Tangible Cosmos · Interactive Science Classroom
The best way to understand the cosmos is
to touch it yourself
From the three-body problem to quantum entanglement — meet the core ideas of modern physics and cosmology through real-time simulations you control by hand. Every picture here is not a pre-rendered image, but a living model your browser draws right now by solving the physics equations itself. Even the three stars dancing in the background are real gravity in action. Each room comes with an in-depth explanation, the key equations, and a fold-out quiz to check your understanding.
↓ Scroll down, or pick a room from the table of contents on the left
PART I — Limits of Prediction
The paradox of classical mechanics: knowing the perfect laws still isn't enough to know the future
CH.01
The Three-Body Problem
Why Newtonian mechanics, flawless for two bodies, collapses in the face of three
▶ Gravity simulator · Figure-eight orbit · Twin universes · Lagrange points
CH.02
Chaos Theory
From the flap of a butterfly's wings to a storm — deterministic chaos
▶ Double pendulum · Lorenz butterfly attractor · Fractal zoom · Bifurcation diagram
CH.10
Entropy & the Arrow of Time
The laws are time-symmetric, so why does time flow in only one direction?
▶ Particle-box diffusion · Rewind experiment · Maxwell's demon
PART II — Time & Space (The Rediscovery)
Time and space are not absolute — Einstein's two revolutions
CH.03
Special Relativity
Move fast enough and time slows down while lengths contract
▶ Light clock · Time dilation & length contraction · Minkowski spacetime diagram
CH.04
General Relativity
Gravity is not a force but curved spacetime
▶ Spacetime fabric · Geodesic orbits · Gravitational-wave ripples
CH.05
Black Holes
A well in spacetime from which not even light can climb back out
▶ Gravitational-lensing observatory · Event horizon · Accretion disk
PART III — Birth & Structure of the Cosmos
Where did the universe come from, and where is it going?
CH.06
The Big Bang & Cosmic Expansion
Every galaxy is receding — space itself is swelling
▶ Hubble expansion simulator · The view from another galaxy · Cosmic timeline
CH.11
Dark Matter
The invisible scaffold of mass that holds galaxies together
▶ Galaxy rotation curve · Dark halo · Gravitational-lensing map
CH.12
The Life of Stars
Every element in our bodies is ash left behind by a star
▶ Build a star · HR-diagram evolutionary tracks · Supernovae and remnants
CH.13
Fate of the Universe
Eternal expansion or a Big Crunch — dark energy holds the key
▶ Friedmann-equation time machine · Three possible futures · Dark energy
PART IV — The Smallest World, Biggest Questions
The microscopic world where intuition breaks down, and the quest for a theory of everything
CH.07
Quantum Mechanics
A world that is a wave until you look, and a particle the moment you do
▶ Double slit · Wavefunction collapse · Quantum tunneling · Decoherence
CH.08
Quantum Entanglement
The spooky link between two particles, instant no matter how far apart
▶ Entangled-pair measurement · Bell correlation graph · The EPR paradox
CH.14
The Standard Model
The 17 fundamental particles that build the universe — the periodic table of matter
▶ Particle collider · Quarks and leptons · Force-carrier particles · The Higgs
CH.09
String Theory
Every particle is a different note played by a single string
▶ The string's music room · Point-particle vs. string scattering · Extra dimensions (Calabi-Yau)
PART V — Are We Alone?
The oldest question posed by observational astronomy — somewhere out among those stars, is there another us?
CH.15
Exoplanet Hunting
Finding invisible planets from the faintest flicker of starlight
▶ Transit light curve · Reconstructing planet size · Radial velocity
CH.16
The Drake Equation
How many civilizations are in the galaxy — and why is it so quiet?
▶ Drake-equation sliders · Civilization map · The Fermi paradox