Friday, August 27, 2010

Light and Sound

I remember once when I was a teen in New Jersey watching a neighbor pounding a metal stake into the ground with hammer at dusk. The interesting part was that I was several houses away and that when the hammer hit, I would see the sparks, but the sound came a couple seconds after. This delay made an impression on me.

Last Sunday evening here in Duluth I re-experienced the same phenomenon during the Garfield Avenue time trials, that is, drag racing. My family and I were up on Skyline Drive, overlooking the bay. Down below on Garfield cars were revving it up and giving it a full go, with gusto. The noise up close must have been deafening, but from where we stood there was no sound at all when the cars leapt from the starting line. Three or four seconds would pass and then we'd hear the muted roar.

The speed of light is approximately 186,282 miles per second, the speed of sound approximately 1,125 feet per second or 768 mph.

Here's one way of comparing. A superloud ka-boom would take about 16 hours before it could be heard on the other side of the world, whereas light would be there (if it could bend) in a fraction of a second. In short, light and sound travel at different speeds.

What I was thinking is how there are things in life that are a little like the differential between light and sound. For example, we see something happen now but the impact of what we saw takes time to reach us.

The bombing of Pearl Harbor was something on this order. The surprise attack hit the news wires almost immediately. The drums of war quickly followed. The mobilization of America's young men and the impact of those war years took longer still.

The collapse of the housing market and the subsequent economic turmoil is another such example. I knew people who saw the light, but it wasn't till later that we heard the moans.

There's an interesting line in Bob Dylan's Lonesome Day Blues that twists this relationship between light and sound on its head. "Last night the wind was whispering, I was trying to make out what it was. I tell myself something's coming, but it never does." What if we think we see light and anticipate an explosion, but the explosion never comes? It's been said that 90% of what we worry about never happens.

I guess that's why history books aren't written in advance. That's really part of the adventure of living because we really don't know what's going to happen next.

Have a thoughtful day, and a very special weekend.

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