7 Mind-Bending Physics Sims People Built with Claude Opus 5.5
Physics is the unexpected breakout genre of the Claude Opus 5.5 wave. Instead of asking the model to explain how something works, builders are asking it to construct the thing and let you poke at it. The numbers show people are hungry for it: a camera lens simulator pulled 3.4M views and 16,011 likes, a life-size LEGO Microduck design hit 8,689 likes, and an official Millrace gristmill demo cleared 10,891 likes.
What unites these seven builds is that the physics is the interface. You drag a focus ring and watch glass elements shift. You throttle a rocket engine and watch shock diamonds bloom. You swing a magnet through a coil and read the EMF off an oscilloscope. Several were one-shotted, and the ones that weren't still came together in hours, not weeks.
Here are the seven most viral physics builds in the directory, ranked by virality score, with what makes each one worth your time.
01
DemoMillrace — Overshot Gristmill Simulator
by Claude (@claudeai)· 1.9M followers
♥ 10.9K · 788.4K views· Oct 2, 2026
The official @claudeai account showed off Millrace, an overshot gristmill you operate by adjusting sluice gate opening and head pressure. Flow in L/s, wheel RPM, torque and flour output all update live. It earned 10,891 likes and 788k views. What stands out is the engineering depth: section, explode and wireframe views turn a toy into a proper teardown tool.
“Lots of inventive things made with Claude these past few weeks. A few of our favorites: A working watermill, built with Opus 5.5. ”
02
DemoInduction Bench — Live Electromagnetic Field Lab
by The Bugged Dev (@thebuggeddev)· 14.7K followers
♥ 2.8K · 322.3K views· Sep 28, 2026
@thebuggeddev shipped Induction Bench, a full electromagnetic induction lab in the browser. A magnet swings through a copper coil while field lines glow on a log scale from 1 mT to 1 T, next to a galvanometer, oscilloscope and flux-linkage plot. It has 2,789 likes and 322k views. Tweak turns, wire material and coil angle and the readouts respond, which is rare for a one-page demo.
“Maybe if physics had always been this easy to visualize and learn, we might have had more physicists than ever. AI is making learning so much easier to understand and actually fun. This is an electromagnetic field visualization built using Claude Opus 5.5. I do not think I have ever understood this subject better than I did by simply seeing it visualized like this 😅”
What this tells us
The pattern across all seven is that Opus 5.5 is not just generating pretty visuals; it is building models with internal consistency. Flow rates feed RPM, RPM feeds power, field lines feed EMF. People share these because you can interact with them and the numbers hold together. The highest-scoring entry, the lens lab, was a single prompt and 86 minutes of runtime. Expect more builders to treat the model as a simulation engineer rather than an illustrator, especially for education and engineering explainers.