OK, this has made me mad. John Horgan, author of the much-debated (and unread-by-me) "The End of Science", has managed to secure himself the last page of this week's New York Times Book Review on which to tell us that "Einstein Has Left the Building."

"End of Science" was notorious when it came out in the mid-90's, since it claimed that most of the major discoveries had already been made (shades of the pre-Quantum era!) and that there was little left to do in fundamental physics but fill in a few details. The obvious point it seemed he missed was that science always looks this way, until it doesn't. In 1996 we had no accelerating universe, no WMAP, no RHIC (I must get my plugs in where I can!). In 2005 we simply know more than we did 10 years ago, but if science policy makers would have taken Horgan seriously (at least at the book-review level) we wouldn't have learned nearly as much, since they would have been under the impression there was nothing left to do.

The new article leaves a bad taste in my mouth as the World Year comes to a close. Horgan muses on how nothing important happened in 2005 despite all of the WYOP hype. Moreover, he seems to be implying that all of the attention paid to Einstein just makes us more cognizant of the possibility that there will never be another of his ilk. Rather than grapple with the big questions of the limits of time, space, and even technology, he argues that physics is far too involved with questions beyond the realm of testability, trotting out the usual complaints from him and others about the inaccessibility of string theory, extra dimensions, etc.

I have no interest in taking him on point-by-point, but I think he misses several obvious points. Firstly, even Einstein was "no Einstein" in 1905. The papers came out, and took years for the importance of all of them to be fully recognized by the scientific community. Thus, 2005 may well be a watershed year in science, but we just won't know that for at least a few years.

Of course, that comment could and does apply to any year. What really frustrates me is that he has missed the point of the world year of physics altogether. While the hype may have been over-the-top at times, it really revealed that people -- normal people, everywhere -- really like to hear about, and talk about, science. Moreover, while we may not get too many Einstein's, both in terms of depth and breadth of intellect, as well as moral commitment, we've at least reawakened a general sense that 1) science is important (take that, Dover), and 2) it's made by individuals (and not just institutions and governments, but that's another rant), and 3) no-one knows when a major discovery will happen. I can't imagine that the world experts in 1904 would have seen 1905 coming around the corner -- and I have trouble believing that science writers, or anyone, can predict the shape of the science to come. That said, nor should they preclude that science from happening by fomenting radical skepticism about the whole project.

OK, I'm not mad anymore. Back to work!

## Sunday, January 01, 2006

Subscribe to:
Post Comments (Atom)

## 19 comments:

The thing I disliked most about that essay was towards the end where he seems to cast science as becoming increasingly immoral, or lost its morals altogether. It’s something I tend to see a lot of religious icons saying these days, giving examples of the atomic bomb, and ethics in genetic engineering. This essay makes it seem as though science is destroying our society, when in fact science is the only means in which we can make it better.

Hi Pete --

Your rebuttal to Horgan is certainly correct and important, that revolutionary ideas could be coming out at any time whose nature wouldn't become clear until later. And, at least some interesting stuff has happened in the last ten years!

I'd be curious for your opinion on an idea that comes up from time to time on this subject: that there are no/fewer Einsteins around these days because there are no/fewer generalists. Specifically, there are no/fewer physicists employed as generalists since the research funding structure makes much more efficient use of specialists. As the latter-day heir of Gell-Mann I assume you have sympathy for the generalist! but don't let me speak for you....

Paul

I love how contemporary physics opens the imagination and creates such wonder. Nothing is more beautiful than discovery. I'm not even a physicst, and that article made me mad too.

The unknown & the future always!

DID EINSTEIN PREDICT THE DEATH OF PHYSICS?

The following two quotations are extremely important:

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."

Einstein at the end of his career:

"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."

So Einstein knew what had happened. Perhaps at that time (1954) the death of physics was still reversible. Now there is no hope. This civilization seems to be suicidal.

