anon14946: We will never see more than this planet because we will destroy ourselves way before we ever get far enough into space to even matter.
Me: No, we'll never get there because we won't be human by the time we -could- get there, according to current understanding of science. Nothing travels faster than light. Unless we can find a way to move the way the Universe does (which is faster but isn't involving the actual movement of matter so it may not be possible) it would take us 80,000 years to reach just the far side of our galaxy (our galaxy is 100,000 light years across, but we're only 30,000 cy from the center of our galaxy so its closer). It'd take millions of years to get elsewhere. Whatever we are, we won't be what we are now by then. Also, if you're referring to all the things that we're doing that threaten to wipe us out (nuclear weapons, global warming, etc), actually we'll likely survive it... well, 1% of us anyway.
anon14721: big bang would lead you to expect expansion in all directions Simultaneously, all particles expanding outwardly spherically. So how can the universe be flat?
Me: The 'Bang' is an easily misunderstood idea. It's not an explosion in the conventional sense (which would leave us with an ever-expanding sphere of matter around a core of nothing). Instead it refers to when matter started spreading out, fast. As for the 'flatness', what that means is that, for the most part, if you travel in a straight line you'll just keep -going- in a straight line without that line being altered. It's not describing every part of the universe, mostly just the huge empty gaps between stars/galaxies where there isn't anything to pull on you.
anon8411: I have been always thinking about the survival of light created by big bang to travel 14 billion years without losing its momentum and force?
Me: Momentum and force are aspects that only get altered by other things. In empty space if you throw a ball it'll go in a straight line and never slow or lose force because there's nothing to slow it down. On earth if you do the same thing there's all this inconvenient air in the way and then gravity pulls it to the ground where there's friction and other objects to get in the way. Light traveling 14 billion cy to get here never had to put up with that.
glava2005: if the universe was created 14 billion years ago the farthest any matter could travel is 14 billion light years in each direction which adds to 28 billion light years across...? so how did we get to 156 billion?
Me: The problem here is one of expansion versus travel. Matter/Energy cannot move faster than the speed of light. However the reason the universe is expanding has nothing to do with moving matter. Space is stretching (for lack of a better word). It's actually, as I understand it, largely like the Warp Drive of Star Trek and similar. The idea there is that you make a bubble of space and sit your ship inside. Then you move the section of space. Since space isn't matter or energy there's no limit to how fast such a pocket could move. Here, the space between bits of matter (like galaxies) is expanding, getting wide, and there's no limit on how fast it can do that. The interesting thing, though, is that it seems to be stretching like a rubber sheet. That is, the further away from us something is, the faster away from us it's traveling. So to get 156 light years, start 14 billion light years away and send a beam of light. Have it travel for 100 years, and it'll have moved 100 cy closer to us, but the space behind it, and therefore the space between the light and the object that created it, has expanded in the mean time and is therefore more than 100 cy. Do this for 14 billion years, add up all the expansion as we think it's happening, and you get 156 billion light years.
anon11306: If the big bang theory, and it's just a theory i might add
Me: This is ignorance of science and the word theory. The problem is that people use it the wrong way (so no fault to the poster, it's the language that is to blame). A 'theory' is not just some idea that someone came up with. It's something that people thought about, did tests to confirm, and has survived the attempts of every other scientist in the field to shoot it down. Just think about it: Einstein is world famous because he came up with his theories that describe gravity. But someone already did that. Sir Isaac Newton. Einstein's equations work better, they are more accurate (although not completely, which is why Science is currently getting into Dark Matter and Dark Energy, both of which are really weird stuff). When most people say 'I have a theory' what they mean is 'I have a hypothesis'. A guess. An idea. It takes years and years of study, debate, modification, and so on to turn a hypothesis into a Theory. Does this mean the Big Bang Theory is right? No. All it means is that, so far, no one, with thousands of people who could make their career and be famous in the scientific community for centuries, has yet been able to come up with observations or tests that show the Big Bang Theory is wrong. These next bits deal with God. My apologies to those I will insult by disagreeing with and by being an atheist.
anon8682: Why do some people refuse to believe the universe was created? Since we live in the universe we cannot even begin to explain what if anything was here prior to the start. The only logical answer is God.
Me: Well, some people refuse to believe that GOD created the universe, not that the universe was created. Current scientific thinking says the Big Bang created the universe, and that this Big Bang wasn't an intelligent being but just a consequence of the laws of its own existence. However I find your last statement to be truly insulting. Since we can't figure out what came before, and likely never will be able to, the only logical answer is God? How about this: We can never figure out what came before, so the only logical answer is that we were created by a kid in science class from a universe of which we are a sub-set? Or we were created by the Easter Bunny? There's no 'logic' there, you're just saying that your answer has to be right because science doesn't have an answer for you. Unless you are saying God is 'all those things which we as a species do not understand'. In which case God ceases to be an entity with intelligence, motives, plans, and whims and is relegated to the status of 'stuff we don't know'. A mystery to be solved and nothing more. Appeals to God of any sort are not logical. They are belief based and nothing more. I accept that God _could_ exist, but I have found no reason to suggest that he/she/it _must_ exist. And, as someone else pointed out, using 'God' as the initial cause of everything does you no good. Before the universe existed, there was God. Well... what came before God? Who created God? And if you believe God always existed, why not believe that the initial compressed dot that was the universe always existed?
anon5172: If the so called "edge" of what we conclude to be the beginning of "time" or the start of the so-called "big-bang" is only as far back as we can see due to light being way tooooo dim to see in the first place then how can anyone make an assumption as to the age in the first place? God created the heavens and the universe.
Me: The 'edge' is the 'causal edge', that is the furthest point away from us that anything could possibly be and still have some sort of effect upon the earth (such as a light in the sky). The problem with objects that far away isn't that the light is too dim. We can see them just fine (all right, we can see whole galaxies at that distance, and they show up as dots of light like stars but still). The problem is there hasn't been enough time for the light of anything further away to have reached us yet. Since no matter or energy from further than that can reach us, it doesn't much matter if it's there. It'll never affect us.