12 “Facts” You Learned in School That Are Totally Wrong
Some myths are so common that teachers, textbooks and even parents pass them along without a second thought. We rounded up the biggest ones — and the surprising truth behind each. Keep score: how many did you believe?
1The “tongue map”
Remember that diagram showing sweet on the tip and bitter at the back? It’s wrong. It traces back to a 1901 German paper that was later exaggerated in translation. Every part of your tongue that has taste buds can detect all five basic tastes: sweet, salty, sour, bitter and umami.
2You only use 10% of your brain
Brain scans show that pretty much every region of your brain is active over the course of a day — even during sleep. Your brain is only about 2% of your body weight but burns roughly 20% of your energy. Evolution doesn’t keep an organ that expensive around to leave 90% of it idle.
3Napoleon was tiny
Napoleon was about 5’7” (170 cm) — roughly average for a Frenchman of his time. The mix-up came from French inches, which were longer than English inches, so his recorded height of “5 foot 2” sounded short to British ears. British cartoonists happily ran with it.
4Goldfish have a 3-second memory
Researchers have trained goldfish to push levers, respond to specific sounds, and remember feeding times for months. Your goldfish probably remembers you better than you think.
5The Great Wall of China is visible from space
Not with the naked eye from the Moon, and barely (if at all) from low orbit. The wall is long but very narrow, and it’s built from materials that blend into the landscape. China’s first astronaut, Yang Liwei, said he couldn’t see it.
6Bulls hate the color red
Cattle can’t really tell red apart from other colors. What makes a bull charge is the movement of the cape. The cape is red for a much grimmer reason: it helps hide blood.
7Your blood is blue until it touches air
Human blood is always red. Oxygen-poor blood is darker red, but still red. Veins only look blue because of the way light travels through your skin before it reaches your eyes.
8Lightning never strikes the same place twice
Tall objects get hit over and over. The Empire State Building is struck around 20 to 25 times a year on average.
9Vikings wore horned helmets
There’s no evidence they did. The only nearly complete Viking helmet ever found has no horns. The look was popularized in 1876 by a costume designer for Richard Wagner’s opera cycle The Ring of the Nibelung.
10Columbus proved the Earth was round
Educated Europeans had known the Earth was round for about 2,000 years. The ancient Greek scholar Eratosthenes even estimated its size around 240 BC. Columbus’s critics actually argued the Earth was bigger than he claimed — and they were right.
11Cracking your knuckles causes arthritis
That pop is gas bubbles in the fluid around your joints. One doctor, Donald Unger, cracked the knuckles on only his left hand for more than 60 years to test the theory. Neither hand got arthritis — and he won an Ig Nobel Prize for the experiment.
12Hair and nails keep growing after death
They don’t. After death the skin dries out and pulls back, which makes hair and nails look longer. Creepy, but it’s an illusion.
