Galileo is arguably known to every physicist. When he was in school, he became famous for his opposition to Aristotle. And Aristotle was Alexander's teacher, Plato's teacher. He is known as one of the Three Great Masters of Greece, along with Socrates. He once went to the Leaning Tower of Pisa to do a free-fall experiment, and proved that objects of different masses fall from the same height at the same time, and they will fall to the ground at the same time, and the speed is the same. From this, he came up with the law of free fall. But I just want to ask why this is the case? I tried to explain it in terms of gravitational potential energy, but I could only conclude that the mass is faster. Then use momentum, which is equal to mass multiplied by velocity. It stands to reason that the momentum of the two balls should be the same. However, in this case, the velocity of the ball with a large mass is small. I thought about it, but momentum is not the same. We know that the greater the mass of the object, the greater the kinetic energy. And kinetic energy is equal to momentum multiplied by velocity, and the momentum is also greater. So, can we conclude that their velocities are equal? Actually, no. Although I have tried to explain it in terms of the law of conservation of momentum, it is not possible to be very overshadowed. So, how should we explain it? Apply work? Two objects land and fall at the same time, and they are still at the same height. In this way, isn't the work done by the two of them in the vertical direction the same? And we know that the work done by an object is related to energy. In other words, the change in energy of both objects while falling is the same. But is the energy they get the same in the first place? Naturally it's different. Because it's easy to think that a massive object doesn't bounce high, while a small object doesn't bounce high. Still in terms of work, objects with small masses do more work. So, the object with less mass gains more energy. Is this counter-intuitive? Faster with less mass? Actually, it's easy to understand. The bird is small, but it can walk faster than a human can walk. Actually, that's not necessarily the case. Because Galileo used a ball. If it were to use a different shape of an object, it would be different, because the object rotates as it falls. Why is there a rotation? It turns out that the falling object is impacting the air, and the surrounding air acts on the object. I don't know if you notice why no diver is spinning when diving instead of just diving headlong into the water? That's because this jump is more in line with the law of free fall.

With all that said, it's time to return to the Galileo cannon. Anyone who has watched the video knows that four spheres with decreasing mass from bottom to top are used. Why is the topmost ball bounced so high? That's because the three balls at the bottom all transfer energy to it, and this is the reason why a person on the trampoline can bounce a very high height without much force during bungee jumping. Mizukawa is interested in the problem of free fall, so he is able to talk about it endlessly

The mountain is not high, and there is a fairy name. The water is not deep, and if there is a dragon, it will be spiritual. Si is a burrow, but Wu Dexin. The moss marks are green, and the grass is green. There is a lot of talk and laughter, and there is no white ding. You can tune the piano and read the Golden Sutra. There is no silk and bamboo, and there is no case. This place of discussion is precious precisely because of a few of us enthusiasts. Although we are not in a high-rise building, our character has been moving closer to that of our ancestors. We revere the sages, but we also question them. As Plato said, I love my teacher, and I love the truth even more. is like Han Feizi, although he studied under Confucian masters, he created his own school of legalism. Just like Confucius said, the three principles and five constants, that is not something we should abide by. However, what he said about the threesome must have my teacher should be believed.

We know that the Galileo cannon used spheres of different volumes, so what if it was the same volume? The topmost sphere will still bounce up, but the bounce will not be as high. It is inappropriate to say that it is the same volume, it should be the same shape. Why are several spheres with the same radius less effective than spheres with different radii? It turns out that the elastic potential energy is related to the difference in the mass of two objects. The greater the mass difference, the greater the elastic potential energy. Conversely, if the mass difference is zero, the elastic potential energy is almost zero. However, not paying for zero. There is still a little insignificant elastic potential energy between two spheres of the same mass.

Shape is the key to determining all the properties of an object. Galileo ignored the role of shape in his study of free fall. In the Galilean cannon, if you use a square, the second square will actually slip. Unlike spheres, two squares have many points of contact. Since the transmission of force is disordered, the elastic force can act on the second square at any point of contact. The two spheres, on the other hand, have a negligible contact surface, but they can still be seen as a point of contact. Because of this, the completeness of the transmission of force is guaranteed. And this is the effect of the yin shape on the object. The six sons of wind came in one go, and there was no mud and water in the middle.

You've probably heard of the Lelo triangle, but what about the trihedron? There are videos on the web that say that it is it. What if the trihedron is used as the material? No way. Because there is simply no object that can stand on top of it without relying on external forces. However, the object can only have one point of contact with the strangler trihedron, and there can be no contact surface.

If you want to transfer force, then isn't spring the best choice? With a spring, is the height of the top spring equal to the compression length of the bottom spring? Obviously, no. However, there is no doubt that they are directly related. Dueñas said.

I have two questions. First, what happens if you use ice? Second, if the mass of the ball is infinitely close to zero, is the height of the ball bounced close to infinity? First, let's answer the first question. The ice may have been shattered before it could bounce up, which is a situation. There is also the fact that the ice on it has slipped off. Let's look at the second question. We know that the sky is high, but it is only a few million kilometers. And what is infinity? To reach infinity, you have to go into space. And we know that there is no gravity in space, so objects float in space. Since it is not infinite, what is the height at which an object that is infinitely close to zero is bounced up? In fact, when it enters the clouds, it is subjected to a force. And this force will cause it to not continue to fly upwards, but to start falling. So, things are not what they seem.

When Liuzifeng talked about the contact point just now, I wondered how this sphere with an infinite mass approaching zero should stand on another sphere, and how big should the other sphere be? In fact, there are many more such details. Behind everything that seems simple is often a more complex principle, which we don't yet know. A philosopher has said that not knowing one's own ignorance is doubly ignorant. It is precisely because we know that we don't know that we are desperate to know. However, when we know we don't know, that's a kind of knowing. In the exploration of physics, never give up is what we should insist on. Do you think it is logically correct in this regard?

All three of them said, yes!!

Mizukawa straightened his clothes and hair before he slowly said: Physicists believe that time has a beginning and an end. And we also need to increase our knowledge and enrich our horizons. For this, the correct conclusions cannot be said endlessly. Well, a reasonable rest is necessary. I was going to say something, but forget it. Wait until it is cloudy, and then we will continue to discuss the sword in Huashan.

After the words were finished, the people dispersed.