01
Physics · Entry 001
Why Ice Floats
Most solids sink in their own liquid. Ice is weird.
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TOPICS
Every entry in the field guide. Short, true, sourced.
02
Space · Entry 002
Is Our Universe Inside a Black Hole?
What if everything you know - every star, every planet, every YOU - is sitting inside what we usually call the end of everything?
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Human Body · Entry 003
Why We Get Goosebumps
Hundreds of tiny muscles in your skin are still trying to fluff up fur you don't have.
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Animals · Entry 004
The Bird That Bent a Hook
A crow named Betty looked at a piece of straight garden wire and bent it into a hook to fish food out of a tube. She had never seen a hook before. Her brain does not have a cortex.
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Space · Entry 005
Why the Night Sky Is Dark
Look up at the night sky. Most of it is black. That single fact, by itself, tells you the universe is finite, that it had a beginning, and that it is expanding. It took us two hundred years to realize…
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Animals · Entry 006
The Water Bear That Knows When to Die
A tardigrade is a microscopic eight-legged animal smaller than a comma. It can survive boiling, freezing close to absolute zero, gamma rays a thousand times the dose that would kill a person, and ten days in the open vacuum of…
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Earth · Entry 007
The Woman Who Discovered the Greenhouse Effect
August 1856. In a small front yard in Seneca Falls, New York, a 37-year-old amateur scientist named Eunice Newton Foote sets two brass cylinders side by side in the sun. One holds ordinary air. The other holds carbon dioxide. After…
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Human Body · Entry 008
The Destitute Graduate Student Who Discovered Dreaming
December 1952. In a basement room at the University of Chicago, a 30-year-old graduate student with no money for rent has been studying the slow rolling eye movements of his eight-year-old son as the boy sleeps. For months the recording…
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Space · Entry 009
The Day the Sun Tried to Burn the Telegraph Down
September 1, 1859. In a private observatory south of London, a 33-year-old amateur astronomer is sketching the morning's sunspots on a sheet of paper when, between two of the largest spots, a sudden white-light flash erupts. Eighteen hours later, the…
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Entry 010
The Helix He Folded in Bed With the Flu
At Easter weekend in 1948, in Oxford, England, the 47-year-old chemist Linus Pauling was stuck in bed with a bad cold. He had spent years trying to explain how proteins could fold, using the rules of quantum chemistry and the…
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Entry 011
The Postdoc, the Pottery, and the Levitating Magnet
In April 1986, at IBM's research lab in Rüschlikon, Switzerland, two physicists working on a neglected line of ceramic chemistry made a result that overturned a long-standing limit in superconductivity. J. Georg Bednorz, a 36-year-old postdoctoral researcher, and his supervisor…
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Entry 012
Both Numbers Were True
In the autumn of 1973, the University of California, Berkeley faced a charge of discrimination in graduate admissions. Across the whole university, 44% of male applicants were admitted, compared with 35% of women, a difference large enough to seem real,…
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Entry 013
You Are Invited to See the Earth Turn
On 3 February 1851, in the Meridian Hall of the Paris Observatory, Léon Foucault set a long pendulum swinging and showed something no one had managed to demonstrate directly on the ground before: the Earth turns beneath us. Foucault was…
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Entry 014
The Place on Earth Where No Wind Blows
On the surface of Earth, there is always at least one place where the horizontal wind is zero. It might be the eye of a hurricane, a calm spot in a larger weather system, or a brief stagnation point where…
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Entry 015
Lightning in a Jar
In May 1953, at the University of Chicago, graduate student Stanley Lloyd Miller used a sealed glass apparatus, boiling water, methane, ammonia, hydrogen, and a spark to test an idea about the early Earth. Working under Nobel chemist Harold Clayton…
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Entry 016
The Weight of Light
In 1959, in the basement and tower of Harvard University's Jefferson Physical Laboratory in Cambridge, Massachusetts, physicist Robert Pound and graduate student Glen Rebka tested a prediction from Einstein's 1907 equivalence principle: light should change frequency when it moves in…
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Entry 017
The Needle That Almost No One Saw Move
On the evening of 21 April 1820, in a lecture room at the University of Copenhagen, Danish physicist Hans Christian Ørsted set up a test he had been seeking for years. He had been convinced that electricity and magnetism might…
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