5 Mind-Blowing Scientific Mysteries Solved Without Computers
People picture scientific experiments as the most awesomely advanced things possible, because that's literally what they are. They're how we walk up to the very edge of human understanding and start pushing, which can involve building things that make the pyramids look like a pile of stupid rocks in the desert.
We're not so much honoring the gods as firing anti-proton warning shots across their bows.
But there was a time when the most advanced technology was bashing rocks against each other, and we used them to hot wire the universe all the way up to Higgs bosons and international space stations. There is an unbroken chain between monkeys clutching shiny rocks and you with your cellphone.
A frighteningly clear parallel when it runs out of power.
We had the universe's number before we had enough computer power to play Pong.
The Speed of Light
Light: Simply understanding that it has a finite speed is a universe-bending realization. You get to face the fact that everything you see is stuck slightly in the past. (This is easier to believe when reading Supreme Court health care rulings.) You also have to deal with the implications of everything you see squirting energetic particles into your skull-holes.
Yet another reason never to meet Donald Trump in person.
The speed of light in a vacuum is also the speed limit of existence. For everything. Even the laws of physics. If the sun disappeared right now, Earth would continue to orbit for eight minutes before noticing and flying off into space, the exact opposite of a cartoon character running off a cliff. Ole Roemer first measured this universal upper limit back in 1676, when the most advanced light source was the oil lamp. Well, that's a lie. The most advanced light source was the mass-conversion fusion lamp, the same as it was through every moment of human history. But the best light source we'd built at the time was waiting until something died, squeezing it, and setting the death-goo on fire.
"Wow, humanity, that's good too, really."
Roemer was observing the orbit of Io, one of Jupiter's moons, and noticed that the time between eclipses changed as Earth moved toward and away from the satellite. He worked out that light must have a finite speed and did the math on observations spanning the solar system, and his result was off by only 25 percent. That is stunning. He was the first person to nail down the speed of light, and he did it before Newton had published classical mechanics. When others stared into the sky, they saw gods, or pretty shapes. Roemer stared down the universe until it confessed its greatest limitation. He worked out one of the greatest problems of existence using a couple of pieces of melted sand.
"And that Death Star's thermal exhaust port could be a problem."
He went on to become the chief of the Copenhagen police and install the city's first streetlights. Having mastered light, it was now his to command.
Speed of Light: Rise of the Machines
Measurements of reality's maximum racing speed continued with strategies including Fizeau's toothed wheel, Foucault's rotating mirror, and various other experiments that sound like magical items in a Dungeons & Dragons/Saw crossover. In 1924, Albert A. Michelson elevated these mechanical attempts to an unprecedented degree by measuring the speed of light between Mounts Wilson and San Antonio.
The core of the experiment was a rapidly rotating vertical octagonal mirror-column, so this experiment would have looked just as at home in an evil genius' lair or with a Chaos sorcerer attempting to summon the dark gods. Especially since the mirror-column was driven by compressed air, so it sounded like it was screaming. And it exploded at high speed in an early trial.
The experimental procedure was brilliant. Light from a high voltage arc light was directed to the rotating mirror on Mount Wilson. At precise angles, it would be reflected toward another mirror on Mount San Antonio, over 35 kilometers away. This light was reflected back to Mount Wilson, and if the mirror had rotated exactly the right amount in the time that took, it would be in position to reflect the light out for observation. When the output light shone, the speed of the mirror told you the speed of light.
The light started at Source S. Note how the apparatus masters light so well, it doubles as an early attempt at lightsaber design.
Light was observed at a speed of 528 rotations per second, giving a speed of light (with corrections for the atmosphere) of 299,820 kilometers per second, which differs from modern measurements by less than 4 km/s. They managed that with an arc light, a motor, a bunch of mirrors, and being up high. They used the parts for a lighthouse to build a light interrogation chamber.
The Charge on an Electron
When you think of someone working out fundamental subatomic values, you picture the sort of particle accelerator that could give Cybertron a colonoscopy. You don't picture a battery, metal plates, and dripping oil. In 1909, Robert A. Millikan and Harvey Fletcher worked out a fundamental constant of existence with the same equipment as someone fixing a leak on a Chevy pickup.
Or Rube Goldberg's cistern.
A mist of oil drops was squirted into a vacuum chamber between metal plates. Some of the drops would be charged by friction in the process, and only those drops could be drawn upward against gravity by an electric field between the plates. By observing through a lens and turning the field on and off, the experimenters measured the terminal velocity of drops as they rose and fell. This allowed them to calculate each droplet's mass and charge. They repeated this dozens of times for scores of drops and found that the charge was always a multiple of the same value: the charge on the electron.
They were able to measure subatomic values using submillimeter instruments. They defined one of the most fundamental particles in existence by staring at it through a lens and making it dance up and down like a cheap peepshow. They worked out the quantum of charge at a time when many people didn't believe charge even had one.
