The failure of string theory "is not so much a particular theory but a style of doing science that was well suited to the problems we faced in the middle part of the twentieth century but is ill suited to the kinds of fundamental problems we face now." According to Mr. Smolin, there are five such fundamental problems for which we need a new style of science to solve:
1. Combine general relativity and quantum theory into a single theory that can claim to be the complete theory of nature. This is called the problem of quantum gravity.
2. Resolve the problems in the foundations of quantum mechanics, either by making sense of the theory as it stands or by inventing a new theory that does make sense.
3. Determine whether or not the various particles and forces can be unified in a theory that explains them all as manifestations of a single, fundamental entity.
4. Explain how the values of the free constants in the standard model of particle physics are chosen in nature.
Yet, for Mr. Smolin, the deeper problem is not string theory per se; it is in the social structure of science itself. In a penultimate chapter on "how science really works," Mr. Smolin sings the praises of thinking outside of the box, including and especially the staid and delimiting box of academia. The system is set up to create scientists who are risk-averse, and granting tenure doesn't help: "Too much job security, too much power, and too little accountability for older people. Too little job security, too little power, and too much accountability for younger people in the prime of their creative, risk-taking years."
Mr. Smolin concludes that we must do two things: "We must recognize and fight the symptoms of groupthink, and we must open the doors to a wide range of independent thinkers, being sure to make room for the peculiar characters needed to make a revolution." How can you spot one of these young revolutionaries? Easy. Find someone already doing science this way, or "find at least one accomplished person in the candidate's field who is deeply excited about what the candidate is trying to do," and, just to be sure, "find at least one professor who thinks the candidate is a terrible scientist and bound to fail."
Wednesday, September 27, 2006
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THE FIELD, THE PARTICLES AND THE DEATH OF PHYSICS
At the end of his career (in 1954) Einstein predicts a possible death of physics:
"I consider it quite possible that physics cannot be based on the field concept,i.e., on continuous structures. In that case, nothing remains of my entire castle in the air, gravitation theory included, [and of] the rest of modern physics."
The choice Einstein had to make between the concept of light as a continuous field and the concept of light as discontinuous particles (photons) is rarely mentioned in the literature but still there are eloquent quotations:
http://www.pbs.org/wgbh/nova/einstein/genius/ :
"Genius Among Geniuses" by Thomas Levenson
"And then, in June, Einstein completes special relativity, which adds a twist to the story: Einstein's March paper treated light as particles, but special relativity sees light as a continuous field of waves. Alice's Red Queen can accept many impossible things before breakfast, but it takes a supremely confident mind to do so. Einstein, age 26, sees light as wave and particle, picking the attribute he needs to confront each problem in turn. Now that's tough."
http://www.powells.com/cgi-bin/biblio?inkey=4-0486406768-0 :
"Relativity and Its Roots" by Banesh Hoffmann:
(I do not have the text in English so I am giving it in French)
Banesh Hoffmann, "La relativite, histoire d'une grande idee", Pour la Science, Paris, 1999, p. 112:
"De plus, si l'on admet que la lumiere est constituee de particules, comme Einstein l'avait suggere dans son premier article, 13 semaines plus tot, le second principe parait absurde: une pierre jetee d'un train qui roule tres vite fait bien plus de degats que si on la jette d'un train a l'arret. Or, d'apres Einstein, la vitesse d'une certaine particule ne serait pas independante du mouvement du corps qui l'emet! Si nous considerons que la lumiere est composee de particules qui obeissent aux lois de Newton, ces particules se conformeront a la relativite newtonienne. Dans ce cas, il n'est pas necessaire de recourir a la contraction des longueurs, au temps local ou a la transformation de Lorentz pour expliquer l'echec de l'experience de Michelson-Morley. Einstein, comme nous l'avons vu, resista cependant a la tentation d'expliquer ces echecs a l'aide des idees newtoniennes, simples et familieres. Il introduisit son second postulat, plus ou moins evident lorsqu'on pensait en termes d'ondes dans l'ether."
Clearly, the particle model of light finds its support in the negative result of Michelson-Morley experiment. It is also consistent with the third equation of Maxwell (Faraday's induction law) as implied at the beginning of Einstein's 1905 paper:
http://www.fourmilab.ch/etexts/einstein/specrel/www/
(The "customary view" Einstein refers to is the ether model of Maxwell that Maxwell himself abandoned in the end; the fact that the particle model of light naturally contradicts the ether model by no means implies that the particle model is inconsistent with the Faraday's induction law, although the mythology says otherwise.)
Pentcho Valev
pvalev@yahoo.com
Pentcho, I take it that you're one of those aetherists people for which sci.physics.relativity was formed. My experience with these people has been that the ether thing prevents them from ever making it past relativity to discover the quantum vacuum.
I do not have the text in English so I am giving it in French)
I've been accused to giving it in Greek, so make yourself at home... ;)
Newton
That much I understood.
Hmmm... a meeting of the minds?
You'd have to be a physics illiterate to make a statement like that.
Thank you for the nice comment tho!
Island, I can appreciate your logic of the ball not being in your court.... but ... etc.
You would presmuably support Smolin's statements about fighting groupthink ....
What's interesting in this post, is that you leave it as somehow obvious to the reader as to which of Smolin's comments you approve of and which you don't ... like a longstanding private joke.
Although the ball may not be in your court in principle, it must help your case to spell out such points and reasoning.
BTW you mention somewhere else aboit "explanation and causation" (probably in the Burton Richer piece ?). I think this is at the core of your problem.
Take care,
Ian
I don't disagree with anything that Lee Smolin says in this part of the quoted article, so that's the reason that I left it as it stands without need for further comment.
Lee Smolin says many things that make a lot of sense to me, even if I don't agree with his cosmology.
