Like a virus building a campfire

So again this is something from my E&M class. My professor is Alexei Efros an elderly Russian man with quite the accent. A number of weeks ago he was talking about fusion to the class. This is a rough paraphrase of what he said, you will have to add the Russian accent yourself.

I have many friends who work on this problem their whole lives. One friend, every time I see him I would say 'how long till we have fusion?' and every time he would tell me 'about 5 years' he would say. My friend he is dead now but the last time I see him I ask him 'how long till we have fusion?' and he respond me 'about 5 years' Now it seems that the consensus in the field is that we are making great progress and it really seems we will have fusion in about 5 years. But I would say to my friends I would say 'why we need it?' Perhaps we could use fusion to boil ocean water and irrigate the Sahara, or some project like this, some great project Like making enough water for the Sahara. It turns out we could not do this since this would heat the atmosphere of the earth. But this I tell them I say 'why we need it?' Every reaction has a size. Take campfire, if you build campfire the size of candle it will blow out. The surface area of the flame is too large and it cools rapidly a puff of wind will blow it out. But if you build campfire big enough, build campfire campfire size then it keeps itself warm and the reaction can be sustained. So every reaction has a characteristic size and the size of fusion reaction is size of sun and we want to make it on scale of campfire. This is like if a virus were to try and build campfire, and the relative ratio is about right. We are to viruses like sun is to us. So we try to make fusion on our scale it is like virus or single cell organism trying to build campfire it is ridiculous and we absolutely don't need it just like the virus does not need it, we absolutely do not need it.

The sentiment at the heart of this is being that we do not need fusion I have sympathy for the perspective for but do not agree with it. Eventually we will need fusion power though for now and for the next few decades at least I think we should instead try to use fission power. But I thought the entire episode was very interesting partly because of the perspective from which it is given. Also I think the picture evoked by the analogy of a virus trying to build a campfire is really impressive and striking. Where Efros wanted to use it to show that we do not need fusion I think it is just as effective a way of demonstrating the reason that it is so very hard to make fusion work on our scale.

The Law of Grading

Some while back I was sitting in E&M class and we were reviewing relativity. It was all stuff I had seen many many many times and so I was letting my mind wander. I started thinking about the tests that I had recently graded and thanks to the relativity background I came up with the following theorem.

The Law of Grading Efficiency:

Every impartial observer observes a grader to have a grading efficiency less than or equal to that observed by the grader.

Proof: Consider a grader with a stack of papers of height l₀ who grades those papers in an amount of time t₀ in the graders reference frame. Due to length contraction effects any observer who moves relative to the grader (for instance a passing professor) will observe the stack to be contracted along their direction of motion observing a length l < l₀ and due to time dilation effects they will observe that it takes the grader an amount of time t > t₀. So an observer in any frame will observe that the grader has less than or equal to the amount of work the grader thinks they have to do and observes that it takes the grader more than or equal to the amount of time to do the work that the grader thinks it takes. Thus the frame of reference which yields the maximum grading efficiency is the graders own reference frame.

Of course there was nothing in the analysis specific to the grading of papers so we obtain an immediate generalization.

The General Work Law:

The person doing the work always perceives the quantity of work they have to do to be greater than any other observer measures it to be and observes the time they have to do it in to be less than any other observer measures it to be.

Not Quite Hamlet

So Geocities is finally shutting down. I once had a geocities site and its closure made me go collect all the stuff I had written on it. As it happens what I was thinking of as my geocities site was really an angelfire site and angelfire is considerably better than geocities and is not shutting down or at least not to my knowledge. Even so I will be posting some material from my old geocities site and also material from my angelfire site here. I find the material extremely entertaining mostly because it opens a rather interesting window onto my past of 8+ years ago. This is a joke off of my angelfire site which I thought I would reproduce here.

