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Neuroscience was once considered a subject so technical that even other kinds of scientists avoided it. But as it became a leading discipline, it sparked wide public interest, fed by books promising that it would solve age-old problems like how to get rich (Your Money and Your Brain: How the New Science of Neuroeconomics Can Help Make You Rich), whether we have souls (The Spiritual Brain: A Neuroscientist’s Case for the Existence of the Soul), and why men and women act differently (The Female Brain).

While brain science hasn’t yet solved every human puzzle (be patient!), it has the potential to increase our insight. At the same time, some popular myths have created misunderstandings about how our brains work. Is the brain really divided into two halves? Are left-handed people more intelligent? Do men and women truly have different brains? Find out below.

True: The Brain Is Divided in Half

The human brain has two hemispheres that look like mirror images and are connected by fibers called the corpus callosum. The right side controls the left side of the body, and vice versa.

Beginning in the 1960s, research on “split-brain” patients established differences in the functions of the two sides. In these patients, the corpus callosum had been cut out as a treatment for epilepsy. Early experiments showed, for example, that the left side does most of our language processing. However, the corpus callosum allows for much cooperation between the two sides. The right side perceives humor and intonation in speech, and in people who suffer strokes on the left side, the right side can compensate, picking up language functions.

False: Right-Brained People Are More Creative

There’s no evidence that anyone is “right-brained” or “left-brained.” Brain imaging studies of more than 1,000 children and adults through age 29 failed to find evidence that one side was stronger or more active than the other. People use their right and left sides depending on what they’re doing.

As for which side is “more creative,” there’s no good reason to give that status to the right. The left side of the brain is the storyteller, filling in the blanks when we have incomplete information — definitely creative!

False (Probably): Left-Handers Are More Intelligent

People tend to use their left hands for some tasks and their right hands for others, so whether you are left-handed or right-handed is a matter of degree. There may be some differences in how left-handers and right-handers process information, but this area is largely unstudied.

There is a little bit of evidence that people who are inconsistent about which hand they use may be more flexible thinkers. But in large meta-analyses using the classifications “left” and “right” for handedness, there was no serious difference in IQ.

True: Male and Female Brains Are Different

Women usually have slightly smaller brains than men do, even after adjusting for their overall size. (It’s worth noting that human brain size does not correlate with intelligence; Albert Einstein had a smaller-than-average brain, for example.) The volume of certain regions in the brain also differs between men and women, perhaps because of how genes and hormones play a role in brain development. For example, women have more volume in the prefrontal cortex, and men have more in the occipital region.

Differences between male and female brains are worth taking seriously, as they may help explain why men and women are not equally vulnerable to some mental illnesses. Women are more likely to be diagnosed with depression and anxiety, for example, while men suffer from more substance abuse.

False: Men Have Better Spatial Awareness

For decades, it has been thought that men perform better on tests of “spatial cognition,” most often a test recognizing a shape that has been rotated. Ability on that test seems to predict better performance in math and science.

However, a 2020 study of students at the University of Limerick, Ireland, found that men and women approached the task differently but performed just as well.

False: Your Brain Stores Memories

Your computer has files that you can pull up as needed. That’s not how the brain works. Instead, it reconstructs memories when called upon, starting with the big picture and then filling in details. Each time you ask it to remember an event, the reconstruction will occur differently and likely will have a slightly different result.

We need to trust our memories to function, though it’s worth staying open-minded about inaccuracies. Some research suggests that if you can quickly produce a memory and feel confident about it, you are more likely to be accurate.

False: Depression Involves Lack of Serotonin

Prozac became available to Americans in late 1987, followed by Zoloft in 1992. Pfizer advertised Zoloft as addressing a “chemical imbalance” in the brain, paving the way for a number of selective serotonin reuptake inhibitor (SSRIs) drugs that would be prescribed to people with symptoms of depression and anxiety.

The problem: No one knows what the correct levels for serotonin or other neurochemicals should be, and depressed or anxious people do not consistently show any difference in their serotonin function, as journalist and neuroscientist Christian Jarrett explains in Great Myths of the Brain. L-tryptophan, which boosts serotonin, doesn’t reliably give depressed people a boost, and tamping down healthy people’s levels of serotonin depresses some but not others. One antidepressant that is not approved in the United States but is used in Europe, tianeptine, actually reduces circulating serotonin. It is also not clear whether these widely popular antidepressants are more powerful than a placebo. When they are, one possibility is that the medications are, in fact, addressing a brain problem — just not a lack of serotonin.