Pentcho Valev

pvalev@yahoo.com

EINSTEIN'S PRINCIPLE OF VARIABILITY OF THE SPEED OF LIGHT

Einstein's 1911 equation c'=c(1+V/c^2), where c' is the speed of light as measured by an observer, c=300000km/s is the initial speed of light relative to the light source and V is the gravitational potential relative to the point where light is emitted, proves the validity of the following principle:

Since the probability that V=0 is virtually zero, light NEVER travels in space with speed c=300000km/s; its speed is either higher or lower than that value (V>0 or V<0).

Pentcho Valev

pvalev@yahoo.com

EINSTEINIANS RETURN TO NEWTON

http://arxiv.org/PS_cache/astro-ph/pdf/9910/9910325.pdf

Gravitation Without Curved Space-time

Kris Krogh

p.12: "The gravitational frequency shift in Einstein’s 1911 variable-speed-of-light theory was v=v0(1+phi/c^2) which agrees with Eq. (13) to the first order. But there was no effect on lambda, or the dimensions of measuring rods, corresponding to Eq. (14). Consequently, the speed of light in a gravitational potential was c=c0(1+phi/c^2)."

Pentcho Valev

pvalev@yahoo.com

HOW EINSTEINIANS EARN THEIR LIVING

http://www.amazon.com/Faster-Than-Speed-Light-Speculation/dp/0738205257

"In Faster Than the Speed of Light, Magueijo reveals the short, brilliant history of his possibly groundbreaking speculation--VSL, or Variable Light Speed. This notion--that the speed of light changed as the universe expanded after the Big Bang--contradicts no less prominent a figure than Albert Einstein. Because of this, Magueijo has suffered more than a few slings and arrows from hidebound, jealous, or perplexed colleagues. But the young scientist persisted, found a few important allies, and finally managed to shake up the establishment enough to get the attention he merited and craved."

Einstein defined the variability of the speed of light as the dependence of the speed of photons on the speed of the light source. The application of the equivalence principle converts this into the statement that, in a gravitational field, the speed of light "varies with position", as Einstein himself put it in Chapter 22 in his "Relativity" (but did not say that varying with position in a gravitational field is equivalent to depending on the speed of the light source in the absence of a gravitational field).

It is easy to see that Magueijo's Variable Light Speed in fact confirms Einstein's second postulate - the principle of INVARIABILITY of the speed of light. One would be unable to claim that light was faster in the past and is slower now if its speed were not invariable relative to the speed of the light source or in a gravitational field. Then why should Magueijo be presented as the Martyr contradicting Divine Albert and persecuted by jealous colleagues? Money, money, money......

Pentcho Valev

pvalev@yahoo.com

EINSTEINIANS TELL THE ABSOLUTE TRUTH

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.....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."

Absolutely true indeed. Since the gravitational redshift factor 1+V/c^2 is obviously a corollary of Einstein's variable-speed-of-light equation, Einsteinians will state clearly one day:

The gravitational redshift is due to the variability of the speed of light in a gravitational field, not to the absurd gravitational time dilation as we used to teach.

Pentcho Valev

pvalev@yahoo.com

EINSTEINIANS STOPPED WORSHIPPING DIVINE ALBERT

Einsteinians stopped worshipping Divine Albert

http://www.youtube.com/watch?v=vx35zMyFJ94

http://www.physicsforums.com/blog/2006/03/16/albert-hubo-an-einstein-robot/

http://www.haverford.edu/physics-astro/songs/divine.htm

because they just discovered in 1918 Divine Albert had explained the twin paradox in an obscure way:

http://meetings.aps.org/Meeting/MAR07/Event/63304

2007 APS March Meeting Monday–Friday, March 5–9, 2007; Denver, Colorado Session X21: General Theory Abstract: X21.00005 : Einstein's Obscure 1918 Special Relativity Paper Author: Tom Morton (Northrop Grumman Corp)

In his "obscure 1918 special relativity paper" Divine Albert said the asymmetrical aging was due to acceleration experienced by the travelling twin. Why did Divine Albert say so? Later Einsteinians discovered the twin paradox had nothing to do with acceleration - see Problem 19, "Modified twin paradox", on p. 49, solution on p. 65, in

http://www.courses.fas.harvard.edu/~phys16/Textbook/ch10.pdf

True, rationality in science has been irreversibly destroyed and scientists would learn by rote and then teach anything: "due to acceleration", "not due to acceleration" and even "both due to acceleration and not due to acceleration". Still, just in case, Einsteinians temporarily stopped worshipping Divine Albert.