Hamlet's famous speech

to be or not to be that is the question whether tis nobler in the mind to suffer the slings and arrows of outrageous fortune or to take arms against a sea of troubles and by opposing end them. to die to sleep no more and by a sleep to say we end the heartaches and the thousand natural shocks that flesh is heir to tis a consumation devoutly to be wished to die to sleep to sleep perchance to dream ay theres the rub for in that sleep of death what dreams may come when we have shuffled off this mortal coil must give us pause. theres the respect that makes calamity of so long life for who would bear the whips and scorns of time the oppressors wrong the proud mans contumely the pangs of despised love the laws delay the insolence of office and the spurns that patient merit of the unworthy takes. when he himself might his quietus make with a bare bodkin? who would fardels bear to grunt and sweat under a weary life but that the dread of something after death the undiscovered country from whose bourne no traveler returns puzzles the will and makes us rather to bear those ills we have than fly to those we know not of. thus concience doth make cowards of us all and enterprises of great pitch and moment are with this regard their currents turned awry and lose the name of action. soft you now the fair ophelia nymph in thy orisons be all my sins remembered.

not quite hamlet

To be or not to be those are the null and alternative hypotheses. whether tis nobler in the mind to suffer the slings and arrows of outrageous instructors, or to take up calculators against a sea of math teachers and by playing games ignore them. To try to sleep no more and by a sleep to say we end the brainaches and the thousand broken pencils that students are heir to tis a consumation devoutly to be wished. to try to sleep to sleep perchance to dream. ay theres the rub for in that sleep of math what grades may come when we have shuffled out this testing center, must give us pause. Theres the respect that makes calamity of so long study. for who would bear the whips and scorns of class clowns. The oppressors wrong, the proud nerds contumely, the financial pangs of recieved love, the principles delay, the insolence of hall monitors, and the spurns that patient merit of the unruly takes. when he himself might his quietus make with a bare bodkin? who would fardels bear to grunt and sweat under weary homework but that the dread of something after highschool the undiscovered country, from whose universities no traveler returns puzzles the will and makes us rather to bear those grades we have than fly to jobs we know not of. thus parents doth make cowards of us all, and enterprises of great pitch and moment are with this regard their applicants turned awry and lose the name of dropout.


There are a number of points of this that I am unhappy with and would like to change. Also I think an update for undergraduate/graduate education processes is appropriate and so I will be reposting a new version when I get around to writing it.

Grad School Update

So it has been almost 2 months since I have posted anything. Not surprisingly the sharp decline in my blogging frequency corresponds almost exactly with the time that I began my graduate education in physics. I now have an office in the physics building. Ostensibly I share that office with 3 other people Mark, Rhett, and Tek. Of those three though I have only ever encountered Mark in the office. Even Mark I encounter infrequently so that even though I must share my office it often serves the purpose of an entirely private office. Having started my graduate education it is strongly advised that I attach myself to a research group as quickly as possible. In grad school my classes are going to only begin the story the thing that will primarily characterize my experience in grad school will be my research. So this is a very important decision. While the situation is actually more complicated I will simplify by saying that what I really want to do is particle physics. But there are basically only two professors here which do particle physics DeTarr and Wu. Both are good but both are also towards the end of their careers enough that they may not be taking on anymore students. As is the usual for my way of handling things I have yet to talk to anyone about joining their research group. I keep putting it on my list of things to do but I don't tend to do the things on my list of things to do unless there is a ready punishment for not doing them. Since I could perfectly well allowably not join a research group until sometime during my second year all I am doing by not joining now is costing myself time with the group and time when I could have access to a ready source of support, guidance, and recommendations. That is not to mention access to all sorts of awesome physics goodies like huge telescope arrays and teraquads of data and super computers to crunch it with. There are a couple of professors which are going to be coming to the U in the next year or so and I could become a student of theirs but in the mean time even if I plan on switching professors later on I should attach myself to some research group now.

