Not just Plato, Aristoteles even more. He kept Mechanics for 2000 in the dark ages, by assuming that heavier objects fall faster than lighter objects in proportion to their weight. He argued that a 10-pound stone would fall 10 times faster than a 1-pound stone. Continuous force is needed for continuous motion - without a force pushing it, a moving object would immediately stop.
In fact continuous force leads to continuous acceleration. A bit of mathematics would have helped.
"He kept Mechanics for 2000 in the dark ages,"
You can blame him for being wrong at first, but somewhere around, oh, 200 years later (very, very conservatively), the people who treated him as an unimpeachable source really ought to be assigned about 100% of the responsibility.
"A bit of mathematics would have helped."
Your use of modern terminology in the previous sentence leads me to think you're not clear on how primitive mathematics is for Aristotle. The calculus you are referencing comes from give-or-take two thousand years in the future, and while you can make a case that physics was "held back" by some very bad understandings, I think if you survey the history of mathematical development that you can't really make that argument for math [1]. Are you personally ready to stand and give an account to the future for failing to understand concepts that will be considered obvious and taught to whatever the equivalent of schoolchildren is in the year 4025 AD? 'Cause I wouldn't take that responsibility on.
[1]: What I mean here is that while mathematicians also had some errors, that just by the nature of math being built up from the ground those errors were never as fundamental as the physics errors because there was always a clear sense of what was well-grounded versus speculation. You have things like the casual assumption of Euclid's parallel postulate being true, but that didn't really "hold back" mathematics in the same way; it prevented the investigation of hyperbolic and spherical geometry but not discovering and/or investigating a new field is radically different than being persistently wrong about an existing one for centuries at a time.
Just to note all those points of Aristotle were corrected by Galileo, before calculus.
One thing that Galileo did more systematically than his precursors was that he found ways to treat time geometrically, as a spatial magnitude, so then he could draw distance-time graphs, and velocity-time graphs, which helped him in coming up with his law of fall (distance in free fall is proportional to the square of the time taken to fall), and then to deduce that the trajectory of a projectile is a parabola
> you're not clear on how primitive mathematics is for Aristotle
Completely agree, and to add some color: Aristotle lived about 100 years after Pythagoras, meaning in his time a²+b²=c² was groundbreaking material.
They didn’t even have access to algebraic notation (IIRC, an innovation of the Islamic Golden Age, a result of cross-pollinating Greek geometry with Indian arithmetic). So the groundbreaking material was that famous diagram of a right triangle with squares constructed on each side.
Interestingly, there is no actual reference to Pythagoras for this discovery until 5 centuries later, by Greek authors Plutarch and Cicero attributing this theorem specifically to Pythagoras.
However, Pythagoras’ Theorem is often linked to the Babylonians. There are implications of the theory on a fragment of a clay tablet from Babylonia in the Plimpton 322, dating back to approximately 1800 BCE.
Question: Why do things move?
Before Aristotle: Um, Zeus’s will I guess. No need to look further.
Aristotle: Great question! I don’t really know. But maybe that’s something we should investigate and reason about so that we can understand how our world works. Hmmm, maybe… like this?
After Aristotle: What he said. No need to look further.
I think he’d have been horrified at the idea that we could stop investigating, and yet.
It’s actually a very reasonable approximation within a certain regime:
https://arxiv.org/abs/1312.4057
There’s a reason people without training in sciences sometimes have the intuition that heavier things fall faster. This intuition isn’t developed in a vacuum (hah).
You can disprove this idea even in a simple thought experiment, you don't even need an actual experiment. If I take 2 large stones, connect them with a string so it's 1 object, will that object fall twice as fast than the 2 stones fall separately?
Working under the theory that large dense things fall faster than small things, you'd expect that the large stone would drag the small stone. Much like if you attach a piece of wood to a rock with a rope and throw it in water, the rock will drag the wood down.
You'd probably argue that even though they are connected with a string they are still 2 things and there's a density gap between the two of them.
Now, if you try and figure out what makes a thing a thing, it starts breaking down. But if you've already have the working theory, then making an explanation isn't terribly hard.
That will depend on the length of the rope, once aerodynamic effects are taken into account
He didn’t keep anything in the dark ages. He asked questions about things in a way nobody had and few came after inquired deeper.
Also if you read his physics tons of his questions are still relevant because he is asking more than “what’s the position of this object after falling” but “why is the object even moving”.
Aristotleles lived 2000 years and kept people from dropping two objects off a cliff at the same time the entire time?
I'd say something else entirely kept the rest of humanity from experimenting and sharing their knowledge about this.
He did not keep anybody anywhere.
People decided to blindly believe him, without reasoning nor checking.
Given that 80% of the world today believe on some form of god, this must be something ingrained in our minds to follow something instead of being skeptical.