Two speeds of light in Einstein's general relativity

According to Einstein's general relativity, the speed of light falling towards the source of gravity decreases - in the gravitational field of the Earth the acceleration of falling photons is negative, -2g. Yet an observer at rest with respect to the source of gravity will always measure the speed of light to be constant, c. Einsteinians are unable to explain the two-speeds conundrum so some of them teach that the speed of falling light is variable (decreases), the majority teach that it is constant:

http://www.physlink.com/Education/AskExperts/ae13.cfm
"Contrary to intuition, the speed of light (properly defined) decreases as the black hole is approached."

http://www.speed-light.info/speed_of_light_variable.htm
"Einstein wrote this paper in 1911 in German. (...) ...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+φ/c^2) where φ is the gravitational potential relative to the point where the speed of light c0 is measured. Simply put: Light appears to travel slower in stronger gravitational fields (near bigger mass). (...) You can find a more sophisticated derivation later by Einstein (1955) from the full theory of general relativity in the weak field approximation. (...) Namely the 1955 approximation shows a variation in km/sec twice as much as first predicted in 1911."

http://www.mathpages.com/rr/s6-01/6-01.htm
"Specifically, Einstein wrote in 1911 that the speed of light at a place with the gravitational potential φ would be c(1+φ/c^2), where c is the nominal speed of light in the absence of gravity. In geometrical units we define c=1, so Einstein's 1911 formula can be written simply as c'=1+φ. However, this formula for the speed of light (not to mention this whole approach to gravity) turned out to be incorrect, as Einstein realized during the years leading up to 1915 and the completion of the general theory. (...) ...we have c_r =1+2φ, which corresponds to Einstein's 1911 equation, except that we have a factor of 2 instead of 1 on the potential term."

http://math.ucr.edu/home/baez/physic..._of_light.html
Updated 2014 by Don Koks. Original by Steve Carlip (1997) and Philip Gibbs 1996: "So consider the question: "Can we say that light confined to the vicinity of the ceiling of this room is travelling faster than light confined to the vicinity of the floor?". For simplicity, let's take Earth as not rotating, because that complicates the question! The answer is then that (1) an observer stationed on the ceiling measures the light on the ceiling to be travelling with speed c, (2) an observer stationed on the floor measures the light on the floor to be travelling at c..."

http://www.knetbooks.com/search-resu...&referrer=KBCJ
Brian Cox, Jeff Forshaw, p. 236: "If the light falls in strict accord with the principle of equivalence, then, as it falls, its energy should increase by exactly the same fraction that it increases for any other thing we could imagine dropping. We need to know what happens to the light as it gains energy. In other words, what can Pound and Rebka expect to see at the bottom of their laboratory when the dropped light arrives? There is only one way for the light to increase its energy. We know that it cannot speed up, because it is already traveling at the universal speed limit, but it can increase its frequency."

http://helios.gsfc.nasa.gov/qa_sp_gr.html
Dr. Eric Christian: "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."

http://www.oapt.ca/newsletter/2004-0...Searchable.pdf
Richard Epp: "One may imagine the photon losing energy as it climbs against the Earth's gravitational field much like a rock thrown upward loses kinetic energy as it slows down, the main difference being that the photon does not slow down; it always moves at the speed of light."

Logically, the two speeds of light - the variable and the constant - are needed to vindicate the idiotic gravitational time dilation (fabricated by Einstein in 1911) and to make general relativity compatible with the gravitational redshift originally predicted by Newton's emission theory of light:

http://www.einstein-online.info/spot...t_white_dwarfs
Albert Einstein Institute: "One of the three classical tests for general relativity is the gravitational redshift of light or other forms of electromagnetic radiation. However, in contrast to the other two tests - the gravitational deflection of light and the relativistic perihelion shift -, you do not need general relativity to derive the correct prediction for the gravitational redshift. A combination of Newtonian gravity, a particle theory of light, and the weak equivalence principle (gravitating mass equals inertial mass) suffices. (...) The gravitational redshift was first measured on earth in 1960-65 by Pound, Rebka, and Snider at Harvard University..."

