How does light travel away from a star near the outer reaches of the cosmos? Does the light curve through space-time curvature, but if so then where does it go? Or is there dark matter beyond the most distant stars? I believe that matter curves in space and time but I don't think that space itself has physical properties. Thank you for your attempts to help in this matter.
2007-06-24 15:33:03 · 6 answers · asked by David L 4 in Science & Mathematics ➔ Astronomy & Space
In some ways you can think of it as a speed limit instead of a space limit.
A star at the edge of the cosmos is actually just furthest from us, and traveling away from us at very nearly the speed of light.
Naturally if you asked one of its inhabitants what was going on, they would say they were standing still and WE were the ones hurtling away at the speed of light.
If you're familiar with Special Relativity you might know that objects that are traveling very quickly also move forward in time much more slowly. So for the furthest stars in the universe (from us) they would be creeping ever so slowly forward in time. They would still be hot and dense--in the first few seconds of the big bang itself--exploding out at enormous speed, but viewed in slow motion from here.
So what we have is a dense* layer of outward expanding plasma, the near surface of which IS visible in the Infra-Red--is called the Cosmic Background Radiation.
(*On top of the greater density due to the time dilation effect, it is also length contracted radially.)
Your question was about the region just beyond the furthest matter. I think you run into some mathematical infinities if you think about it.
First of all, if you are on the other side of that wall, you have an object approaching you at the speed of light. You're not going to see it until it's absorbed you.
Second, if you could feel its effects before it hit you, it's infinitely dense, and you gotta wonder if you'd be gravitationally attracted to it--if so what is the effect of infinite gravity?
What I'm curious about is when an object falls into a black hole, deep inside beyond the event horizon is there anyplace where it could actually accelerate beyond the speed of light, and if so, does time reverse, and if time reverses is the object falling in or flying outward from the center?
2007-06-24 16:09:35 · answer #1 · answered by Jon 3 · 0⤊ 0⤋
The cosmos does not have a center point; all points are equivalent. The present edge of the universe is 13.6 billion light years from us -- or from anywhere else. But it isn't really an edge; if you traveled at nearly the speed of light for that distance, you would still be billions of light years from the farthest detectable objects because of the expansion of the universe. In short, even though the universe is of finite size, it has no boundaries. A common analogy is to suppose a bug on the surface of a balloon; the bug may go where it pleases, but never encounters an edge. Now, if you suppose that the balloon is expanding, you have a fairly reasonable model of the universe.
2007-06-24 22:40:43 · answer #2 · answered by Anonymous · 2⤊ 0⤋
There is no center of the cosmos, just like there is no place on Earth that is the center. The center of the Earth is deep inside, not on the surface. The center of the cosmos, if you can even define such a thing, would be deep in the 4th dimension or something like that, and not in our 3 dimensional space at all. If you are confused by that, you are experiencing a similar confusion that average people in 1492 might have experienced trying to wrap their minds around the round Earth. But in 1492, highly educated people all knew the Earth was round just like today scientists know the universe is a curved spacetime continuum,
2007-06-24 22:45:45 · answer #3 · answered by campbelp2002 7 · 0⤊ 1⤋
Lets say the place you are talking about is just outside our universe. There space has no properties because it doesn't exist. Where there is no matter, space and time cease to exist. There is also no boundary point to cross outside our universe you can't escape the universe because space and time expand a head of you. So you can never get to or see outside of our universe.
2007-06-24 22:43:54 · answer #4 · answered by Roadkill 6 · 0⤊ 0⤋
i dont know the answer but i think everyone else misunderstood the question. david does not assume there is a center of the universe. there is however, a center of the dispersion of matter in the universe and what i think david is asking about the properties of the universe outside of the expanding field of matter.
2007-06-24 23:23:04 · answer #5 · answered by Anonymous · 0⤊ 0⤋
The nature of space is the same no matter where it is.
It differs only in density,which has a maximum,at it's beginning,and a minimum when it goes out of existence.
2007-06-25 08:12:05 · answer #6 · answered by Billy Butthead 7 · 0⤊ 0⤋