We just spoke for five minutes about mathematics. Of course you can talk for hours, days, months about mathematics, and maybe one thing I want to add about Leibniz. Leibniz was an incredible man. Probably the last person who wanted to know everything. Everything. Of course, it's not possible anymore today. But Leibniz was a physicist, a philosopher, he was a mathematician, a logician, et cetera, et cetera. By the way, he invented a, probably the first calculating machine. And I was always intrigued about mathematics without computers. And when I, I studied the work of Leibniz, I realized he invented this calculating machine. And it's a good way to maybe to remember that sometimes the constraint is a good way to be creative and we will be back on that lecture number five. Now let's give up a bit mathematics, we're going to focus on another discipline, astronomy. Astronomy. A long history, more than 2,000 years, again, again. And what's the astronomy in the eyes of our six giants? Of course, the six giants or six guides are not enough. There are some thinker, main thinker, but connected to the astronomy you can see them in blue. Of course you have Keppler, Copernicus, Galileo etc, etc. The history of astronomy is fascinating, fascinating. But for a philosopher, when you look with the eyes of a philosopher, you see strange connection. And the connection, the first one I want to talk about is between Kepler and Plato. Kepler, maybe you know. Probably you know. So, Copernicus said the sun is in the middle and planets are circling around. But Kepler made a little update, he said no, those are not perfect circle they are more ellipse. And Kepler is famous for his three laws, the laws of Kepler. When you read the, the life of Kepler. You see a strange connection with Plato. Plato was another good mathematician and he was convinced and even prove you only have five perfect solids. What's a perfect solid? It's like a cube. If you take a cube, the six faces are exactly the same, perfectly. Same for a pyramid. You have three, no four, triangles. It's, the four faces of the pyramid are completely, exactly the same. And Plato showed you only have five solids like that. Of course, the three others are more sophisticated and I cannot describe them with my hands. But Plato proved you only have five perfect solids. Kepler read that and said, this is not a coincidence. If there are five perfect solids, this must be somehow connected to the organi, organization of the world, of the solar system. And he was convinced, at that time we only knew five planets, and the, the, Mars, Venus, et cetera, only five. So he tried to show that the organization of the world was connected to the solids of Plato. And the proportion were kept from one world into the other. Of course, not true. But it, it shows how philosophy, science, and in the end everything it is connected. Another good example is of course Newton. Again the life of Newton is unbelievable. Genius like that, well it's hard to imagine. But to make a long story short, what did Newton? Probably like putting together the two physics of Aristotle. For Aristotle, of course his physic was completely wrong but interesting. The start was like the beginning of thinking. And for Aristotle, you have, you had two physics. One, above the moon which is perfect, perfect movement, you can predict like eclipse and the move of the planets perfect physics. And under the moon, another world, according to Aristotle, where life exists. So, you're born, then you grow and then you die and this is true for human being, this is true for fruit, this is for animal, etc. So, for Aristotle, two completely different physics. And what Newton did, he showed you only have one. He put the two physics together. So, history said, he saw this apple falling on the ground. And the question was not for Newton; why is this apple falling down on the ground. The real question was; why this apple is falling and the moon doesn't fall. And he showed that the answer was the same reason. It's the Law of Newton, of course. For the same law. And by the same law and through the same law, you can explain that the apples going to fall and the moon won't fall. So that's why I put those two physics together in one mind and it's good to have Newton as a guide. Last but not least, the connection between Descartes and Newton. Of course, they were like two different centuries. So why did I put some connection between Descartes and Newton? Because it was a huge debate. At the time of Newton, there was a lot of people who completely denied, refused to admit Newton's view of the world. And there were more member of the fan club of Decartes. And Decartes was convinced there, the, there is always something, the world is bit like huge machine. For Newton, to explain Newton's flow. You don't need to have something between the moon and the earth. The gravity is alone, doesn't depend on what's in between. For Descartes, no, for Descartes the world was like a big machine. Like a big clock. He theory, Descartes, was called the whirlpool, the whirlpool theory. He was convinced that you have whirlpool everywhere, and Newton completely disagreed with that. And it was a huge debate and at the end of Newton finally people admit, admit, okay Newton is right. But the history of ideas and journey through the world of ideas, it's very often you meet like big battle, big battle. Like Leibniz and Newton for the invention of the calculus. Here, Descartes and Newton for the, how, to explain how the world is working. It's strange because in a way Newton was used the x and y invented by Descartes. So he was, but on the other hand he was a real, not an enemy but really against Descartes. And few people know, but Newton for example has not hm, how should I call it? He was not a convinced alchemy is possible, but he did a lot of research to put from, from copper to gold, et cetera, et cetera. So, and that's why such an approach to the world of ideas is useful. In the end, I, an idea always comes out of a human being's mind. And when you look at history. And if, when you walk in the world of ideas through people the way we do, we do now. It's, it's really rich as an approach. You realize that people that have qualities and sometimes defaults and they are human beings like you and me, etc. So just to finish this history of history, this quick look at the history of astronomy, a very last one. I put a connection between Kant and Copernic. Of course, Kant is not connected to the history of astronomy as far as I know. But one thing is interesting. Kant once said, I am the Copernic of the mind. This is funny. What was his, what did he want to tell. For many many centuries, you have this relation, relationship between the mind and the world. We so, lecture number two you remember: The world in front of you. And you, with your perception, etcetera. So, and Kant puts this relationship upside down. Before Kant, people were convinced that the world is the real issue. A human being should understand how it works. And Kant put this binom upside down. He said no, no, no. We built the way we see the world. He put it upside down and that's why he said himself, I am the Copernic of the mind. So, even if Kant was not connected and concerned by the astronomy, somehow you can connect astronomy and Immanuel Kant. [BLANK_AUDIO]
