Futility Closet

Contributed by Mrs. M.L. Dow to a cookbook compiled by the Ladies of Trinity Church, Claremont, N.H., 1899:

4 1/2 cups 1st Kings 4:22
1 1/2 cups Judges 5:25
2 cups Jeremiah 6:...

A puzzle by National Security Agency applied research mathematician Nicholas R., from the agency’s October 2016 Puzzle Periodical:

Eddie, Layne, Kurt, and Chris are locked in a heated game of CyberChance...

“Mr. Chairman, before we put the motion ‘That the motion be now put,’ should we not first put the motion ‘That the motion “That the motion be now put” be now put’?” — Punch, 1952

In 1990, physicist Joseph Polchinski described a puzzling situation: Suppose a billiard ball were sent through a traversable wormhole into the past, where it knocked its earlier self off course, away from the wormhole...

You’re tiling a floor with 4×1 and 2×2 tiles when you accidentally break one. A tile of the other shape is available. Show that it’s not possible to cover the floor by rearranging the tiles.