http://pirsa.org/09020042/
Einsteinians Richard Epp and Robert Myers: "Our universe has a split personality"

Absolutely correct. According to this schizophrenic universe, the speed of light is often constant, sometimes variable, and, in one special case discovered by Steve Carlip, both variable and constant:

http://www.astronomynotes.com/relativity/s4.htm
"Prediction: light escaping from a large mass should lose energy---the wavelength must increase since the speed of light is constant. Stronger surface gravity produces a greater increase in the wavelength. This is a consequence of time dilation. Suppose person A on the massive object decides to send light of a specific frequency f to person B all of the time. So every second, f wave crests leave person A. The same wave crests are received by person B in an interval of time interval of (1+z) seconds. He receives the waves at a frequency of f/(1+z). Remember that the speed of light c = (the frequency f) (the wavelength L). If the frequency is reduced by (1+z) times, the wavelength must INcrease by (1+z) times: L_atB = (1+z) L_atA. In the doppler effect, this lengthening of the wavelength is called a redshift. For gravity, the effect is called a gravitational redshift."

http://helios.gsfc.nasa.gov/qa_sp_gr.html
"Is light affected by gravity? If so, how can the speed of light be constant? Wouldn't the light coming off of the Sun be slower than the light we make here? If not, why doesn't light escape a black hole? Yes, light is affected by gravity, but not in its speed. General Relativity (our best guess as to how the Universe works) gives two effects of gravity on light. It can bend light (which includes effects such as gravitational lensing), and it can change the energy of light. But it changes the energy by shifting the frequency of the light (gravitational redshift) not by changing light speed. Gravity bends light by warping space so that what the light beam sees as "straight" is not straight to an outside observer. The speed of light is still constant." Dr. Eric Christian

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....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."

http://www.blazelabs.com/f-g-gcont.asp
"So, faced with this evidence most readers must be wondering why we learn about the importance of the constancy of speed of light. Did Einstein miss this? Sometimes I find out that what's written in our textbooks is just a biased version taken from the original work, so after searching within the original text of the theory of GR by Einstein, I found this quote:"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity ; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light)." - Albert Einstein (1879-1955) - The General Theory of Relativity: Chapter 22 - A Few Inferences from the General Principle of Relativity-. Today we find that since the Special Theory of Relativity unfortunately became part of the so called mainstream science, it is considered a sacrilege to even suggest that the speed of light be anything other than a constant. This is somewhat surprising since even Einstein himself suggested in a paper "On the Influence of Gravitation on the Propagation of Light," Annalen der Physik, 35, 1911, that the speed of light might vary with the gravitational potential. Indeed, the variation of the speed of light in a vacuum or space is explicitly shown in Einstein's calculation for the angle at which light should bend upon the influence of gravity. One can find his calculation in his paper. The result is c'=c(1+V/c^2) where V is the gravitational potential relative to the point where the measurement is taken. 1+V/c^2 is also known as the gravitational redshift factor."

http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html
Steve Carlip: "Einstein went on to discover a more general theory of relativity which explained gravity in terms of curved spacetime, and he talked about the speed of light changing in this new theory. In the 1920 book "Relativity: the special and general theory" he wrote: ". . . according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [. . .] cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position." Since Einstein talks of velocity (a vector quantity: speed with direction) rather than speed alone, it is not clear that he meant the speed will change, but the reference to special relativity suggests that he did mean so. This interpretation is perfectly valid and makes good physical sense, but a more modern interpretation is that the speed of light is constant in general relativity."

Pentcho Valev
pvalev@yahoo.com

Pentcho: http://pirsa.org/09020042/
Einsteinians Richard Epp and Robert Myers: "Our universe has a split personality"

Absolutely correct. According to this schizophrenic universe, the speed of light is often constant, sometimes variable, and, in one special case discovered by Steve Carlip, both variable and constant:

cinci: Ever read what you post Pentcho. This article doesnt say anything about the speed of light. Here's the first sentence in the abstract: "Our universe has a split personality: quantum and relativity."
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Of course, Cinci, relativity has nothing to do with the speed of light.

Quantum theory attempts to understand the atomic nucleus from experiments that destroy the nucleus. The fact that the debris travels at relativistic speed is irrelevant too. You ate your Popsicle too fast.

Pentcho: http://pirsa.org/09020042/
Einsteinians Richard Epp and Robert Myers: "Our universe has a split personality"

Absolutely correct. According to this schizophrenic universe, the speed of light is often constant, sometimes variable, and, in one special case discovered by Steve Carlip, both variable and constant:

cinci: Ever read what you post Pentcho. This article doesnt say anything about the speed of light. Here's the first sentence in the abstract: "Our universe has a split personality: quantum and relativity."


