Particle Physics Playground

Freeform Feynman diagram sandbox, parameter tuning, and physics challenges

Free Exploration

You've learned the fundamentals — now explore freely! Build any Feynman diagram you can imagine, tune the parameters of the Standard Model to see what happens, test your knowledge with challenges, and explore the full Standard Model overview.

Interaction Builder

A full-featured Feynman diagram sandbox. Place vertices, connect them with propagators of any type, and build complex interaction diagrams from scratch.

0 vertices, 0 propagators

What If? Parameter Explorer

What would the universe look like if the electron were heavier? If the strong force were weaker? Tune the fundamental parameters and see whether atoms, nuclei, and chemistry can still exist.

0.51 MeV
2.16 MeV
4.67 MeV
137
0.118
246.00 GeV
This universe can support life

Physics Challenges

Test your particle physics knowledge with a series of challenges covering particles, forces, conservation laws, and Feynman diagrams.

Challenge 1 of 5

The Complete Standard Model

See all 17 fundamental particles and their interactions in a single beautiful overview. Click any particle to highlight which forces it participates in.

Click a particle to highlight its interactions
QuarksLeptonsGaugeHiggs

Decay Calculator

Select any particle and see its decay modes, branching ratios, and lifetime. Watch a population of particles decay in real time following the exponential law.

500
τ = 1560.0 ×10⁻²⁵ s

Congratulations!

You've explored the full Standard Model of particle physics — from the particle zoo to Feynman diagrams, from QCD confinement to the Higgs mechanism, from collider physics to conservation laws. The Standard Model is humanity's most precise description of nature at the fundamental level. Keep exploring!