness" by John Cacioppo. I read the description of a New Yorker who started a relationship with an old girlfriend who was not thriving in the city. In the midst of the ensuing misery, he is staring out the window and sees the image of a sad, lonely person. At first he thinks this is himself, but then the image moves backwards, and he sees it is someone mirroring him out the window! This connection pulls him out of himself, allowing him to see his situation more clearly.The story made me cry. Ok, just a little.
Here's an interview with Cacioppo.
Actually, I'll add that while reading this book, I was noticing the focus on statistics which was annoying me. There's an interplay between personal antecdote and supposedly objective analysis. It was also the discussions about genes that bothered me. Like the gap between these two ways of understanding is too great.

a name for yourself

2008-09-09T09:56:00.000-07:00

I seem to be pretty good at pushing things close to completion and then leaving them there. I somehow lack that spirit to really run with something. The way I think of it is that I build up structure so that I can enjoy the benefits of things in a relaxed way. Having to jump up and down in glory and deal with people who either didn't get as far as you or want to pull you higher, just isn't fun for me. But maybe defining yourself isn't so bad? Maybe there are new realms of uncertainty you enter?
I just keep thinking of John Cusack in High Fidelity when he finally decides to commit to a relationship:

I can see now I never really committed to Laura. I always had one foot out the door, and that prevented me from doing a lot of things, like thinking about my future and... I guess it made more sense to commit to nothing, keep my options open. And that's suicide. By tiny, tiny increments.

ready to give up

2008-09-08T08:26:00.000-07:00

Just one of those days where it seems like I just can't keep going on in the same way.
Whatever that means.

coming together

2008-09-06T18:23:00.001-07:00

Our minds can live in many places at the same time.
I feel spread across the country, spread across disciplines, philosophies, loyalties, lifestyles.
I blame it on the internet sometimes- my scattered approach, but really my use of the internet as a tool developed naturally. At each step it seemed to solve a prearticulated problem. On the other hand, what often comes to mind is those stories about wish fulfillment. The ways in which getting what we ask for is what destroys us.
Maybe its just been too long since I've been in touch with a certain voice inside me. The voice that does cross boundaries and includes the various parts of me.
Maybe because I am working, holding things in suspension, creating small environments for things to grow, I can't access this voice. And I'm overwhelmed by too many pieces at the same time. I worry that there is no end. That its just one expanding blow after another with not enough glue to put it together.
I enjoyed painting for the first time in awhile. This is what painting is for me. It is putting things together. I used to think that I could put anything down on the paper or canvas and find a way to make it harmonious. Maybe giving up on this is why I've been unable to paint for so long. But maybe its time to believe in it again. But belief in the more humble sense of a longing and dreaming rather than a "must get it done now".

unstable

2008-08-22T16:38:00.000-07:00

I have this funny feeling of sitting at the top of a bowling ball. Certainly it must have something to do with the amount of effort (useless perhaps?) I've been putting into thinking about how to approach the dynamic aperture problem. Find the separatrices and beyond that is unstable.

But its also a feeling from reading Peter Woit's Not Even Wrong blog for awhile, and considering the turn on of the LHC and the turn-off of so much US particle physics. I've never know quite enough about particle physics to be really excited about finding the Higgs boson. I never really got past renormalization and feel like there's something not so good about it, or that the lesson it is teaching needs to go all the way back to the beginning.

And with the Bush administration having already done its damage, google mostly taken over people's brains, I just really don't know where things will go next. What I usually do in times like this is just wait. I try to be quiet, to not make any decisions, and to let things play themselves out. Then I get swept in whatever direction. I don't like this feeling of complete uncertainty. Its familiar, but its reached a deeper level now. I know myself enough to know that I probably still have agendas, but at the moment they all seem dangerous and wrong. There is nothing to do but wait.

move slowly

2008-08-08T18:30:00.000-07:00

Action items:
* brother changed name
* wedding to attend (not my own)
* books being neglected
* more time for self not involving tossing keystrokes into big mouth of lattice optimization and evaluation and politics of avoiding blame

ahhhh

2008-07-13T09:25:00.001-07:00

This is a very satisfying link.

narrative amidst chaos

2008-07-08T13:16:00.000-07:00

What do we say when there is nothing clear to say?
When according to your standards, you want to shout: "mush!"
The tree was covered in dark spindly bark. It was surrounded by small bushes with crisp green waxy leaves. This region of the forest had long been considered problematic. It was in fact just a restful region surrounded by stone walls rather by accident. Nothing really that special, just a confluence of hard to categorize, misty and perhaps obscure lives, corners and the usual uncertainty.

learning things from the ground up (or being buried in the mud?)

2008-06-19T20:03:00.000-07:00

I feel like I've been learning certain things lately in the slowest, worst way possible.
I have to get results out of this code that I didn't write, but I have been trying to turn into something more friendly, familiar and reliable. I collaborate with one other person who has slightly different aspects of the code he is interested in developing. We try to keep in synch, but changing things break other things and I often find myself with a broken code and the tortuous question of whether to push on and fix the problems or go back to a slightly worse previous version that I know works (or at least the parts I have checked).

During this process, I am forced to learn about things that I don't feel like learning at that particular time. In the end I do learn certain things, and after I know them, I also have a sense of how they can break, how one can confuse them for something else.

I'm somewhat reminded of a comment by one of my physics professors during college relating to thermodynamics. One of the math professors suggested that there is a beautiful way to understand thermodynamics. If one just understands a certain structure, then thermodynamics fits into it very nicely. (sorry for vagueness, I never actually learned thermodynamics very well)
But the physics professor responded that he thought it was better for students to first muck around in details before getting the clearer grander picture.

So what am I afraid of? I do learn in this process. I think the problem is that I am encountering real design flaws, or perhaps imperfect implementation. As a result, I will likely never actually rise to that level of clarity, and then have only gained an extremely obscure skill: familiarity with a code very few people use. Perhaps I won't know the ultimate value of this until later. I have a feeling that much of the technical details I am learning could be learned much faster and easier in some other way. But perhaps there are lessons involving people, egos, creations, and collaboration that will be very valuable (if I can ever escape from this situation!!)