Re:Gravity Kills Schrödinger's Cat
by simonh on Sunday June 21, 2015 @05:22AM
(#9752763)
Are there regions of the universe that have never been causally connected? They all originated in the same event, so I'd be surprised if that's true, but I'm no expert. I know cosmic inflation during the big bang was superluminal, but I have to concede I'm not completely familiar with the consequences of that, so good point.
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Indeed, the fact that they are moving apart at superluminal speeds is exactly why they have never been causally connected. The fact that such non-causally connected islands still "look the same" is called the horizon problem (https://en.wikipedia.org/wiki/Horizon_problem), and it is one of the issues that Guth's inflation might solve (https://en.wikipedia.org/wiki/Inflation_(cosmology)#Horizon_...).