Interactive science, explained twice
Every answer, twice — and a machine to prove it.
Grab the thing. Drag it. Break it. Every question here comes with a simulator you can poke at, and an answer written two ways: plainly for a curious kid, and fully for the curious grown-up.
177 simulators · 13 fields · free, no sign-up
The idea · see it move, then read it twice
Drag the sun down to the horizon and watch the blue drain to red.
PLATE 01 · RAYLEIGH SCATTERING
Sun altitude 62° above horizon
Or just drag the sun across the sky.
Air the light crosses
1.1× noon
Blue scattered away
35%
What reaches your eye, by colour
violetred
Sunlight looks white but it's secretly every colour mixed together. Blue light is
the bounciest, so it ricochets off the air all over the sky — that's why the sky looks
blue. Drag the sun down low and the light has to travel through
so much more air that all the blue bounces away before it reaches you. Only the
warm reds get through — a sunset.
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Everyday Physics 20 platesOpen → Space & Astronomy 16 platesOpen → Electricity & Electronics 13 platesOpen → Computers, Visually 15 platesOpen → Chemistry 15 platesOpen → Biology 15 platesOpen → Mathematics, Made Visual 14 platesOpen → Your Body 16 platesOpen → Weather & the Earth 14 platesOpen → Myth-Busting 11 platesOpen → Heat & Energy 10 platesOpen → Engineering & Materials 7 platesOpen → Animals & Nature 12 platesOpen →
A few that surprise people · all 177 sit under their field ↑
Plate 41Open → What is a black hole, really? Fire a light ray past it — a wide pass whips by, a close one vanishes. Plate 38Open → The Monty Hall problem Play a round on your gut, then run two hundred and count. Plate 61Open → Why does the Moon cause tides? Spin Earth and watch your coast dip into a bulge twice a day. Plate 42Open → How do vaccines work? Run the vaccine, then face the real germ and watch memory crush it. Plate 63Open → Why can't you unscramble an egg? Stir the tidy box and watch disorder climb — un-mixing does nothing. Plate 56Open → How does GPS know where you are? Two rings leave you guessing; three pin you down.
— ;colony