I think the Internet is a good opportunity to allow students to obtain the best educational resources at the lowest cost. I feel that my value has been magnified to the maximum extent by the Internet. This is my original intention, and I hope I can continue to stick to this original intention.
— Li Yongle
On February 23, 2019, Li Yongle, a physics teacher at the Affiliated High School of China National People's Congress, gave a keynote speech on "Popular Science and Life" at the Guan Academy. Focusing on topics such as bugs in the wandering earth and his own experience of becoming a popular science internet celebrity, Li Yongle said that science is closely related to our lives, and the popular science videos he made can make some netizens who did not know much about science and feel proud of "I can also understand science."
The following are the key points of the introduction compiled by Guan Academy.
1. Why do you like to listen to my lectures after graduation? 1'29
I think maybe the reason is that I am willing to arrange the profound mathematics and scientific content in new ways so that everyone can understand it more easily. At the same time, I closely link science with life, so that everyone feels that science is useful and that everyone understands the connection between basic research and practical applications. Through a few minutes of video, I can explain a principle clearly, so that everyone can understand a tool and a phenomenon in life, so that some netizens who didn’t know much about science have the pride that I can also understand science.
2. Scientific knowledge on the wandering earth
2.1 Is it true that the sun is about to age in the wandering earth? 2'29
The life span of the sun is 10 billion years, and now it only takes 4.6 billion years, and there are still 5 billion years for the sun to flash helium, and in the movie, this time is advanced to 2074. I told the audience that this movie has both a scientific foundation and a fantasy component.
2.2 Why is the earth so close to Jupiter during the wandering journey? 5'02
The earth is close to Jupiter because it is necessary to use Jupiter's gravitational slingshot effect. If we want the Earth to escape from the solar system, we must have a sufficiently high speed, and Jupiter can just provide us with such a springboard for acceleration.
We can simply compare the principle of gravity slingshot to the collision of small balls.
Similarly, when the Earth approaches Jupiter, the mass of Jupiter is much greater than the mass of the Earth, equivalent to the train just now. The process of the Earth being captured by Jupiter's gravity and relies on speed to escape from Jupiter is like a collision between a small ball and a train. As long as we adjust the angle, the Earth can steal some energy from Jupiter to achieve acceleration. This acceleration effect is very considerable and is enough to help the earth escape from the gravity of the sun.
2.3 Gravitational Slingshot Effect has been mastered by humans 7'21
1961, Michael Minovich, a young scholar of UCLA, discovered that in the late 1970s, the solar system would provide an excellent opportunity for gravitational slingshots: Jupiter, Saturn , Uranus , and Neptune are all located on the same side of the sun. If an artificial satellite is launched, and the gravitational slingshots of these four planets are accelerated in turn, you can visit these four planets with very little fuel within 12 years. If you miss this opportunity, you will have to wait for another 176 next time.
Under his lobbying, NASA launched the Voyager 2 and Voyager 1 satellites in 1977.
In addition to the Voyager, Galileo , Cassini , messenger , ulyses and other space detectors all use the gravitational slingshot effect.
2.4 What is the limit of Loch? 10'43
If the earth is close to Jupiter, Jupiter's gravity will also cause objects on the earth's surface to be subjected to tidal forces. If the distance between the two is too close, the tidal force of exceeds the earth's gravity on objects, and the objects on the ground will fly into the air. In this process, the molecular forces between objects are not enough to resist tidal forces, and the earth will scatter like a ball of loose sand.
Some scientists believe that Saturn's halo was formed because the asteroid entered Saturn's Loch limit, and the tidal force tear the asteroid apart, thus forming a halo.
2.5 Lochy limit is the biggest flaw of wandering earth 17'40
Jupiter-The rigid body Lochy limit of the earth is inside the earth, and the fluid Lochy limit is 35,000 kilometers away from the surface of Jupiter. In other words, only if the distance between the Earth's surface and Jupiter's surface is less than 35,000 kilometers, will the air and ocean on the Earth's surface be torn into the air by Jupiter. The film says that the distance between the wood and the earth is 70,000 kilometers, and Jupiter absorbs a lot of the earth's atmosphere, which is unreasonable.
What is more interesting is: artificial intelligence MOSS gives the specific value of the Roch limit on its display screen, and it draws both the Roch limits of Jupiter-Earth on the outside of Jupiter.
If we try to distinguish the numbers written above, we will find that the two Loch limits calculated by MOSS are about 890,000 kilometers and 1.71 million kilometers respectively, which is very different from the video and even greater than the actual value.
I carefully searched for the data source and finally found that the video actually mistakenly regarded the Rossie limit of the Sun-July as the Rossie limit of the Jupiter-Earth.
Maybe MOSS is wrong, he just wants to defect.
Despite this, "The Wandering Earth" is still the best domestic science fiction film in recent years. Not only has the visual effect been greatly improved, but more importantly, this movie has aroused everyone's interest in science.
science fiction film is a seed that will take root and sprout in the heart of a child. We can never imagine what kind of tree this seed will grow into.
3. Science is everywhere
3.1 Why do shared bicycles engage in a money-burning war? The 20'59
shared bicycle model is actually not making money quickly. The investment of tens of billions of dollars has exceeded the expected returns. Why do all kinds of funds still enter this industry crazily? The reason for
can be explained clearly through the example of "one dollar auction".
end result is that a dollar bill will be sold for more than $1. This is actually an economic model: the US dollar auction trap. : Martin Schubic, an economist at Yale University , is the posed question.
Although both of them are in a loss state, no matter who wins this dollar, it cannot change the outcome of the loss. However, in order to reduce one's own losses, he had to bite the bullet and raise the price until one party could not stand it and withdrew, and the other party won a tragic victory.
3.2 International relations can also be explained scientifically by 30'09
more typical game theory examples such as the problem of pirates' gold coins, prisoner's dilemma problem, smart pig game problem, etc., which many people are familiar with. Today I want to talk about an example that you may not be familiar with: Coward Game.
In the coward game, there are two Nash equilibrium points, some are beneficial to A and some are beneficial to B. In order to make the situation develop in a direction that is beneficial to them, both A and B will inevitably choose a strategy, which is to pretend to fight to the end.
Russell proposed this game to explain the most serious crisis in the world at that time, and it was also the closest crisis to destruction in humanity in history - Cuban missile crisis .
In fact, both sides are trying to pretend to fight with each other to the end, but they will show weakness at critical moments to avoid both sides dying together.
4. I want ordinary people to obtain high-quality educational resources at the lowest price 42'29
I think the Internet is a good opportunity to allow students to obtain the best-quality educational resources at the lowest price.
By chance, a netizen posted the video "What's going on in Leap Years" I recorded a few years ago to the Internet, and later it was forwarded to other websites. Many big Vs reprinted it, and the total number of views on the entire network was tens of millions. I was flattered. In fact, science is closely related to our lives.
One night, I looked for Riemann online about information, and found that the number one video in search engines was my video. At this moment, I felt a lot of accomplishment, no less than my student who got the international gold medal.
I feel that my value has been magnified to the maximum extent by the Internet. This is my original intention, and I hope I can continue to stick to this original intention.
More exciting lectures are available at Guan Academy (WeChat id: guanschool)
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