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Showing posts from May, 2026

Richard Feynman (9) - Newton's Theory of Universal Gravitation

  So from this law, he would confirm the idea that the force is toward the sun and from knowing how the periods of the different planets vary with the distance away from the sun, it's possible to determine how that force must weaken at different distances and he was able to determine that the force must vary inversely as the square of the distance. Now so far, he hasn't said anything because he only said the two things which Kepler said, in different language. one is exactly equivalent to the statement that the force is forward the sun,  the other exactly equivalent to the statement that the law is inversely as a square of the distance But people had seen in telescopes that Jupiter's satelites are going around Jupiter. It looked like a little solar system. So the satelites were attracted to Jupiter. And the moon is attraceted to the earth and goes around the earth. It's attracted in the same way. So it looks like everything's attracted to everything  else. The next ...

Prof Jonathan Gruber (1.12) - Positive vs. Normative Economics Explained on Ebay

  This model (Supply and Demand) raises a very important distinction that we're gonna focus on this semester. It's gonna trip you up. I guarantee you a number of times. So, I want you very careful thinking about this, which is the distinction between positive economics and normative economics. Positive economics study the way things are.  Normative economics is a study of the way things should be.  Now to consider to understand this let's consider a great example of economics at work which is eBay. When eBay came along, I know it is older than all of you, but it's younger than me.  When eBay came along, economists were very excited because economists love auctions. Auctions are, if you will, the standard market that used to exist in, you know, 15th century England. It's literally people bidding against each other in a way that reveals who wants the good the most. And what's wonderful about that, and we'll come back to this throughout the semester, is it ha...

Veritasium (1.5) - The Birth of Replication

This fact hints at an important law that governs our void,  The law of stability . Unstable blobs fall apart and vanish. Stable ones endure.   Now, watch what happens if we speed this up dramatically, maybe a couple of years per second, maybe even a couple million . You can see our blobs keep getting random jolts of energy, so they combine with others to form more complex compounds. Most attempts fail and fall apart, but every so often, by pure chance, you get a compound that is more stable than the blobs it's made of.   This doesn't happen because the blobs want to build more complex structures. It's just because these new configurations happen to be more favorable in the environment. And now when these complicated compounds become abundant enough, they too get a chance to combine, making our void increasingly complex. And one day, by accident, this causes an extremely unique shape to form, one with a special property.  See, the blobs it's made of just happen ...