Lies You Learned In Science Class

The world is full of incredibly awesome natural phenomena. Unfortunately, the shiniest of these phenomena you learned about as a child does not exist. Diamonds, the story goes, are made from coal that's been subjected to a huge amount of pressure. Superman says so, so it must be true, right?

But according to Dr. Kat Arney and The Naked Scientists, geological studies have shown natural diamonds were actually created about a billion years ago by factors such as temperatures in the thousands of degrees and the kind of pressure you'd feel if you had around 100 miles of earth and rock on top of you. Those forces acted on carbon-rich minerals to form diamonds, and diamonds can also be formed by high-impact strikes caused by meteorites either hitting the Earth or hitting each other in space. What definitely wasn't involved? Coal.

We know coal has nothing to do with diamonds because coal only started forming about 300 million or 400 million years ago (give or take), long after the Earth started making diamonds. In order to get coal, you need plants, and plants didn't happen until about 450 million years ago. That makes diamonds even cooler. It makes your teacher less cool.

You were probably quizzed on the map of your taste buds before you were old enough to make any inappropriate tongue jokes. You were taught your taste buds were arranged in groups and you tasted different things — bitter, salty, sweet, and sour — in different areas of the tongue. If you were the kid who put a salty pretzel on the tip of your tongue and wondered why you could still taste saltiness, you were right to be skeptical.

The tongue map dates back to 1901, and according to LiveScience, it was the work of a German scientist named D.P. Hanig. He was measuring how sensitive certain areas of the tongue were to certain tastes, and later that turned into the idea that different parts of the tongue only taste certain things. We even know who screwed things up: a Harvard psychology historian with the epic name of Edwin Boring. He transcribed Hanig's data in 1942 but didn't label his graph correctly.

It's wrong for another reason, too, because people also have the ability to taste something called umami. That's not even on the standard tongue map. It's almost as if the tongue is an extremely complex and sensitive object that can't be easily reduced to pithy half-truths.

Think back to what you were told defines a mammal, and you'll probably remember something about giving birth to live young, having hair or fur, and being warm-blooded. It's in the generally accepted definition of being a mammal, so this one can't possibly be wrong. Can it?

Of course it is, because it turns out teachers lie all the darn time. According to BBC Earth, there are some mammals that bend the definition of warm-blooded to the point of breaking. In case you forgot, warm-blooded creatures maintain a constant body temperature, like a human's toasty 98.6 degrees. But there's a subdivision of mammals no one told you about, animals whose core temperature varies, and not by a small amount. The Arctic ground squirrel (the cute little guy above) has been found to drop its body temperature to 26 degrees, and yes, that means it should freeze solid... but it doesn't. That's an extreme example, but there are other mammals who are clearly not the traditional definition of warm-blooded, like the pygmy mouse lemur and the naked mole rat.

In fact, the very idea of calling something "warm-blooded" has fallen out of fashion with the actual science world. According to The Washington Post, scientists now prefer terms like endothermic (animals that regulate their own body temperature), ectothermic (animals that can't retain body heat), and heterothermic (animals that do a bit of both). Man, was your science teacher wrong.

"But ... I can see them! Right there! In that picture!" you might be saying. Well, your eyes deceive you. Here's how.

Whenever anyone draws a rainbow, they'll go with seven standard colors: red, orange, yellow, green, blue, indigo, and violet. But The Telegraph suggests picking seven colors is just the Western world continuing its obsession with seven: days of the week, musical scales, and all that jazz. It was Isaac Newton who decided on seven colors when he was observing rainbows from his self-imposed quarantine outside plague-ridden Cambridge. He added orange and indigo to the previous five. If you go back further, you'll find Greek philosophers said there were three (red, yellow-green, and purple). Homer, for some reason, insisted there was only one color in a rainbow: purple. (No one knows what was up with Homer.)

Not so clear now, is it? The answer is even worse: There's no "real" number to find. The rainbow's shading from one color to the next means there's no definite, solid way to separate one from another. ScienceBlogs worked out the math, using wavelengths to estimate that there are around a million different colors you're actually seeing when you look at a rainbow. And purple is one of them.

This idea is so prevalent even among adults that entire movies are based on the premise that using more than 10% of your brain will turn you into some sort of superpowered demigod. Those movies are stupid movies.

Scientific American has debunked this entire myth and has possibly even found the source of the idea, if not for the incredibly specific number of 10% — it's a 1907 text called "The Energies of Men." But it's just not true. Now, although our brain makes up a relatively small percentage of our meat-sack, it uses about 20% of the energy we burn. Researchers have used imaging technology to get a peek at which parts of the brain govern which functions, and all of it is used (although not always at the same time) for both conscious and unconscious activities. The brain is even going while sleeping. Mayo Clinic neurologist John Henley erases any doubt: "Evidence would show over a day you use 100% of the brain." Sorry, folks. You've already got all the brainpower you're going to get.