Pentcho Valev

Here is the conundrum again: According to Einstein's general relativity, the speed of light falling towards the source of gravity decreases - in the gravitational field of the Earth the acceleration of falling photons is negative, -2g. Yet an observer at rest with respect to the source of gravity will always measure the speed of light to be constant, c. Einsteinians have no idea why there should be two speeds of light - variable and constant - and teach either one or the other (never both at the same time). Needless to say, such "teaching" is counterproductive - Einstein remains a deity (the bigger the confusion, the more intense the worshiping), but science is dying:

http://www2.macleans.ca/2013/09/05/p...odern-physics/
Neil Turok: "It's the ultimate catastrophe: that theoretical physics has led to this crazy situation where the physicists are utterly confused and seem not to have any predictions at all."

http://www.nature.com/news/scientifi...hysics-1.16535
George Ellis and Joe Silk: "This year, debates in physics circles took a worrying turn. Faced with difficulties in applying fundamental theories to the observed Universe, some researchers called for a change in how theoretical physics is done. They began to argue - explicitly - that if a theory is sufficiently elegant and explanatory, it need not be tested experimentally, breaking with centuries of philosophical tradition of defining scientific knowledge as empirical."

http://www.nytimes.com/2015/06/07/op...f-physics.html
Adam Frank, professor of astrophysics at the University of Rochester, and Marcelo Gleiser, professor of physics and astronomy at Dartmouth College: "A Crisis at the Edge of Physics. Do physicists need empirical evidence to confirm their theories? You may think that the answer is an obvious yes, experimental confirmation being the very heart of science. But a growing controversy at the frontiers of physics and cosmology suggests that the situation is not so simple. (...) ...a mounting concern in fundamental physics: Today, our most ambitious science can seem at odds with the empirical methodology that has historically given the field its credibility."

http://www.prospectmagazine.co.uk/fe...tific-theories
Frank Close, professor of physics at the University of Oxford: "In recent years, however, many physicists have developed theories of great mathematical elegance, but which are beyond the reach of empirical falsification, even in principle. The uncomfortable question that arises is whether they can still be regarded as science. Some scientists are proposing that the definition of what is "scientific" be loosened, while others fear that to do so could open the door for pseudo-scientists or charlatans to mislead the public and claim equal space for their views."

http://www.math.columbia.edu/~woit/wordpress/?p=7266
Peter Woit: "As far as this stuff goes, we're now not only at John Horgan's "End of Science", but gone past it already and deep into something different."

Pentcho Valev

The truth about the speed of light in a gravitational field:

http://s3.amazonaws.com/cramster-res...t-lens_PPT.pdf
"If we accept the principle of equivalence, we must also accept that light falls in a gravitational field with the same acceleration as material bodies."

That is, the gravitational redshift (blueshift) is not the result of time dilation (there is no time dilation) - it is the result of the variation of the speed of light in a gravitational field predicted by Newton's emission theory of light:

http://www.einstein-online.info/spot...t_white_dwarfs
Albert Einstein Institute: "One of the three classical tests for general relativity is the gravitational redshift of light or other forms of electromagnetic radiation. However, in contrast to the other two tests - the gravitational deflection of light and the relativistic perihelion shift -, you do not need general relativity to derive the correct prediction for the gravitational redshift. A combination of Newtonian gravity, a particle theory of light, and the weak equivalence principle (gravitating mass equals inertial mass) suffices. (...) The gravitational redshift was first measured on earth in 1960-65 by Pound, Rebka, and Snider at Harvard University..." x

http://courses.physics.illinois.edu/...ctures/l13.pdf
University of Illinois at Urbana-Champaign: "Consider a falling object. ITS SPEED INCREASES AS IT IS FALLING. Hence, if we were to associate a frequency with that object the frequency should increase accordingly as it falls to earth. Because of the equivalence between gravitational and inertial mass, WE SHOULD OBSERVE THE SAME EFFECT FOR LIGHT. So lets shine a light beam from the top of a very tall building. If we can measure the frequency shift as the light beam descends the building, we should be able to discern how gravity affects a falling light beam. This was done by Pound and Rebka in 1960. They shone a light from the top of the Jefferson tower at Harvard and measured the frequency shift. The frequency shift was tiny but in agreement with the theoretical prediction."

http://www.printsasia.com/book/relat...ann-0486406768
Banesh Hoffmann: "In an accelerated sky laboratory, and therefore also in the corresponding earth laboratory, the frequence of arrival of light pulses is lower than the ticking rate of the upper clocks even though all the clocks go at the same rate. (...) As a result the experimenter at the ceiling of the sky laboratory will see with his own eyes that the floor clock is going at a slower rate than the ceiling clock - even though, as I have stressed, both are going at the same rate. (...) The gravitational red shift does not arise from changes in the intrinsic rates of clocks. It arises from what befalls light signals as they traverse space and time in the presence of gravitation."

Pentcho Valev