Auroras: The Northern Lights
Charged particles from the Sun, steered down the magnetic field, make the air glow. With a storm dial that widens the auroral oval, an altitude cross-section that shows why height decides the colour, and a four-question quiz.
Open the explainer → History · slide deckGutenberg’s printing press
How Gutenberg's press worked — movable type, the hand mold, the ink, the press — and why it broke the Church's monopoly on knowledge.
Open the deck → PhysicsThe Doppler effect
Why a siren rises then drops as it passes — pitch is an arrival rate, and a moving source bunches the waves ahead and stretches them behind. With a live wavefront sim and a speed-to-pitch slider.
Open the explainer → Film · slide deckFilm noir: the grammar of shadow
How to read a film-noir frame: low-key light, venetian-blind bars, the canted angle, and the doomed voiceover. With a light-lab that splits a face into shadow, a tilt-and-bars composer, and an annotated frame to decode.
Open the deck → PolicyThe EU AI Act
How Europe's AI law works — the four risk tiers, the fines, and the post-Omnibus 2026 timeline. With a risk pyramid, an eight-system classifier, a worked high-risk compliance example, and a live fines calculator.
Open the explainer → Law · slide deckWhat "fair use" actually means
A four-factor balancing test decided case by case, with no word count or 10% rule. The landmark cases, the Warhol recalibration, and a scenario tool that scores your read against the courts.
Open the deck → EconomicsHow fractional reserve banking works
Banks keep a sliver of your deposit and lend the rest, and that lending creates most of the broad money in the economy. With a live ledger, the money multiplier, and where the textbook model breaks down.
Open the explainer → Equity comp · slide deckISO vs. NSO stock options
Both give a startup employee the same right — buy shares at a fixed strike. The difference is when the IRS taxes the spread, and at what rate. With a four-slider exercise-and-sale calculator, a two-clock holding-period demo, and the 2026 AMT numbers.
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