Episode 20: Torques And Gyroscopes - The Mechanical Universe

Рет қаралды 48,707

7 жыл бұрын

Episode 20. Torques and Gyroscopes: From spinning tops to the precession of the equinoxes.
“The Mechanical Universe,” is a critically-acclaimed series of 52 thirty-minute videos covering the basic topics of an introductory university physics course.
Each program in the series opens and closes with Caltech Professor David Goodstein providing philosophical, historical and often humorous insight into the subject at hand while lecturing to his freshman physics class. The series contains hundreds of computer animation segments, created by Dr. James F. Blinn, as the primary tool of instruction. Dynamic location footage and historical re-creations are also used to stress the fact that science is a human endeavor.
The series was originally produced as a broadcast telecourse in 1985 by Caltech and Intelecom, Inc. with program funding from the Annenberg/CPB Project.
The online version of the series is sponsored by the Information Science and Technology initiative at Caltech. ist.caltech.edu
©1985 California Institute of Technology, The Corporation for Community College Television, and The Annenberg/CPB Project

Пікірлер: 41

@stanleycates1972 4 жыл бұрын

Making me love physics at 83. Fascinating and willing to accept while accepting maths I have no desire to follow in detail. No wonder Newton was so revered. Now 86, watching again.

@vickash1072 2 жыл бұрын

happy to read this comment 🙏

@stanleycates1972 2 жыл бұрын

@@vickash1072 thank you

@Sunspot1225. 10 ай бұрын

76 here and ditto, my friend.

@JR-iu8yl 8 ай бұрын

Without accepting/understanding the maths there's only duck much one can understand it is literally the language of the universe.

@mnada72 5 жыл бұрын

This is the most difficult episode till now

@kingsurya3215 2 жыл бұрын

This was so satisfying, thnx Caltech

@universocalculado4639 3 жыл бұрын

Esse efeito da roda de bicicleta que foi descrito é muito louco , até parece mágica ! Mais um excelente episódio dessa série , aprendi que a qualidade de um giroscópio está ligada ao fato desse giroscópio não sofrer muita precessão e , que a velocidade de precessão e igual ao torque dividido pelo momento angular ou seja ( Ω = τ / L ) .

@brainstormingsharing1309 3 жыл бұрын

Absolutely well done and definitely keep it up!!! 👍👍👍👍👍

@ermiasawoke192 Жыл бұрын

So addictive, wow!

@afonsodeportugal 5 жыл бұрын

6:48 “A spinning wheel has angular momentum. It’s not the force that changes angular momentum. It’s the twist”. 7:55 “Torque is the twisting force that causes rotation and it’s equal to r x F. According to the equation τ = dL/dT the angular momentum will rotate sideways”. 10:50 Precession of a spinning top: “when the top is tilted, even a little bit, the result is torque, which nudges the angular momentum of the top around and in a little circle”. 15:55 Precession of a wheel and of a spinning top: “when an object precesses, the tip of its angular momentum vector moves in uniform circular motion with a constant angular speed called Ω, which is the rate of precession”. In uniform circular motion, v = ω.r; in the same way, τ = Ω.L 17:03 How to minimize the gyroscope’s precession? We can deduce that Ω = R.g /(ω.r²). Thus, the gyroscope will precess least if it’s spinning fast (big ω), the wheel is large (big r) and if it’s carefully balanced (small R). 18:08 The best gyroscope on Earth it’s Earth itself. 23:52 “Like any other gyroscope, the Earth precesses; rotating about its axis causes the Earth to bulge slightly at the equator; the sun’s gravity, acting most strongly on the nearest bulge, exerts a small torque about the Earth’s center when the sun is on one side of the Earth… and when the sun is on the other side, a torque in the same direction”.

@kingcrimson9555 2 ай бұрын

goat

@leonsantamaria9845 8 ай бұрын

La fuerza centrifuga, de la rueda, en el angulo momentum...previene la caida libre de la misma , en la constante llamada gravedad.....facinante ........🤔👍

@abelardodiaz6276 4 жыл бұрын

No debemos olvidar que la regla de la mano derecha se definió como tal, para coincidir con la explicación de 09:15 . No confundir que la naturaleza sigue al torque, sino que el torque(en su definición de mano derecha) sigue a la naturaleza.

@abelardodiaz6276 4 жыл бұрын

Actually, that is the best explanation in internet 09:15

@JasonKavetis 6 жыл бұрын

were these videos filmed at Caltech or somewhere else?

@douglasstrother6584 4 жыл бұрын

Looks like a Cal Tech lecture hall.

@mnada72 5 жыл бұрын

24:17 shouldn't the torque point to the other direction ?

@victorpaesplinio2865 4 жыл бұрын

It is a bit complicated to visualize it but the vectors make angles in the representation. In the first case, using the right hand rule, the torque vector should points out the screen. That's because the position vector is "above" the force vector. When the Sun is in the other side, the position vector is "bellow" the force vector. When you close your right hand in the correct way you will see that the torque vector also points out the screen.

@whirledpeas3477 3 жыл бұрын

@@victorpaesplinio2865 Spelling Correctly is not that difficult.

@davidwilkie9551 9 ай бұрын

3D-T Physics of log-antilog 2-ness i-reflection picture-plane containment.. and so on.

@jimtwisted1984 3 жыл бұрын

This looks like something from the 70”s.

@franciscodelrinam4007 Жыл бұрын

15:30

@comic4relief Жыл бұрын

1:06 Lady narrator sounds like Lily Tomlin. Not in credits.

@izdiharrose3446 5 жыл бұрын

I need a woman that real knows torquing j/k

@comic4relief Жыл бұрын

In some of the episodes of this show the professor's commentary seems useless.

@why-no-investigation-reports 2 жыл бұрын

... a high school problem.

@jnhrtmn 2 жыл бұрын

That first animation was close to the cause, but she makes a declaration about the sides while missing what caused it. She just says "it jogs." What does that mean? Conservation laws don't cause anything, and actually, spin momentum doesn't even play a part in the cause. The rate from the spin is the only part of spinning that participates in CAUSE. The gyroscope is a macroscopic toy, and the modern scientific method is so comfortable with math and mnemonic devices touted for cause that they have missed a very beautiful mechanism here. The use of angular momentum in math mashes several different effects together along with the one true CAUSE of the gyroscopic effect that you have not seen, and you won't.