Thursday, September 27, 2007
We will deliver the petition to Security Council members and media interviewing leaders at the UN all week, and make sure the Burmese know about our efforts too. This is one of those moments where the world can make a difference.
Together, we are sending a strong message to the UN and warning the generals that the world will not tolerate violence and repression -- it's time for a change.
The more people sign, the more powerful the message will be. So please send the following link to your friends and family if you haven't already:
Thanks again for your help,
Paul, Ricken, Pascal, Iain, Graziela, Galit and the Avaaz team
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Tuesday, September 25, 2007
The four Wikipedia entries.
And then RA Sharipov, Quick Introduction to Tensor Analysis, together with a short summary piece on the language of tensors.
And then, if enough courage is on hand, Elia Diodati's category labelled Bookshelf.
I first knew of this guy's existence through a random link to his blog, and again when a friend mentioned that his Linear Algebra notes (presumably available here) are better than any similar textbook she's ever seen.
He graduated with honours at age 16 and obtained his PhD at age 21. It is however worth noting his advice on whether one has to be a genius to do maths; briefly, the answer is no.
A link from the genius page also reveals this, How to be a genius, which is tremendously interesting and not particular to the field of maths.
Terry Tao also has a tongue-in-cheek link to the Declaration of Linear Independence, and a more sober link to the Seven Warning Signs of Bogus Science, whose introduction is interesting, the 7 signs not so much so.
Finite Simple Group of Order Two
A maths a cappella love song. Worth hearing without the lyrics first. Lyrics here.
Sunday, September 23, 2007
Wednesday, September 12, 2007
In another piece, titled "Heart of Steel", I was interested in using a literal connection between the chemistry in the protein and the chemistry on the sculpture's surface. I made a complete human hemoglobin (1A3N) out of a certain kind of steel known as 'weathering steel'. This special alloy initially rusts like ordinary steel but eventually stops because the special oxide layer it builds up is not water soluble and thus protects it from further corrosion. I finished the piece with a shiny surface and installed it. Upon its unveiling it was still gleaming, but after a few rain showers the color started to change and within half a year it was dark red. What had completely changed the look of the sculpture is of course the same chemical reaction that occurs when we breathe: Iron binds to oxygen.
Heart of Steel (Hemoglobin), 2005 Weathering steel and glass, height 5'
Location: 1st Street/"A" Avenue, City of Lake Oswego, Oregon
Thursday, September 06, 2007
Monday, September 03, 2007
Feynman's Nobel Prize lecture
"We have a habit in writing articles published in scientific journals to make the work as finished as possible, to cover all the tracks, to not worry about the blind alleys or to describe how you had the wrong idea first, and so on. So there isn't any place to publish, in a dignified manner, what you actually did in order to get to do the work, although, there has been in these days, some interest in this kind of thing. Since winning the prize is a personal thing, I thought I could be excused in this particular situation, if I were to talk personally about my relationship to quantum electrodynamics, rather than to discuss the subject itself in a refined and finished fashion. Furthermore, since there are three people who have won the prize in physics, if they are all going to be talking about quantum electrodynamics itself, one might become bored with the subject. So, what I would like to tell you about today are the sequence of events, really the sequence of ideas, which occurred, and by which I finally came out the other end with an unsolved problem for which I ultimately received a prize.
I realize that a truly scientific paper would be of greater value, but such a paper I could publish in regular journals. So, I shall use this Nobel Lecture as an opportunity to do something of less value, but which I cannot do elsewhere. I ask your indulgence in another manner. I shall include details of anecdotes which are of no value either scientifically, nor for understanding the development of ideas. They are included only to make the lecture more entertaining.
Now, this has the attractive feature that it solves both problems at once. First, I can say immediately, I don't let the electron act on itself, I just let this act on that, hence, no self-energy! Secondly, there is not an infinite number of degrees of freedom in the field. There is no field at all; or if you insist on thinking in terms of ideas like that of a field, this field is always completely determined by the action of the particles which produce it. [...]
That was the beginning, and the idea seemed so obvious to me and so elegant that I fell deeply in love with it. And, like falling in love with a woman, it is only possible if you do not know much about her, so you cannot see her faults. The faults will become apparent later, but after the love is strong enough to hold you to her. So, I was held to this theory, in spite of all difficulties, by my youthful enthusiasm.
