People That Changed the World: Archimedes

Hello, I'm Lois Letchford, author of the book Reversed: A Memoir and a literacy problem solver who loves sharing the history of our world and the history of mankind. We've gone from making fire to where we are today. And what are some of the steps in between that helped us go from Learning simple things to what we do today, putting man on the moon and flying to Mars. So from this book, Eureka, I'm reading firstly about Archimedes of Syracuse, and he lived at 287 to 212 BCE. BC, before Christ. So we've got the higher number first, the lower number second, and it states it's the single most important scientist of the ancient world, probably the greatest genius of the ancient world. Archimedes was born into an aristocratic family in Syracuse on the island of Sicily. His father was the astronomer called Phildilus, and the family was likely related to Syracuse's ruler of Hieron II. And this may be why, after receiving his education in mathematics at Alexandria, Archimedes returned to Syracuse rather than stay on in that great city of learning. One of the most frequently repeated stories of Archimedes concerns his discovery of the famous Archimedean principle. Supposedly, Herion had recently had a ground gold crown made and was suspicious the craftsman might have cheated him by alloying some silver into the gold. He asked Archimedes to find out the truth, at the same time stressing that the crown shouldn't be in any way damaged. Archimedes Archimedes was puzzled as to how to do this, until one day, climbing into his bath, he sloshed some water over the side. He immediately realised that he could fill a container to the brim with water, carefully lowering the crown into it, and then, by measuring the volume of the water that spilled over the container's side, establish the volume of each Even such a complicated structure as a crown. Since gold and silver have different densities, by weighing the crown he could find out if it was gold or not. According to the legend, he was so excited by this brainwave that he ran naked, dripping all the way to Hieron's palace to tell him about it, shouting, Eureka! I've got it! As he did so. Allied to this realization was his discovery of the principle of buoyancy, the principle of flotation. If something is floating in water, the water is displaced. The water it displaces has the same weight as a floating object. If you float a plastic duck in your bath, very little of the duck is below the waterline. In other words, the duck has displaced very little water. This is because it has a very low average density, being made up mainly of air inside it. Try the same with a piece of wood, and a much higher proportion will be underwater. Archimedes did a lot of work on the principle of the lever. It was well known that if you put the fulcrum of your lever close to a heavy object, you need to apply relatively little effort to the other end in order to move the object. On the other hand, you have to move the lever's far end quite a distance in order to move the object just a little. Archimedes worked out the mathematics of this and made the boast again, given a place to stand and lever long enough, he could move the world. Heron suggested— supposedly questioned this and challenged Archimedes to move, if not the world, something impressively heavy. The story goes that Archimedes, having realized that a block and pulley Is really a specialized system of levers, even if it doesn't look like it, was able to single-handedly pull a ship out of the water and up the beach. In the field of mathematics, he calculated a very precise value for pi. He proved it must lie— translated into decimals— 3.14085. And 3.14286. Since its actual value to 5 decimal places is 3.14159, you can see how close Archimedes was. So that's where I'm going to stop now because that's enough, and we can read more about all of these people who made an impact on In giving us the knowledge that we have today, and we still know. Thank you. Please hit like, hit subscribe, share it with others, and learn more about Archimedes, who was born in BC before Christ. Thank you.