Mental Floss

BIG QUESTIONS

Person holding a lighter to a $100 bill

The next time you feel a burning desire to torch your Benjamins, think twice. Burning money—or intentionally damaging it in any way—is illegal.

Eden Gordon




Confederate and Union soldiers fighting during the Battle of Allatoona Pass: the high-stakes battle that popularized "hold the fort."

Discover the Civil War origin behind the phrase "hold the fort," from General Sherman’s battle signals to popular gospel hymns.

Jane Alexander




Ever wondered why a secret advantage is called an "ace in the hole"? Discover the 19th-century poker origins behind this iconic idiom.

Paul Anthony Jones


The Prague Astronomical Clock, first installed in 1410.

Ever wonder why we say "o'clock"? Discover the medieval origin of the phrase, how mechanical clocks changed timekeeping, and why the contraction stuck.

Nitya Rao






The phrase “pie in the sky” has a surprisingly dark history. Learn how labor activist Joe Hill coined the expression in a song in 1911.

Paul Anthony Jones

Why are basketballs orange? Learn how the familiar color came about and why it replaced the dark brown balls once used in the sport.

Paul Anthony Jones








Why do we say “add insult to injury”? Discover the surprising history behind this common phrase, which dates back to Ancient Rome.

Jane Alexander