My Brain Hurts!

OK so my morning:
Dragged myself out of bed about 8:40 and got out the door about 9:00. Grabbed A Bacon egg and cheese (mmm, yummy), coffee and fruit cup (crappy) from the 'barista cafe' (aka East St Deli prior to 10:30) and then headed down to Baker A51 (Geagle) for my calc exam.
It wasn't too bad. I did realized 30 sec after I handed the test in a minute before time was called that I just needed to do the integral test to figure out that one of the series converges. Oh well. I did get the Newton's Methon one, which seems to stump lotsa people I talked to.
Following that I headed over to Physics. We were presented with another example of what happens with E&M physics starts messing with relativity: So lets say you're looking at a wire with a current flowing along it. There're electrons flowing down this wire in one direction or the other with a drift velocity, v-bar. They generate a magnetic field mu/4pi * I(dl x r)/r^2. However, the wire was electrically neutral before the current and so there's still a net-charge density of zero (if you count the electrons and protons in a given length of wire, there're the same in number, thus the net charge is zero). Since there's no net charge there's no E (electric field).
Two major consequences of relativity are time dilation and distance contraction. If you move fast things happen slower and things look smaller/closer together in an amount based on your relative speeds.
So lets say you move along the wire, in either direction. The electrons are moving relative to the wire, right? And the protons are basically fixed within the wire. This means that your speed relative to the wire - v-bar != your speed relative to the wire - proton speed. Therefore as you move the distance between electrons contracts a different amount than the distance between the protons and a net charge forms on the wire because the charge densities of electrons and protons change by different amounts. This is what causes E fields to form due to moving frames of reference.
And then we had a quiz, except the quiz wasn't that bad. It was about cyclotrons and motional emf, neither of which involved relativity.
Then I got to head up one floor and take my econ exam, which was much easier than I expected, but it was still an hour long test, which makes it a total of 50+50+20ish minutes I had in 150 minutes of classes this morning. I know you're all jealous.

In better news, a package arrived for me (I'm about to go get it) most likely carrying my new pair of shoes! I also got a B+/A- (not sure where how the letter grades are divided) on my last Physics test! Yay!