Common misconceptions

12 completely false "facts" everyone believes to be true

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Many of us have grown up thinking that bats are blind, that we can't go swimming right after lunch, that we only have five senses, or that camels store water in their humps. Wait, do you still believe in any of these things? Don't worry! To prevent you from continuing to spread wrong ideas, we have compiled a list of 12 myths that we all believe to be true but are actually false. Do you dare to question your common sense?

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It’s interesting how some ideas remain common sense for centuries without us questioning their veracity. A great example is the notion that we have only five senses, a concept that was developed by Aristotle more than 2,300 years ago and is still taught today from early childhood.

Fortunately, the advancement of science allows us to better understand the complexity and diversity of the world around us. Today, scientists argue that we have far more than just five senses—anywhere from 20 to 30—including thermoception, pain, hormonal sense, and balance, among many others.

Image: David McEachan

Contrary to what you may have thought all your life, pure water is not a good conductor of electricity. What really conducts electricity in water are its impurities, such as salts and minerals.

For example, tap water, which contains several dissolved ions, is a good conductor. In contrast, distilled water molecules have no free electrons to transfer an electric current. Hence, when handling electrical appliances near water, the real danger doesn't come from the water itself, but from its impurities.

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This is a typical scene in movies: a tough character taking a swig of some spirit before crossing a snow-covered field as an antidote to the cold. Although it is a widespread idea, it is not something you should imitate.

In fact, alcohol causes your body temperature to drop. Alcohol produces a momentary sensation of warmth by dilating blood vessels and directing blood to the surface of the skin, but before long, the body's core temperature drops, and you feel colder. Did you know that?

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No matter what your parents told you as a child, there is no scientific evidence that swimming after eating is dangerous. The assumption that you should wait at least an hour stems from the idea that after we eat, all the blood travels to the stomach and the body is not able to adequately supply the muscles.

As convincing as this may sound, the truth is that our body manages to maintain muscle work while we digest. In fact, some professional swimmers eat immediately before a competition to have enough energy to perform well.

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One of the most widespread myths in neuroscience is that we only use 10% of our brains. In reality, we use it all, even when we are doing nothing.

This misconception probably arose at the end of the 19th century. Since then, scientists have been able to determine that our entire brain is active thanks to modern neuroimaging techniques, such as functional magnetic resonance imaging. Despite the evidence, popular culture, the media, and even some scholars continue to perpetuate the myth that we only use 10% of our brains. So remember, no matter what you hear out there, your brain is never off; it’s active even when you sleep.

Image: R. J. Mathar, CC0, via Wikimedia Commons

Sleepwalking is a sleep disorder that occurs when people, usually children or young adults, walk or do other activities while they are still asleep.

Contrary to popular belief, waking a sleepwalker is unlikely to pose a major health risk. Moreover, according to experts, in the event of witnessing someone in such a state, the wise thing to do is to help them back to bed and, if necessary, wake them up.

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Camels can indeed stay hydrated even in the most inhospitable, arid, and hot environments. However, a common misconception is that these animals store water in their humps.

In reality, their humps are filled with fat, which provides them with energy for long distances. So, how do they manage to last up to 10 days without drinking water? The main key lies in their kidneys, which are able to concentrate urine to prevent water loss. In addition, their fur protects them from the ambient heat, preventing perspiration, and the mucosal structure of their nose can retain 66% of the moisture in the air.

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Knuckle cracking is a common habit. You might have noticed that many people do it, often without giving it much thought. For others, that characteristic popping sound raises concerns about its impact on health, such as its possible link to arthritis.

However, there is no conclusive scientific evidence that the manipulation of joints is associated with the development of arthritis. Numerous studies have found no correlation between knuckle cracking and chronic joint inflammation. In fact, this habit is usually harmless and is often simply a way to release tension.

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Setting your phone to airplane mode when boarding a flight seems like common sense. You wouldn't be crazy to think that your phone's signal could interfere with an airplane's navigation systems, potentially causing a disaster. However, the need for airplane mode is largely a myth.

There is actually no evidence that a cell phone has ever interfered with aircraft systems. The real reason airlines don't allow phone communications in the air is to avoid disturbing noises. Let's be honest, the majority of travelers probably prefer the silence anyway.