Pentcho Valev

pvalev@yahoo.com

REFRACTION: NEWTON WAS RIGHT

According to Newton's model of discontinuous (corpuscular) light structure, in the vicinity of water light particles receive more attraction than in air. Therefore, BEFORE the particles reach the surface of the water, their trajectory starts curving; the refraction is due to this curvature. According to the model of continuous light structure (electromagnetic field), AFTER entering the water waves move slower and this delay explains the refraction.

Clearly the curvature predicted by Newton makes the "continuous" explanation at least redundant: since the change in direction starts BEFORE the photons reaching the water surface, at the moment of penetration the refraction is already determined and subsequent events, including the change of the speed of light in water, are not very important.

Paradoxically, it is this change of the speed of light in water that definitively converted 19th century physicists to the "continuous" concept. Leon Foucault, 1850: "Ces resultats accusent une vitesse de la lumiere moindre dans l'eau que dans l'air, et confirment pleinement, selon les vues de M. Arago, les indications de la theorie des ondulations."

Einstein confirmed both the discontinuous nature of light and the curvature in the vicinity of bodies but never abandoned the model of continuous light structure which proved too profitable. Still at the end of his life he said: "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."

Pentcho Valev

pvalev@yahoo.com

DIFFRACTION: NEWTON WAS RIGHT

In explaining diffraction textbooks recognize "a slight bending of the wave front at the edges". However "at the edges" could mean either "near the edges" or "as it grazes the edges". "Near the edges" implies that bodies can attract photons; in fact, that was the essence of Newton's explanation of diffraction. In Opticks he wrote: "Do not bodies act upon light at a distance, and by their action bend its rays; and is not this action strongest at a least distance?".

If said attraction is really the cause of diffraction, as Newton believed, the theory describing light in terms of a continuous field is false. Ironically, compelled by observations, the famous defender of the wave theory of light Fresnel abandoned "as it grazes the edges" and adopted "near the edges", thereby virtually confirming Newton's idea. He wrote: "....quelques reflexions et observations nouvelles m'ont fait douter de l'exactitude d'une hypothese dont j'etais parti pour calculer mes formules: que le centre d'ondulation de la lumiere reflechie etait toujours au bord meme du corps, ou, ce qui revient au meme, que la lumiere inflechie ne pouvait provenir que des rayons qui ont touche sa surface.....la lumiere inflechie ne provient pas seulement de celle qui a rase les biseaux, mais encore des rayons qui en sont passes a des distances sensibles."

Pentcho Valev

pvalev@yahoo.com

EINSTEINIANS AGAINST EINSTEIN'S SECOND POSTULATE

http://www.amazon.com/Introduction-Special-Relativity-2-nd/dp/0198539525

"My first remark is that I cannot understand the reason why textbooks in English (as this one) insist in deriving the Lorentz transformation using Einstein's second postulate on the speed of light: as already pointed out by Jean-Marc Levy-Leblond (Am. J. Phys., Vol. 44, pp. 271-277, 1976), this second postulate is not only superfluous but also epistemological misleading -- see, e.g., the French textbook by J. Hladik and M. Chrysos (Introduction a la Relativite Restreinte, Dunod, Paris, 2001) which can be bought at Amazon.fr."

Incredible! Absolutely incredible! This Jean-Marc Levy-Leblond should be locked in a dark room with a single picture on the wall:

http://www.bnl.gov/community/Tours/EinsteinPics/Einsteine.jpg

If he can't sing the hymn "Divine Einstein" (many Einsteinians are not programmed for music) he should at least learn by rote this:

http://www.haverford.edu/physics-astro/songs/divineEinstein.htm

Finally, he should be forced to visit centers for children education where he should shout endlessly, together with the children:

http://www.bnl.gov/community/Tours/TYSaDTW.asp

"Einstein! Einstein! He's our man! Einstein! Einstein! He's our man! If he can't solve it, no one can!"

