We went hiking on Saturday (I'm sure Shannon will provide the details you're interested in) but my favorite part of the hike was the water skeeters. You've probably all seen them scoot across the surface of the water, and you've possibly also heard the physics lecture about surface tension, but that isn't the neat part. The tiny weight of the bug doesn't break the surface of the water, but it does depress it, making tiny little depressions in the surface of the otherwise smooth water. But now there is a curved air/water interface, and it acts like a lens! The light from the sun is bent away by the curved water surface and as a result, each leg casts a
huge shadow on the bottom of the pool.
In the picture, you can see the eight shadows from the eight legs. The long small legs are the ones it uses to paddle around. Most of it's weight is on the legs that bend the water the most, which cast the largest shadow.
But where does the light go then? Well, a tiny amount of it hits the water at just the right angle to be reflected back, which you can see in the picture. But most of the light is sent to the edge of the dark shadow which is noticeably brighter in the picture. Hooray physics!
In the picture, you can see the eight shadows from the eight legs. The long small legs are the ones it uses to paddle around. Most of it's weight is on the legs that bend the water the most, which cast the largest shadow.
6 comments:
Nice capture of lights and shadows and all that jazz.
I don't think these bugs are very cute, but their shadows, that is a different story. Kind of like how fantasy is much better looking than reality.
You can take the nerd out of the physics class . . . but you can't teach him biology.
Bugs have only 6 legs; the other depressions seem to be from his antennae.
Can I claim that I ment "legs" in the generic sense of "any appendage which bears weight"? It would be just like biologists to discover a bug that walks on it's antennae but insist that they aren't legs because they attach to the body wrong or something like that.
"Just like biologists" ?! Legs are legs, antennae are antennae. I know of a critter that uses its front legs like a blind person's white cane, to feel their way around because they don't have antennae, but they are still legs. Bearing no weight at all.
Hmmmph. Physicists. You guys can't even agree on what a planet is.
Hey now, those are astronomers. And I don't know any physicsts that really want to claim them. It's just a hold over from the times of Newton and Galileo.
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