The world is an ovoid - round for anyone of a less geometrical bent - there was a time when this statement challenged the intellects of most regular folks. This is no longer the case, but why?

The stars are not lights affixed to the Celestial Orb.
The Sun does not revolve around the Earth.
Masturbation will not make your fingers pregnant in the afterlife - I just couldn't resist that one.-
You get where I'm going with this right?

Why don't we believe these once unshakable truths anymore? The reason is evidence! We have seen our planet from space; it is most definitely round, and there it goes spinning like a top, tilted over at a twenty three degree angle, doing laps around our star at a rather alarming speed when I stop to think about it. The reason is most definitely not because I said so. Evidence is a wonderful thing, our scientists eat it up; breakfast lunch, dinner and late night snacks.

That Which Is Seen

The word evidence is derived from the Latin evident meaning: obvious, which stems from the Latin ob vium meaning: in the way. So literally, we are talking about something obvious and in the way. Evidence can be seen. If you stand far enough away, you can watch the Earth orbit the Sun. Any telescope and a little bit of patience shatters the illusion that the Stars are lights fixed in place. I'm not even going to bother with the pregnant fingers thing.

We often cite evidence as proof. Of course there are other kinds of proof. Any competent mathematician can prove the Hubble constant. Mathematical proofs however generally need to be demonstrated physically before they can move beyond the realm of the theoretical. Physics is like that too. You can get some really crazy stuff spilling out of those big brains. Take General Relativity for example, take it as far as you like, it still makes most people's eyes water. The faster you go, the heavier you get, and the shorter you get. As if to make up for that time slows down. This kind of silliness is enough to make anyone a little nervous, but it turns out to be true! Without taking into account the time dilation effects of acceleration, my GPS system would as often as not take me somewhere I didn't actually want to go; a good example of what we call evidence. We can actually measure the effect.

The Sun'll Come Out... Tomorrow

Now we turn to something else entirely; belief. Belief is not proof. It matters not a whit how many of us believe something, more believers does not make something more likely to be true. Belief is complete certainty in the complete absence of evidence. Most people don't really rely too much on belief in their everyday lives - believe it or not - despite protestations by some to the contrary, we don't plan our tomorrows based on the belief that the sun will rise. We base our expectation on an accumulated lifetime of evidence. Even on a completely overcast day the effects of sunlight on the Earth are easily measurable. Belief is a form of trust. We often base our belief on character, reputation and weirdly enough popularity. The popularity aspect is a fairly new development for our species.

For many of us, belief trumps all comers. Facts can't stand against it. They are simply brushed aside like ants at a picnic. Logic withers under the wild eyed gaze of believers. Reason twists and writhes in exquisite torment as cries of triumphant ignorance drown it's moderate tones. Beliefs seem to hold a special place in our minds. For some they give comfort, for some an excuse. For some they provide meaning, yet for those of us who cling to reason, they toll heavily, somber like a death knell. Will they lead us to paradise? Unlikely.

Andrew's Second Law

" For the believer, the strength of belief increases geometrically with the unlikeliness of the object of belief."

I will attempt to illustrate my point.

Let's go back to the whole Earth centric model of the universe. This belief at one time was widespread. If fact it seemed pretty obvious to our limited perspective. Down through the centuries, this belief periodically fell under attack by a few with the imagination to see beyond the obvious. Eventually a few people - Nicolai Copernicus, Galileo etc. proved them wrong, and gradually the belief faded. By the time the space programs came along there really wasn't any serious opposition. But the belief itself really wasn't that unlikely.

And Now, Behind Curtain Number Two!

I am here. I don't need to smack myself in the head to prove it. I don't have to believe it.

You also, are wherever you are. While this seems a tiny little bit of a fraction less certain to me. It remains incredibly likely. I can accept it. If however, you tell me your have a personal relationship with an all powerful being who is responsible for all of creation, and that he really wants me to give one tenth of everything I earn to your organization, the scales tip pretty hard in the opposite direction. If you tell me that this being wants me to fly a plane into a building, killing thousands of innocent people, you are going to have to introduce me to your friend personally, and I'm going to need to record the conversation on video. Unlikely barely begins to describe these statements.

For believers, the incredible unlikeliness of these ideas seems to present no difficulty. In fact it seems that the more unlikely the claim, the more steadfastly they cling to their belief. Many  intellectual christians seem willing to abandon many tenets of their faith in the face of overwhelming evidence to the contrary. The virgin birth? Well maybe it's a problem with translation. Loaves and fishes, well that's an allegory of course. The actual nourishment was spiritual. But don't screw with the resurrection. There were witnesses! It's right there in the book! I know because I have a personal relationship with the guy. We talk to each other all the time! If it isn't true, why do so many people believe it?

Science is working on why some of us us seem to need to believe in gods, while some of us can get by just fine without giving them a second thought. We are gaining a more complete understanding of how our big brains work. For believers, I don't think future discoveries in this area will have any impact on the certainty of their beliefs. It just doesn't seem to work that way. Is it a symptom of the unlikeliness factor. I just don't know for sure, but I believe it is.