Most of the time when we talk about science, there are a lot of careful methods and meticulous calculations involved.

But occasionally, it can get a bit … unconventional. Over the years, there have been some things done in the name of science that were pretty outrageous, even if they taught us something along the way.

Some of them were just outrageously stupid. Others were both stupid and really sad. Here are six of them. [1.

Isaac Newton] Isaac Newton is best known for discovering gravity, but he also did a lot of research in optics. Around 1665, he began studying prisms and how they interact with light, and his experiments were among the first to demonstrate that white light can be split up into a spectrum of colors. But his curiosity about light and color wasn’t limited to physics.

He was also interested in how the mind perceived the idea of color, and how physical sensations in his eye could affect his perception. So he stuck a bodkin -- aka a long thin needle -- almost directly into his eye. Or more specifically, between his eyeball and the bone near the back of his eye socket.

Because that’s totally a great idea. He used the bodkin to poke different parts along his eyeball, and he noticed that different colored spots would appear. He also found that the colors changed depending on the pressure he applied and the amount of light in the room.

For a less dangerous and terrifying experiment, you can see something similar if you rub your eyes while they’re closed. We now know that what Newton experienced came from photoreceptors called cones, which are specialized cells in your retina. Cone cells contribute to your perception of color by responding to different wavelengths of light.

By applying pressure to his eyeball, Newton was essentially stimulating these cells as if they were being hit by light. Which I’m sure was cool, but you’d think Newton would’ve realized that eyes are pretty delicate, and that poking them with a giant needle would be risky. He was okay, but that doesn’t mean it was a smart thing to do. [2.

Isaac Newton, AGAIN] The bodkin incident wasn’t the only time Newton was careless with his eyes. He also performed an experiment where he was trying to evoke afterimages — those fuzzy shapes or spots you see after looking at a bright light, like a camera flash. Afterimages happen when the photoreceptor cells in your retina become overstimulated, and remain active for a while even after the light is gone.

To recreate this effect, Newton decided to go into a dark room with a mirror and stare at the reflection of the sun with his right eye. When he looked away, he noticed a spot. So he stared at the sun again.

And again. Because sometimes you don’t learn the first time. After a while, he noticed that the image of the sun had made such a lasting impression that he could even see the spot if he closed his right eye and opened his left one.

And he realized he might have damaged his eyes when he couldn’t see anything but the image of the sun wherever he looked. So, he locked himself in a dark room for about three days until his vision started to return, but it took several months to go back to normal. Today, we know that Newton likely suffered from solar retinopathy, or damage to the retina caused by bright light or ultraviolet rays from the sun.

That’s why wearing protective eyewear while welding or watching a solar eclipse is so important. [3. Sir Humphrey Davy ] Speaking of precautions, if you’ve ever taken a science class, you probably know that safety is the first thing you talk about when you step foot in a lab. Well, unless it’s 1799 and you’re working with Sir Humphrey Davy.

Before Davy became one of the most famous figures in science history, he was a lab assistant at the Pneumatic Institution in England. And his work was focused on determining the medical uses for different gases. He tested them by setting up reactions, then inhaling the unknown gas products and noting their effects, without any idea of how dangerous the gases might be.

One gas, which Davy’s boss had worked with before, had especially unusual effects. It was nitrous oxide, and when Davy inhaled it, he felt like his senses were heightened, and had the urge to laugh at everything. We still don’t totally understand how nitrous oxide works in our bodies, but we do know that it can lead to euphoria.

It’s also associated with reduced anxiety and a higher threshold for pain, which is why some dentists use it. Typically, dentists give patients a dose of half nitrous oxide and half oxygen at about 5 liters per minute. But on one occasion, Davy inhaled about 15 liters of pure nitrous oxide in 7 minutes to determine the effects of the dosage.

And, thankfully, didn’t hurt himself. Instead, he liked the experience so much that, after work hours, he encouraged his friends to inhale it out of silk bags. It became almost a social trend, used by poets and philosophers to heighten their senses and supposedly bring them closer to their art.

Davy’s risk-taking helped launch his fame as a chemist, and a few years later, he discovered the elements sodium, potassium, calcium, magnesium, strontium, and barium. Which is an impressively long list. But he didn’t do it by inhaling them.

Still, during his career, he did breathe in a lot more than the relatively harmless nitrous oxide. All the exposure to toxic gases probably took a toll on his health, and at just over the age of 50, he quickly became ill and suffered a stroke and heart attack. Davy had one of the most successful careers in science, but ultimately, the thing caused him to rise to fame also likely caused his death. [4.

Stubbins Ffirth] Another risk-taker was Stubbins Ffirth, who arguably has one of the coolest names in science. He also has one of the most disgusting stories, so … you’ve been warned. In 1804, to obtain his medical degree, Ffirth put his life on the line to research yellow fever.

