please stop debating and just GO PERFORM THE EXPERIMENT

aristotle would have been so annoying if he had the internet

editor’s note: it turns out that, once again, people are being too harsh on Aristotle, myself included. Thank you to reader

Vosmyorka

for bringing this paper defending Aristotle to my attention. The author points out that Aristotle’s theories accurately predict behavior at constant velocity, and are good for understanding the behavior of objects in fluids (like they are on Earth, for instance). This adds a beautiful nuance to the piece: even very good, defensible theories are often wrong, and we always need to invent tests to kill our darlings. Theories are not your friends. Theories are your enemies, and tests are your weapons to destroy them. Go out there, run some experiments, and kill some theories.

In 350 BCE Aristotle famously declared, “We see that bodies which have a greater impulse either of weight or of lightness…move faster over an equal space, and in the ratio which their magnitudes bear to each other.”¹ In other words: heavy objects fall faster than light objects.

Aristotle was wrong! And he wasn't a little bit wrong, he was WRONG WRONG. Like, if you just went outside and dropped two differently weighted stones from any cliff, you could immediately prove how wrong he was.

(edit: Aristotle is wrong, but only for accelerating objects. At terminal velocity in a fluid, heavier objects DO fall faster over an equal space, proportionally to (the square root) of their magnitudes.)²

Most people just believed Aristotle because he was a really smart guy, and so of course we just believe him. “Why would we go measure anything? That sounds hard!” But a funny thing happened… people kept coming up with data that didn't match any of Aristotle’s predictions, and then people kept adding more qualifications to Aristotle’s theory to try to make it work. For example, medieval scholars explained away failures by insisting that “in thicker fluids bodies really do fall faster”³ and for nearly two millennia the scholarly shrug was literally “Aristotle said it, so I believe it!”

(edit: see, “in thicker fluids, bodies really do fall faster” is actually a good point. Terminal velocity in a fluid really does increase with weight, even though acceleration does not. The problem here is with our terminology around “fall faster”. Do we mean during acceleration, or at terminal velocity?)

It wasn't until 1589, nearly 1939 years (!!!!!) later that Galileo actually performed the damn experiment and proved that Aristotle was just talking out of his ass.

(edit: it is crazy that it took 2000 years to show that different objects experienced the same acceleration due to gravity, but also Aristotle was probably not talking out of his ass. He did a pretty good job describing the physics of motion in fluids, though he could not imagine gravity.)

And that's how I feel when I see people on the internet discuss “theories”, and then propose solutions, as if you understand things now that you’ve discussed them!!

You are like Aristotle. You think you understand because you can come up with a theory, but HUMANS CAN'T SEE THE TRUTH THROUGH THEORY ALONE. Our senses are great, but they’re also ridiculously easy to trick. Look at these two tables.

Shepard tabletops

I theorize that the left tabletop is a different shape (longer, thinner) than the right tabletop (wider, more square). The problem is, I am wrong. The two tabletops are exactly the same size. No one would theorize they are the same size, but they are.

Unfortunately, there is no obvious way for me to know right away that they are exactly the same size. I need to invent a test, and for that I need to get creative. This idea that we can invent our own tests is called “Science”. You can probably invent some way to test the size of the tables fairly easily (maybe try a tool like photoshop, or a ruler).

But the point is this: until we test our theories, we simply can’t know.⁴

Theory-cels on the internet bother me, because they are disinterested in the truth. What they want is the power to determine right and wrong, without putting in any of the work to figure out HOW to determine right from wrong.

Because who needs measurement? Who needs experimentation, when we can just assume we are right via THEORY. The attitude is simply: "I'm smart, I'm rarely wrong, and people agree with me, so I must be right -- besides, it's obvious that a bowling ball will fall faster than a pebble, isn't it?" (and just because it really is obvious, I must reiterate that a bowling ball DOES NOT fall faster than a pebble in real life. They fall at the same speed. They will hit the ground at the same time when dropped from the same height, as long as neither reaches terminal velocity. The bowling ball will actually fall a bit slower due to air resistance. You can see for yourself.)

I worry there is nothing more dangerous than an idiot with a theory, who is too dumb to figure out a good test, which might prove it wrong. Such an idiot would happily drive humanity off a cliff with their theories, while convincing us they were right. And all for what?? Because they were either too confident, or too inept, to:
1. design a test
2. go outside and perform the experiment
3. look at the results

I'm not saying designing tests is easy, but come on people, you cannot just debate each other’s theories all day for the rest of your lives. When will you start being serious? This is not rocket science. (though, ironically, it is exactly the process you need to invent rocket science — namely, regular, old fashioned Science).

1. blog.ezyang.com

2. see this paper on Aristotle’s physics: https://philsci-archive.pitt.edu/10964/4/Aristotele.pdf

3. https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/Astronomy_for_Educators_%28Barth%29/06%3A_Exploring_Gravity/6.03%3A_Galileos_Falling_Bodies?utm_source=chatgpt.com

4. Even after we test our theories, we don’t know if they are true in all cases, we only know they are true in our test cases. And if we do a lot of tests, we can theorize that something is true universally.