Any Aristotle Fans out There?

[fnord_too]

Showing that the speed of light is constant does not really impact Newton's concept of gravity in any obvious way, and I do not know if they showed that the speed of light is constant relative to a non accelerating frame of reference (in a vaccum nothing can accelerate to C, (though technically some things can be traveling faster than C at all times, theoretically), but outside of a vacuum objects can travel faster than the speed of light in that medium.)

The acceleration limit thing is pretty subtle, and as far as I know really only has an impact on special relativity, not general relativity. I don't know a lot about general relativity, so I cannot say, but it is the theory of general relativity that explains the differences between Newtonian predictions and observation of gravitational activity on a large scale, if memory serves.

I would argue, also, that thought experiments most certainly will not suffice. Aristotle had those, and used logic based on false assumptions, but never tested the predictions. It is very easy to say these things today, but for over a thousand years Aristotle's thoughts were considered absolutely correct in Europe. The smartest people of the times bought them, (though in fairness, not buying them meant going against the most powerful entity in that sphere).

As to the body of motion thing, I still don't see your point. Everything from his observation came to a rest unless something forced it to move, and moving things took continued energy. Maybe he could have looked up at the clouds and though "now just what the hell is moving those things? that is counter to my theory" or maybe he could have looked to the heavens and though "what moves all those stars around us?" Again, I am not trying to argue that he was incredibly smart or not, just that if his theories were consistent with the way he viewed and observed the world, then you cannot realy take the fact that he was wrong as evidence that he was not amongst the smartest.

Personally, I cannot forgive the whole falling faster thing, to me that is just lazy, but logic and math were more his thing. I think a lot of the Greek philosophers were crippled by an inate belief that there was a simple order to the world. Simple in that there was an order that man could by pure thought arrive at and understand. The proof that irrational numbers existed was a huge blow to this concept. Who knows how many people the knowledge of transcental numbers (i.e. non algebraic numbers, like e and pi) would have gotten murdered. (The proof that the square root of two was irrational, though accepted as quite correct, got the prover drowned for destroying the concept that all numbers were rational if the stories are true.)

I am sorry I misinterpretted your conceptual error bit. I read your statement to mean that if someone thought something out and published it that any material error was unacceptable.

At any rate, I'm tired of arguing the counter point here because I agree with your statement. I certainly would not call Aristotle a moron, I think as a mathematician he added a lot of value, but sadly his work on physics really held Europe back. (I think there was some surgeon in the middle ages who was quoted as saying something along the lines of "It is amazing all the things that stem from the brain. I would believe that it was the center of sensation if Aristotle did not tell us differently." UGH!)

[drudman]

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Its an unreasonable belief, for someone who is supposed to be real smart. I guarantee that neither Einstein nor Newton would have thought that if they lived back then.

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This is the most ridiculous thing I've ever heard.

Newton was an imbecile by the way for not knowing that time was not absolute.

And everyone knows Einstein was a dunce for not knowing about quantum uncertainty.

I guarantee that Joe Physics Graduate would have known better if he lived back then.

[FoxwoodsFiend]

You really like the Nichomachean Ethics? I just don't particularly like a vague virtue ethics that says the good man is the type of person that has good qualities and does good things without giving us any criteria by which to judge why it is that those qualities and deeds are good in the first place. By what lights are we supposed to judge the "virtues"?
Caveat: I only read Aristotle for an intro-level survey course so I'm willing to listen but my teacher's assistant didn't really have any answers to this question

[BZ_Zorro]

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And everyone knows Einstein was a dunce for not knowing about quantum uncertainty.

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Even being facetious you touch on a good point. It wasn't that Einstein should have guessed QM before his time, he knew about it, saw the clear evidence, and rejected it for many years. He publicy spoke against it even when his contemporaries could clearly see it was true. Work of a genius?

[West]

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By the way, I agree that if he thought heavier objects fell faster than light ones, aside from air friction, that really did make him a moron, even if he was too lazy to do an experiment. Thought experiments would suffice. Imagine two metal balls falling side by side. As they are falling attach them with a string. That will make them fall faster? Alternatively imagine a hollow metal ball and an equally weighted smaller solid ball falling at the same speed. Now put the smaller ball inside the bigger one. Again it is obvious the falling speed doesn't change though the new object is twice as heavy.

