15 Commonly Believed Scientific Facts That Have Now Been Proven False

Pete Law

As science continues to advance, our understanding of the world around us is constantly refined, however, many scientific misconceptions remain deeply ingrained—even as new research debunks them. In this article, we explore some widely believed “facts” that have actually been proven false by science.

Goldfish Have Terrible Memories

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Contrary to popular belief, goldfish have good memories and can perform learned tasks (like navigating to and from a place within their tank) for a food reward. The BBC states that Oxford University researchers concluded that goldfish had memories far longer than a few seconds.

Lightning Never Strikes the Same Place Twice

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The opposite is actually true! The Weather Network reports, “While the odds of being struck by lightning are low, the chances of lightning striking the same place twice are high.” Because certain “spots” are higher or more conductive, they may be struck multiple times over time or even in a single storm.

The 5-Second Rule

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The idea that you have exactly 5 seconds to eat that bit of pizza off the dirty floor before bacteria leap onto it has been quashed by researchers at Rutgers University, who found that bacteria transfer instantly. We recommend grabbing a fresh slice instead!

Humans Only Use 10% of Their Brains

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Experts at the Scientific American say that “the ’10 percent myth’ is so wrong it is almost laughable.” While using 100% of our brains at once would be akin to having a seizure, that doesn’t mean we don’t use all of it. It’s like a traffic light; you don’t have every light on at once, but every bulb is essential!

Cracking Your Knuckles Causes Arthritis

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No, cracking your knuckles doesn’t significantly increase your chance of developing arthritis in your hands, as Harvard Health reveals. The noise results from bubbles bursting in the lubricating fluid surrounding each joint. But they don’t recommend it anyway because “knuckle crackers” exhibit a reduced ability to “grip” objects.

Bananas Grow on Trees

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I’m sorry, but no, they don’t! Banana plants are not botanically classified as trees but as large herbaceous plants called palms. Although sometimes called “palm trees,” palms are more accurately described as giant, woody herbs, more closely related to grass than to trees.

Dogs See in Black and White

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The Big Think reveals that “dogs lack some of the light receptors in their eyes that allow human beings to see certain colors, particularly in the red and green range. But canines can still see yellow and blue.” So, if you’re making your dog a birthday card, ditch the monochrome designs and splash some yellow on there!

Sugar Causes Hyperactivity in Children

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While parents may like to use this as an excuse to restrict sweet treats, WebMD states that not one study on the subject has found a significant link between sugar consumption and hyperactivity. However, science can agree that sugar still isn’t great for their teeth.

Glass Is a Slow-Moving Liquid

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New Scientist says that chemists classify glass as neither a liquid nor a solid but something in between these two states of matter. They call it “an amorphous solid” because its structure isn’t as rigid as a true solid, but its atoms cannot move around as freely as those in a liquid. Put simply, it’s weird!

Eating at Night Makes You Fat

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Fear not, midnight snackers; as long as you aren’t eating extra calories at night, the time you eat doesn’t significantly affect weight gain. The most important factor in weight regulation is your daily, overall calorie consumption- not the time of day you chow down!

Your Tongue Has a “Taste Map”

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Many of us learned that different areas of the tongue respond to different tastes- sweet, salty, bitter, and sour. The Smithsonian Institute reports that taste receptors are actually distributed evenly- so you can taste the sourness of a lemon slice no matter where you squeeze it on your tongue!

Lemmings Are Suicidal

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A 1957 Disney documentary showed an apparent lemming mass suicide as individuals leaped from a cliff edge. While boom/bust lemming populations do sometimes have casualties while traveling in groups to find new territory, the reality of the footage is far worse- filmmakers staged the event by deliberately pushing dozens of lemmings to their deaths.

Drinking Alcohol Warms You Up

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Worryingly, the opposite is true. Drinkaware says, “Alcohol affects the blood vessels just below your skin. They open up, and more blood and heat flow into them. That takes blood and heat away from the core of your body.” So it’s actually easier to get dangerously cold when drinking alcohol.

Shaving Makes Hair Grow Back Quicker

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Contrary to popular belief, shaving doesn’t affect the root of the hair strand, so it can’t impact growth. Sharpologist explains that the myth came about because cutting hair makes it blunter and coarser at the end, and new growth is typically darker due to a lack of sun bleaching.

Humans Only Have 5 Senses

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Many of us were taught that sight, hearing, taste, smell, and touch are the five ways humans can perceive their environment. But modern science has added proprioception (body awareness), nociception (pain detection), and thermoreception (temperature sensitivity) to our list of senses.