XKCD: Sky Color - Feynman recounted another good one upperclassmen would use on freshmen physics students: When you look at words in a mirror, how come they're reversed left to right but not top to bottom? What's special about the horizontal axis?
how to grow moss.Take a clump of healthy moss and crumble it into your blender. Add 2 cups of buttermilk and 2 cups of water. Blend at the lowest speed until it is completely mixed and the consistency of a thin milk shake.