Why does toast always land butter-side down?
Tumbling toast, Murphy’s Law and the fundamental constants
Toast really does tend to land butter-side down, and the reason is the size of tables (and of humans).
Ig Nobel 1996
When toast slides off a table it starts rotating, but a normal table is not high enough for it to complete a full turn before it hits the floor. So it usually lands after half a turn: butter-side down.
The author goes further: tables are the height they are because humans are the height we are, which is set by the fundamental constants of physics. The universe is anti-breakfast.
If you want it butter-up, eat on a 3-metre table.