Laws vs. theories

We touched on this a little in class today, and here’s a little more commentary.  Does biology have laws?

I’m glad you noticed that the classification of some of the examples we went through today is context-dependent.  Salt water is a solution, a homogeneous mixture, unless the salt concentration is so high it’s supersaturated…and then, once salt fails to dissolve or precipitates out of solution, we have a heterogeneous mixture.  Smart class!  Too bad I didn’t bring stickers today.

Because we discussed the compressibility of gases today, I feel obligated to show you why compressed gases are dangerous.

All that potential energy can be released pretty quickly if the valve snaps off…and the compressed gas will violently de-compress itself.