Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

Start with one fact. Explore it, go deeper, then follow whichever branch catches your imagination.

Choose subjects for a surprise

Exploring any topic

Begin your discovery

Your next discovery is one click away.

Choose one or more subjects above, or leave Any Topic selected and let curiosity decide.

Engineering

Why Suspension Bridges Sway Instead of Snapping

Quick fact

Most suspension bridges are built to sway a meter or more sideways in strong winds — and that flexibility is exactly what keeps them from snapping, because it lets the bridge absorb and scatter the enormous energy of the wind.

Why this is interesting

You’ve probably felt a bridge tremble under your feet, but have you ever wondered why it doesn’t just crack and fall apart? The secret is that the bridge is actually designed to dance.