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Bats hunt in the dark by echolocation, which means they use self-produced sound echoes that bounce off objects to help them navigate. But that doesn't mean that they can't see.

Bats are not blind at all; in fact, they have pretty good vision. Although they can't see as well as humans, they can see better than many mammals —they can distinguish shapes, contrasts, and some colors. So, despite their nocturnal habits and the many popular sayings we like to repeat, bats have pretty good eyesight.

Image: Brian McGowan

We're sorry to be the ones to debunk this myth, but it's time you knew that gravity exists everywhere in the universe. The term "zero gravity" is often used to describe the conditions experienced by astronauts in space, but it's a bit misleading, as gravity is never truly zero.

The more correct term to describe the phenomenon experienced by astronauts when they are on the International Space Station, for example, would be "microgravity".

Image: Vivek Doshi

Fictional characters such as Winnie the Pooh helped fuel this myth. While it is true that it’s common to see bears eating honey, it is the bees and larvae they are really interested in.

While honey alone provides them with some vitamins, minerals, and calories, such as sugar, the insects found inside the beehives give them the protein they need to stay strong.

Decoding

Being a "treasured guest" is not a compliment. This is the hidden meaning

Have you ever heard "Code Adam" while shopping for groceries at Walmart? Or maybe you’ve heard how "Dr. Firestone" was being paged during a routine hospital visit. They sound like harmless announcements. But behind these ordinary words are secret codes staff use to signal emergencies without causing panic. From hospitals and supermarkets to airports and Disney Parks, these phrases quietly warn employees that something is happening. You hope you never hear them, but if you do, it helps to know exactly what they mean.

We all love getting special attention at airports or hotel desks, but if you hear the clerk call you a "treasured guest," don’t feel so flattered. You may not be as VIP as one could think.

In the hospitality industry, "treasured guest" has become a humorous bit of industry folklore to describe someone causing trouble. Maybe a customer yelling at staff over expired coupons, demanding impossible accommodations, or throwing a full-blown tantrum at the front desk. Whatever it is, the phrase has become the staff’s secret way to warn co-workers without escalating the situation in front of the customers. Most guests don’t realize the meaning, but once you know it, you may start hearing it more often. We just hope it’s not about you.

Imagine you’re pushing a shopping cart through Walmart when suddenly the overhead speaker announces, "Code Adam." You can easily assume it’s some kind of employee meeting or cleanup request. But when you see them start locking the exits and moving around, you know something’s wrong.

This code was created in 1994 by Walmart in collaboration with the National Center for Missing & Exploited Children (NCMEC), in memory of the tragic case of 6-year-old Adam Walsh. Adam was abducted from a Sears department store in 1981 while shopping with his mother. His father, John Walsh, later became famous for hosting the TV program America’s Most Wanted and advocating for missing children. Even if Adam’s story ended in tragedy, Walmart created the emergency system in Adam’s memory, and other retailers soon adopted it nationwide, intending to have a quick response to missing or abducted children.

You’re sitting in a hospital waiting room during a routine check-up when you suddenly hear "Code Blue, Room 214." Most people immediately know it sounds serious, even if they are not entirely sure why.

The phrase "Code Blue" is used at hospitals to draw the necessary staff and equipment to perform a resuscitation. It was created in the early 1960s at Beathany Medical Center by Dr. Hughes Day. Before then, hospital resuscitations were often chaotic and poorly coordinated. In 1961, Dr. Day received a grant to build one of America’s first cardiac care centers, and he developed both the Code Blue alert system and the modern crash cart to improve survival rates during cardiac emergencies. Today, the system is used in hospitals across the country, sometimes with specialized versions like "Code Blue Pediatric" or "Code Blue Neonate."

Imagine visiting a loved one in the hospital when the intercom calmly announces, "Paging Dr. Firectone to the third floor." Your head surely goes, "Dr. Firestone’s probably having a busy day up there." He is, but it’s not what you think.

The phrase is actually a discreet fire alert used to warn staff about smoke, flames, or overheating equipment without frightening patients and visitors. Hospitals adopted these coded announcements after realizing that openly yelling "fire" over loudspeakers could create panic, especially among patients who aren’t able to move quickly. "Code Red" is an alternative used by many health centers today, but it also hints at the situation while keeping hallways calm.

