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.

Physics

Wave Theory of Light

Quick fact

Christiaan Huygens proposed the wave theory of light in 1678, but it took over 100 years and Thomas Young's double-slit experiment (1801) for the idea to gain widespread acceptance.

Why this is interesting

You’ve seen rainbows and colors in soap bubbles, but have you ever wondered how light can bend around corners or cancel itself out? That mystery leads to a surprising answer: light is a wave.