A Fundamental Crisis in Science
EINSTEINIANS WILL UNMASK EINSTEIN
In Appendix 3 in his "Relativity" Einstein starts from the time dilation factor
1/gamma = (1-v^2/c^2)^(1/2)
and eventually deduces the frequency shift factor
1+V/c^2
where V is the gravitational potential. In the process Einstein replaces the time dilation factor 1/gamma with its Taylor approximation
1-v^2/2c^2
and for almost 100 years Einsteinians have been absolutely sure that this replacement can only be due to Einstein's genial intuition and sense of harmony. However lately Einsteinians with powerful intellects have been haunted by a difficult question: Why should the approximation 1-v^2/2c^2 be more suitable than the exact quantity 1/gamma? The inquiry is going to turn into a panic since the frequency shift factor 1+V/c^2 can be rigorously deduced from the principle of variability of the speed of light and this alternative deduction involves no suspicious approximations at all:
http://www.physlink.com/Education/AskExperts/ae13.cfm :
"So, it is absolutely true that the speed of light is _not_ constant in a gravitational field [which, by the equivalence principle, applies as well to accelerating (non-inertial) frames of reference]. If this were not so, there would be no bending of light by the gravitational field of stars. One can do a simple Huyghens reconstruction of a wave front, taking into account the different speed of advance of the wavefront at different distances from the star (variation of speed of light), to derive the deflection of the light by the star.
Indeed, this is exactly how Einstein did the calculation in:
"On the Influence of Gravitation on the Propagation of Light," Annalen der Physik, 35, 1911.
which predated the full formal development of general relativity by about four years. This paper is widely available in English. You can find a copy beginning on page 99 of the Dover book "The Principle of Relativity." You will find in section 3 of that paper, Einstein's derivation of the (variable) speed of light in a gravitational potential, eqn (3). The result is,
c' = c0 ( 1 + V / c^2 )
where V is the gravitational potential relative to the point where the speed of light c0 is measured."
Einsteinians love Einstein passionately but, on the other hand, their honest hearts would not tolerate any trickery. As soon as they manage to understand why Einstein hid the obviously correct deduction
VARIABLE SPEED OF LIGHT -> FREQUENCY SHIFT
and replaced it with the trumped-up deduction
TIME DILATION -> FREQUENCY SHIFT
they will unmask him. There can be no doubt about that.
Pentcho Valev
pvalev@yahoo.com
RELATIVITY AND SELF-DESTRUCTION
Photons move in a gravitational field and either undergo acceleration (e.g. their speed becomes c'>c=300000km/s) or do not undergo acceleration (that is, their speed remains c=300000km/s). If they undergo acceleration the frequency shift detected by the receiver is due to the variable speed of light, in accordance with the formula c'=Lf', where L is wavelength and f is frequency. If the photons do not undergo acceleration the frequency shift detected by the receiver is due to gravitational time dilation and variable wavelength, in accordance with the formula c=L'f'. It is easy to see that c'=Lf' and c=L'f' are the only possibilities. Roughly speaking, either variable speed of light and no gravitational time dilation, or gravitational time dilation and constant speed of light.
Initially Einstein chose c'=Lf':
http://www.physlink.com/Education/AskExperts/ae13.cfm :
"So, it is absolutely true that the speed of light is _not_ constant in a gravitational field [which, by the equivalence principle, applies as well to accelerating (non-inertial) frames of reference]. If this were not so, there would be no bending of light by the gravitational field of stars. One can do a simple Huyghens reconstruction of a wave front, taking into account the different speed of advance of the wavefront at different distances from the star (variation of speed of light), to derive the deflection of the light by the star.
Indeed, this is exactly how Einstein did the calculation in:
"On the Influence of Gravitation on the Propagation of Light," Annalen der Physik, 35, 1911.
which predated the full formal development of general relativity by about four years. This paper is widely available in English. You can find a copy beginning on page 99 of the Dover book "The Principle of Relativity." You will find in section 3 of that paper, Einstein's derivation of the (variable) speed of light in a gravitational potential, eqn (3). The result is,
c' = c0 ( 1 + V / c^2 )
where V is the gravitational potential relative to the point where the speed of light c0 is measured."
However later Einstein had to camouflage the fact that the frequency shift is due to variable speed of light and introduced gravitational time dilation - a concept extremely dangerous for human rationality. Two identical clocks in identical conditions (identical gravitational fields) allegedly have different rates. Rationality is immediately destroyed and the victim starts worshipping both the miracle and its creator.
Pentcho Valev
pvalev@yahoo.com
STANDARD PHYSICS EDUCATION (introduces ABSURDITY):
"Two bombs lie on a train platform, a distance L apart. As a train passes by at speed v, the bombs explode simultaneously (in the platform frame) and leave marks on the train. Due to the length contraction of the train, we know that the marks on the train will be a distance gamma.L apart when viewed in the train's frame (since this distance is what is length-contracted down to the given distance L in the platform frame). How would someone on the train quantitatively explain to you why the marks are gamma.L apart, considering the bombs are only a distance L/gamma apart in the train frame?"
( http://www.courses.fas.harvard.edu/~phys16/Textbook/ch10.pdf p.46)
HONEST PHYSICS EDUCATION (would introduce REDUCTIO AD ABSURDUM):
Two unbreakable barriers are installed on a train platform, a distance L apart. As a train passes by at speed v, the barriers fall simultaneously (in the platform frame) and block the railway. The proper length of the train is greater than L but, due to the length contraction of the train, right before the barriers fall, the observer in the platform frame sees the train occupying only a short segment of the distance between the barriers. In other words, the observer sees the barriers catching the train. How long is the caught train?
Pentcho Valev
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