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They say beauty only runs skin deep, but learning even a little bit about your largest organ may give you new appreciation for the external. From literally holding us in to protecting us from the ravages of the world without, our skin is pretty incredible. Here are six beautiful facts you might not know about human skin.

Skin Really Is Your Biggest Organ

It can be tempting to think of skin as the scientific equivalent of the frosting on your body’s cake, but it’s an organ as complex and important as the heart or liver. It’s also really heavy: The scientific consensus is that the entire, three-layer organ makes up about 16% of a human’s weight — equal to about 20 pounds for a 125-pound person. That’s the equivalent of four bricks or a miniature schnauzer. If you consider only the external surface of the skin, that weighs about 6% of the weight of any given person.

Your next-heaviest organs — the liver (3 pounds), brain (3 pounds), and lungs (2.2 pounds) — don’t even compare. Thanks to its vast surface area and triple-layered composition, your skin efficiently keeps your other organs from getting out and other stuff from getting in, all while flexing, stretching, and renewing itself continuously.

Skin Is a Habitat All Its Own

You may have heard of the gut microbiome, but did you know your skin has its own microbiome, too? Your skin plays host to millions of microorganisms — tiny microbial communities that hitch a ride on, and even help, the exterior of your body.

The types of microorganisms that live on your skin vary depending on what type of terrain they encounter: moist or oily, exposed or enfolded, hairy or bare. They fall into four categories: viruses, bacteria, fungi, and mites. And they don’t just live there rent-free: Some of the critters crawling on your skin right now are thought to perhaps even play a part in teaching your T cells how to respond to harmful invaders. Others, like the common S. epidermidis, actually help your body defend itself against water loss and other damage.

Your skin colonies also change as you age. In fact, baby skin is thought to be sterile until the moment it encounters the world outside the womb. That’s when an important time for skin microbiome growth begins — a developmental heyday for your skin’s immune system. As a result, the skin microbiomes of babies and adults are thought to vary significantly, though research on both is still in its infancy.

Your Diet Can Influence Your Skin’s Color

Folktales about carrots improving your night vision are mere propaganda. But there’s truth to the old line that you “are what you eat” — and it can be found on your skin’s surface, which can actually change color when you consume lots of the pigments found in red, yellow, and orange veggies like carrots. Known as carotenoids, these pigments impart what scientists call an “attractive yellow-orange color to skin.”

Sound like a ploy by Big Carrot? It isn’t. Carotenoid pigments can build up in the skin, producing a yellowish hue that is associated with a healthier body. That’s where the attraction part comes in: In a variety of studies, researchers have shown that people prefer the appearance of people who eat lots of carotenoids, likely because they signal a person has a healthy diet and higher perceived health. Both indicate the person is a desirable mate — all the more reason to grab a carrot and chow down.

If We’re Going to Mars, We’re Going to Need Better Skin Care

Astronauts returning to Earth don’t just have to readjust to gravity: Many contend with skin issues. In fact, researchers note that skin problems are the most common health conditions experienced by astronauts, far outpacing skin ailments on Earth. Astronauts’ skin has endured everything from irritation due to on-board equipment to dryness and infections on space flights and at the International Space Station. Research has even shown that the complex skin microbiome undergoes changes while in space.

Microgravity, radiation, and the harsh environment of spacecraft seem to be the culprit, but scientists are still learning more about how space travel affects skin. With long-term space missions to Mars and elsewhere on the horizon, finding out how space affects skin has become a priority for researchers and private industry alike. As a result, a Colgate-Palmolive skin care company staged the first-ever in-space skin care experiment in 2022, and in 2023 another private sector experiment on the International Space Station is expected to test how lab-grown skin tissue grows in space. Insights from those studies and future inquiries could lead to the development of new skin protectants or inform skin care products down here on Earth, helping the planet-bound protect themselves against the ordinary ravages of aging.