Pentcho Valev

pvalev@yahoo.com

EINSTEIN'S SECOND LAW

http://www.physicstoday.org/vol-60/iss-1/12_2.html :

"Why no Einstein's laws? Since my undergraduate days, I have been puzzled by the fact that we have Newton's laws of motion but only Einstein's theory of special relativity. We have finished celebrating the 100th anniversary of the publication of the theory of special relativity, and it seems to me that after a century of validation, it's time to rename it as more than just a theory. I propose that we, as physicists, define a set of Einstein's laws, just as we have Newton's laws, Coulomb's law, or Faraday's law. I begin the discussion by offering the following three laws: The laws of physics are identical in all non-accelerating (that is, inertial) frames. The vacuum speed of light, c, is the same for all inertial frames. The total energy E of a body of mass m and momentum p is given by E = [√m2c4 + p2c2]. In particular, the energy of a body measured in its own rest frame is given by E = mc2, and the energy of a massless body is E = pc."

Consider again Einstein's Second Law:

Einstein's Second Law (original version): "The vacuum speed of light, c, is the same for all inertial frames." (In fact, the original 1905 version of Einstein's Second Law was a bit different but this is irrelevant here.)

This extremely important Law was improved by Einstein himself in the following way:

Einstein's Second Law (improved): The observer's frame may be inertial but if the observer and the light source are at different gravitational potentials, the speed of light is variable and obeys the equation c'=c(1+V/c^2), where V is the gravitational potential relative to the light source.

This improved version of Einstein's Second Law was gloriously confirmed in 1960 when Pound and Rebka measured a gravitational redshift factor equal to 1+V/c^2. Then clever Einsteinians deduced the ultimate version of Einstein's Second Law:

Einstein's Second Law (ultimate version): If the relative speed of the observer and the emitting body is zero, light is always propagated in empty space with a variable speed c'=c(1+V/c^2) where c is the initial speed of photons relative to the emitting body and V is the gravitational potential relative to the place of emission. Equivalently, if the observer and the place of emission are at the same gravitational potential, light is always propagated in empty space with a variable speed c'=c+v where v is the relative speed of the observer and the emitting body.

Clever Einsteinians were going to inform the world about the ultimate version of Einstein's Second Law but suddenly they realised the ultimate version was incompatible with the original version. The money-spinner called the theory of relativity was in danger so clever Einsteinians postponed the publication of the ultimate version until some new money-spinner was devised.

Pentcho Valev

pvalev@yahoo.com

It is quite funny to see how physics can come to an end when it is full off errors.

Errors starting from the 1850's:

**Maxwell's field concept. Originated from Weber's conversion factor of light to go from electrostatic to electrodynamic processes.

**Helmholtz assumption that energy conservation is seemingly violated when dealing with Gauss and Weber electrodynamics.

**Unjustified denial that the drift of the ether was measured. Miller measured an ether drift.

**Lorentz uses the invention of electromagnetic mass to explain the so-called null-result of ether-drift. He creates the basis of time dilation and length contraction.

**Einstein's use of "relativity" not only electrodynamically but also kinematically. All the absurdity (twin's paradox) comes from the kinematic part. He gives a complete reïnterpretation of relativity which is even more erraneous then the former one.

**Einstein's modification of his special relativity with general relativity in a 1918 paper patch to account for the criticism on the SR theory.

**Eddington's "verification" of the general theory of relativity. (Solar Eclipse 1919) For ideological/political post-war reasons the theory "had to be" correct. He rejected 4/5 of his data because it didnot fit the theory.

**Unjustified acceptance that Hubble stated that the red shift is due to curvature of space-and time. Hubble never claimed that.

**Planck used mathematical trick to derive black-body radiation. E = h*v. Birth of the reckless photon.

**Niels Bohr makes use of classical mechanics to describe motions of electrons around the nucleus. He should have used electrodynamics. But no, he makes a postulate: "the notion of stationary states, where ordinary mechanics is valid, but electrodynamics invalid." The same applies for other physicists like Thompson at that time.

**Heisenberg should have noticed that others could describe the Pashenback and Zeemann-effect without his weird matrix-mechanic theory. Woldemor Voigt approach was much more appealing.

