|That's not dangerous at all... (And that fence isn't as high as it looks.)|
This morning when Donna and I walked over to Physics, I noticed for the first time a large tank of liquid nitrogen near the Physics building. I couldn't help but think of a catastrophic explosion I had heard of as a result of failed pressure-relief devices in a tank of liquid nitrogen.
In Physics Bill continued our discussion on charges from yesterday, and the similarity between the electric force and the gravitational force (for example, if you are anywhere inside a large (planet-sized) hollow sphere, you will feel no gravity because all of the forces cancel out, and if a charge is inside a charged hollow sphere, it will feel no charge either).
Then we did a short lab where we measured the speed of sound through air and the speed of electricity using oscilloscopes. As it turns out, given that we found the speed of light in glass earlier, and we measured the speed of electricity today, fiber optic cables don't actually carry messages much faster than electricity.
|This 1936 Bugatti 57G won every race it entered.|
We had lunch an hour earlier than usual, so that we could get back by 12:30 to catch our bus. We took our bus to the Simeone Foundation Automotive Museum. In a huge cleared out space in the center of the museum, we practiced pushing bowling balls around with brooms, and then raced each other around the track. (It was supposed to teach us about inertia. It taught us that brooms are made for light things and bowling balls are very heavy.)
Then we looked around the museum for the remaining hour and Bill told us the physics and the history of each car. He also showed us the development and progression of technology, usually in ways that better utilized physics to get the most out of a car.
On the way back from the museum, I sat next to Bill and we had a great discussion about the problems with Bernoulli's effect and the contradictions in the many different explanations of why a spinning ball curves.