There's a reason why cats, the agile acrobats of the animal kingdom, possess the reputation of having nine lives. With their uncanny talent for landing on their feet, these feisty felines may seem invincible. But don't be fooled by their flips; that impressive "righting reflex," which they typically hone within seven weeks of birth, comes with limitations.

The righting reflex is a unique ability that helps cats navigate tumbles. With their super-flexible spines (packed with more vertebrae than ours) and an exceptional sense of balance, they instinctively turn mid-air to land on their feet. Researchers have added to this idea with the "bend-and-twist" model, likening the cat's body to two connected cylinders (forming its front and back halves). By bending and twisting these cylinders in opposite directions, the cat's overall spinning motion (angular momentum) cancels out. So, when the cat straightens again, despite starting with no initial spin, it ends up facing an upright direction.

But gravity remains undefeated. As veterinarian Roswitha Steinbacher explained to The Science Explorer: "Sometimes such a plunge has no consequences for the cats. But often, they suffer serious injuries. It mainly depends on the height of the fall. If it is too low, the animals often hit the ground on the side of their body. When cats fall from very high, they can correct their body position and land on their feet." Even then, Steinbacher says, the fall can still cause traumatic injuries. 

Listed as one of the seven construction wonders in the world, the Great Wall of China is a dragon snaking across the landscape and a symbol of human resilience etched in earth. But trust us, no matter how hard you try, you won't spot it from a distance as far as space — at least not without some high-powered binoculars.

The Guardian features remarks from Yang Liwei, China's first astronaut, who returned after traveling more than 600,000 kilometers and completing 14 orbits back in 2003: "The scenery was very beautiful," he shared in a televised interview. "But I didn't see the Great Wall." In addition, those who have visited space and gazed back at Earth describe observing mostly an expanse of white clouds and blue seas with specks of vegetation.

According to Scientific American, the wall's visibility from space is surprisingly limited, contrary to its grand reputation here on ground level. Only within a narrow window of low orbit, under specific weather and lighting conditions, does it emerge on machines, telescopes, and satellites. In fact, you'd actually have better luck seeing structures like desert roads from this "orbital perspective" than the famed Great Wall. So, the bottom line is that the "mightiest work of man" isn't the solo standout visible structure from space. It's a bit like trying to find a needle in a haystack — not the easiest task, especially when you're zooming through space at ultra-high speed.

Over the years, you've probably come across the five-second rule (or some variation thereof), which basically says that if you're able to pick up food that has dropped on the floor within five seconds, you won't give nasty germs enough time to make your sandwich or slice of cake unsafe to eat. But while the idea of snatching that rogue french fry from the floor and declaring it germ-free sounds tempting, the reality is more complicated than it seems. 

Healthline asserts that several factors contribute to the severity of cross-contamination (and thus, the likelihood of contracting a foodborne illness). These include, but are not limited to, moisture, the surface type, and the duration of contact with the ground. While most healthy adults might be relatively safe in specific scenarios, the situation differs for young children, pregnant women, and older adults, as they face an increased risk of developing complications from consuming contaminated food.

Based on observations from a 2016 study published in Applied and Environmental Microbiology, researchers found that transfer rates of the bacteria Enterobacter aerogenes are higher in moist foods like watermelon compared to dry foods like crackers. Similarly, longer contact times lead to increased transfers across all types of food and surfaces. Regardless, the bottom line is clear: Any contact with a surface is an open invitation for microscopic hitchhikers. Just toss the fallen food, and your stomach will thank you later.

The story of glass isn't as clear as it seems. Imagine a world where Lego bricks didn't snap into perfect rows but instead merged into a colorful, shapeless blob. That's the world of amorphous solids, and glass is its crown jewel. Unlike its crystalline cousins with their neat, orderly atomic arrangements, glass throws the rulebook out the window.

During the transition from liquid to solid states in most materials, molecules swiftly reorganize themselves, forming a repeating knit pattern known as "long-range order." Per an explainer from New Scientist, the transition for glass doesn't work this way. Rather than an abrupt shift, the molecules' motion gradually decelerates as the temperature decreases. In return, this preserves the "structural disorder" inherent to a liquid while looking and behaving like a solid (as far as the human eye is concerned).

