Thursday, July 10, 2014

Charge Ahead

Today I woke up with a vague feeling that there was too much light in my room. Then I looked at my alarm clock and found that it was 8:30 and my alarm hadn't gone off. As soon as I rushed outside to head to class,  I saw that the entire street was flooded and there were four-foot jets of water shooting up, because a pipe had broken at the top of the street. Donna and I made it to the Physics building with five minutes to spare, so, since I'd missed breakfast, I stopped to buy a muffin from the cart right outside the Physics building.

Bill likes to keep our attention by electrocuting himself while lecturing

In physics, we learned about electrical charges. We reviewed the basics (like charges repel, opposite charges attract) and we rubbed plastic pens on our shirts to make them pick up bits of paper. Electric charges are a fundamental property of matter and cause interactions between objects, creating forces (the electric force, named such for obvious reasons). Charge is measured in units of coulombs, and a coulomb is 6 x 10^18, or a billion billion electrons.

A strange type of squid; it has the largest eye-to-body ratio of any animal
Then Alison Sweeney came in and gave a lecture on biophysics. She works with mid-level sea creatures, which are basically creatures that live in a dark void, since they are far above the ocean floor, far below the surface, away from the shores and only exposed to very very dim sunlight. Many of them have unique adaptions that have optical tricks that utilize the physics of light in order to better survive.

An analogy between electric fields and gravitational fields
After meeting John for lunch, we came back to physics class and did a lab on electricity. We built different kinds of circuits to measure the relationship between voltage and current, and to find the resistance of the resistors we were using. We also found that light bulbs do not obey Ohm's Law, because the filament changes resistance as it is used and heated. Then we made Play-Doh the resistor, and found that you could not measure the resistance in Play-Doh with any accuracy at all, because it dries out incredibly fast as the electricity moves through it, increasing its resistance.

1 comment:

  1. Your pictures are fantastic. The one with Bill has me cracking up!