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How a computer finds one flipped bit and fixes it: Hamming's code A bit can flip in memory, on a disk or in a radio signal, and nothing tells you which one went wrong. In 1950 Richard Hamming published a code that finds the… Computing4 min read9 Oct Why fishing less gave the Adriatic more sharks: foxes, rabbits and a loop When fishing slowed during the First World War, the Adriatic catch held a bigger share of sharks and rays, not a smaller one. Mathematician Vito Volterra… Biology3 min read8 Oct Why the Moon always shows us the same face: tidal locking The Moon does spin. It turns exactly once for every trip around the Earth, so the same face always points our way. Walk around a chair while always facing it… Earth & Space3 min read7 Oct Why 0.1 + 0.2 isn't 0.3: flip the 64 bits a computer uses for decimals Type 0.1 + 0.2 into almost any programming language and you get 0.30000000000000004. Nothing is broken. Computers count in powers of two, and a tenth is an… Computing3 min read6 Oct How a leopard gets its spots: Turing's two-chemical pattern machine A leopard's spots and a zebra's stripes start out as a smooth sheet of near-identical cells. In 1952 Alan Turing showed that two interacting chemicals, one… Biology3 min read5 Oct Why one day on Mercury lasts two Mercury years Mercury circles the Sun in 88 Earth days and spins once every 58.6 days. That odd pairing, three spins for every two orbits, means one sunrise to the next… Earth & Space3 min read4 Oct How a Bloom filter says "definitely not" using just a few bits How can a computer check whether a word is on a huge list using only a few bits per entry? A Bloom filter flips a handful of switches for every word you add… Computing3 min read3 Oct Why Spanish sounds faster than Vietnamese yet says just as much Listen to Spanish or Japanese and it seems to rush past; Vietnamese or Thai can sound almost unhurried. Yet when researchers timed 170 people reading the same… Language5 min read29 Sep Why astronauts float: the space station never stops falling Astronauts on the International Space Station look weightless, but at 400 km up, Earth's gravity is still about 90% as strong as on the ground. The trick is… Earth & Space4 min read28 Sep Why Mars sometimes walks backwards across the sky Every 26 months or so, Mars slows down, stops, and drifts backwards against the stars for a couple of months before carrying on. Ancient astronomers built… Earth & Space4 min read27 Sep Why English spelling doesn't match how words sound Around 1400, English spelling roughly matched speech. Bite sounded close to "beet", meet roughly like "mate", and house like "hoose". Then, over about three… Language5 min read26 Sep How a computer adds 7 + 1 using nothing but switches A computer chip has no idea what numbers are. It only has switches: billions of transistors that are either on or off. Yet wire a few of those switches into… Computing5 min read26 Sep