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Oct15-11, 12:05 PM
P: 1,115
Quote Quote by Sam Gralla View Post
Well, spheres made of different stuff (e.g., with different elasticity properties) will deform differently, and consequently will produce different metrics. It could be that under some assumptions the result will be independent of the matter model--but if you're asking about distortion, I doubt it. Since you seem to be wondering about some established calculation that seems to make preferred use of coordinates, maybe you could link to some reference to see how they define the problem there.
I'm confused. My understanding is that by metric we understand the spacetime metric of SM or MM, owing to the relatively massive shell, in which the small test body is immersed. And that mechanical distortion of said body does not constitute some added metric, or appreciably alter the embedding metric owing to the shell. Besides, it was stipulated that mechanical distortions are either eliminated or compensated for. And one can simply apply a limiting process, ie let specific stiffness -> 'near infinite', a common enough idealization surely.