> This semester, I took an astronomy class, which I absolutely love. However, I can't comprehend most of it because I can't get over how big the universe is. Not that this is anything new, or anything. But this fascinates, and more than a little scares me.

The universe is far too big for anyone to really comprehend. We can grasp its hugeness with examples, like "if this grapefruit were our galaxy then the next nearest one would be on Mars," but we can't really wrap our heads around the truly immense distances involved. We live on a planet on which you can't travel more than 16,000 miles. That is our upper limit, and it's quite a distance. In astronomical terms, of course, that's nothing.

> We've been learning about the other planets in our solar system, and they, too, fascinate me. Nobody has ever set foot on any of them, and because of that, we know so little about them.

Size again. You're talking entire planets there, most of which are bigger than little old Earth. And of Earth, we know so little. It's a famous statement that we know more about other planets than we do our own oceans. Whether or not that's correct, it's fairly right. We've only been able to explore deep space (and deep water) for such a limited time. It's really no wonder that we're so clueless about it all.

> Also, I find it fascinating the things that we DON'T know: why magnetic fields work, for instance. We know HOW they work, but we have no idea WHY they work. Oh, we can speculate all we'd like, but in the end, we still have no idea why the universe works the way it does. We just know that it does work.

There are a few of those such things present in the universe. Simple axioms of reality; things that hold true simply because they do. Slowly, we're eroding the unknown down by working out why certain things behave the way they do, but when it comes down to it there will always be questions to which science answer "it just does." There's the four forces, for example. Magnetic, gravitational, strong nuclear (holding atoms together) and weak nuclear (holding atoms to atoms). Some of them (I forget which) have been "unified", meaning that we now have fewer basic forces. At best, a grand unified theory could reduce this down to one. That still makes one mysterious force govern the interaction of all matter.

Something that surprised me when I first heard it is that we don't know what friction is. Or at least, we were told that we didn't know when we were told. Maybe we do now. But friction is such a basic idea, and it's something that we've been utilising scientifically for, well, ever. Yet we don't (or didn't) know why - it just happened, and happened in a predictable manner.

Quantum physics. Now there's a great idea. Stuff that people sinply don't understand and can't explain. Actions and reactions that just seem to happen, without revealing why. Instantaneous data transfer - faster than the speed of light - is possible, if you know what you're doing. And we're designing computers that use quantum phenomena in order to work quickly. Computers that we couldn't understand.

> The universe is huge.

That is such a deep statement, dude.

Matthew