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

Acoustic Impedance: What It Is and Why It Matters

Quick fact

Air has an acoustic impedance of about 413 Pa·s/m, while water has about 1.48 million Pa·s/m—roughly 3,600 times greater.

Why this is interesting

Why can you hear sounds through a wall but not clearly through a sheet of foam? The answer lies in a property called acoustic impedance.