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

Reflection

Quick fact

The law of reflection was known to ancient Greeks; Euclid described it around 300 BC. It applies to all wave phenomena, including light, sound, and water waves.

Why this is interesting

Have you ever wondered why you can see your face clearly in a mirror but not on a plain wall? The answer lies in a simple yet powerful phenomenon: reflection.