Watch the Second Law of Thermodynamics in real-time: dS/dt ≥ 0
Green (S): Entropy increases from LOW → HIGH (ordered → disordered)
Red (dS/dt): Rate of increase starts HIGH → decays to ZERO (exponential approach to equilibrium)
The Second Law: dS/dt ≥ 0 - entropy ALWAYS increases!
Notice how when entropy climbs rapidly (steep green), the rate is high (red peak). As entropy levels off, the rate decays toward zero.
This is irreversible! You can't un-scramble an egg. Time flows forward because entropy increases.
There are actually multiple "arrows of time" that all mysteriously point the same direction:
1. Thermodynamic: Entropy increases (this simulation!)
2. Cosmological: Universe expands
3. Psychological: We remember past, not future
4. Causal: Causes precede effects
5. Radiation: Waves spread outward, not inward
The mystery: Most fundamental physics laws (Newton, Maxwell, Schrödinger) are time-reversible - they work equally well backward and forward! But the Second Law is the only fundamental asymmetry that breaks this symmetry.
This simulation shows the arrow of time in action. The particles will NEVER spontaneously return to their clustered state. That's why you can't un-break a glass or watch smoke flow back into a cigarette.