Arrow of time — why time has a single direction · entropy

ARROW OF TIME SIMULATION

▸ Initializing a deterministic particle system in the container…

▸ Loading the Second Law of Thermodynamics: ΔS ≥ 0

▸ Building 5 processes: ink · gas · mixing · shatter · heat

▸ Linking the entropy S vs time curve (only goes up)

▸ Enabling the Reverse switch (illustrates "looks wrong")…

▸ Ready — Online. ✅

Entropy clock

➡️ Disorder

Process—

Entropy (S)—

% mixed/diffused—

Time direction—

Reversible?—

Viewing—

Selected—

Notes

Macroscopic processes do not reverse on their own because entropy (disorder) only increases — that is the Second Law of Thermodynamics. Each molecular collision is reversible, but the number of "mixed" arrangements overwhelms the "clumped" ones, so the system always drifts toward disorder. The direction of rising entropy = the direction of the future.

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Drag the scrub bar below the scene (or ▶/⏸) to go from ORDER → DISORDER · click ⏪ Reverse to see the scene run backward (ink self-gathers, glass re-assembles) = looks wrong · click a "Scenario" to change process · click a process / concept for details

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Entropy S & % mixed over time — only goes UP in the forward direction entropy S% mixed