It’s a viral disease that can cause fever, muscle and joint pain, and jaundice — or yellowing of the skin, which is where the name comes from. It’s a common virus in tropical areas, but in 1793, a large epidemic killed thousands of people in Philadelphia. The prominent doctors at the time hypothesized that the disease was due to rotten coffee imports, brackish water, or something called miasma — by which they basically meant “bad air.” But Ffirth wanted to figure out the true cause of the disease, and he suspected it had to do with the patients ’ black vomit.

And that’s where it got nasty. First, he fed the vomit to dogs. They wouldn’t get sick, so he injected it into the veins of both dogs and cats — but there were no results there, either.

So he decided to expose himself to it. Which was noble of him, I guess, but still very dumb. He poured vomit into open cuts and into his eyes, boiled it and inhaled the gases, and eventually just drank the stuff.

And when he still didn’t get sick, he repeated the experiments using other bodily fluids from infected patients. Ultimately, despite all these dangerous experiments, he never got sick, so he concluded that yellow fever couldn’t be an infectious disease. What Ffirth didn’t know is that infectious diseases don’t always pass from person to person directly.

Because we’ve since learned that yellow fever is actually spread by mosquitos. Thankfully, we also now have a vaccine and preventative measures to protect us from the virus. And it doesn’t even involve drinking bodily fluids! [5.

Louis Slotin] Over a hundred years later, in the 1940s, scientists like Louis Slotin were still making bad decisions — except this time, they involved nuclear weapons. So the stakes were a little higher. It was a few months after World War II ended, and the scientists who’d developed the first two atomic bombs at the secret Los Alamos Laboratory in New Mexico were studying a third nuclear core.

If the war had still been going, it would’ve been developed into another bomb. But since the war was over, they were instead using it to study exactly what happens when a nuclear reactor goes supercritical, and how to get it there. Nuclear reactors work because elements like plutonium radiate neutrons.

And when there are enough free neutrons bouncing around in an enclosed space, it can create a self-sustaining chain reaction. If the reaction rate gets high enough, it becomes supercritical, and the plutonium atoms split apart in fission reactions that release a ton of energy. Slotin led a team that worked on the third plutonium core, trying to bring the reaction as close to supercritical as possible so they could study it.

Their core was surrounded by two halves of a beryllium sphere, which was great at reflecting neutrons and letting them bounce around. To prevent the core from going supercritical, Slotin needed to keep the two halves of the beryllium sphere separated, so the reaction couldn’t get out of control. Except, instead of using the pre-approved spacing blocks, Slotin just wedged a screwdriver between the two halves.

It had worked a dozen times before, and he was the expert, so why not? But Slotin should have realized how dangerous it was. His predecessor, Harry Daghlian, had died from radiation poisoning just months earlier.

From the same plutonium core. In Daghlian’s case, he was conducting an experiment that used bricks to reflect the neutrons. At one point, a brick slipped out of his hands, making the reactor go supercritical.

He was able to knock off the brick and stop the reaction, but his exposure to the radiation killed him after only 25 days. Despite that accident, Slotin just kept using his screwdriver. And this time, it didn’t go so well.

As he slowly lowered the two halves closer and closer together, the screwdriver slipped. The nuclear core immediately created a fission reaction, causing a radioactive flash of blue light. After only 9 days, Slotin died of severe radiation poisoning.

It’s calculated that he was exposed to 1000 rads of radiation — more than twice the lethal dose. After his death, the core was dubbed the “demon core”, and all hands-on criticality research at Los Alamos was terminated. [6. Werner Forssmann] In 1956, Werner Forssmann, André Cournand, and Dickinson Richards collectively won the Nobel Prize for Physiology or Medicine for their work on a technique known as heart catheterization.

But the research actually began almost 30 years earlier in 1929, when Forssmann broke all the rules to prove a point. Fresh out of medical school, he began a surgical residency, which allowed him to pursue one of his big ideas. He’d read about inserting catheters into the animals’ hearts as a diagnostic technique to measure the pressure in their hearts.

And he wondered if this was possible in humans, too. His mentor supported his ideas, but like any reasonable person, encouraged him to do more research to make sure the procedure was safe. But Forssmann was convinced that it was doable, so he went ahead and tried it ... on himself.

He used a ureteral catheter — a long, skinny tube normally used to drain urine from bladders — and inserted it into a major vein in his arm. Then, he pushed the catheter about 65 centimeters up his vein towards his heart. As if that wasn’t intense enough, he casually walked through the hospital to the X-ray room — with the catheter still in his arm! — and had a nurse help him use the X-ray to guide the catheter into a chamber in his heart.

It was really risky, and Forssman got in trouble with the hospital for breaking the rules, but it worked! And over 10 years later, thanks to additional work by Cournand and Richards, heart catheterization became accepted in the medical community. In the end, it might have been worth it for Forssmann, since he was fine and the experiment eventually led to a Nobel Prize.

But he risked both his career and his life in the process — and as scientists like Davy and Slotin learned the hard way, ignoring safety can end in tragedy. From their stories, we can learn how to become better scientists and curious thinkers — but we can also learn to have more common sense than they did. Because, sometimes, really smart people can make really bad decisions.

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