
20190403: The Edge of an Infinite Universe
 00:46: It’s boundary is called the particle horizon.
 01:22: To review: the particle horizon defines the limit of the visible past, and there’s also cosmic event horizon defining the limit of the visible future.


20160302: What’s Wrong With the Big Bang Theory?
 07:05: Another way to say this is that those edges of the universe have always been beyond each other's particle horizons.


20151007: The Speed of Light is NOT About Light
 11:17: RedomaxRedomax asks what you would see if you traveled 18 times the distance to the particle horizon to come back to where you started.
 11:26: ... that number, 18 times the particle horizon, only applies if the universe has positive curvature, making it a ...


20150930: What Happens At The Edge Of The Universe?
 01:47: We call this the particle horizon of the universe.
 01:56: Anything inside the particle horizon is referred to as the known universe.
 02:33: To travel to the particle horizon, we need to move through expanding space.
 03:33: The event horizon of the universe is actually closer to us than the particle horizon.
 04:22: But for now, let's just assume we have a nice Alcubierreclass warpship and we burn the mass energy of entire stars to chase the particle horizon.
 04:36: Remember, the particle horizon is just defined by the limit of our current view.
 04:43: Wait a minute, and my particle horizon expands.
 04:46: Travel to the particle horizon instantaneously and you'll see the Milky Way as a cute baby CMB blob on your new particle horizon.
 05:37: So if it's true, what happens if you cross the particle horizon?
 06:46: ... you'd need to travel an absolute minimum of 18 times the distance to the particle horizon to get back to where you started, assuming expansion froze for the whole ...
