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

Snell's Law for Sound Waves

Quick fact

Snell's Law for sound waves is used in sonar technology to map underwater environments by predicting how sound bends in the ocean.

Why this is interesting

Have you ever noticed that sound seems to bend around corners or travel differently in water than in air? It’s all about how sound waves change direction when moving through different materials.