Maker / Scenes / Shrinking ring
Scene
Shrinking ring
The ring gets 1.5% smaller every time the ball hits it, until the ball no longer fits. Each bounce plays the next note of In the Hall of the Mountain King.
Make this videoWhat happens
The ring starts with a radius of 470 pixels and the ball's is 24. There is no gravity. The ball starts in the middle at 1,500 pixels a second and gets 0.3% faster on each hit. Every hit shrinks the ring by 1.5%, and when the ring is less than 1.7 times the ball's size the ball is stuck and the video ends.
That takes 162 bounces every time, because 470 × 0.985 to the power of 162 is the first value under the limit. With no gravity and a start in the dead center, the ball flies back and forth along one diameter, so a different variation only rotates the line it travels on.
What you hear
The ring gets smaller and the ball gets faster, so the time between hits keeps shrinking and the melody accelerates on its own. By the end the notes come so close together that they blur into a trill before the final hit.
Songs that fit
In the Hall of the Mountain King is the default because it is written to speed up, so the acceleration sounds deliberate. Anything with a strong repeating figure works well here.
Make your own
Open Shrinking ring in the maker, pick a song or upload a MIDI file, and download the MP4. Variation 14 is the one in the preview above. The same variation number always gives the same video, so you can share a link and get identical results.
Other scenes
- Spinning hexagon: The spinning hexagon test with a gap in one wall. The spin speeds up with every bounce.
- Escape the rings: A ball bounces inside 22 spinning rings. Each ring has a gap, and the ring breaks once the ball gets through it.
- Galton board: 300 balls fall through 12 rows of pegs. Each bin has its own note, so you hear the bell curve fill in.
- Growing ball: The ball gets a little bigger on every bounce until it fills the circle.
- Every bounce adds a ball: Every bounce can add another ball, up to 200 of them, while a slowly widening gap lets them out.
- 100 strings: Each hit ties a string to the ring and speeds the ball up. The ring has to hold 100 of them.
- Color war: Two balls paint the ring in their own colour. Whoever owns more of it after 30 seconds wins.
- Ball race: Four balls, one small spinning exit. First one out wins.