Another quote from
Anatoly Alekseyevich Logunov, a theoretical physcist:
https://pdfroom.com/books/the-theory-of-gravity/X623zYb6g4Z"GRT does not comply with the equivalence principle,
does not explain the equality of the inert and active
gravitational masses, and gives no unique prediction
for gravitational effects. It does not contain the usual
conservation laws of energy–momentum and of angu-
lar momentum of matter."
GRT = General Relativity Theory, as defined earlier in the paper:
"Therein, also, critical comments are presented con-
cerning general relativity theory (GRT), which still remain in
force."
Here is another quote, from
a publication of the AIAA on p.99:
"Newton proposed two formulas: the law of motion, F = ma, and the law of gravitation, F = GMm/r
2. The mass, m, has two distinct meanings in the two formulas, one as the receptacle of inertia, the other as the source and receptacle of gravitation; yet somehow the two are identical. Stated another way, if m
i and m
g are respectively inertial and gravitational mass, then for any two bodies A and B, regardless of what substance they are, the quantity
appears to be identically zero. It was just this identity that Einstein denominated a principle (weak equivalence) and extended (strong equivalence) to all the laws of phyics in accelerated frames, whether the acceleration is ineitial or gravitational in origin. Strong equivalence is the basis on which it becomes possible in general relativity to represent gravitation by a curvature of spacetime.
Contrary to what is sometimes thought, however, general relativity does not explain equivalence. The principle is an assumption that, once made, allows the effects of gravity to be represented thus. The phenomenon remains a mystery and still needs testing."