Friday, September 16, 2011

Imaginary Numbers

If there's one thing more constructive and informational than a good Dinner Table Conversation it's a very long drive. When you live out west, or in the country, you learn this very quickly, because every drive is a Very Long Drive. Tonight was no exception.

It was an hour drive into the city for my Dad's speech club meeting. He took me out to dinner, and then we went to Barnes and Noble, and there I planted myself in the Science section and found some complicated books on theoretical science. I'm a science fiction writer; I don't care how sound the science is, just that it's cool. I didn't really have enough time to sort out what any of the writers were talking about before it was time for the drive back home, so I asked my dad the fatal question: 

"Do you know anything about string theory?"
"It's completely bogus."
"Well, besides that..."

Because, you see, all I knew was that it involved 10 or 11 dimensions. This confused me, because I understood three spacial dimensions, and the fourth time dimension, and I could almost figure out how you could have a fifth dimension... but ten? Where were they? What did they do? Why do you need that many? The best I could figure they were alternate dimensions, but then why have only ten? Why not more?

"No, they're completely different."

Back to go forward, says DarkTrench, so backwards we went. Back to Einstein and the relativity. We talked about the double split experiment and quantum physics. Then we went back further and talked about Newton and calculus. And finally we got around to the point...

"What is the square root of negative x?"

Um... good question.

Actually... very good question.

Actually... what is the square root of negative x??

Well, says my dad, it's i. (Or j, actually, depending on if you're a mathematician or an electrical engineer. Because if you an EE than i stands current, hence the need for j. Did you know that before now?) It's an imaginary number. It doesn't exist. You can do math with it, but it isn't really there. You just imagined it.

It's like having two mechanical pieces that need to be fit together inside a tiny box. There's not enough room to do it, so you take them out of the box, fit them together and put them back in. Only there's nothing outside the box.

Well, this is good. This makes sense. This is a working, practical solution to an obnoxious problem. People use this every day. They build things and go their way not realizing what a dangerous tool they have put into the hands of theoretical scientists...

Imaginary Dimensions. It's a bit like hyperspace, a mythical wonderful world where the laws of physics don't apply. M-Theory (or string theory as it's also known) is the theory of inventing dimensions to solve insoluble problems outside of the known universe. Such as traveling faster than light. And the ten dimensions it uses to explain these things don't actually exist, anymore than the words that flow from a writer's pen.

Amazing how simple it all is once you get space and time out of your head.