Monday, September 29, 2003

Now I remember why I like science so much

I've been thinking about the speed of light, and relativity. There are many strange things that come out of relativity, once you make the assumption that the speed of light is constant. The whole thing falls apart if that assumption isn't correct... our understanding of nuclear energy, the size and age of the universe, hell even the way computers work, all of it is based on 'c' being a constant.

So what if 'c' isn't a constant? Recently astrophysicists have made some observations that could only be true if either the electron charge or the speed of light had changed, and both of these values are supposed to be inviolable constants. This has some interesting implications for physics... and personally I've been waiting for something like this to come around, since modern scientists have been pretty smug even though some of their theories (dark matter, for instance) are ridiculous. Shaking the foundation of the knowledge base may cause everything to settle into a new, hopefully more realistic, explanation of how the universe works.

The speed of light is so far beyond the human scale that it doesn't really make much of an impression on people... it's too big to wrap our minds around. A group of physicists investigating a new kind of matter called a 'Bose-Einstein condensate' found a way to change that a couple of years ago, when they slowed the speed of light to 38 miles per hour. It's long been known that materials with an index of refraction, like water or glass, 'bend' light by slowing it down... and there have been theories that exotic materials such as the Bose-Einstein condensate would have a more pronounced effect on light, but until recently it was impossible to build the equipment to try it (incredibly strong vacuum and a temperature within a few billionths of a degree of absolute zero are two of the necessary conditions, for example).

Some less esoteric properties of light are simpler to observe. For instance, the speed of light (in the form of electromagnetic waves) in ordinary matter (in the form of chocolate) can be measured with your microwave oven. And when you are done, you get to eat the experiment. See? Science rocks.