Jose: Of course, Cinci, relativity has nothing to do with the speed of light.

cinci: The article Pentcho cited has nothing to do with that aspect of relativity and deals only with the well knonw fact that relativity and quantum mechanics are not completely compatible. Why don't you read along with us here Jose. Move your lips if you have to.
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Jose: Quantum theory attempts to understand the atomic nucleus from experiments that destroy the nucleus. The fact that the debris travels at relativistic speed is irrelevant too. You ate your Popsicle too fast.

cinci: Well no Jose, special relativity is taken into account in quantum mechanics and in experiments on the nucleus. It's a big part of designing the sensing equipment in colliders.
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Pentcho Valev wrote:
> http://pirsa.org/09020042/
> Einsteinians Richard Epp and Robert Myers: "Our universe has a split
> personality"

Generally the schizophrenic universe teaches Einsteinians how to fiercely fight Newton's emission theory of light, but sometimes it tells them to do the opposite. They obey and even go as far as to rediscover the forbidden 18th century optics:

http://www.aip.org/history/einstein/essay-einstein-relativity.htm
John Stachel: "The idea that a light beam consisted of a stream of particles had been espoused by Newton and maintained its popularity into the middle of the 19th century. It was called the "emission theory" of light, a phrase I shall use. The need to explain the phenomena of interference, diffraction and polarization of light gradually led physicists to abandon the emission theory in favor of the competing wave theory, previously its less-favored rival. Maxwell's explanation of light as a type of electromagnetic wave seemed to end the controversy with a definitive victory of the wave theory. However, if Einstein was right (as events slowly proved he was) the story must be much more complicated. Einstein was aware of the difficulties with Maxwell's theory-and of the need for what we now call a quantum theory of electromagnetic radiation-well before publishing his SRT paper. He regarded Maxwell's equations as some sort of statistical average-of what he did not know, of course-which worked very well to explain many optical phenomena, but could not be used to explain all the interactions of light and matter. A notable feature of his first light quantum paper is that it almost completely avoids mention of the ether, even in discussing Maxwell's theory. Giving up the ether concept allowed Einstein to envisage the possibility that a beam of light was "an independent structure," as he put it a few years later, "which is radiated by the light source, just as in Newton's emission theory of light."......If we model a beam of light as a stream of particles, the two principles can still be obeyed. A few years later (1909), Einstein first publicly expressed the view that an adequate future theory of light would have to be some sort of fusion of the wave and emission theories. This is an example of how the special theory of relativity functioned as a theory of principle, limiting but not fixing the choice of a constructive theory of light."

http://press.princeton.edu/chapters/i6272.html
John Stachel: "As a theory of principle (see above), the theory of relativity provides important guidelines in the search for such a satisfactory theory. Einstein anticipated the ultimate construction of "a complete worldview that is in accord with the principle of relativity."[25] In the meantime, the theory offered clues to the construction of such a worldview. One clue concerns the structure of electromagnetic radiation. Not only is the theory compatible with an emission theory of radiation, since it implies that the velocity of light is always the same relative to its source; the theory also requires that radiation transfer mass between an emitter and an absorber, reinforcing Einstein's light quantum hypothesis that radiation manifests a particulate structure under certain circumstances. He maintained that "the next phase in the development of theoretical physics will bring us a theory of light, which may be regarded as a sort of fusion of the undulatory and emission theories of light."

http://www.mfo.de/programme/schedule/2006/08c/OWR_2006_10.pdf
Jean Eisenstaedt: "At the end of the 18th century, a natural extension of Newton's dynamics to light was developed but immediately forgotten. A body of works completed the Principia with a relativistic optics of moving bodies, the discovery of the Doppler-Fizeau effect some sixty years before Doppler, and many other effects and ideas which represent a fascinating preamble to Einstein relativities. It was simply supposed that 'a body-light', as Newton named it, was subject to the whole dynamics of the Principia in much the same way as were material particles; thus it was subject to the Galilean relativity and its velocity was supposed to be variable. Of course it was subject to the short range 'refringent' force of the corpuscular theory of light --which is part of the Principia-- but also to the long range force of gravitation which induces Newton's theory of gravitation. The fact that the 'mass' of a corpuscle of light was not known did not constitute a problem since it does not appear in the Newtonian (or Einsteinian) equations of motion. It was precisely what John Michell (1724-1793), Robert Blair (1748-1828), Johann G. von Soldner (1776-1833) and Fran¸cois Arago (1786-1853) were to do at the end of the 18th century and the beginning the 19th century in the context of Newton's dynamics. Actually this 'completed' Newtonian theory of light and material corpuscle seems to have been implicitly accepted at the time. In such a Newtonian context, not only Soldner's calculation of the deviation of light in a gravitational field was understood, but also dark bodies (cousins of black holes). A natural (Galilean and thus relativistic) optics of moving bodies was also developed which easily explained aberration and implied as well the essence of what we call today the Doppler effect. Moreover, at the same time the structure of -- but also the questions raised by-- the Michelson experiment was understood. Most of this corpus has long been forgotten. The Michell-Blair-Arago effect, prior to Doppler's effect, is entirely unknown to physicists and historians. As to the influence of gravitation on light, the story was very superficially known but had never been studied in any detail. Moreover, the existence of a theory dealing with light, relativity and gravitation, embedded in Newton's Principia was completely ignored by physicists and by historians as well. But it was a simple and natural way to deal with the question of light, relativity (and gravitation) in a Newtonian context. EINSTEIN HIMSELF DID NOT KNOW OF THIS NEWTONIAN THEORY OF LIGHT AND HE DID NOT RELY ON IT IN HIS OWN RESEARCH."

Pentcho Valev
pvalev@yahoo.com