Tattoos Are Permanent Thanks to Dead Immune Cells

If your mom warned you that your ink is forever when you announced your intention to get a tattoo, she was right. But not for the reason you might think. While common wisdom has it that tattoo ink bypasses the permeable top layers of the skin and remains embedded in the dermis, the second skin layer, the truth is a bit more complicated — and more interesting. Recent research has revealed that macrophages, a type of white blood cell that specializes in gobbling up invasive pathogens, mistake tattoo ink for an infectious cell and flock to the scene to protect the body from the foreign substance. They show up, encircle the ink, and process it.

If macrophages clean up the ink, and the immune cells aren’t immortal, then why do tattoo markings last so long? Scientists asked the same question, and mouse studies led to an eerie answer: Once the macrophages die off, even more macrophages are thought to swoop in, eating the ink their dead brethren once contained. This generational turnover means tattoo ink can last for years with minimal fading — and keep Mom’s name intact for a lifetime.

The Bible Contains Ancient Skin-Care Advice

The Bible may be a religious text, but it’s also packed with information and stories about skin care. Researchers consider the Book of Job’s description of the long-suffering Job’s chronic skin boils an accurate and early depiction of an actual genetic disease called AD-HIES (loss-of-function, autosomal dominant hyper-IgE syndrome). Nicknamed Job syndrome, the genetic disorder causes, you guessed it, boils all over the body.

A slightly lovelier tale can be found in the Old Testament story of Esther, which refers to a 12-month-long beauty and purification ritual undergone by would-be concubines of King Ahasuerus of Persia. Along with her fellow applicants to the king’s harem, Esther spends six months applying oil of myrrh to her body, and another six months putting on perfumes and other cosmetics. Only after the women have spent months doing the biblical equivalent of a makeover are they qualified for the king’s romantic consideration.

But what is myrrh, and why was it part of the elaborate beauty ritual? The name comes from Commiphora myrrha, a spiny, squat tree with fragrant sap that was used in religious rituals, to perfume cosmetic oils, and even as medicine to treat achy muscles and wounds. It wasn’t just placebo: The prized resin is stuffed full of substances that have anti-inflammatory and antimicrobial properties, which may also have improved the look of the skin.

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Your home is full of quotidian mysteries. Why can’t I get Wi-Fi in this one room? Why am I constantly getting shocked when I touch a door handle? Why do my hands feel slimy after I just washed them? Some of these questions have relatively simple scientific answers, while others involve understanding a little physics. Read on to discover the science behind some everyday household enigmas — plus tips for how to deal with them.

Why Does Wi-Fi Have Dead Zones?

Wi-Fi, which stands for “Wireless Fidelity,” uses radio waves to send signals, and just as with regular radio waves, it can be disrupted or impeded — mainly by thick walls and metal barriers. It also degrades over distance.

While AM and FM radio broadcasts cover the ranges of kilohertz and megahertz, respectively, Wi-Fi transmits in gigahertz (or a billion cycles per second). That allows Wi-Fi signals to carry an immense amount of information, while severely limiting its range. Many Wi-Fi routers come with two network frequencies — 2.4 GHz and 5 GHz. The first frequency carries a lower bandwidth (aka speed) but can reach farther distances, whereas 5 GHz is faster but can’t travel as far. If you’re experiencing Wi-Fi dead zones, try switching to the farther-reaching 2.4 GHz frequency (if available), or investing in a Wi-Fi extender that can boost these data-heavy signals.

Interestingly, microwave ovens operate on a frequency very similar to Wi-Fi networks, at around 2.412 GHz to 2.472 GHz, so sometimes Wi-Fi can be disrupted when you’re warming up your dinner. Speaking of which …

How Do Microwaves Work? (And Why Shouldn’t You Microwave Metal?)

You might think the science behind microwaves is relatively simple — the machine produces microwaves (as its name suggests), which in turn warm up your food. However, that’s only partially correct. While it’s true that microwaves warm up food, it’s not the food itself that’s being warmed, but the water inside the food. Microwaves, along with X-rays, radio waves, gamma rays, and visible light, are part of the electromagnetic spectrum. But microwaves contain an interesting property — they’re readily absorbed by water, fats, and sugars. These materials absorb microwaves as atomic motion, essentially vibrating the water molecules in food, which in turn produces heat. Of course, this is only part of the microwave’s convenient food-warming equation, as this slice of the electromagnetic spectrum isn’t absorbed by plastic, glass, and most ceramics, making it a convenient way to heat up food without heating up its container.

