Valid Argument I:

Premise 1: In a gravitational field the speed of falling light INCREASES - photons fall with the same acceleration as ordinary falling bodies (g = 9..8 m/s^2 near Earth's surface), as predicted by Newton's theory.

Premise 2: The formula (frequency)=(speed of light)/(wavelength) is correct.

Conclusion: Gravitational time dilation does not exist - Einstein's general relativity is nonsense.

Valid Argument II:

Premise 1: In a gravitational field the speed of falling light DECREASES - the acceleration of falling photons is NEGATIVE, -2g near Earth's surface.

Premise 2: The formula (frequency)=(speed of light)/(wavelength) is correct.

Conclusion: Gravitational time dilation does exist.

Premise 1 in Valid Argument II is an idiotic fudge factor Einstein had to introduce in his general relativity, in order to reconcile the miraculous gravitational time dilation he had fabricated in 1911 and the gravitational redshift predicted by Newton's theory:

"Contrary to intuition, the speed of light (properly defined) decreases as the black hole is approached. [...] If the photon, the 'particle' of light, is thought of as behaving like a massive object, it would indeed be accelerated to higher speeds as it falls toward a black hole. However, the photon has no mass and so behaves in a manner that is not intuitively obvious." http://www.physlink.com/Education/AskExperts/ae13.cfm

"...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.speed-light.info/speed_of_light_variable.htm

"Thus, as φ becomes increasingly negative (i.e., as the magnitude of the potential increases), the radial "speed of light" c_r defined in terms of the Schwarzschild parameters t and r is reduced to less than the nominal value of c." https://www.mathpages.com/rr/s6-01/6-01.htm

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