Scientific American provides a more in-depth look at the transformation process. Glass manufacturing begins with rapidly cooling a (typically silica-laced) material from its liquid state. But the material doesn't harden instantly; instead, it enters a supercooled liquid phase, or in simpler terms, an "intermediate state between liquid and glass." Further cooling below the glass-transition temperature slows molecular movement, causing the material to transform into the glass we're all familiar with.

The illustration is iconic at this point: Isaac Newton, sporting his signature hairdo and lounging beneath an apple tree, suddenly gets bonked on the head by a juicy projectile, and is instantly struck with an epiphany about the nature of gravity. It's a scene etched in our collective memory. But when placed under historical scrutiny, this version of the story is like a half-baked apple soufflé: it might taste good, but it doesn't quite hold its form.

While written records suggest an apple did indeed play a role in Newton's journey toward gravity, it never landed on his head. As New Scientist explains, the truth is hidden in a manuscript titled "Memoirs of Sir Isaac Newton's Life," published in 1752 by pioneering Newton biographer William Stukeley. As the passage goes: "It was occasion'd by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself..." This observation, of course, was what sparked Newton's ponderings about the revolutionary universal law of gravitation. As for the apple-on-Newton's-head story, though — it's pretty much applecr–, er, apocryphal.

Peel back the yellow skin of a banana, and you expect to find... well, a banana, right? But beneath that sunkissed sweetness lies a botanical double agent, hiding sugary secrets. The banana tree, as most people may call it, isn't a tree at all — and the banana itself is actually a berry in disguise.

Technically speaking, the banana plant is an herb. As expert Himani Saklani from the Forest Research Institute explained (via Science ABC): "What you call a tree isn't actually a tree, but an herb. Just like mint, grass, and rosemary, the banana plant is also an herb." Per the article, herbs are characterized by their soft, delicate foliage and lack of hemicellulose and lignin (which influence the "woody" characteristic of the tree trunks we're all familiar with). On top of that, these herbaceous plants typically complete their life cycle annually and biannually (within one or two growing seasons), although some may persist for several years.

In line with this, botanist Julia Morton writes in her book Fruits of Warm Climates that the term "banana" encompasses diverse plant species and hybrids within the genus Musa of the Musaceae family. The fruits that these species produce have seeds and fleshy layers, and come from the single ovary of a single flower; in other words, they're berries, despite not being a visual fit for the traditional image of a berry (via FlipScience).

It's time to settle this, once and for all: Does it really take fewer muscles to smile than to frown? Well, what constitutes a "real" smile is subjective — and to complicate matters further, we don't all have an equal number of facial muscles at our disposal.

First, let's dispel the myth of a standardized facial map. Per Nature, our faces are actually more unique than we realize. Research shows we can have anywhere between 14 and 22 individual muscles dedicated to contorting our faces. So, the number needed for a smile or a frown can vary from person to person, adding a dash of mystery to the equation. Following this, Live Science emphasizes that comparing "true" and "false" smiles is a challenging task with somewhat confusing parameters. Plus, smiles can express many emotions beyond just happiness, and whether each emotion has its own unique facial muscle map is still debated to this day.

To provide a more quantitative analysis, David H. Song, a plastic surgeon at the University of Chicago Hospitals, shares a detailed list of all the relevant facial muscles with The Straight Dope. Based on the provided count, it takes a grand total of 12 principal muscles for a full smile; meanwhile, frowning only requires 11. But here's the twist: Despite needing more muscles, smiling actually takes less effort, since human beings have the inherent tendency to smile more often, leading to better-trained muscles.

You learned a lot about evolution and Charles Darwin's theories, but unfortunately, you were taught all kinds of lies. Let's just talk about one piece of the evolutionary puzzle here: the missing link.

Anthropologist Cameron McPherson Smith and author Charles Sullivan explain what's going on in this one (via Skeptical Inquirer). The term "missing link" suggests there's an individual animal that fills in a gap between an organism with one set of traits and the "future" version of that same organism, but that's not how evolution works. At all. Contrary to our theories a few hundred years ago, species aren't arranged in neat "chains" or "trees." Lots of things have changed in 400 years, but while we had no problem giving up outhouses, we've clung to this outdated idea of a missing link. Instead of thinking of evolution as a chain, think of it more as colors. Smith and Sullivan say the better way to explain evolution is in shades, so let's do that. Take a crayon. Start coloring, but make it darker and darker as you go on. At some point, that pink is going to become red, and it's sort of the same color, but not. See?

There's no one color that bridges the gap between pink and red, like there's no one missing link that connects modern species to their ancient ancestors. Now, please excuse us. This space-faring dinosaur getting sucked into a black hole isn't going to draw itself.