But have you ever accidentally put a piece of metal in a microwave? Yikes. What’s happening to create this explosive situation is that the microwaves are moving the free electrons found in the conductive metal’s surface, which causes the object to reflect microwaves. If the metal is smooth all over, such as a spoon, this won’t likely be a problem, but sharp edges like the tines on a fork will produce sparks and potentially catch some flammable material in the microwave on fire. A microwaved metal will also create an imbalance with dielectric breakdown in air, which can cause an electrical arc that can punch a hole in the interior wall, rendering the microwave too unsafe to use. Long story short, just don’t put metal in the microwave — ever.

What Causes Static Electricity?

Static electricity was the doorway through which humanity first explored the phenomenon known as electromagnetism. The ancient Greek thinker Thales of Miletus, occasionally considered the world’s first scientist, rubbed a piece of amber against hemp and cat fur to study its effects (the name for “amber” in Greek is actually elektron). Today scientists call Thales’ discovery the triboelectric effect, or the process of producing electricity by rubbing. This effect sometimes occurs when two insulators (materials that inhibit the flow of electricity) rub together. One insulating object, such as a wool carpet, will lose electrons, while another, maybe a rubber-soled shoe, gains electrons. After rubbing these two insulators together, your body now possesses a small electric charge. Because those rubber shoes on your feet inhibit electrons, you can’t dissipate this charge, so once your body touches a conductor (such as a metal door handle), you experience an electric shock. Because dry air is also an insulator, the triboelectric effect is particularly prominent during the cold and dry winter months.

Want to circumvent those nasty little shocks? Avoid wearing wool socks and rubber-soled shoes in the house, and run a humidifier or two. Because water is a great conductor, more moisture in the air will help dissipate an electric shock accumulated within your body.

What Is Hard Water?

Not all water is the same, though it may look similar at first glance. Towns and cities throughout the U.S. have varying degrees of “hard” or “soft” water. Despite the more common uses of these adjectives, “hard” and “soft” don’t refer to the actual texture of water, but instead serve as shorthand for the amount of calcium, magnesium, and other dissolved metals found in a particular water supply. Hard water, for example, has high levels of these two minerals, at around 121 to 180 mg/L, whereas soft water comes in at less than 60 mg/L.

There are a few easy ways to tell if your home has hard or soft water. The most common side effect of hard water is that it tends to leave your hands somewhat slimy after washing with soap. That’s because soap reacts with the calcium in the water to create a thin film of soap scum. Hard water can also leave residue on plates and cutlery run through the dishwasher, decrease a home’s water pressure due to mineral deposits in pipes, and also affect the performance of appliances such as electric water heaters and coffee makers.

Luckily, hard water isn’t considered hazardous to a person’s health (and can even supply a healthy dose of calcium and magnesium). However, due to some of its annoying side effects, some homeowners choose to install water-softening systems that use a porous plastic resin to replace calcium and magnesium ions with less disruptive sodium ions.

How Do Surge Protectors Work?

According to a 2022 survey, the average American home has 22 connected devices, and many of those gadgets — along with others not connected to Wi-Fi — need to be protected from transient voltage, otherwise known as a power surge. The most common example of a power surge is often lightning strikes, but that’s actually the least common cause (and a surge protector can’t withstand the millions of volts delivered by a lightning strike anyway). What’s more common are power-hungry devices, whether hair dryers, refrigerators, or air conditioners, disrupting the flow of electricity in the home with their voracious energy demands. That’s why surge protectors are always a good idea, but especially when you need to plug a lot of things into a single outlet, such as for a media center or office.

Most outlets in U.S. homes are rated for 120 volts. If an unexpected surge sends voltage higher than that threshold for even a few nanoseconds, the results can be disastrous. Surge protectors serve as a kind of pressure valve protecting your gadgets from an electronic meltdown. Any time a surge protector detects voltage above the 120-volt threshold, it diverts excess voltage with a metal oxide varistor to its own grounding wire, protecting all your plugged-in devices in the process. Also, if you think you can rely on your home’s circuit breaker to protect your stuff — think again. Circuit breakers are only designed to protect against current overload, not surges and spikes.