Newton's Cradle Screensaver
Newton's Cradle is a free, in-browser screensaver of the executive desk toy, where one ball swings and momentum click-clacks through the row to launch the ball at the far end, forever. It runs instantly on a canvas with no download or install. Press ESC to exit.
How the Newton's Cradle screensaver works
A row of polished steel balls — 5 by default, adjustable from 3 to 7 — hangs from a bar by paired threads. Ball size and spacing are computed from the screen and ball count so the cradle always fits and stays evenly spaced.
The motion runs on a single repeating cycle split into four quarters. In the first quarter the left ball swings down to the row; in the second the right ball swings out; in the third it falls back; in the fourth the left ball swings out again — reproducing the familiar click-clack where only the end balls move while the middle stays still.
Each end ball's angle is driven by a sine or cosine curve across its quarter of the cycle, giving a natural ease in and out at the top of each swing. The middle balls are held at zero angle, exactly as in the real toy where the impulse passes straight through them.
The Speed setting sets the cycle length — higher speed means a shorter, faster swing — and each ball is shaded with a radial gradient from a white highlight to a darkened base so it reads as a reflective metal sphere.
A worked example
With the defaults — 5 balls, speed 4, ball color #cdd3dc on background #0c0e15 — five chrome spheres hang from a bar and the end balls take turns swinging out while the middle three stay put, repeating endlessly. Set Balls to 7 for a longer cradle, or push Speed to 10 to shorten the cycle into a brisk click-clack.
Settings & tips
- Use the Balls slider (3–7) to set how long the cradle is; only the two end balls ever swing.
- Adjust Speed (1–10) to set the swing rate — low for a slow, hypnotic sway, high for a snappy click-clack.
- Match the Ball color to your decor and pick a dark Background so the metallic highlights pop.
Frequently asked questions
- Is the Newton's Cradle screensaver free?
- Yes. It runs free in your browser with no download, install, or account. The cradle starts swinging as soon as the page loads.
- How do I exit the Newton's Cradle screensaver?
- Press the ESC key to exit at any time and return to the page.
- How many balls can the cradle have?
- The Balls slider lets you set between 3 and 7 balls. Only the two end balls swing while the middle ones stay still.
- Does it have click-clack sound?
- No, the screensaver is a silent visual animation of the desk toy's motion, so it stays quiet on an idle screen.
- Does Newton's Cradle work on a Mac or phone?
- Yes. It runs on an HTML canvas in any modern browser, so it works on Windows, macOS, Linux, and mobile devices without a plugin.