Big Bang

First off, we of coure do not consider Newtonian cosmology for even a second. General Relativity is the only contender we have for cosmology at the moment (with a couple of slight variations as unlikely possibilities).In GR we can have a finite static universe, such as the Einstein Static Universe (ESU). Such a universe is (hyper)spherical in cross-section, which removes any edge problems. This would not suffer from Olber's Paradox, and so the sky could still be dark (though you might want to think about light rays that circumnavigate the universe).A contracting universe is quite possible for a finite universe... it will have simply finished expanding from an initial singularity, and commenced its inwards collapse back to a singularity. The sky will not remain black as the collapse proceeds.But overall, what you are suggesting is generally correct. Given most reasonable conditions, the universe has a singularity in its past. What the singularity means is another question, and one for quantum gravity. With the singularity removed, the t=0 point could be smoothed off (like removing the knot in a balloon) or extended such that there is a (potentially infinte) t

Hi Phat, good to see you over in this neck of the woods Theories on the singularity are what we call quantum gravity. Gravity is the science of the universe as a whole. Quantum theory is the science of the exceptionally small. So what happens when the entire universe is exceptionally small? QG! It is also highly relevant for the singularities found in black holes.There are a number of approaches to QG, the two most prominent being String Theory and Loop Gravity... both are still very much in their infancy although they have given potential clues as to the real nature of the singularity.A typical GR singularity is a region of space-time that has divergent (infinite) curvature. Talking about fitting one into the palm of one's hand is only ever going to lead to confusion and erroneous thinking, so I'll leave that to the horrible popular science accounts! You can have a black hole the size of a tennis ball, but it would be wrong to say that the singularity inside is this small or this big. We usually imagine a singularity as being a point, but this is not always correct. I guess the initial Big Bang singularity of a finite universe is usefully thought of as a point... but that point is the entire universe at that moment, so the concept of holding it is so ill-defined it makes my head hurt That's the size of the observable universe. This is almost certainly the tiniest fraction of the total, but whether the total is infinte or not is an "open" question (ha ha, cosmologist joke).Yes, an infinite universe is very interesting philosophically, and I am surprised not to have seen questions on this in my short time here. Want to open a thread???

I know what you mean. But that is what I love about deep physics... it reveals more and more about the character of God. For example, there is a discussion on the site that has recently discussed whether God knows the future. Relativity reveals that time is far more subtle and complex than is generally understood, and to say that God does not know, or chooses not to know the future begs the question of "future from which vantage point in the universe?" Unless God's view on the universe is restricted to a single location with a specified acceleration, the concept of "future" is ill-defined. Thus I conclude that God must reside outside time, if He is to retain any divine-like characteristics...

Hi Bandie8, welcome to EvC The trouble with the stuff you've posted is that it all sounds so reasonable. You could spend most of your life without ever meeting a real scientist who specialises in cosmology and relativity, and get away with these "sound bite" attacks on the big bang. Most people would think you sound very clever and knowledgable, and might say "oh well, so much for the big bang".The trouble is, one day you might meet a real scientist who actually knows something about these subjects in great depth, and this scientist might be really mean and laugh long and hard at the stupidity of the things you are saying... he might gather his scientist friends round, and they would all be rolling on the ground, tears streaming down their faces...Well, today you have met two real cosmologists on this forum. I don't know about Son Goku, but I'm not mean (having known SG for a while, I don't think he's mean either) So I'll simply say that the person who taught you these things is doing you a huge disservice becasue he is making you say stupid, non-sensical things, that may sound reasonable and clever, but are in actual fact complete gobbledigook. I'm a Christian and I get the sense you probably are too. I really really don't like it when someone feeds a fellow Christian garbage like this. It makes me quite angry.Now you may not believe in the big bang, and that is fine. But please please please do not make yourself look stupid by quoting someone else's idiotic nonsense. Let them take the flak, not you. If you believe in a literal Genesis creation, just leave it at that.

Sorry Percy, meant to reply to this at the time. And here's probably not the place, but the thread's quiet at the moment so I may as well...I think there are some important points here. Firstly, I am concerned with giving illegitimate questions legitimate answers for fear of giving the original questions some level of credibility. You know where these "problems" were gleaned! That site delivers these problems with "authority" and no little contempt. This has obviously rubbed off on our poster here Simply replying with the basic science just provides a counter-argument, a different view, one that can be ignored, especially as we are dealing with science far beyond the level of most readers including our poster. Before we can discuss the science rationally, my personal view has become that some of that initial contempt and false-authority must be erroded. This has come from many years of dealing with hyper-intelligent but seriously mis-informed school students and Cambridge undergrads. BTW, the worst offender I have had the misfortune of knowing goes by the alias cavediver...Your thoughts?

Thanks! I've moved this over there now Message 2