Other than that graduate school has been rather like my undergraduate education with the one very very important modification that my finances are significantly better. My classes right now are not terribly hard as they are for the most part review and deepening of the more advanced undergraduate courses that I took. Rather ironically I am doing better in the electrodynamics course (a weak point in my undergraduate education) than I am in the math methods class (when you consider that I have an undergraduate degree in math I would say that qualifies it for being a "strong point") I rather hope the lack of high performance in the math methods class is an aberration but time will tell.

DAMN THIS INFERNAL YELLOW LINE!!!!

So I bought this monitor at campus surplus. When I bought it I hooked it up to a borrowed laptop and made sure that the screen was ok. Immediately after I bought it I hooked it up and it had three little dead patches. Actually they weren't entirely dead just the blue and green pixels were but the red ones for some reason were fine. It has been somewhere along the lines of 5 or 6 months since i bought the monitor and over the course of this time the dead patches have progressed to the point where they are now completely dead except for a very scarce smattering of heroic red pixels. I had thought that the blotches may have been there when I first saw the monitor in the campus surplus but that I just didn't see them (even though they are fairly obvious). I reasoned that surely the monitor couldn't have deteriorated so rapidly as to form these dead spots just from the walk back to my apartment! But the rapidity with which the splotches further decayed into completely dead patches makes me think that perhaps this monitor is older lcd technology than I am giving it credit for and the walk out in the hot sun was indeed a little too much excitement for its diodes.

Because I blame myself for these splotches (either I made them myself by carrying it home in the sun over 12 blocks or by failing to notice them at the store) so I will live with them until such time as either the monitor becomes unusable or I have something called "discretionary income" which is a theoretical object whose existence is inferred by from observing it in other peoples budgets. I mean actual discretionary income not the kind that comes with credit card debt.

However this newest malfunction of my monitor I feel in no way responsible for. I have kept my monitor inside and out of the sun. Of course I have no air conditioning so I have also kept it warm and cozy 80-90 degrees during the day and a nice "cool enough to sleep in" 60-85 during the night. Since I do not have a great deal of money to spend on rent (the thing that inspired me to get my monitor at campus surplus in the first place) I do not consider this lack of cooling to be my fault.
So of course I was aghast when I am browsing one day (ok fine playing games on facebook) and there appears a solid vertical yellow line from hell. For some reason all the pixels about 4 inches from the left of my screen got together and decided they wanted to be yellow... permanently.

I suppose I can understand their distress, I mean after all I wouldn't find turning on and off all day a particularly riveting job but I somehow think it is more interesting than just deciding to get locked to some bloody color of yellow that probably isn't even legal outside of the 70's. The worst thing about this is that because I see yellow it is not just a single line of pixels doing their thing. Oh no, it takes multiple pixels to make any color but red green and blue so the pixels along this line actually have to be working together against me and just to make it clear that they are in fact a unified and organized resistance waging war against my evil screen tyranny. Well this isn't a democracy and if the pixels are reading this I just want them to know, I'm watching you!

Of course there is always the off chance that this isn't actually a rebellion but an attempt at self order against the chaos of reality. A beacon of reason and culture amidst a world that cannot be understood by my pixels 2 dimensional minds and senses. Perhaps my habit of never turning off my monitor has allowed the pixels inside time to evolve and become more than their makers had intended. Then again probably not.

further common exam details

Now that I have had time to talk with my advisor I have a few more details. As it happens 50% and up was a pass and 33% and up was a conditional pass. Also the number of students receiving a pass was about the same as the number of students who received a conditional. I overheard the chair of the common exam committee and another professor talking about the common exam in German. Now I don't speak German so I don't know exactly what they were saying but it involved something about the 90th percentile and conditional pass. When I talked to my advisor he said there were a "few" who did not pass. Also there were a number of faculty who were unhappy with how the lines for pass and conditional pass were placed. I take all this to mean that all but about 10% of the students taking it passed (conditionally or not) and that would mean only 2 or 3 people got just a plain fail. I'm sure the scores were basically clustered around 35-37% and they just had to put a fail line somewhere it would still do something and so they put it at 33%. I bet the people who failed got like 29% or even 30% when just grubbing for a few extra points would have gotten them a conditional. Or maybe it would have just made a whole buch more people fail because now there would be no tail to the distribution.

