Friday, September 3, 2010

Shadow


Yesterday I was waiting for the bus in Golden and it was 9:30PM. It was dark and cars were passing every minute or so. The bus was supposed to get there by 9:19, so I was starting to get impatient and started pacing. I'm not much of a pacer, but that was the best thing I could think of doing at the moment. I noticed the shadow of the bus stop sign moving whenever a car would pass. The headlights were shining on the sign and the shadow would move along the bench. In my pacing I started walking along the shadow and wondered, if I know the speed of the shadow, can I calculated how fast the car is moving? Nope. Can't do it.

I was so disappointed, but i realized why I couldn't do the calculation. The shadow is just a projection from a moving light source, past the sign, onto the bench. The shadow doesn't contain every piece of information that the light source and object contains. There's always a loss of information for a projection. Like if you saw two shadows of people with identical head shapes, but different noses, you'd never be able to figure out who had the bigger nose. It's sad, I know. And even if you had an infinite number of shadows, you'd know who had the bigger nose, but wouldn't know if either person had eyeballs, unless they had particularly bulgy eye balls. So projections are cool, but they always have a loss of information.

Thecool thing is that the more projections you have, the more information you have. That's why 2 eyes are better than one. Two different perspectives or projections allow you to have depth perception. And if we had 2 more eyeballs on our hands, then we'd have even better depth perception. We only have depth perception for things that are moderately close, because when you're looking at Russia from Palin's backyard, the picture in one eyeball is about the same as the picture in the other eyeball. The eyeball separation is so close compared to the long distance that it doesn't really make a difference. It's basically two copies of the same picture.

In calculus, a derivative is a loss of information (like a projection) and an integral is an increase of information (like an antiprojection (whatever that is)). So it goes to show that an integral is way cooler than a derivative for this reason:
  • A derivative is an old fashioned overhead projector that your high school literature teacher used to tell you that The Great Gatsby is the best book ever.
  • An integral is the hologram that your high school physics teacher used to set-in-stone that physics is so much cooler than any other subject.
'nough said.

So now you know that I like physics and math, but don't really like The Great Gatsby...One of the things that I passionately dislike. Sorry for the extremely nerdy post.

1 comment:

  1. I like the picture Banks. The Blog was insightful.

    ReplyDelete