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EINSTEINIANA : THE GRAVITATIONAL REDSHIFT HOAX



 
 
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Old December 27th 13, 07:26 PM posted to sci.astro
Pentcho Valev
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Default EINSTEINIANA : THE GRAVITATIONAL REDSHIFT HOAX

http://news.sciencemag.org/space/201...nsteins-theory
"Galaxy Clusters Validate Einstein's Theory (...) The researchers, led by Radek Wojtak of the Niels Bohr Institute at the University of Copenhagen, set out to test a classic prediction of general relativity: that light will lose energy as it is escaping a gravitational field. The stronger the field, the greater the energy loss suffered by the light. As a result, photons emitted from the center of a galaxy cluster - a massive object containing thousands of galaxies - should lose more energy than photons coming from the edge of the cluster because gravity is strongest in the center. (...) The effect is known as gravitational redshifting. (...) David Spergel, an astrophysicist at Princeton University, compliments Wojtak and his colleagues on "cleverly combining" a large cluster data set to detect a "subtle effect." Spergel says, "This is another victory for Einstein. ... This cluster test suggests that we do live in a strange universe with dark matter and dark energy, but one in which Einstein's theory of gravity is valid on large scales."

More precise measurements of the gravitational redshift, as those performed in the Pound-Rebka experiment, confirm 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..."

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. Consider a light beam that is travelling away from a gravitational field. Its frequency should shift to lower values.. This is known as the gravitational red shift of light."

That is, just like the speed of any material object, the speed of light increases as light is falling in a gravitational field and decreases if the light is travelling away from the gravitational field. The relevant equation given by Newton's emission theory of light is:

c' = c(1±gh/c^2)

and the frequency shift measured by Pound and Rebka unequivocally confirmed the emission theory's prediction:

f' = f(1±gh/c^2)

An important implication is that the gravitational redshift of the light coming to the Earth from distant astronomical objects is due to the simple fact that the speed of that light (relative to the Earth) is decreased.

According to general relativity, the speed of light varies twice as fast as the speed of ordinary matter in a gravitational field: c'=c(1±2gh/c^2). This variation is obviously incompatible with the frequency shift measured by Pound and Rebka:

http://poincare.matf.bg.ac.rs/~rvikt..._Cosmology.pdf
Relativity, Gravitation, and Cosmology, T. Cheng

p.49: This implies that the speed of light as measured by the remote observer is reduced by gravity as

c(r) = (1 + phi(r)/c^2)c (3.39)

Namely, the speed of light will be seen by an observer (with his coordinate clock) to vary from position to position as the gravitational potential varies from position to position.

p.93: Namely, the retardation of a light signal is twice as large as that given in (3.39)

c(r) = (1 + 2phi(r)/c^2)c (6.28)
________________________________________________
[end of quotation]

Equation (3.39) in the quotation above gives the variation of the speed of light with the gravitational potential predicted by Newton's emission theory of light.

Equation (6.28) in the quotation above gives the variation of the speed of light with the gravitational potential predicted by Einstein's general relativity. Note the factor 2 on the potential term. This factor makes the general relativity's prediction incompatible with the frequency variation f(r)=(1+phi(r)/c^2)f measured in the Pound-Rebka experiment.

See also:

http://arxiv.org/pdf/gr-qc/9909014v1.pdf
Steve Carlip: "It is well known that the deflection of light is twice that predicted by Newtonian theory; in this sense, at least, light falls with twice the acceleration of ordinary "slow" matter."

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+phi/c^2) where phi is the gravitational potential relative to the point where the speed of light co is measured. (...) 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.ita.uni-heidelberg.de/res...s/JeruLect.pdf
LECTURES ON GRAVITATIONAL LENSING, RAMESH NARAYAN AND MATTHIAS BARTELMANN, p. 3: " The effect of spacetime curvature on the light paths can then be expressed in terms of an effective index of refraction n, which is given by (e.g. Schneider et al. 1992):
n = 1-(2/c^2)phi = 1+(2/c^2)|phi|
Note that the Newtonian potential is negative if it is defined such that it approaches zero at infinity. As in normal geometrical optics, a refractive index n1 implies that light travels slower than in free vacuum. Thus, the effective speed of a ray of light in a gravitational field is:
v = c/n ~ c-(2/c)|phi| "

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 phi would be c(1+phi/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+phi. 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+2phi, which corresponds to Einstein's 1911 equation, except that we have a factor of 2 instead of 1 on the potential term."

Pentcho Valev
 




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