Sunday, November 06, 2005

Weird Science: Michelson-Morley


Now you may think that Albert Michelson and Edward Morley were the inspirations for M&M chocolates - but that would be wrong (M and M chocolates were named after their inventors, Forrest Mars and Bruce Murrie) Anyhow, Michelson and Morley weren’t as much interested in chocolate as they were in light’s behavior - and began to experiment on it.

Their experiment with light did lead to one of the greatest inspirations of all time though (Space- time actually). By this I mean the general theory of relativity as concocted by Albert Einstein. But I’m leaping ahead at light speed, so I need to slow down and explain a little first.

Let’s go back in time now about one hundred and twenty years. People of that time had no microwave ovens, MP3 players or Tim Horton coffee outlets. This did not make them idiots, in fact it gave them opportunities to futz around with ideas and experiment on the unknown without the interference of refined chocolate or Reality TV. But of course people futzing around with the unknown hasn’t ever changed, so is irrelevant here.

What I am meaning to say is back then the general belief was that electromagnetic waves (light included) traveled through space, but they thought space was not a nearly empty vacuum. They believed it was filled with ether. Ether being a medium of material which could transmit electromagnetic waves. Okay, maybe some back then were idiots - but that too is irrelevant and continues even today.

Basically Michelson and Morley designed an experiment using an interferometer (a device which measures the frequency of electromagnetic waves) to detect the speed difference of light as the earth moved through the ether. The first one of many they performed was in 1881. The idea was if the earth was cruising the ether at many miles a second there would be a distinct difference in the speed of light in the direction of earth’s travel through the ether and at right angles to it. Sounds logical, right?

Wrong! The speed of light remained constant proving, or rather disproving the existence of ether. This experiment cast major light (yes a pun, I’m reading Piers Anthony right now and can’t help it) on the properties of the speed of light and lead many physicists down a much clearer path.

So the ether hypotheses was dead wrong. And what a wrong it was. This time only one wrong made a right, and put Einstein on to the idea of general relativity leading to the most famous equation E=Mc(squared) ever - so far anyhow.
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