Galileo's "falling bodies" experiment re-created at Pisa

Galileo's "falling bodes" experiment re-created at the Leaning Tower of Pisa on May 31, 2009, by physicist Steve Shore of the University of Pisa. Movie by science journalist Dan Falk.

[@1337RobinG]

dude, you're such a help with my A-Levels. really apreciate the Video

[@jfuite]

Regarding the equations at the end, danfalkscience states, "the two effects cancel each other out, that's why the rate of fall is independent of the mass". It's interesting that the two effects actually DO cancel each other out, considering mass is involved with seemingly very different phenomena: gravity and inertia (a concept defined independent from gravity).

[@DrewHasselback]

Thanks Dan!

[@awuma]

More relevant is that SIZE determines air resistance. If the balls have the same size but different masses, at the same speed the air resistance force is the same, but the less massive ball has less inertia and so slows down more. Despite the air resistance increasing with the square of the speed, the less massive ball slows down more. One has to make air resistance proportional to mass, like gravity, for this to work. Similarly shaped but variously sized bottles of water are good.

[@nainabla]

exactly...His experiment should be held in a vacuum room and not at the pisa tower. If the object were dropped from 5.000meters the heavier object would fall faster than a lighter object because of the air resistance.. The difference between the falling object thrown at 56 meters(pisa tower) is not visible to an eye because the objects doesnt reach a high speed so the air ressistance does not affect them a lot.. So aristotles theory is right in non vacuum place and gallileos theory is right in a vacuum place...

[@AnonConda]

This works over short distances, or in a vacuum. However when you consider the terminal velocities.... For an object to hit terminal velocity, the force of air friction must equal the force of gravity, F=ma. The 'a' being the acceleration of gravity, you can see that the variable 'm' means that for objects of higher density more air friction is needed to equal F. In other words, a denser ball must attain higher speeds for the air friction to overcome its weight, and has a higher terminal vel.

[@Chinstrap-w7m]

thx, it's grea to see how should be being there in the galilei's time

[@jursamaj]

@marcusaureliooze If you read up on it, Aristotle *thought* about it, and decided, without doing any empirical tests. He simply didn't bother. A feather and a hammer are very different objects, in many ways than just their weights. Proper experimenting controls for those differences. Aristotle didn't just say they would fall differently, but in proportion to their weights. Drop 1 and 2 pound balls (same diameter) 20 feet, and the difference should be significant. It isn't.

[@rcole128]

Loved this video. Show it in my Physics classes every year, but now the sound is gone. Only the music work. I hope you can fix it.

[@notguitargatekeeper]

yeah what happened?

[@Roddy1965]

Let me see if I get this right. So if the lighter object falls faster, she is a witch? ; ) Nice work Dan. Very professional.

[@DarqeDestroyer]

The narrator sounds like Sheldon Cooper.

[@jerhms]

DarqeDestroyer That's how us nerds sound. Its just a fact of life.

[@insirtusernamehere]

@HK379 An object in space will accelerate towards another object because of gravity. On Earth this is about 9.8 meters per second, but if Earth was heavier. So say you jump out of a plane. You might think 20 seconds later you would be going nearly 196 meters per second, but due to air resistance you will go slower. You accelerate towards Earth at 9.8 meters per second, but if you are air resistant, like a parachute, you will accelerate slower and your max rate of descent will be lower.

[@shamsterthehamster]

Why do they fall at the same time when dropped from the leaning tower? Isn't air present near the Leaning Tower of Pisa? *Nobody* explains this to me and I feel dumb!

[@kiranchaudhary8407]

Damm, same here

[@insirtusernamehere]

@marcusaureliooze In my science textbook the Earth includes the different air levels that extend up miles above the Earth's surface. It does not really matter though.

[@uracistbastard]

Galileo's "falling bodies" experiment re-created at Pisa - 23,000 views Chinese girl on the right - 6,423,086 view Not ironic at all

[@WeaselWJ]

Good video!

[@Roncace]

and the apollo 15 feather and hammer experiment confirmed it even further

[@danfalkscience]

Yep!