**Pauli's invention of the neutrino to explain the continuous Beta-spectrum. The start of a long serie of events: quantum theory in danger => two options: 1) reject quantum theory 2) create new particle. Now we got tons of particles.

**The existence of Quantum Gravity, Quantum Chromodynamics, Standard Model, String Theory, M-theory,...

THE PRINCIPLE EINSTEIN DID NOT INTRODUCE

Scientists all know Einstein managed to deduce his divine theory from a few simple principles. An ordinary mortal cannot do so and in scientific (not religious) hymns Einstein is referred to as "dee-vine Einstein":

No-one’s as dee-vine as Albert Einstein

Not Maxwell, Curie, or Bohr!

He explained the photo-electric effect,

And launched quantum physics with his intellect!

His fame went glo-bell, he won the Nobel --

He should have been given four!

No-one’s as dee-vine as Albert Einstein,

Professor with brains galore!

No-one could outshine Professor Einstein --

Egad, could that guy derive!

He gave us special relativity,

That’s always made him a hero to me!

Brownian motion, my true devotion,

He mastered back in aught-five!

No-one’s as dee-vine as Albert Einstein,

Professor in overdrive!

Yet assume some additional principle, one that Einstein did not find it suitable to introduce, is indispensable:

http://www.physorg.com/news90697187.html

"First suggested by Albert Einstein more than 100 years ago, the paradox deals with the effects of time in the context of travel at near the speed of light. Einstein originally used the example of two clocks – one motionless, one in transit. He stated that, due to the laws of physics, clocks being transported near the speed of light would move more slowly than clocks that remained stationary....Einstein and other scientists have attempted to resolve this problem before, but none of the formulas they presented proved satisfactory. Kak’s findings were published online in the International Journal of Theoretical Physics, and will appear in the upcoming print version of the publication. "I solved the paradox by incorporating a new principle within the relativity framework that defines motion not in relation to individual objects, such as the two twins with respect to each other, but in relation to distant stars," said Kak."

If the new principle is really essential, there is no reason why Einsteinians should continue to sing "dee-vine Einstein" so fiercely. If, in the absence of the additional principle, some of Einstein's results prove only suggested but not rigorously deduced, "dee-vine Einstein" should be reduced to "Einstein" or just "Albert". However Kak, the discoverer of the additional principle, should automatically become "dee-vine Kak". That would be fair: after all, Einstein made enough money in days long gone although his deductions were invalid whereas now Kak's situation is different.

Pentcho Valev

pvalev@yahoo.com

SHOCK AND HORROR AND VARIABLE SPEED OF LIGHT

A few years ago Einstein's hypnotists found it suitable to make some more money by challenging Einstein's principle of constancy of the speed of light:

http://www.prospect-magazine.co.uk/article_details.php?id=5538

Paul Davies: "Einstein's famous equation E=mc2 is the only scientific formula known to just about everyone. The "c" here stands for the speed of light. It is one of the most fundamental of the basic constants of physics. Or is it? In recent years a few maverick scientists have claimed that the speed of light might not be constant at all. Shock, horror! Does this mean the next Great Revolution in Science is just around the corner?"

The "maverick scientists" created various "Variable Speed of Light" theories, became famous, got enough money and of course there was no Great Revolution in Science around the corner. So now there are no shock and horror in Einstein's cult and the selfsame Paul Davies can happily return to the original idiocy based on Einstein's false principle of constancy of the speed of light:

http://www.asuwebdevil.com/issues/2007/02/23/news/699963

"For this prof, it's only a matter of time.....Davies said an object traveling at a given speed experiences time slower relative to a stationary object. The faster the object moves, the slower it experiences time, he said. If a man traveled at 99 percent the speed of light for a certain amount of time to a point in space, then turned around and came back, he would find people on Earth aged years more than he did."

There is another reason why relativity hypnotists experience so much happiness now. The "maverick scientists" managed to discredit the true principle of variability of the speed of light (c'=c(1+V/c^2) or c'=c+v) that Einstein himself introduced when he did not know how else to explain the gravitational redshift. So when one tries to explain that the speed of light is variable the standard reaction is something like this: "What? Variable speed of light? Magueijo's theory? That is not serious!"

