Spacetime can exist in numerous forms, two of the main ideas are either Mach's Principle or an Independent Structure of Spacetime (ISST) (one that exists without matter to "create" it).
A universe which has an ISST must obey certain rules. We know that all motion is relative, we know that the "force" from gravity is proportional to mass and we know that "force" from gravity is also proportional to relative velocity.
The biggest problem with the idea of an ISST is that gravity is proportional to relative velocity. Any one body curves spacetime an infinite number of ways, depending on velocity relative to what it's being measured against. To put it another way, you have a single structure of spacetime but infinitely different measurements of how it is curved.
No comments:
Post a Comment