Philosophy
The Problem of Induction and Scientific Knowledge
Quick fact
The Scottish philosopher David Hume identified this problem in the 18th century, arguing that our belief in cause-and-effect is based on habit, not reason—a challenge that still unsettles scientists and philosophers today.
Why this is interesting
Every time you drop a ball, it falls to the ground. But what if, on the very next drop, it floated upward? How could you prove it won't?