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I don't really see how your thought experiments would have allowed Aristotle to draw any conclusions without doing an actual test. Presumably whatever string you are thinking of isn't going to add a lot of mass relative to a metal ball, so why couldn't he think it possible that it might fall "slightly faster"?

Regarding putting a smaller metal ball inside a hollow ball that has an equal weight, it seems to me that this isn't going to allow him to conclude anything, because unless the smaller ball is connected to the hollow ball, it's not really one object. And if they are connected, why couldn't he think that the now heavier object would fall faster, without having done any experiments to the contrary?

I'm just taking issue with your suggesting that he could have drawn conclusions had he merely been able to envision your thought experiments, nothing more.

[fnord_too]

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I don't really see how your thought experiments would have allowed Aristotle to draw any conclusions without doing an actual test. Presumably whatever string you are thinking of isn't going to add a lot of mass relative to a metal ball, so why couldn't he think it possible that it might fall "slightly faster"?



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I think what he meant was, you have say two 10 pound balls, drop them, they fall at the same rate. Now tie a string between them, so you have a 20 pound mass, does it now drop faster? This assumes that Aristotle wasn't thinking of rigid bodies when he made the statement. But...

The whole point of the scientific method is that the way things work is often non intuitive or counter intuitive, so thought experiments are basically treating physics like math. You assume some things, and derive.

It's easy for us today to poke wholes in what Aristotle said, but that is not the same thing as poking holes in his reasoning. Certainly, the example DS points out would probably have made Aristotle think, but I would guess that when Aristotle thought about the problem he was thinking of solid bodies, and the answer was so "obvious" that he never considered unusual circumstances that would cast doubt on the theory. I tend to agree that his reasoning on physics (and physiology) was pretty sloppy (from what little I have read), but as I alluded to before, I think most of that is due to the belief that the world can be understood and explained by pure thought, not even realizing that the fundamental tenets of what one "knows" as obviously true are based on observation. In math, this works. You start with axioms that are assumed true and show what that implies. There is no reality to conflict, unless you assert that the math models reality; there are only errors in pure logic.

[BZ_Zorro]

The string experiment is irrelevant. I think the idea was (obviously) that denser objects fell faster, not ones with more weight.

[fnord_too]

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The string experiment is irrelevant. I think the idea was (obviously) that denser objects fell faster, not ones with more weight.

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Maybe, I haven't read his works. I had always heard weight, but that does not mean that is what he wrote.

[carlo]

"Aside from air friction"--If air friction is considered do we have a different ball game? Why would Aristotle play physics without considering air friction? The abstracting thinking of this day(remove the air,etc.)appears to be somewhat removed from the reality its protagonists seek.

Aristotle can be rightly said to be the initiator of our western logical methodology. As the teacher of Alexander and his conquests they brought to the East the medicine and scientific arts which returned to the west via Islam is a modified state. Alexandria was the center of this learning which I believe was destroyed in conflict with the west. To the west--logic which culminated in the writings of Aquinas. The thought processes of our scientists today are a continuation of the Scholastic thought processes and especially Aquinas. To the east-a more ancient scientific and medical perception which was atavistically endowed.

Bye the bye--does Michelosen-Morley really prove anything about light or does it only display the interaction of light with a particular physical object? If a boxer punches his opponent in the arm and causes black and blueing does it follow that the boxers punch(arm) contains the black and blueing?

regards,
carlo

[Aisthesis]

Do you know where he said this? I'm assuming it's somewhere in his Physics (rough direction would be sufficient for me to look it up, not necessarily an exact spot, although it you have that, better still).

Anyhow, it surprizes me somewhat, as Aristotle was actually a very keen observer (and I do agree that creating theories grossly out of touch with realities is a major blunder). I'd really like to see the context.

For Aristotle, to my knowledge, the whole idea of inertia/impetus as well as friction are a bit of a problem. He did have a gravitational theory that isn't too bad (objects moving toward their "natural places" depending on whether they are heavy/light, etc.--all tying together with his theory of the four elements).

But I honestly don't know how he dealt with issues like the trajectory of a ball that you throw, as well as its speed.

I SUSPECT (please correct me here, too, if I'm wrong) that it wasn't Aristotle himself but rather some of his successors who was "refuted" with Galileo's famous leaning tower of Pisa experiment (essentially, drop a baseball and a marble, and they will both hit the ground at the same time).

Very interesting stuff... I'd like to check out what Aristotle actually said about it.