Skip to main content

Fun fact from the author of Physics for poets

He points out that an egg made of gold will fall down in water noticeably faster than one made of aluminum (okay, I'm adjusting things here). Why? not because they have noticeably different rates of acceleration (they don't, as Galileo pointed out). Rather because they have different terminal velocities. Tim: is that true? If so, we can try to rid the Aristotelians of the embarrassment caused by Galileo by claiming that Aristotle, in saying that a denser things falls faster, had terminal velocity in mind. Not entirely a joke, as he had in mind the relation between the push exerted by an object and the resistance of its environment. So maybe if there had been a tower as high as the Burj Dubai, the results might have been different.

Oh, but the truth is that Aristotle was unaware of terminal velocity. He noted in three places (Twice in the Physics and once in On the Heavens) that things accelerated as they got closer to the earth, giving the impression that they would continue doing so indefinitely.

Comments

Unknown said…
It's true.
4:56 PM
Leo White said…
This comment has been removed by the author.
11:23 PM
Leo White said…
Lemmee try that again...
But isn't there a point at which the resistance posed by the air equals the downward force of gravity, so that accelration stops? For example, I think that at a certain point skydivers stop accelerating when their velocity has reached somewhere around 160 to 200 mph.
11:25 PM
Post a Comment

Popular posts from this blog

Dembski's "specified compexity" semiotics and teleology (both ad intra and ad extra)

Integral to Dembski's idea of specified complexity (SC) is the notion that something extrinsic to evolution is the source of the specification in how it develops. He compares SC to the message sent by space aliens in the movie "Contact." In that movie, earthbound scientists determine that radio waves originating in from somewhere in our galaxy are actually a signal being sent by space aliens. The scientists determine that these waves are a signal is the fact that they indicate prime numbers in a way that a random occurrence would not. What is interesting to me is the fact that Dembski relies upon an analogy with a sign rather than a machine. Like a machine, signs are produced by an intelligent being for the sake of something beyond themselves. Machines, if you will, have a meaning. Signs, if you will, produce knowledge. But the meaning/knowledge is in both cases something other than the machine/sign itself. Both signs and machines are purposeful or teleological
Post a Comment
Read more

continuing the discussion with Tim in a new post

Hi Tim, I am posting my reply here, because the great blogmeister won't let me put it all in a comment. Me thinks I get your point: is it that we can name and chimps can't, so therefore we are of greater value than chimps? Naming is something above and beyond what a chimp can do, right? In other words, you are illustrating the point I am making (if I catch your drift). My argument is only a sketch, but I think adding the ability to name names, as it were, is still not enough to make the argument seem cogent. For one can still ask why we prefer being able to name over other skills had by animals but not by humans. The objector would demand a more convincing reason. The answer I have in mind is, to put it briefly, that there is something infinite about human beings in comparison with the subhuman. That "something" has to do with our ability to think of the meaning of the cosmos. Whereas one might say"He's got the whole world in His han
2 comments
Read more

particular/universal event/rule

While listening to a recorded lecture on Quine's Two Dogmas of Empiricism, it occurred to me that every rule is in a way, a fact about the world. Think about baseball: from the p.o.v. of an individual player, a baseball rule is not a thing but a guide for acting and interpreting the actions of others.  But this rule, like the action it guides, is part of a concrete individual --i.e., part of an institution that has come into existence at a particular place and time, has endured and  may eventually go out of existence.  The baseball rule, as a feature of that individual, is likewise individual.  The term "baseball rule," on the one hand, links us to a unique cultural event; it can, on the other hand, name a certain type of being.  In this way, it transgresses the boundary between proper and common noun. If there were no such overlap, then we might be tempted to divide our ontology between a bunch of facts "out there" and a bunch of common nouns "in here.&qu
Post a Comment
Read more