This is one of the experiments that gets across the part of science often missed in headlines: the atrocious amounts of hard and fiddly work. Science isn't a sudden moment of shouting "Eureka!" and sprinting down the street stark naked. It's the laborious hours of filling out all the paperwork resulting from public nudity.
And that's why scientists wear lab coats.
This mistake is why many people think they can argue about science the same way they argue about relationships, politics, and all the other imaginary human entertainments. They think that a single verbal counterpoint can undo what went before. But science is based on reams of data. Saying "That's just what they say" doesn't discount reams of empirical proof; it just announces who shouldn't be allowed in the room when the grown-ups are talking.
The Universal Constant of Gravitation Is a Load of Balls
Gravity is the weakest of the four fundamental forces. You normally need an entire planet to notice it. Some teachers demonstrate the weakness of the force by holding up two objects and saying, "There is gravitational attraction between these, but you can't see it." Henry Cavendish said, "You're just not looking hard enough."
"And Roemer is looking the wrong way."
Cavendish discovered hydrogen, weighed the entire planet, and pretty much single-handedly discovered most of the next century's progress in electromagnetism, but he only bothered to tell people about the first two. We found out about the other stuff when other scientists examined his notes a century after his death and discovered that he'd kept quiet about pretty much solving the universe because he didn't want to bother anyone.
His apparatus was first built by the Rev. John Michell, who sadly died before being able to undertake the experiment, and it passed on to Cavendish. He ended up upgrading most of it in order to weigh the world in his shed, which is not a euphemism for using an outhouse.
"Forget the weight of the Earth. Last night's Chili's now feels more like the atmosphere of Venus."
The apparatus was a horizontal rod suspended from the center by a twisting string. Large lead spheres at the end of the rod were attracted to smaller spheres suspended about 20 centimeters away from the ends. By measuring the twist of the wire, the force between the spheres could be measured. By measuring the oscillation of the wire, the tension constant of the wire could be found. Between them, these gave a relation between the weight of the spheres and the weight of the planet. And the smaller spheres weighed less than 2 kilograms. He caught the universal force of gravitation with less lead than some people need to bag a goose. (Of course he had those big balls too, but that goes without saying when someone takes on the weight of the entire world they're standing on).
"Forget progress, I'm winning fights with unarmed birds!"
The experiment was ridiculously sensitive, and observations would take hours. He measured the swaying rods inside a closed box using small holes and telescopes, which meant he must have looked like the first Internet user, going out to peer into a box for hours while working on his balls.
"But remember, we tell stock photo that I'm 'typing,' OK?"
He determined the average density of the Earth, around five and a half times that of water, and his final answer was only 1 percent off. He measured the planet with hardware that looked like a playground toy. He took on the world with weights most people wouldn't even use as a warm-up. The results would be used to find the mass of the planet and the first accurate value for G, the universal constant of gravitation, one of the startup constants for our entire reality. He performed this experiment before we built the first steam-powered railway.
Wave Nature of Light
The double slit experiment sounds like ladies inventing a kind of sex that doesn't need men, but had even more amazing effects on the world: It proved the wave nature of light. One of the most ridiculous conclusions of light's wave nature is that two waves can cancel each other out if conditions are right: Two lights can make a dark. It was ridiculous right up until Thomas Young demonstrated it at the start of the 19th century.
Young shone sunlight through one slit to get a source, then directed that through two more slits, but got a huge number of lines on the screen, which sounds like a glitch in reality's graphic engine, but is exactly what happened. The light waves from the two slits have to travel different distances to reach a point on the board. The waves add up or cancel each other out depending on how far they have to travel (and also whether they arrive lined up with each other or out of phase). The result is that instead of two bands of light, you get a central bright line and alternating bands of light and dark, like reality's bar code. Young's original patterns consisted of several colors of bands due to the multiple wavelengths in sunlight. With lasers, we can now get crisp patterns.
KITT is built into all of reality, not just a car.
It's one of the most striking results in physics, which was useful for Young, because at the time he was going up against the theories of Isaac Newton, who said that light moved in straight lines as particles. But the great thing about science is that it doesn't matter who said something, only what they said, and whether it can be tested. Science is built to boil out as much petty human bullshit as possible so that we can get on with achieving things. Quantum mechanics would later turn this fundamental conflict into a Sesame Street episode, explaining that Newton and Young were both right, but that they'd have to work together if they wanted to solve even more exciting problems. Little things like the structure of reality and the beginning of time.
You know, those things we're working on right now.
Luke enjoys more research in the Search for the Perfect Martini Ratio and applies military processing to personal interaction with Conversational SIGINT.
Behold more science with positronium annihilation gamma-ray lasers in 6 Man-Made Materials You Won't Believe Exist and intergalactic hypervelocity stars with 5 Awesome Stars from Beyond the Other Stars.
Luke has a website, tumbles, and responds to every single tweet.
