After two weekends during which I could not do mathematics – although I did do mathematics during the week last week – I discovered on Thursday that the world was supposed to end today. Damn, I would lose a third weekend!

I did get a kick out of one thing. The U.S. Centers for Disease Control issued a warning about how to prepare for an attack by zombies. Really.

Of course, once you read the sentence that says that preparations are pretty much the same for any disaster, you realize that they are merely taking advantage of the prediction in order to put out their standard advice about disaster preparation.

I wouldn’t be surprised if the bureaucracy stomps all over them for their imagination and initiative – after all, by definition, the whole point of bureaucracy is to follow the rules meticulously regardless of consequences – but I for one will fondly remember this CDC bulletin as the noteworthy event associated with the prediction of doom this weekend.

Anyway, I returned to work on Wednesday and not a lot of mathematics has happened since.

So let me get about mathematics. My alter ego the kid is sitting here eyeing Fairchild’s “Color Appearance Models” (a return to color theory?)… and my alter ego the grad student will be doing the first 19 pages of Landau & Lifshitz’ “Theory of Elasticity” (stress and strain in thin-walled structures)… my alter ego the blogger needs to put out another projectile post.

Actually, I need to put out 1.5 posts: in addition to an example which is more informative graphically than the ship and fort problem (same problem but different numbers), I need to put out the derivation of the equations for simple projectile motion. Yes, that derivation is elementary – once you’ve had calculus. Nevertheless, it was one of the things I worked out carefully for myself when I was a freshman… as a way of making sure that I knew exactly how this new college mathematics gave me the equations I had memorized in high school. (Math and physics derivations just do not look the same. I know that particularly well, having TA’d both physics and calculus simultaneously to the same students.)

But I’m not sure this derivation is enough for a regular Monday night post… and yet I don’t want to just tack it onto the end of the next projectile post. But I said I would put it out when I first presented the equations. We’ll see how it plays out.

Finally, I have no idea at all what mathematics my grown-up alter ego wants to work on this weekend. That’s OK… he’ll find something.

## Leave a Reply