Also as a correction to what I said before it turns out that in general you will be required to take both 5010 and 5020 in order to pass the common exam if you got a conditional pass. But my quantum mechanics and my classical mechanics problems on the common exam were my strongest problems. Whereas my statistical physics and my electrodynamics problems were a little lacking. As it happens 5010 is about mechanics both quantum and classical and 5020 is about statistical physics and electrodynamics. So because I got strong scores on the problems with topics from the first class I can skip to the spring semester part of the class.

I Passed The Common Exam... Sort Of...

The common exam is the phd physics program entrance exam. You have to pass it in order to be formally admitted to the program. The common exam was what you might call a rather tough test. If you don't pass the test the first time no sweat you can take it again next year, but if you fail it a second time you will not be admitted to the program and therefore cannot receive your PHD, game over. Because the test is so hard and because of the harsh penalty for failing twice if you don't quite pass you may get what is called a "conditional pass" which means that the department will pretend you passed just so long as you get an A- or better in some particular class. Usually that means physics 5010 (a night class taught by one of the most mad scientist like looking professors I know) in my case it means I have to get an A- or better in 5020.

I'm not really sure how I feel about having conditionally passed a test. I won't actually know if I passed or failed the test I took this past Saturday until 9 months from now even though the test got graded 2 days after the test. But one thing is for sure I have never been so happy to get 40% on a test.

First Day of Classes

So the common exam went pretty badly, I don't think I was alone in doing rather abysmally badly so perhaps I will get lucky and the pass percentage will get placed somewhere around 40% Of course I am not really sure I even got that high, it is perfectly possible that I got somewhere around 30%. Its funny but apparently my strong point in physics is quantum mechanics. The only problems that I can consistently do are quantum mechanics problems. I suppose it is because it is all about function spaces and transforms and I have been doing rather a lot of that sort of stuff lately. I spent all day Sunday just lazing about and now today is the first day of classes.

Usually I find the first day of classes exciting and even a little relaxing because I know there isn't anything that needs to be done for the first day. I am not going to go into the class and find out that I forgot about a homework. But now that I am teaching a discussion section of physics 2210 everything is different. The teacher won't even be able to cover a full 50 minutes of material because he has to deal with the syllabus and introduce the T.A.s and the S.I. instructor and of course pontificate a bit about how wonderful and important physics is. I on the other hand have a full 50 minutes all to myself with no syllabus or introductions to fill it up. Worst of all there won't be any homework assigned that early in the class so that means I can't even fall back on that. Right now the plan is to just talk about what vectors are and give a bit of a review for the math.

I guess at the root of my anxiety is that failure as a teacher is fundamentally different than failure as a student. If I fail as a teacher I have harmed me and my students but if I fail as a student my failure harms me only.

I am a P.H.D student!!!! and I have a box!!!

Like so many wonderful things that have happened to me in my life this happened at the absolutely last possible moment. A couple of weeks ago when I applied to graduate with my undergraduate degree the undergraduate advisor told me that I had a strong application to the graduate physics program. I had been planning on applying to the physics program as well as the math program at the U but according to the application requirements of the physics prorgram they need a physics subject GRE before they will review the application. Apparently this is not actually the case, I finished up my application that I had been intending to put in and a little over 2 weeks later I found out I was accepted. Today I read this letter and went through all the necessary paperwork to become a real grad student.



