@ Kathleen Rosser

The very space-time concept has been shown as absolutely baseless where as theories of relativity are also shown as baseless whereas the very application of General Theory of Relativity to gravitation is absurd because the gravitational force has been shown to be electromagnetic force. For your information the Theory of Relativity is under open challenge since last twelve years. My all papers are on the ResearchGate so read as you would have to read three papers.

Dear Preston Guynn, Your summary of my question is to the point. Thanks for the contribution. You say, "The phrase spacetime curvature simply means that space and time are relative." Perhaps I was not explicit enough. By "spacetime curvature" I meant the property of spacetime such that its RIemann curvature is nonzero, as opposed to flat Minkowski spacetime, which has zero curvature. Special relativity is of course not in doubt here. I agree that GR does not appear to offer an accurate description of many of the gravitational phenomena we observe in the universe.

The question

“In general relativity, is gravity truly geometry for bodies of any mass? Ie. is all gravitational motion fully determined by a spacetime metric?”

- has a rather short, but scinentifically complete, correct answer: “gravitational motion” i.e. motion of a body in Gravity field,

- as that rigorously scinentifically proven in the Shevchenko-Tokarevsky’s Planck scale informational physical model, two main papers are

https://www.researchgate.net/publication/354418793_The_Informational_Conception_and_the_Base_of_Physics, and

https://www.researchgate.net/publication/383127718_The_Informational_Physical_Model_and_Fundamental_Problems_in_Physics

- fundamentally by no means can be specifically determined by a spacetime metric. Matter’s spacetime is fundamentally absolute, fundamentally flat, fundamentally continuous, and fundamentally “Cartesian”, spacetime that has metrics (at least) (cτ,X,Y,Z, g,w,e,s,ct).

- what is really some “empty container” with fundamentally infinite dimensions, where the emptiness fundamentally by no means be impacted by anything in Matter and by no means can impact on anything in Matter.

Gravity is fundamentally nothing else than some fundamental Nature force, which nothing does with the spacetime, as all other [Weak, Electric, Nuclear/Strong] Force nothing do.

More about what Gravity [and Electric Nuclear] Force is, see section “Mediation of the fundamental forces in complex systems” in 2-nd link above, to read SS posts in https://www.researchgate.net/post/NO47What_is_Force_a_Field_Where_is_the_Force_Field_How_does_it_appear_Is_the_Force_Field_a_Regulating_Effect_of_the_Energy-Momentum_Field/1, pages 1,2 it is useful as well.

Cheers

@ All the members of ResearchGate

All participants of this discussion

Please read the papers of Jan Slowak though not published in peer-reviewed journals but written such that even schoolboys knowing simple algebra can understand that Lorentz transformation, theory of relativity, Space-time Concept are simply nonsense and the discussions are about something which is nonsense is simply wastage of time.

Thank you readers. The question here is nontrivial. Confirming the inadequacy of GR, Baumgarte et al. (Phys. Rev. D, 2024) explore numerical methods to simulate black hole collisions with neutron stars of similar mass, using Newtonian concepts like 3-momentum on conformal flat space. Thus the answer to my question, "Can [the test mass staying at the center of mass of the space capsule] be proven ... using the formalism of GR?" is No.

Indeed, GR alone cannot tell us whether massive objects follow geodesics, and thus whether gravity is physically geometry. The issue of geometric gravity is not only nontrivial, it is critical for determining whether we need quantum gravity at all. For if gravity is merely the curvature of background spacetime, there is arguably nothing to quantize. But if gravity is NOT physically geometry, then it is akin to a force, and the logical next step is quantization.

A large body of literature is devoted to failed attempts to quantize gravity. Are these attempts in vain? Or are they pioneering endeavors toward an ultimate correct theory? This is a crucial question for the progress of physics today.

The papers of Baumgarte et al.:

https://arxiv.org/pdf/2405.10365

Article Primordial black holes captured by neutron stars: Relativist...

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