Maybe I shouldn't have started this blog now, not with everything that's been going on.

On the fourth day of the third week of classes for the first trimester of the new school year, I had my latest lecture with my Introduction to Electricity and Magnetism class.

Continuing from our discussion of electric fields generated by single particles and system of particles, we proceeded to electric fields generated by some generic solid objects.

For this I introduced them to the linear charge density (lambda) for conductive rods, and even rods bent into the shape of rings, and the general form of the electric field given the radius and the distance from the central axis.

For the example I asked for the summation of the electric field at one point due to two rings with the same center, but one had a positive charge and the other negative, and thus the vectors were in opposite directions.

I also gave them the surface charge density (sigma) for conducting plates, again based on the radius, but for this one they had to get the electric field due to a round plate with a round hole in the center, so they had to solve for the field due to a plate with the larger radius first, then subtract a ring with the smaller radius.

Their first long exam for all the topics we’ve discussed so far (going all the way back to electrostatic force) is on their next meeting.

The next day, I had the second quiz for my Mathematical Methods One class. It had only one item less than their previous quiz, but apparently the questions were more involving than before.

The first one to finish, the same one as last time, passed his paper at the fifty-minute mark, ten minutes later than he did during the prior week. And there were more students (almost ten) who were still solving by the time the end of the period rolled around, as opposed to only a couple in the first quiz. Not that I’m proud that they found it a bit more difficult. But it is inevitable that the topics would become increasingly complicated. I just hoped that they would be able to adjust more easily.

In Science Fiction Literature class “Red Planet” and “Stepford Wives” (the recent release) were discussed. They were supposed to watch “I, Robot” but the copy they had would not work on any of the players in the media lab. I guess the general discussion is still on artificial intelligence and human enhancements (using the different “levels” of cyborgs as given in one article they were assigned to read), but comments on the exploration part of the theme in the replacement movie will have to be set aside and reopened in a later session.

And that’s all for session 621. For now, class dismissed.