Pentcho Valev

2021-04-07 22:50:48 UTC

Question: "If a light beam is sent tangent across earth would it curve at 9.8 m/s^2?" https://physics.stackexchange.com/questions/627464/if-a-light-beam-is-sent-tangent-across-earth-would-it-curve-at-9-8-rm-m-s2/627496

MY ANSWER: "Yes the light beam would curve at 9.8 m/s^2, as per Newton's theory":

"To see why a deflection of light would be expected, consider Figure 2-17, which shows a beam of light entering an accelerating compartment. Successive positions of the compartment are shown at equal time intervals. Because the compartment is accelerating, the distance it moves in each time interval increases with time. The path of the beam of light, as observed from inside the compartment, is therefore a parabola. But according to the equivalence principle, there is no way to distinguish between an accelerating compartment and one with uniform velocity in a uniform gravitational field. We conclude, therefore, that A BEAM OF LIGHT WILL ACCELERATE IN A GRAVITATIONAL FIELD AS DO OBJECTS WITH REST MASS. For example, near the surface of Earth light will fall with acceleration 9.8 m/s^2." http://web.pdx.edu/~pmoeck/books/Tipler_Llewellyn.pdf

AN EINSTEINIAN'S ANSWER: "Yes it will curve, but not at 9.8 m/s^2 as predicted by Newton's theory. Its curvature will be twice that value as predicted by General Relativity."

Who is right?

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Pentcho Valev

MY ANSWER: "Yes the light beam would curve at 9.8 m/s^2, as per Newton's theory":

"To see why a deflection of light would be expected, consider Figure 2-17, which shows a beam of light entering an accelerating compartment. Successive positions of the compartment are shown at equal time intervals. Because the compartment is accelerating, the distance it moves in each time interval increases with time. The path of the beam of light, as observed from inside the compartment, is therefore a parabola. But according to the equivalence principle, there is no way to distinguish between an accelerating compartment and one with uniform velocity in a uniform gravitational field. We conclude, therefore, that A BEAM OF LIGHT WILL ACCELERATE IN A GRAVITATIONAL FIELD AS DO OBJECTS WITH REST MASS. For example, near the surface of Earth light will fall with acceleration 9.8 m/s^2." http://web.pdx.edu/~pmoeck/books/Tipler_Llewellyn.pdf

AN EINSTEINIAN'S ANSWER: "Yes it will curve, but not at 9.8 m/s^2 as predicted by Newton's theory. Its curvature will be twice that value as predicted by General Relativity."

Who is right?

See more here: https://twitter.com/pentcho_valev

Pentcho Valev