Saved on this device

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

The Navier–Stokes Equations and the Mystery of Fluid Flow

Quick fact

The Clay Mathematics Institute offers a $1 million prize for a proof that the Navier–Stokes equations always have smooth, physically reasonable solutions—or for a valid counterexample showing they don't.

Why this is interesting

We can predict the path of a thrown ball, but we can't prove that the equations describing a flowing river will always have a smooth solution. Why is something so everyday so mathematically elusive?