Simulator

An empty stage: nothing is here until you switch it on. Every concept in the physics directory is a module — particles are matter you can place, laws are rules you can enable, theorems are instruments that measure the running world, and the fundamental constants are dials set to their real CODATA values. The engine runs in raw SI, double precision, end to end; magnitude is handled by a logarithmic zoom from femtometers to planetary orbits and a time warp from attoseconds to days per second, and the equation stack shows exactly what is being integrated at any moment. Key experiments load as presets: Cavendish weighing the Earth, Rutherford discovering the nucleus, Millikan balancing an oil droplet until the charge comes out an integer.

What can be switched on

Matter

Particles you can place in the vacuum, with PDG masses, charges, and lifetimes.

• Higgs Boson — charge 0 (neutral)
• Electron — charge −1 e
• Positron — charge +1 e
• Proton — charge +1 e
• Neutron — charge 0 (neutral)
• Up Quark — confined; never observed free
• Down Quark — confined; never observed free
• Charm Quark — confined; never observed free
• Strange Quark — confined; never observed free
• Top Quark — confined; never observed free
• Bottom Quark — confined; never observed free
• Photon — charge 0 (neutral)
• W Boson — charge ±1 e
• Z Boson — charge 0 (neutral)
• Gluon — confined; never observed free
• Electron Neutrino — identity only in this regime
• Muon Neutrino — identity only in this regime
• Tau Neutrino — identity only in this regime
• Muon — charge −1 e
• Tau Lepton — charge −1 e

Rules

Interaction laws you switch on. The equation stack shows exactly what is being integrated.

• Newton's Laws of Motion — F = m·a
• Law of Universal Gravitation — F = G·m₁·m₂/r²
• Maxwell's Equations — F = q₁·q₂/4πε₀r²

Constants

CODATA values, adjustable. Real physics by default; counterfactual physics on request.

• Speed of Light — c = 299792458 m·s⁻¹
• Planck Constant — h = 6.62607015 × 10⁻³⁴ J·Hz⁻¹
• Reduced Planck Constant — ħ = 1.054571817 × 10⁻³⁴ J·s
• Gravitational Constant — G = 6.6743 × 10⁻¹¹ m³·kg⁻¹·s⁻²
• Elementary Charge — e = 1.602176634 × 10⁻¹⁹ C
• Boltzmann Constant — k_B = 1.380649 × 10⁻²³ J·K⁻¹
• Avogadro Constant — N_A = 6.02214076 × 10²³ mol⁻¹
• Fine-Structure Constant — α = 0.0072973525643
• Electron Mass — mₑ = 9.1093837139 × 10⁻³¹ kg
• Proton Mass — mₚ = 1.67262192595 × 10⁻²⁷ kg
• Neutron Mass — mₙ = 1.67492750056 × 10⁻²⁷ kg
• Rydberg Constant — R∞ = 10973731.568157 m⁻¹
• Bohr Radius — a₀ = 5.29177210544 × 10⁻¹¹ m
• Vacuum Permittivity — ε₀ = 8.8541878188 × 10⁻¹² F·m⁻¹
• Vacuum Permeability — μ₀ = 1.25663706127 × 10⁻⁶ N·A⁻²
• Molar Gas Constant — R = 8.314462618 J·mol⁻¹·K⁻¹
• Stefan-Boltzmann Constant — σ = 5.670374419 × 10⁻⁸ W·m⁻²·K⁻⁴
• Faraday Constant — F = 96485.33212 C·mol⁻¹
• Atomic Mass Constant — u = 1.66053906892 × 10⁻²⁷ kg
• Bohr Magneton — μ_B = 9.2740100657 × 10⁻²⁴ J·T⁻¹
• Compton Wavelength — λ_C = 2.42631023538 × 10⁻¹² m
• Classical Electron Radius — rₑ = 2.8179403205 × 10⁻¹⁵ m
• Standard Gravity — g₀ = 9.80665 m·s⁻²
• Wien Displacement Constant — b = 0.002897771955 m·K

Instruments

Theorems as measurement: readouts that watch the running world.

• Noether's Theorem

Experiments

Key experiments as reproducible preset configurations.

• Rutherford Gold Foil Experiment — Alpha-particle scattering experiment that revealed the dense, positively charged atomic nucleus.
• Millikan Oil Drop Experiment — Measured the elementary electric charge of a single electron.
• Cavendish Experiment — First laboratory measurement of the gravitational attraction between masses, weighing the Earth.

This is the classical regime: Newtonian point dynamics under gravity and electrostatics, integrated symplectically with an adaptive timestep. There is no radiation reaction, no speed limit, and no quantum behavior here yet — those arrive as further regimes, honestly labelled. Particle data joins the Particle Data Group (CC BY 4.0); constants are CODATA 2022 values from NIST.