Archimedes

So it's been a very busy week! My step-son, Medium-Dude, is in town. He visits every summer for about a month and hangs out in the big city with us. He lives the rest of the year in the midwest with his mom. He's ten, and he's a great kid with lots of energy.

Since the Tummy's at work all day, and I have the summer off, Medium and I hang out during the day. Last week, we went to Brooklyn Museum and saw the mummies. (There's even a cat mummy!) We went to the Prospect Park Zoo and the Lefferts House and then wandered around Prospect Park all day. We went to Coney Island and swam and rode the Cyclone. And, my favorite trip so far, we went to the NY Hall of Science in Queens.

Now, I am a self-professed math geek, but it's rare that my geekiness really comes out like it does at that museum. They have such cool stuff! And I just have to share something. Archimedes is just the coolest guy ever. I mean, wow. They have, in the math section in the Hall of Science, a model that Archimedes thought up. He didn't build it (I don't think). But he thought of it and realized that it could be built. It's a balance with a cylinder on one side and a cone and sphere on the other side. The cone and the sphere are each the same height as the cylinder. And the diameter of the cylinder, base of the cone and the sphere are all the same. And it balances. Of course it does, because a cylinder has a volume of pi*r*r*h and a cone has a volume of one-third*pi*r*r*h and a sphere has a volume of four-thirds*pi*r*r*r which, since 2r = h, is two-thirds*pi*r*r*h. (I'd use better math symbols, but it won't let me post them.)

So, I can understand it using algebra and some formulae I already know, but how did Archimedes do it in his head???? Without the algebra, because it wasn't around at the time. In fact, he's the one who came up with the formula for the volume of a sphere, because the volumes of a cylinder and cone were already known. It just blew my mind.

One last thing before we go get stuff to make cookies to take on our picnic in Bryant Park tonight. I received an award! From my sister, the amazing Mary at Shazam in the Kitchen. It was so sweet of her to think of my little ole blog. And I love her too! (because she's the only one who read and understood my whole Archimedes thing.