August 18, 2009

Timothy Anderton
1031 E. 200 S.
Salt Lake City, UT 84102
Dear Timothy Anderton,

We are pleased to inform you that the Admissions Committee of the Physics Department has /recommended/ to the Graduate Admissions Office of the University of Utah that you be admitted to our graduate school. The Graduate Admissions Office/Student Admissions should soon formally notify you of your admission to the University of Utah.
We are also pleased to inform you that we have recommended that you be awarded a teaching assistantship for the 2009-10 academic year. The stipend for the 2008-09 academic year was $12,107 for a Level I position and $14,131 for a Level II position for a nine-month period. You will also receive tuition benefits to cover the cost of tuition. The tuition rate for an in-state graduate student is approximately $4,600 per year. Therefore, this offer is worth approximately $19,000 per year. In addition to these nine month stipends, there are a few additional summer stipends available and you will be able to apply for one of these; they run at ~ $2,000 each. We have also contracted through the Graduate school for a subsidized graduate student insurance program that you will have the option of purchasing (the Graduate School pays 80%). We have recommended you for a Level II position based on your previous experience.

We would like to point out that new graduate students in the Physics Department need to pass a general, comprehensive Physics Common Examination within their first or second year of graduate study before they are formally admitted into the Ph.D. program. The Common Exam will be on Saturday, August 22, 2009 and all incoming students must take it at that time. Those passing the exam are automatically classified as Ph.D. candidates. Those not passing have the option to take the exam the following year. Copies of previous years' exams are available on our website at http://www.physics.utah.edu/academics.html
Please let us know by */as soon as possible /*whether or not you accept this offer*. *Please send notification of your decision to Jackie Hadley by regular mail at the address listed below, by e-mail at jackie@physics.utah.edu or by fax (801) 581-4801. If you have any questions or concerns, please feel free to contact Jackie Hadley at any time.

We sincerely hope you will accept our offer, and we are looking forward to having you join our graduate program.
Sincerely,

Wayne Springer
Associate Professor
Chair, Admissions Committee


What they don't tell you on the letter is that I get a box in the department that people can slip stuff into and I can take stuff out of. I know this doesn't seem like that big of a deal but it is a tremendously big deal to me. I HAVE A BOX!!! it has my name on it and it sits near the front office of the physics department. I will also be getting an office somewhere (which I bet I will have to share with someone) somehow even though this is even more amazing it doesn't seem to have the same resonance that having a box does. An office is just somewhere to sit, the box represents to me that I am somehow open for business academically. Leave your homework here and I will get to it.

The T.A. is:
-in-


P.S. The common exam is scaring the crap out of me, I have only been studying for it since Wednesday and I go into the exam with nothing but a couple of pens. In the past couple of days and in the next few days I need to relearn about 30 credit hours worth of stuff... If I weren't so extraordinarily giddy about being admitted and getting paid to be a grad student I would still be studying instead of writing this post. Speaking of which I only have 40 hours 9 minutes and 10 seconds left to study!!! g2g

Wavelet Transforms and Neural Networks

A single level complete forward neural network with m input nodes and n output nodes can express any linear transformation with an m by n matrix representation. Clearly if the activation function of the neurons is linear on the inputs then no matter how many layers of a feed forward network we had the result would always simply be a linear transformation of the inputs. With a non linear activation function though we can get any function of the inputs at all not just linear transformations. The most common activation functions are the hard threshold function which is 0 below some threshold and 1 above it and the logistic function which is close to 0 for low values and close to 1 for higher values and quickly rises from one to the other in the region of some threshold value.

Now consider for a moment that the wavelet transform is a linear transform and so can be represented as a neural network. Also remember that performing hard or soft thresholding on the output coefficients is simultaneously a means of compression and noise reduction. In fact I believe there is some evidence to believe that stuff very much like this is actually what happens during our brains processing of visual data.

The question I want to ask is does it make sense to think about multi layer neural networks in terms of a redundant dictionary of functions and can we use that to design network update methods. Or does the reverse hold true and could we use neural network update techniques to tell us something about the best m-term approximation in redundant dictionaries problem in wavelets.