[@insirtusernamehere]

@jursamaj They knew about it, but they didn't really define it or give a reason for it. It's like being taught a concept and not understanding it. You can say when it works and how to use it, but can't you say how it works. They knew about the wind, as they showed through their knowledge of sails, but they didn't know why it worked like that.

[@blancaroca8786]

nice costumes and idea . Air resistence will affect the football more than the bowlingball because it is lighter, especially when speed gets high for long drops

[@nainabla]

exactly..His experiment should be held in a vacuum room and not at the pisa tower. If the object were dropped from 5.000meters the heavier object would fall faster than a lighter object because of the air resistance.. The difference between the falling object thrown at 56 meters(pisa tower) is not visible to an eye because the objects doesnt reach a high speed so the air ressistance does not affect them a lot.. So aristotles theory is right in non vacuum place and gallileos theory is right in a vacuum place...

[@danfalkscience]

True!

[@donkarpuz4316]

Try this experiment with a Big kishta, ans a small kishta

[@wingchun6036]

Can you fix the sound please?

[@jehovah945]

according to my evaluation you must remove air friction before you begin the experiment otherwise its nothing..where talking of how fast the velocity of the stones not the outside force.....

[@izabelabajda9]

Yea

[@benjamim880]

Does the voice on this video sound really weird to anyone else?

[@Allan-et5ig]

Nope.

[@jehovah945]

ill go with arestotle theory twice as big twice as fast but the experiment will not be in the leaning tower of pisa..100 times the height of the leaning tower .. the twice as big is twice as fast..blackhole, galactic plain pole shift,nuetrinus faster than light. can be computed by not using your equation.. you cannot compute particle faster than light using einstien equation.. thats the law..

[@jursamaj]

@insirtusernamehere marcusaureliooze said that atmospheric friction was unheard of back then. As I said, and you've admitted, it wasn't. They were well aware of it. Whether they had it precisely defined & quantified is irrelevant.

[@evangelosnikitopoulos]

In the 1640s the astronomer Giovanni Riccioli dropped balls of the same shape but of different weights from the Assinelli tower in Bologna, and the heavier balls always landed first, disproving Galileo's assertion. Funny no one talks about that experiment...

[@shomarially7482]

I liked and subbed

[@craigmckinley4760]

The sound is fuct

[@murrayarnold3402]

ok, so if Galileo had dropped a 30cm balloon filled with hydrogen it would have fallen at the same speed as a 30cm steel ball!! Must be something special about the physics at Pisa

[@danfalkscience]

The law that Galileo discovered -- like any law of nature -- applies across particular domain. In this case, the law breaks down if air resistance or buoyancy are significant factors -- as they would be for a hydrogen-filled balloon. (I recommend helium, however; it's safer! ;) )

[@1-4-johnny.cash.fan-8-8]

If it was in a vacuum without air, yes. However, air resistance is a major factor. Learn physics before saying ignorant things

[@jursamaj]

See, for all there smarts, this demonstrates the problem with Aristotle, Plato, and their ilk. They tended to make proclamations of "fact" after thinking about something, and felt doing an experiment to prove it wasn't necessary. :P

[@jehovah945]

the force should be equivalent to the force in galleleo expirement at high scale.. say what?you cannot do this do it.at both ends. plus and minus after that you think....

[@jursamaj]

@marcusaureliooze Hindsight? How about common sense? If I sit in my room and come up with an idea, the next step is to check if I'm right. These philosophers felt that experimenting was "beneath them", so their proclamation was sufficient. It doesn't take hindsight to know that's foolish.

[@evangelosnikitopoulos]

What are you talking about? All of ancient physics were based on observation. What Aristotle taught is still 100% valid: arxiv.org/pdf/1312.4057.pdf

[@omar_muzyxr8245]

anyone from 2022

[@CapKITZ]

Aristotle was *always* wrong

[@guillemarescaalberola743]

Galileuu

[@whatevermakesyouhappy]

This guy really posted this with the worst stereo audio of all time. This should be called migraine simulator. Absolutely cringe inducing