2006-09-22 20:01:53 · 9 answers · asked by Godcreature 1 in Science & Mathematics ➔ Astronomy & Space
There are three estimations for the radius of the Universe:
1-13.7 light years.
2-46 light years.
3-76 light years.
The last one is the best as I think.
2006-09-22 20:10:31 · answer #1 · answered by Mohammed F 1 · 0⤊ 0⤋
The best guesses by cosmologists are that the universe is finite and boundless, and probably around 12 - 15 billion light years across.
To put that in perspective, our Milky Way galaxy is around 100,000 light years across, the nearest star is about 4 light years away.
By 'boundless' they mean, if you took off in a super-fast spaceship, you'd never get to "the end"--you'd simply come back to your starting point from the other direction.
This is sort of like if you started flying around the Earth at the equator and keep going completely straight, never turned left or right. If you didn't know the planet was a huge ball, you might be very surprised to find yourself back at your starting point after some days flying time.
Well, same thing with the universe, only you'd need a lot more than a few years, and a few lifetimes; eventually, you'd get back to your starting point.
So how is that possible? Well, just like the Earth seems flat when you're flying over it in a plane, actually, the flat surface is curved, but so slightly you can't really see it. But on a planetary scale, it curves enough, so it wraps completely around--and without realizing it, thinking you're flying "completely straight" you eventually get back to the beginning.
The universe is also "curved" (by gravity) and the best theories available believe that it is curved enough, that it "wraps completely around" in a way that we, as 3-dimensional creatures, cannot be completely aware of, and that eventually you'd get back to the beginning again. (There are other, competing theories, that say the amount of mass in the universe doesn't create enough gravity to completely wrap it around; if those theories are correct, you would never come back to the starting point again.)
Just to complicate things, the universe is expanding, so as soon as you finish measuring it, you'll be off because it'll be bigger by then.
It's "finite", because while it would take a long, long, long time to get back to the beginning, it wouldn't take forever, and there are some ways to estimate the apparent "width" (if you want to call it that, given that it's boundless and has no "edges" you can stick the ruler on) of the universe.
2006-09-23 03:24:42 · answer #2 · answered by Peter C 4 · 0⤊ 0⤋
Because the known universe is so large, measuring it in terms of distance is pointless. When astronomers describe the size of space, they use the concept of a light year. A light year is the distance that light travels in one year, or 6 trillion miles. The universe is known to be expanding, but it's current size is generally considered to be 14 billion light years across.
2006-09-23 03:11:48 · answer #3 · answered by Henry S 1 · 1⤊ 0⤋
Recent studies indicate that the universe is expanding at an accelerating rate. Therefore, it is impossible to even guess at its size. More important it is likely that the universe cannot be described in dimensions that we understand, so length, width and height are not relevant in what certainly is a multidimensional scenario.
2006-09-23 03:17:45 · answer #4 · answered by Anonymous · 0⤊ 0⤋
We dont know. We only know what we are able to see temp wise after the big bang. The universe could be wider but the objects that far out may have hit entrophy. So we can only estimate on what we see.
2006-09-23 03:06:33 · answer #5 · answered by Anonymous · 0⤊ 0⤋
in light years, anywhere from 16 to 32 light years long, depending on how long it is to one end from the other. an argument about it is also about the age, which is also under dispute since some stars seem to be older than the univers based on the blue-red shift factors for the distance to different stars.
2006-09-23 03:07:22 · answer #6 · answered by de bossy one 6 · 0⤊ 0⤋
It's so big it's scary. Did you know that at most points in the universe you can't see anything? That's because no light has got there yet.
2006-09-23 03:08:45 · answer #7 · answered by the universe 5 · 0⤊ 0⤋
There is no way to answer a question about the unknown. As far as I know it is ifinite.
2006-09-23 03:06:02 · answer #8 · answered by Derek 4 · 0⤊ 0⤋
Did you want that in inches or feet? Please be clearer as to what you want to know. Inches, feet, yards, meters..........?
2006-09-23 03:26:45 · answer #9 · answered by Anonymous · 0⤊ 0⤋