The thought of the day regards angular momenum and figure skaters. I'm not sure that any physics student has studied the concept of angular momentum without the example of the figure skater. She pulls in her arms, decreasing her moment of inertia, thus increasing her angular velocity. It's an algebra equation set in motion. The picture in the textbook took my mind completely off of physics, though:
The sight of butt crack invariably takes one's mind elsewhere. In this case, the sight evoked a sense of empathy for humanity. This was in an engineering physics textbook. The readers are interested in building cell-phones, SUVs, smart bombs, etc. The idea that this audience must rely on a figure skater to understand a key concept says something about not taking too much pride in technological dominance. Mainly this: the things we do to express ourselves have value beyond what we may immediately understand. And people who build technology owe a debt to the figure skaters of this world. --GLS