Max's Singing Plate

What you'll learn

• When a plate vibrates, some lines on it stay perfectly still.
• Sand gets bounced away from the shaking parts and piles up on the still lines.
• Those still lines are called nodes — the sand is drawing where the sound isn't.
• A plate only makes a pattern at its own special frequencies. That's resonance.
• Higher notes fit more still lines onto the plate, so the pattern gets busier.

How to play

1. Drag the frequency dial slowly and watch for the sand to suddenly leap.
2. Use the arrow buttons to hop straight to the next pattern if you get stuck.
3. Press Auto-sweep and just watch the plate work through all of them.
4. Tap the plate to sprinkle more sand wherever you like.

FAQ

Why does the sand make a pattern?

Sand bounces off any part of the plate that is moving, and it can only stay put where the plate is still. So it collects along the still lines.

Why does nothing happen at most frequencies?

The plate only vibrates strongly at its own resonant frequencies. In between, it hardly responds at all — the same reason a swing only works if you push at the right rhythm.

I can't hear anything.

Tap the plate once to let the browser start the sound, and check the sound button. Very low notes are also too deep for most laptop and phone speakers, though the sand still works.