Why does toast always land butter side down?

The answer

Toast really does tend to land butter side down when it slides off a table, and the reason is the table. A slice that tips off the edge starts to rotate, and at a typical table height it only has time to turn about half a flip before it hits the floor, so the side that was facing up ends up facing down. A taller table would give it time for a full turn. Physicist Robert Matthews tested this, and won an Ig Nobel Prize for physics in 1996 for his work on it. In this made-up case from Matter of Record Files, Inspector Fig nudged slice after slice off a table, and every one landed butter side down, and then jam side down.