When heat is said to rise, we are referring to only one of the ways that heat can be transmitted---convection. Focusing exclusively on convection is what creates the conundrum. But what is convection? The warmer molecules of a fluid like air will move apart and become less dense. As a result their weight will be... Continue Reading →
In the 15 years that I spent at my last school, the caretakers rarely, if ever, dusted the top border of the chalkboard. I used their laziness to my advantage, revealing to students that it was evidence that the chalk particles from my constant erasing were small enough to be deflected upwards by the random... Continue Reading →
For years, my wife and I have had lots of alcohol around the house that we haven't drunk. A few months ago, I realized that very small amounts make an excellent solvent to wash off the writing from our calendar. But yesterday I came up with an even better idea. On Friday she brought home... Continue Reading →
