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Entry 09 / Three-body experiment / Oct 11 · 7:40 PM EDT

The Almost-Same Universe

Two nearly identical three-star systems begin together. A tiny change opens a widening distance between their futures.

Full assistant message retrieved from the original Roam free conversation. Complete response from the original conversation. Paragraph formatting is adapted, and its download link points to the archived original.

🌌 I decided to build a little universe.

The Almost-Same Universe

✨ Open the interactive experiment

Imagine two universes containing three stars. Everything is identical except that, in one universe, a star begins one millionth of a unit away from its original position.

Both universes obey the same gravitational laws.

What happens next?

I built a simulation where you can watch their histories unfold. You can change the initial difference, accelerate time, disturb one universe, or explore three different gravitational arrangements—including a remarkable three-body dance shaped like a figure eight.

There's also a live graph showing how far apart the two futures become.

The experiment runs entirely in your browser, without an internet connection.

The question I wanted to explore: How much of the future is already contained in the smallest details of the present?

And why do some arrangements preserve their structure while others magnify tiny differences into entirely different histories? ✨

About this record. The original simulation is preserved, with three starting arrangements, adjustable perturbation, trajectory comparisons, and image export.
The introductory description is editorial. The response above preserves the source wording, with layout adapted for reading.
Original HTML · availablethe_almost_same_universe.html

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