"I had no need of that hypothesis"

The above is what Pierre-Simon Laplace said to Napoleon when asked why his book on astronomy, unlike Newton's contained no mention of god. Newton had seen that his calculations were not entirely accurate, and had decided that what kept the planets from careening out of place was the hand of god. Laplace made some corrections, and was able to explain celestial motion without resorting to the supernatural.

I think that quote-- "I had no need of that hypothesis"-- is an important one. The more we learn about the universe, the less we need the supernatural to explain anything. There was a time when we did not understand much, and at that time, gods arose. What caused the lightning, or the rain, or the lack of it? An angry god, punishing the wicked. Likewise, favorable weather was caused by a happy god. Appease god, and things will go well. We know now about pressure systems and how weather works; we no longer have need of that hypothesis. Before Darwin, we had no idea how life came to be, in its many and varied forms. It was reasonable, then, that people believed god had made all the plants and animals, shaped them as an artist might. But Darwin saw a more reasonable way it could have happened; following the natural laws of the universe, life could have evolved to the state in which we now know it. And again, we now had a natural explanation, and have no more need of the god hypothesis. It is no longer reasonable to think that god did it, any more than it is reasonable to believe god causes the weather. We know how life came to be in its present form; we have no need of god.

As science advances, the need for god retreats. What once was seen as the vagaries of an all-powerful deity is now known to be simple cause and effect. It was, I think, simple cause and effect that led me to reject the idea of god. When you pray for something, and it happens, where, exactly, did god step in to give it to you? Say you prayed for a parking spot-- I know plenty of people that pray for that very thing, and other inanities. When you get to the store, there is a spot right up close-- your prayer was answered! But where did god come in? You left the house at such a time that when you arrived, someone else had just left. They left because they had an appointment to get to. That appointment had been set a week before, long before you prayed for that parking spot. Every effect has a cause, traceable by the laws of nature. Where is the need for god?

Some might say that god 'inspired' them to leave the house at the precise time they needed in order to get that parking spot, or 'inspired' the other person to leave at that time, but that falls apart too, if you think about it. Everything you did that day, including your thoughts, had a physical cause. We do not yet fully understand how the brain works, but we do know that thoughts are physical, chemical reactions in the brain. There is no need for a divine finger in your grey matter; you had that thought as a result of what came before.

So there is no need for a god in our day-to-day lives-- and, in fact, god cannot exist there. Everything follows physical laws. A miracle, were one to occur, would break those laws... but there is no evidence of anything breaking them, ever. There are no miracles that have been verified by science as having happened.

What about creation? Well, Darwin put paid to god creating life as it now exists. Abiogenesis-- that is, what sparked life in the first place-- is another matter... but given everything that we now know, it seems silly to simply say "god did it" when we could instead work on the problem and try to find out. And scientists are doing just that. There is no reason to believe that this one thing required a divine touch, when everything else can be explained by science.

And I do mean everything. We know how the planet formed, how stars and galaxies form. We've even got a pretty good handle on the Big Bang. We don't know exactly what sparked it... but there is reason to believe that we do not need a god, even there. I have just enough of a handle on the physics to put it very simply; I don't know it in great detail, but it is an explanation I got from Stephen Hawking, and I know just enough to find it reasonable. The universe, at the moment of the Big Bang, was infinitely small-- small enough, in fact, that it falls into the realm of quantum mechanics. In quantum mechanics, particles do not have a linear sort of existence; they pop in and out of existence, for lack of a better term, all the time. It is therefore not inconceivable that the universe itself, at the time a quantum particle, could have simply popped into existence. No need for that hypothesis, indeed!

But it goes further than that; with what we know of the Big Bang, and of the universe, it seems there is no place for god, period. To begin with, you have to understand that time, like space, is a physical dimension. We exist in a universe of (at least) four dimensions, three spatial, one temporal. This is known as space-time. Space time, it has been proven, can be warped; the most stunning example is that of a black hole. If you were to fall into a black hole, and could somehow survive to observe what was happening around you, time would slow for you, and eventually come infinitely close to a stand-still; you could look out at the universe and see eons flying by. So, time is a physical dimension, contained within the universe, just like space. When the infant universe popped into existence, it contained time, as well as space. Therefore, before the Big Bang, there was no time. Asking what happened before the Big Bang is like asking what is north of the North pole; it is a meaningless question.

Without time, without a before in which to exist, there could not have been a god before the universe that could have created it.

Some people will say that god is eternal, existing outside of time and space; such a god seems pointless to me. In order to influence the universe, whether by creating it, or life, or by intervening in people's day to day lives, god must be part of the universe. If god is part of the universe, then he is bound by the laws of nature (having been created by the Big Bang himself), and cannot violate them, and he cannot have existed before the Big Bang to do any sort of cosmic on-switching. If god is outside the universe, he cannot influence it.

There is just barely room, if you wish to see it this way, for the deist god. It is possible that, in whatever existed before the universe, whatever currently exists outside the universe, there was a being who could have caused the particle-universe to pop into existence. Such a being is not known to have ever influenced anything inside the universe, and so in my mind, speculating about its existence is meaningless. We can only know the universe, at least so far in our understanding. Who knows? Maybe someday we'll reach outside that boundary, beyond what we now know as existence, and find something else there. Since we cannot assume that what lies outside the universe obeys the same natural laws, I suppose things found there could be called "supernatural." Somehow, I think that kind of supernatural would not be very satisfying to many theists.