Well, our universe is limited by what can be seen by telescopes. And what can be seen by a scope is limited by the speed of light.
The current understanding is the Big Bang happened 13.7 billion years ago, and I've read that galaxies have been identified that are 12 to 13 billion light-years away. That means the light we are seeing left those galaxies 12 to 13 billion years ago, so we are seeing them as they were in the first billion years or so after the BB.
Beyond that, there is a sphere of haze. There were no galaxies yet to send out any light. Presumably that haze prevents us from seeing any farther. So our universe more or less coincides with "everything produced by our Big Bang."
One could imagine though, that a clear enough spot could exist in the sphere of haze that you could see through it, and beyond to the product of another Big Bang. Probably just a dot, but a whole nother universe, as it existed many billions of years ago.
ok then...
my sister and I had an argument and I don't know anybody smart enough around here to take my side...
She is smart in that she can remember stuff...she is a nurse, and is good. but she doesnt' do well with thinking ?critically?...
she can't take information and make a logical ok, she doesn't believe in natural sciences....for example, we never walked on the moon, there were no dinosaurs, and (this is the one that really drives me nuts) she doesn't believe light 'travels'. It is either on or off.
so we were discussing the stars and I was trying to explain that the light we see is from a long time ago because the stars are so far away it took a long time for it to arrive here...She said: no the light we are seeing is the actual light that the star is giving off right now, this minute.
well I TRIED to make an analogy with water....that if you turned on a hose and let it run for a minute, then turned it off, the water IN the hose already wouldn't just disappear...it would run out the end...she wouldn't accept that analogy because light is not water..
so then we got off into what IS light...(I know, I know: dumb and dumber trying to talk astronomy) and she said: If you have a light bulb that is sealed in a light proof box and you turned it on for a minute then turned it off and left it for a year, when you come back and opened it the light still wouldn't be in there...
so (she says) how could light from a star still exist millions of years later?
do YOU know? cause I am stumped....