You’re standing at a checkout counter when the cashier picks up the phone and quietly says, "I need a Code 10 authorization." If you think that’s just another way to get a supervisor’s approval or technical issue, think again. In reality, the cashier may suspect the credit card is stolen or fraudulent.

Code 10 was developed through a cooperative effort between major credit card companies like Visa and Mastercard, along with international standard organizations. As credit cards became more common in the 1960s and 1970s, stores needed a discreet way to alert banks about suspicious activity without directly accusing customers and potentially putting employees at danger. When a cashier requests a Code 10, the bank’s operator begins asking yes-or-no questions to assess the situation and guide the employee on what to do next.

You’ve probably experienced those long airport security lines. The wait is usually uneventful. But sometimes, you can hear "Code Bravo" over the speakers. Maybe it’s a delay, or maybe it’s an issue with luggage. Within seconds, people stop moving, the security line freezes, and exits may even close. It’s something bigger.

Code Bravo is the emergency phrase used by airport security and the Transportation Security Administration to signal a serious security threat, such as an unattended bag, a breach at a checkpoint, or someone slipping into a restricted area. The term comes from the international phonetic alphabet used in aviation and military communications, where "Bravo" represents the letter B. When this is called, security staff immediately lock down affected areas, stop screening lines, and search for the source of the threat. To passengers, it’s sudden and confusing, but to security, it’s a carefully rehearsed response.

You are heading back to your cabin on a cruise ship when the speakers announce, "Code Alpha, Deck 7." You may think Alpha is related to the captain, but that’s not the case. It means someone on board is suffering a medical emergency.

The phrase comes from the NATO phonetic alphabet, where "Alpha" represents the letter A. In maritime emergency jargon, it became shorthand for a Priority A medical situation requiring immediate response. Cruise lines such as Royal Caribbean and Disney Cruise Line commonly use the term, though some ships use variations like repeating "Alpha" three times. Once the code is announced, onboard medical teams rush toward the specified deck or cabin. If necessary, stretcher crews are mobilized, and in severe cases, the ship may even divert course toward the nearest port for emergency evacuation. Passengers are enjoying the views, but the staff is running to save a life.

Anyone who remembers the CB radio craze of the 1970s probably smiles when they hear "10-4." Movies, truckers, and radio fans turned those number codes into a part of American culture. So if you overhear "10-33" on a police scanner, you might assume it’s just another routine message. But it’s not as simple as it sounds.

The 10-code system was first created in 1937 by Illinois State Police communications director Charles Hopper and later standardized by the Association of Public Safety Communications Officials, better known as APCO. Officers needed short phrases they could understand clearly over crackling radio signals. The 10-33 code commonly means an officer needs emergency assistance. In some departments, it also signals radio silence so dispatchers can focus on the crisis unfolding in real time.

Disney World is amazing, the parks offer something for everyone, and there are things to see wherever you look. But that’s exactly the kind of place where a child can easily disappear into a sea of strollers, balloons, characters, and crowds. For that reason, Disney has developed the "Signal 70," which alerts cast members and security that a child has become separated from their family.

The number comes from older police and emergency radio systems, where "70" was commonly associated with missing persons. Disney adopted the phrase because it allows employees to communicate discreetly without frightening or alarming nearby guests. If a member finds the child, they gently -and magically- escort them to Baby Care Center, where they coordinate the reunion.

Cruises are great to relax, enjoying a good book under the sun with a nice drink by the side. Until you hear "Echo, echo, echo" on the speakers. If you do, something is happening somewhere else on the ship.

The code is used among cruise employees to signal that dangerous winds or a navigational hazard are affecting the ship. It comes from the international maritime phonetic alphabet, where "Echo" stands for the letter E. In maritime signalling, the letter traditionally means "I am altering my course to starboard." And, in time, the phrase became associated with urgent ship maneuvers and weather-related warnings. However urgent, the repetition of the word by three doesn’t represent life-threatening situations. It alerts the crew of a certain hazard to prepare while avoiding panic among passengers.