Then I went to graduate school and somewhere along the line I [...]
So, I learned in the interim when I went to graduate school the glaringly obvious fault of my own theory. But, I was still in love with the original theory, and was still thinking that with it lay the solution to the difficulties of quantum electrodynamics. So, I continued to try on and off to save it somehow. I must have some action develop on a given electron when I accelerate it to account for radiation resistance [...]
We also found that we could reformulate this thing in another way [...]
And, so I dreamed that if I were clever, I would find a formula for the amplitude of a path that was beautiful and simple for three dimensions of space and one of time, which would be equivalent to the Dirac equation, and for which the four components, matrices, and all those other mathematical funny things would come out as a simple consequence - I have never succeeded in that either. But, I did want to mention some of the unsuccessful things on which I spent almost as much effort, as on the things that did work.
I want you to see an interesting point. I did not take the advice of Professor Jehle to find out how it was useful. I never used all that machinery which I had cooked up to solve a single relativistic problem. I hadn't even calculated the self-energy of an electron up to that moment, and was studying the difficulties with the conservation of probability, and so on, without actually doing anything, except discussing the general properties of the theory.
We are struck by the very large number of different physical viewpoints and widely different mathematical formulations that are all equivalent to one another. The method used here, of reasoning in physical terms, therefore, appears to be extremely inefficient. On looking back over the work, I can only feel a kind of regret for the enormous amount of physical reasoning and mathematically re-expression which ends by merely re-expressing what was previously known, [...]
Many different physical ideas can describe the same physical reality. Thus, classical electrodynamics can be described by a field view, or an action at a distance view, etc. Originally, Maxwell filled space with idler wheels, and Faraday with fields lines, but somehow the Maxwell equations themselves are pristine and independent of the elaboration of words attempting a physical description. [...]
Therefore, I think equation guessing might be the best method to proceed to obtain the laws for the part of physics which is presently unknown. Yet, when I was much younger, I tried this equation guessing and I have seen many students try this, but it is very easy to go off in wildly incorrect and impossible directions. I think the problem is not to find the best or most efficient method to proceed to a discovery, but to find any method at all. Physical reasoning does help some people to generate suggestions as to how the unknown may be related to the known. Theories of the known, which are described by different physical ideas may be equivalent in all their predictions and are hence scientifically indistinguishable. However, they are not psychologically identical when trying to move from that base into the unknown. For different views suggest different kinds of modifications which might be made and hence are not equivalent in the hypotheses one generates from them in ones attempt to understand what is not yet understood. I, therefore, think that a good theoretical physicist today might find it useful to have a wide range of physical viewpoints and mathematical expressions of the same theory (for example, of quantum electrodynamics) available to him. This may be asking too much of one man. Then new students should as a class have this. If every individual student follows the same current fashion in expressing and thinking about electrodynamics or field theory, then the variety of hypotheses being generated to understand strong interactions, say, is limited. Perhaps rightly so, for possibly the chance is high that the truth lies in the fashionable direction. But, on the off-chance that it is in another direction - a direction obvious from an unfashionable view of field theory - who will find it? Only someone who has sacrificed himself by teaching himself quantum electrodynamics from a peculiar and unusual point of view; one that he may have to invent for himself. I say sacrificed himself because he most likely will get nothing from it, because the truth may lie in another direction, perhaps even the fashionable one.
But, if my own experience is any guide, the sacrifice is really not great because if the peculiar viewpoint taken is truly experimentally equivalent to the usual in the realm of the known there is always a range of applications and problems in this realm for which the special viewpoint gives one a special power and clarity of thought, which is valuable in itself. Furthermore, in the search for new laws, you always have the psychological excitement of feeling that possible nobody has yet thought of the crazy possibility you are looking at right now.
So what happened to the old theory that I fell in love with as a youth? Well, I would say it's become an old lady, that has very little attractive left in her and the young today will not have their hearts pound anymore when they look at her. But, we can say the best we can for any old woman, that she has been a very good mother and she has given birth to some very good children. And, I thank the Swedish Academy of Sciences for complimenting one of them. Thank you."