General relativity contains a null hypothesis because Einstein ignored refraction of light. And in the proving method Einstein ignored the celestial sphere coordinates system.

A null hypothesis is a statement that one seeks to nullify with evidence to the contrary. For example in the case of general theory of relativity, it seems clear that Einstein ignored refraction of light and ignored the celestial sphere coordinates system.

A null hypothesis of Albert Einstein:

“From these purely theoretical considerations Einstein concluded that light, like any material object, travels in a curve when passing through the gravitational field of a massive body. He suggested that his theory could be put to test by observing the path of starlight in the gravitational field of the Sun. Since the stars are invisible by day, there is only one occasion when Sun and stars can be seen together in the sky, and that is during an eclipse.

Einstein proposed therefore, that photographs be taken of the stars immediately bordering the darkened face of the sun during an eclipse and compared with photographs of those same stars made at another time. According to his theory, the light from the stars surrounding the Sun should be bent inward, toward the Sun, in traversing the Sun’s gravitational field; hence the images of these stars should appear to observer on earth to be shifted outward from their usual positions in the sky.

Einstein calculated the degree of deflection that should be observed and predicted that for the stars closest to the Sun the deviation would be about 1.75 seconds of an arc"(Lincoln Barnett, Universe and Dr.Einstein, London, 1949, Preface by Albert Einstein himself, page 78 - 79).

Einstein ignored the celestial sphere coordinates system:

The celestial sphere is only applicable at a certain time and at a certain place on which such observation is performed. In scientific exposure of astronomy, the instant observation applies. It means, 'that photographs be taken of the stars immediately bordering the darkened face of the sun during an eclipse and compared with photographs of those same stars made at another time ' isn't scientific and deeply wrong.

Unfortunately, we find something like a null hypothesis in F.W.Dyson's statements:

"It seems clear that the effect found must be attributed to the Sun's gravitational field and not, for example, to the refraction by coronal matter" (F.W.Dyson, F.R.S, A Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations made at the Total Eclipse of May 29, 1919).

Actually error in the famous eclipse experiment of 1919:

Einstein calculated the degree of deflection: 1.75 seconds of an arc.

Fact:

Arthur Eddington (1919 eclipse, observed from West Africa): 1.62 seconds of an arc.

Andrew Crommelin (1919 eclipse, observed from Sobral): 0.93 seconds of an arc.

Nobel Committe in 1921 know about this error, that's why Einstein never received Nobel Prize for relativity.

Sorry, no doubt: General relativity has been wrong since the beginning. Deflection of light caused by refraction: i.e.astronomical refraction and terrestrial refraction, not gravity.

New finding about Einstein’s proving method that isn’t scientific and ignored refraction of light, in accordance with— by coincidence — the invention of Professor R. C. Gupta, India, on his paper ‘Bending of Light Near a Star and Gravitational Red/Blue Shift: Alternative Explanation Based on Refraction of Light’.