WING I · ÆTHER
Physics is what is left when you stop asking why. Everything in this wing is computed from the same few laws that run the universe outside your window — no footage, no recordings, nothing pre-baked. Push on any of it and see whether it pushes back correctly.
EXHIBIT I · GRAVITATION
Two bodies under gravity have a closed-form solution. Kepler wrote it down, and it is exact forever. Add a third and the problem stops being solvable — Poincaré proved in 1890 that no such formula exists, only integration, step by step, for as long as you care to watch.
The integrator here is symplectic, so the total energy wobbles about a constant instead of quietly draining away. The drift figure in the corner is the exhibit checking its own honesty: v += a·dt/2 · r += v·dt · v += a·dt/2.
drag on empty space to launch a mass · space pauses · pick a preset
EXHIBIT II · INTERFERENCE
Two slits, two overlapping circles of wave, and wherever crest meets trough the light cancels itself out. That much is Young's, from 1801, and it is why the bands appear at all.
The strange part came later. Turn the source down until photons arrive one at a time, hours apart, and the same striped pattern still assembles itself dot by dot — and there is nothing left for a single photon to interfere with except itself. Switch modes and wait. The noise is real, and so is what surfaces out of it.
The readout measures the band spacing off what has accumulated — a periodogram over the arriving photons, not the formula restated — and sets it beside two predictions. Δx = λL/d is the one in the textbook, and it is a small-angle approximation; the exact two-path geometry is the other. Watch them separate as the screen gets wide.
wave / one photon at a time · d slit gap · λ wavelength · moving the geometry clears the screen
EXHIBIT III · TIME DILATION
A clock made of two mirrors and one photon. At rest the photon goes straight up and straight down, and a tick is however long light takes to make the round trip.
Set the clock moving and the photon has to travel diagonally to keep up — a longer path, at exactly the same speed, because the speed of light is the one quantity not permitted to change. So the tick takes longer. Nothing has been done to time; the geometry simply ran out of other things to give. γ = 1/√(1 − β²)
drag β toward c · the moving grid is the lab frame · twin sends it out and back
EXHIBIT IV · ENTROPY
Two thousand discs, hard walls, perfectly elastic collisions. Every collision in here is reversible — film one, run it backwards, and you would see nothing wrong with it.
Take the partition out and the halves mix within seconds, and then they never unmix, however long you wait. Nothing forbids it. It is only that there are overwhelmingly more ways to be mixed than to be sorted, and the gas has no means of preferring the rare ones. Meanwhile the speed histogram finds Maxwell–Boltzmann on its own and stays there. f(v) ∝ v·e^(−mv²/2kT)
press remove partition · then try putting it back · N and T rescale the gas
EXHIBIT V · FIELDS
Faraday could not do the mathematics, so he drew what he pictured instead: lines threading out of one charge and into another, under tension, crowding together wherever the force is strong. Maxwell then proved the picture was exact.
These lines are not decoration and not a metaphor. Each one is an integral curve of the field, integrated from scratch every single frame — which is why they writhe the instant you move a charge. E = Σ kq r̂ / r²
drag a charge · + / − to add · equipotentials · drop a test charge and watch where it falls