Does it have an end or does it just go on and on forever and ever? Do you think we are the only things that live in the whole of space???? We can only see the universe out to our horizon (essentially the distance of cosmic microwave background radiation about 13.7 billion light years away). The size of the rest of the universe can't really be known. Some cosmologies make our corner of the universe as a "pocket universe" in a much larger multiverse where physical constants (and so the behavior of so called physical laws) vary over unfathomable distances with little universes peppered throughout it. So, we can't really say how big it is, only how big the portion we can actually see is.
13.7 billion light years is the radius of the Universe if you assume the outer boundaries of the Universe has been expanding at the speed of light since the Big Bang 13.7 billion years ago. That is considered a minimum radius by most modern cosmologists, even though it would seem to be the maximum by Einstein's General Relativity. A variation takes into account that space also expands at the speed of light from every point in that expanding sphere as well. The mathematics of that model brings the radius of the Universe to 78 billion light years, or a diameter of 156 billion light years. Whether the Universe "wraps around" is still a matter of debate. No experiment that canbe conceived at this point can test that, because at our current understanding, nothing can travel faster than the speed of light. Any information capable of answering the closed or open Universe question would require information that has travelled many times the speed of light.
We may never know. We're limited by our ability to interpret what we perceive. It's not so long ago that people believed the world was flat, or that it was the centre of the universe. Technology is opening up opportunities to increase our knowledge at a rapid rate, but it may still be that we never know. It seems most unlikely. If it can happen once, in our little system, it can probably happen again in some of the many similar systems out there.
I believe life exists elsewhere, in nearly infinite diversity. It seems mathematically almost inevitable.
There has to be life somewhere else in the universe. You can look at it both religiously and non-religiously. It seems mathmtically improbable that earth is the only planet with life on it. If it is indeed random, with the many countless worlds out there there must be at least one more with life, though there is probably alot more than one. Religiously, it seems sort of pointless for god or any other supreme creator being to create an entire universe and only put something on our little planet. There is disputed evidence of life on Mars (Go to Wikipedia or Goggle and type "Mars Meteorite" or "ALH84001" the serial number of the meteorite). Surveys of various planets and moons in our own solar system show it is probable. Some scientists think that several of Jupiters moons could support microbial life (See Europa, Callisto, and Ganymede). The same for Titan and Enceldus, two of Saturn's moons. A man named Caral Sagan suggested there could be floating lifeforms on Jupiter and Saturn and other gass giants, though it doesn't look like most scientists support the idea. Logically there has to be some life out there somewhere no matter how you look at it. If we'll ever find another intelligent species is something that has yet to be seen.
...nobody really knows... those who claim they do are deluding themselves, needing to feel they must have answers to everything... all the great minds' 'answers' are only theories lacking definitive proof... all in human experience has a beginning and an end, so our minds aren't even equipped to deal with the concept of anything not having both... which is why man-fashioned religions are so popular! ...'twould be the height [or depth!] of ignorance and arrogance to think so... sadly, many humans want to... i'm not one of 'em...
The Universe is as big as it needs to be. Until we find a way to either remove the lightspeed barrier or bypass it through some cosmic loopholes (wormholes where are you), we won't know exactly how big it is. As for life. There have probably been several billion habitable planets in existence. Life formed, evolved, and was destroyed, or lived depending on cosmic luck and possibly sentient involvement, over the billions of years. Most planets probably never got out of the single celled organism stages. Others never developed intelligence. Some might have intelligence, but didn't create what we would call civilization. Others did but died out or stagnated before they reached the stars. Some probably reached the stars, or at least took tentative steps but eventually died out, or lost technology or interest and stagnated. And there are probably a handful that reached the stars and kept going, until they died out from various means possibly simple age, went on to something else, or are still slowly advancing seeing whats out there. With such a big universe anything is possible. Believing that nothing is out there, and theres nothing worth seeing is the height the idiocy and blindness.
There is no religious or scientific reason to believe that there is nothing else out there. There is not religious or scientific reason to believe that there has been nothing before or there will be nothing after us either. Aside from that, the universe I believe doesn't have an end. How can it? What happens when the universe stops? Whats outside of that? A multi-verse? What happens when a multi verse stops?
How big do you want it to be? I will see what I can do to make it so. I am nothing if not accommodating.
I think the answer to the size of the universe could depend on its origins. If it began with a Big Bang, it seems likely that it's finite, though it could still growing. If it was created by an Infinite Being, why couldn't it be infinite? I love the idea that there might be life on other planets. I hope there is. If there isn't, then...why? If we alone live on the only planet, out of billions, that supports life, is it because of a lucky accident, or a divine purpose? That's better answered in the Religion thread, I suppose.
Indeed. Our Universe is defined by the Big Bang. What if there are other Big Bang universes beyond the boundaries of our Universe? Would all BB universes have the same physical laws? What would happen if BB universes began to overlap? Could other universes exist based on a different cosmogeny than a Big Bang, and if so, what properties woud they have? If you are a science fiction writer, and find one BB universe too limiting, how about exploring some of these questions? Even better, if you a physicist, what can you postulate about alternative universes> are there wasy to even test the hypotheses within an existing universe?
I believe that there is life out there somewhere. Maybe not life like we are led to believe from sci-fi movies and the like. But micro organisms, bacteria, things like that have to exist outside of our own planet at least. I mean there are infinate thoughts and theories into all of this and when you think about it manking goes out into space, lands on a planet and surely they are harbouring bacteria or organisms of some kind that may possibly be able to adapt to the surroundings that man takes it to. Is it possible for them to go out of our planet and NOT take any forms of bacteria and organism with them to another planet considering that all you've to do is cough or sneeze and you send germs and what not into the air. Now they are confined for a substantial period of time so surely they would traffic something from their suits out of the vessel in which they have travelled within onto the surface of wherever they happen to be landing. Just something that has always had me curious really.
I believe that there's life out there too. I've seen a number of things in the sky that'll take some explaining. I think that too many people have seen UFO's now for it to not be true.
UFO's I really don't know about myself. But small matter I can believe in. Maybe if there is micro bacteria or something than it will give us proof that life can really exist out there somewhere....
consider the fact that we could be not much more than that 'micro bacteria' to some other, much more highly-developed life form! if we are so much more than that, then something else could be that much more than us...
i often write about it, for that very reason... i think foolishly arrogant humankind deserves to learn it's only one of many much less-developed life forms in the universe...
