Double Pendulum

PHYSICSStudio

A real-time double pendulum chaos simulator with adjustable lengths, masses, gravity, and a fading trail.

UpdatedJan 2025

ExportsPNG, JPG

Runs onAny browser

PriceFree

Overview

A dynamic physics playground.

Double Pendulum solves the equations of motion for two rigid links connected at a pivot. The system is famously chaotic: identical initial conditions can diverge within a few seconds.

Drag the bobs to set a starting configuration, then watch the trail trace the second bob's path. Adjust the rod lengths, masses, gravity, and trail length in the sidebar to explore different regimes.

Features

Built for physics-scale experimentation.

01 / Spotlight

Real-time physics integration

Of two linked pendulum arms.

Tunable rod lengths

Bob masses, gravity, and trail fade for a single or multi-pendulum look.

Drag the bobs

To reposition; the trail traces the second bob's path through phase space.

How to use

Workflow

Steps take about a minute.

Drag either bob to set a starting angle, then let go. Use the sidebar to tune rod lengths, masses, gravity, and trail length. Use Reset to clear the trail, and Export PNG/JPG to save a snapshot.

Use cases

What people use it for

Demonstrating chaos theory and sensitive dependence on initial conditionsLearning about coupled equations of motion and pendulum mechanicsGenerating phase-space trail art for posters or coversInteractive physics demos for classrooms or presentations

FAQ

Common questions

Is this real double-pendulum physics?+

Yes. The solver integrates the full coupled equations of motion for two rigid links under gravity, with the standard small-angle caveat: very high speeds can introduce numerical error.

Why does the trail look different every time I run it?+

The system is chaotic — tiny changes in the starting angle or mass produce wildly different paths. Even with the same slider settings, two runs won't trace the same shape.