See Why

Ten pictures

Math you can see

Einstein thought in pictures. So did the Greeks. A number is just the picture, folded small — and every picture here is already in your life.

Einstein, 1905 — the explainer

E=mc2

A rock on a table looks like stuff. The picture: stuff is a kick that hasn’t happened yet. Push the lump. Unbind it. See why a kilogram is a fortune sitting still.

Open E = mc²

From Greece

  1. 01Why a circle is a little more than 3 squaresCut it. Stack it. Trap it. The short formula is just the picture, folded small.Archimedes, on the island of SyracuseOpen Why a circle is a little more than 3 squares
  2. 02How big is the Earth?One stick. One well. One long walk. That’s enough to measure the whole world.Eratosthenes, in the library at AlexandriaOpen How big is the Earth?
  3. 03How tall is the pyramid?You can’t climb it. You can wait for your shadow — and let the sun do the climbing.Thales, standing in the sand in EgyptOpen How tall is the pyramid?
  4. 04The two small squares fill the big oneA corner that makes an L. Three squares growing off it. Two of them pour into the third.Pythagoras, and everyone who ever tiled a floorOpen The two small squares fill the big one

Then the dent

  1. 06Space is a dent, not a pullNobody tied a rope from the Earth to the sun. The floor of the world is bent, and we slide.Einstein, 1915Open Space is a dent, not a pull

Then it moves

A point on a circle. Watch only the height. The snake that walks out is sound, radio, and light — the same walk, unrolled in time.

  1. 07A circle, unrolled, is a waveA point going around. Watch only the height. That snake is sound, light, and every radio in your pocket.The same circle. Written in time.Open A circle, unrolled, is a wave

A floor, counted twice

Three lengths become a square. The leftover rooms are the 2 in the sentence — each pair, twice.

  1. 08The big square is three squares plus the pairsThree lengths, squared. The leftover rooms are why the 2 is in the sentence.A floor, counted two waysOpen The big square is three squares plus the pairs

Then it grows

Each square is the last two, added. A quarter-turn in each. A spiral walks out.

  1. 09Grow by adding. Turn by a quarter.Each square is the last two, added. A quarter-circle in each. A spiral walks out.The same squares. Born again.Open Grow by adding. Turn by a quarter.

Found before it was seen

Uranus left its ring. The leftover walk drew an X in the sky. In 1846 a telescope landed on the X, and the planet was already there.

  1. 10A planet found by the path, not the glanceUranus would not stay on its ring. The leftover walk drew an X. The planet was sitting on it.Le Verrier’s sum, then Galle’s glass, 1846Open A planet found by the path, not the glance
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