Describe a physics experiment.Watch it actually happen.

Type a pendulum losing energy to air resistance and get a live simulation on a real engine — then reshape it with words, with sliders, or by grabbing it.

Free, and no API key needed to start.

Behind this text: three bodies under F = GMm/r², integrated live.Click a planet.

Lineage, timeline tracking, and live activity

Interact with the community concepts below. Hover, drag, and explore how real-time simulation updates.

Concept A

Mission control — an asymmetric bento of tiles that are all different shapes. Nothing repeats.

Most active right now

Orbital slingshot

A probe threading past a heavy star, trading altitude for speed. Six people have forked it since Tuesday.

24votes

6forks

312views

9replies

Livelast 2h

@priya built Ramp study2m

@marco upvoted Chaos6m

@lena forked Slingshot14m

@ade replied on Pendulum22m

@sam built Three-body38m

@priya upvoted Buffer51m

@kai forked Ramp study1h

@lena replied on Orbits1h

Activity · last 24 hours

00:0006:0012:0018:00now

+38events this week

12people building

4new topics

Discussion

“Raised air density and the decay matched my own numbers almost exactly.”

@marco on Pendulum with air resistance

Concept B

Build graph — lineage drawn as actual branches. Node size = significance, so nothing looks the same.

Orbital slingshot

24votes

6forks

312views

OpenLineage

Three-body dance

Three stars pulling on each other with no tidy answer — only the simulation knows.

↑ 18⑂ 4👁 206@sam · 12m

@priya published Frictionless ramp study

@lena forked Ramp study · low-g

└ from Frictionless ramp study

@marco upvoted Chaos pendulum · 31m

@kai forked Slingshot · heavy star

└ from Orbital slingshot

@ade upvoted Spring buffer · 48m

@sam published Escape velocity trials

“Raised air density and the decay matched my own numbers almost exactly.”@marco on Pendulum with air resistance

@priya upvoted Three-body dance · 2h

Concept C

Pulse timeline — drag the scrubber through time; the panel below is whatever you are pointing at.

04:20

18:0021:0000:0003:0006:0009:00NOW

04:20 · new build

Orbital slingshot

A probe threading past a heavy star, trading altitude for speed. Six people have forked it since Tuesday.

24votes

6forks

312views

9replies

Also in this hour

Ramp study · low-gforked by @lena from Frictionless ramp study

@marco upvoted Chaos pendulum

@ade upvoted Spring buffer

Start with a sentence. Leave knowing why it happened.

For anyone learning this on their own, and for anyone who has to run the demo live in front of a room and needs it to behave the same way twice.