Time dilatopause for black holes

In summary: No I meant that isn't the event horizon defined by the fact that to get out of it, you need to travel at c?...
  • #36
PeterDonis said:
No. The formula you used is for the Schwarzschild radial coordinate, not the altitude above the star's surface.

If you look at the Wikipedia article [1], you will see that the radius of this star is estimated to be 19-41 km. The Schwarzschild ##r## coordinate is not exactly the same as radial distance, but it's close enough that an ##r## value of 3 km is well inside the surface of the neutron star--which means the formula you used is invalid, since it only works in the vacuum region outside the star.

Furthermore, you are completely ignoring what has been said in this thread about the limits on which values of ##r## permit free-fall orbits at all.

You also don't appear to have fully grasped the implications of the Buchdahl Theorem, which I mentioned in post #9, which puts limits on which values of ##r## are possible at the surface of a static object.

I strongly suggest that you take the time to consider fully these items before trying to make up any more scenarios.

https://en.wikipedia.org/wiki/RX_J1856.5−3754
Oh, sorry. My bad 😅
 
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  • #37
It may have been said before in this thread, but I want to point out that at any distance above a spherical body that has a surface (I.e. not a BH), there is a (usually) forced circular orbit such that time signals exchange with the surface will show the clocks running at the same rate.
 
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