(February 23, 2018 at 9:15 pm)vulcanlogician Wrote:(February 23, 2018 at 9:08 pm)polymath257 Wrote: Once again, you have an image of some boundary expanding outwards. That is NOT what the BB model says. There is no 'beyond the universe' spatially. Instead, wherever you are, the basic 'look and feel' is the same: galaxies in all directions.
The universe isn't 'expanding into' some space beyond the universe (even in models where space is finite). Instead, the distances between galaxies *within* the universe are getting larger over time.
In a technical sense, the universe is literally expanding into the future, not into more space.
I think I get what you mean. The universe expands, but not into something. But I'm curious, according to the big bang model (and assuming the universe is finite), is there a place "on the edge" of the universe where one could stand and see the universe in front of him, but if he turns 180 degrees he will see nothing but an abyss? Or does that question even have an answer?
That depends on your definition of “universe”. If universe is taken to mean the set of all space and time, then obviously no where can you see what is not in the set that includes all by definition. But if by universe, you mean only a particular subset of space matching certain criteria, then the answer depends on the criteria.
