3 ms·
A causal boundary, but not a real boundary. That is to say, events separated by that line can never meet, never interact, never observe each other, but they can
by QAPereo 9y ago
A causal boundary, but not a real boundary. That is to say, events separated by that line can never meet, never interact, never observe each other, but they can still exist.
For a “real world” example see: https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates
- fjsolwmv 9y agoThey exist in the sense that the uncountable real numbers exist. The reals you can name are like your light cone. By symmetry it seems that the other reals/ spacetime points should exist, but there's no way to prove they actually do if you're not already "nearby". :-)