Here's a response I just wrote to a discussion. Figured I'd turn my first nexus comment into my first blog too. Enjoy. Or not.
Folks, this is basically the first thread I've read since I just joined the nexus, so if I repeat others, my apologies. Also, I just woke up so I'm a little sleepy, but here it goes.
First, remember that the Big Bang is simply a theory, albeit fairly well supported. But there have always been a few things that nicked my brain about it. The biggest being that there was some little pea in space containing all the matter for our universe. Just sitting there...waiting. Sounds too much like the cosmic teapot to me.
The Big Bang is simply the best theory going, given the knowledge we currently have today. Remember, men of science once believed that leeching and mercury were cures for many, many things. We get things wrong. It's human, as they say. And sometimes, in our rush to "explain the unknown" (which is of course the trouble with all religions), we jump ahead of ourselves. But the other beautiful thing about humans is our curiosity. Many of us NEED to know. And need to know for sure.
So where to from here? My personal favorite theory which continues to gain momentum is that the universe is more of a big balloon. It is at times small, but can only get so small. Physicists know that Planck's Constant has a variety of uses in quantum mechanics, but one of the things to does is show that you can only compress matter so much. There is a stopping point. And guess what? That stopping point is much larger that the size of the "pea" that has to be in order to start the Bang. But WHAT IF there was no Big Bang, but only a Big Bounce? Where a previous universe compressed to a small point and then bounced back out. And like a balloon, when it reaches a certain point, it stops expanding.
Maybe a better example would be a rubber ball dropped from a building. If you watch the ball hit the ground in slow motion, it compresses, squeezes, until... boing! It bounces back to it's original shape. AND with enough energy to fling the ball back up to do it all again.
The great thing about this theory for atheists is that you can avoid the somewhat-moderate religious People who say, "Well, the Big Bang is when God created everything." Because, there was a whole universe BEFORE the Big Bang. The possibilities are truly exciting. A whole universe with different configurations of everything: stars, planets, life. We will of course never know what that could have been like. And if there was one previous universe, then there must have been two, three, even billions. Imagine! It's too much time and energy for my brain, that's for sure. (yes, double meaning. Not a happy accident)
Viable alternate theories to the Big Bang are gathering steam. Physicists admit that even though we've learned a lot, we're just getting started. I'm convinced that the more we learn about our universe, about matter, quantum mechanics, energy, and dark matter (however we find it, if at all), the more likely that a theory closer to the truth will push forward. And, who knows? Maybe that one will be supplanted by an even better one.
The answer to ALL questions about the universe should really be, "Given our current level of understanding, we have some guesses, but, really, we just can't know. Yet."