2
The Magic of Two
The smallest number that can make things grow, split evenly, and run every computer on Earth.
1 · Doubling
Keep doubling
Start with 1. Double it. Double again. It looks slow, then suddenly it explodes.
1
Step 0: 2⁰ = 1
2 · Binary
Computers count in twos
Every switch is off or on, so there are only 2 choices. Tap the switches to make any number from 0 to 255.
0
8 switches make 2×2×2×2×2×2×2×2 = 256 patterns. That's one byte.
3 · Even numbers
Fair shares
Every number that splits into 2 equal groups is even. They light up every other step: 2, 4, 6, 8…
Even + even = even. Odd + odd = even too! Odd + even = odd.
4 · Fold to the Moon
Folding paper
Each fold doubles a 0.1 mm sheet of paper. How many folds to reach the Moon, 384,400 km away?
0.1 mm
0 folds