Bubbles

A bubble's colors are its thickness. Light bounces off the front and the back of the soap film, and the two reflections interfere: some colors cancel and others add up, depending on how thick the film is at that spot. That's a few hundred nanometers, give or take, which is a few hundred millionths of a millimeter.

As the film drains and evaporates, the colors move through the same order Newton wrote down in 1704. Watch the top of a bubble. When it goes clear, the film there has become too thin to reflect much of anything, and the bubble won't last much longer.

The color is computed from the physics. How the bubbles drift and how long they last is tuned for watching, and a real one bursts in a few thousandths of a second, so these are slowed down. With a keyboard, focus the garden and hold the space bar.