Pentcho Valev

pvalev@yahoo.com

NEWTON VERSUS EINSTEIN IN THE ROYAL SOCIETY

Some time ago the Royal Society conducted a poll that gave a conclusion more or less like "Newton is greater than Einstein":

http://www.royalsoc.ac.uk/news.asp?id=3880

This conclusion is misleading. In terms of initial principles the only difference between Newton and Einstein is that Newton regarded light as DISCONTINUOUS particles whose speed, like the speed of other particles, could only be VARIABLE (varies with the speed of the light source), whereas Einstein based his theory on the concept of light as a CONTINUOUS field and postulated that the speed of light was CONSTANT (independent of the speed of the light source). The importance of this initial difference was given by Einstein himself:

Einstein: "If the speed of light is the least bit affected by the speed of the light source, then my whole theory of relativity and theory of gravity is false."

Einstein again: "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."

So Newton cannot be just greater than Einstein. Either the speed of light is independent of the speed of the light source and then Einstein has improved Newton's theory, or the speed of light does depend on the speed of the light source and then Einstein has destroyed modern physics. A new poll is necessary where the question should be: "Who was right about the speed of light?". In a normal world such problems would not be resolved in polls but in Einstein's world that is the only choice.

Pentcho Valev

pvalev@yahoo.com

HOW FRAGILE SCIENCE IS

At first sight, Einstein's crime is a small crime. Initially he adopted the emission theory of light, c'=c+v, where c' is the speed of photons as measured by an observer, c=300000km/s is the CONSTANT speed of the photons RELATIVE TO THE LIGHT SOURCE and v is the relative speed of the source and the observer. Then he realized it would be more profitable for him to become a divine creator of miracles (time dilation, length contraction etc.) and accordingly introduced the false principle of (absolute) constancy of the speed of light, c'=c:

http://philsci-archive.pitt.edu/archive/00001743/02/Norton.pdf John Norton, "Einstein's Investigations of Galilean Covariant Electrodynamics prior to 1905"

In the end Einstein realized the false principle of (absolute) constancy of the speed of light was too dangerous and partially restored the truth by recognizing that the speed of light varied with the gravitational potential (see Chapter 22 in his "Relativity"). However his miracles killed theoretical physics (it was already half dead since entropy miracles had been ravaging for 50 years). So nowadays Einsteinians make money essentially in two ways. On one hand, they continue to destroy human rationality by teaching Einstein's miracles; on the other, they constantly "improve" Einstein's theory by camouflaging the antecedent of the miracles, the false principle of (absolute) constancy of the speed of light. Einsteinians can even go so far as to say Einstein's special relativity is wrong:

http://www.logosjournal.com/issue_4.3/smolin.htm "Quantum theory was not the only theory that bothered Einstein. Few people have appreciated how dissatisfied he was with his own theories of relativity. Special relativity grew out of Einstein's insight that the laws of electromagnetism cannot depend on relative motion and that the speed of light therefore must be always the same, no matter how the source or the observer moves. Among the consequences of that theory are that energy and mass are equivalent (the now-legendary relationship E = mc2) and that time and distance are relative, not absolute. Special relativity was the result of 10 years of intellectual struggle, yet Einstein had convinced himself it was wrong within two years of publishing it."

Scientists would not react to Einsteinians' discovery that special relativity is wrong. They know: just another original way of making money.

Pentcho Valev

pvalev@yahoo.com

TEACHING THE DISCOVERIES OF EINSTEIN

Generally, relativists are excellent teachers:

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, if teachers want their students to understand the real grandeur of Einstein's discoveries, they should set more problems. For instance: A light source on the surface of a huge celestial body, where the gravitational field is enormous, sends light towards a very distant INERTIAL observer (where the field is zero). What speed of light will the observer measure?

Students will learn that, according to Einstein, the speed of light for inertial observers is not only constant but also variable. So students will understand both the grandeur and the essence of Einstein's discoveries.

Pentcho Valev

pvalev@yahoo.com

Post a Comment