Galileo and Einstein vs. Aristotle
Most recent answer: 08/14/2016
- MW (age oldenough)
It's unfortunate that the site you listed, which does a nice job of describing some deep ideas, exaggerated the practical implications. The rate at which things fall through the atmosphere does indeed depend on weight, area, shape, etc. for objects much larger than ping-pong balls, unlike what they say.
Nevertheless, your version, claiming that Aristotle was right that the rate of fall depends just on weight, is wrong in a much deeper sense. It's empirically wrong, since for the same weight different shapes give different rates of fall through the atmosphere, and for different weights the rates of fall are the same if there's no atmosphere. A heavy thing might fall slower if it's more spread out, otherwise putting on a parachute would make you fall faster.. As Galileo pointed out, it doesn't even make sense. If you tie two bowling balls together with a string, does that make them one ball twice as big? Do they follow Aristotle's law and fall twice as fast? In other words, Aristotle's predictions depend on name-calling, i.e. your choice of what to call an "object". Nature doesn't care what names we call it. We need laws, like Einstein's, that make consistent predictions regardless of naming choices.
Mike W.
(published on 08/14/2016)