smokerblog

The Universe on a String

Last night I caught a bit of NOVA's program, The Elegant Universe, which is apparently based on a book of the same name. The show was devoted to explaining the theories of physics that describe how our universe works and what holds it together. It specifically dealt with the tension that exists between mechanical physics and particle physics.

On the one hand, we have the laws first described by Newton and further refined by Einstein in his General Relativity Theory. These do a really good job at explaining the behavior of a universe governed by gravity, i.e., the one we live in every day, not to mention the cosmos filled with planets, stars, galaxies, etc.

On the other hand, we have the world of quantum physics, where the scale is so tiny that gravity plays little or no role. Instead, the weak nuclear force, the strong nuclear force, and electro-magnetism govern events at this scale.

Unfortunately, these two scientific theories are incompatible. Laws which describe the motions of the planets or the speed at which a go-cart rolls down a hill are useless in describing what happens when the nucleus of an atom splits. Similarly, the laws of quantum physics can lead to all kinds of what would be bizarre conclusions if we were to translate them to the world most of us are able to observe.

This wouldn't be a problem except where the two worlds collide, so to speak. In black holes, for instance, where a massive star has collapsed down to an almost impossibly small size, we need both Netwonian/Einsteinian physics to deal with this massive object, and also quantum physics to describe what's happening in the infinitesimal space. The same problem exists when trying to describe the events prior to the big bang.

The (apparent) solution? String Theory. This theory speculates that at a sub-sub-atomic, sub-quanta level, particles are made up of strings or loops of energy that vibrate in a way that determines the nature of the particle for which they are assigned. It's hard to say why this controversial idea works, except to say that the math works out perfectly.

But did I say it's controversial? There is one big problem. We can't see the strings. There are few (if any) options for effectively demonstrating the existence of strings. They are just too small to see.

Not to mention, even though the math is nice and elegant, it describes the universe as existing in ten dimensions. Ten. T-E-N. That's six more than we humans are really comfortable with. (Some humans aren't comfortable with the fourth dimension, time, but we'll just set that aside for now.)

I'd heard this idea before, but it's the kind of thing that the mind (mine, anyway) just boggles at. Try it now, moving from one dimension to another:

1st dimension to 2nd dimension

a point to a line

2nd to 3rda line to a cube

3rd to 4th

a cube to (brain starting to hurt) a cube changing as time passes

4th to 5th

a changing cube to...the sound of my brain exploding

I occasionally can get a toehold on the concept, but only if I concentrate really hard while it's explained very patiently, as they did on last night's show with the example of on ant walking around a telephone cable... yeah, I'm not going to try to explain that here, but check it out for yourself, the entire three-hour show is available online.