3 ms·
As I see it, there’s a vast cognitive chasm between the cosmic event horizon and the event horizon of a black hole, as the former preserves “continuity of local
by qubex 6y ago
As I see it, there’s a vast cognitive chasm between the cosmic event horizon and the event horizon of a black hole, as the former preserves “continuity of locality” (my term) whereas the latter does not. Basically the the former is only an event horizon for us who are very distant from it, whereas the black hole’s horizon is an abrupt threshold in space. I don’t think it’s healthy to confuse the two.
- wnoise 6y agoThe locality is all equally continuous in all these cases. Someone near the black-hole horizon will see nothing unusual, and will not experience a horizon unless they are accelerating like mad to stay there. But someone doing that in flat space will see a horizon too -- see the Rindler coördinatization[1] of Minkowski space. It even has an analogous Rindler horizon, which seems to emit particles from the Unruh Effect[2]. I say seems to because particle number isn't invariant under acceleration. An outside observer will see a particle detector go off, but will interpret the accelerated detector as causing the particles, rather than the horizon. [1] https://en.wikipedia.org/wiki/Rindler_coordinates https://en.wikipedia.org/wiki/Rindler_coordinates [2] https://en.wikipedia.org/wiki/Unruh_effect https://en.wikipedia.org/wiki/Unruh_effect