Timeline for Contradiction in negative mass interactions according to GR
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 10, 2023 at 22:58 | comment | added | Independent Physics | Which is the energy momentum tensor in the Schwarzschild vacuum solution then? (or the one elsewhere) | |
| Oct 10, 2023 at 19:24 | comment | added | MadMax | @Manuel, you are making a basic mistake here. If energy-momentum tensor is null in a region, to find the solution to Einstein equations in that region you still have to know the energy-momentum tensor elsewhere (or via some boundary condition related to the energy-momentum tensor outside of the null area). How is mass $m$ linked to the constant of integration of the Schwarzschild solution? Why don't you link the constant of integration to $5m$, $100m$, or $-100m$? Because it is constrained by the energy-momentum tensor at the origin, which is outside the area you try to find the solution. | |
| Oct 10, 2023 at 17:28 | comment | added | Independent Physics | The energy-momentum tensor in the Schwarzschild solution is null everywhere. But you still have a mass term in the metric solution (which can be negative, and test particles are repelled by the black hole). Why even bother doing that? | |
| Oct 10, 2023 at 13:44 | comment | added | MadMax | @Manuel, please do a simple excise of calculating the energy-momentum tensor of for example the Klein–Gordon action and see how mass enters the picture, and you will understand what I am talking about. | |
| Oct 9, 2023 at 21:50 | comment | added | Independent Physics | I cite Hermann Bondi: "Active gravitational mass occurs for the first time as a constant of integration in Schwarzschild's solution. [...] If, however, the constant is taken to be negative then, in the first approximation, test particles will describe the orbits corresponding to the Newtonian case with repulsion." | |
| Oct 9, 2023 at 21:15 | comment | added | MadMax | @Manuel, the constant of integration is $\sqrt{m^2}$, not $m$. | |
| Oct 9, 2023 at 20:16 | comment | added | Independent Physics | No, mass appears in the Schwarzschild solution as a constant of integration. It is a solution of the vacuum Einstein equations, therefore the stress-energy tensor is null everywhere the metric is defined. | |
| Oct 9, 2023 at 15:00 | history | answered | MadMax | CC BY-SA 4.0 |