16 'Facts' That Have Been Proven False By Science

There are so many "facts" that we repeat time and again, without ever examining whether or not there's any truth behind them.

You can't go swimming after eating. Sharks can smell blood miles away. Dogs can't see colors.

All of these are so well-known that nearly everyone has heard of them. What's more, they're all false.

1. The five-second rule is bogus.

Hiveminer | Hiveminer

Many people drop food on the floor, pick it up immediately, and eat it — arguing that no bacteria can adhere to it within five seconds.

This just isn't true. Food can pick up bacteria nearly instantly, meaning there's no such thing as a safe duration for eating food that's been dropped.

2. McDonald's burgers don't last forever.

Wikimedia Commons | Kici

There's a belief that foods high in preservatives, like fast food or snack cakes, basically last forever without spoiling.

In fact, McDonald's burgers go bad within a day. They might not obviously rot if they're kept in dry, cold conditions, but that doesn't mean they're safe to eat.

3. Lemmings don't leap to their deaths.

Wikimedia Commons | Argus fin

An unfortunate urban legend, this one was unfortunately started by a Disney film crew that wanted to create a more dramatic scene.

They marched scores of lemmings off a cliff, giving rise to a false belief that has persisted for decades.

4. Humans didn't evolve from chimps — we evolved from a common ancestor.

Wikimedia Commons | Thomas Lersch

Evolution is a constant, meaning that other apes have been evolving just as we have.

What does that mean? It means that we didn't come from chimps or gorillas or monkeys — all species came from a common ape ancestor that no longer exists.

5. Sharks can, in fact, get cancer.

Wikimedia Commons | Sharkdiver.com

The myth that sharks can't get cancer was started by a guy trying to sell shark cartilage as a cancer treatment.

Scientists have actually observed cancer in various shark species over the years — more than enough to debunk the claims.

6. Sharks can't smell blood from miles away.

Wikimedia Commons | suneko

Sticking with the shark beat, let's debunk the myth that sharks can smell blood from miles away.

The ocean is big, and although sharks have a keen sense of smell, they can smell blood from a few hundred yards away — not miles.

7. Chocolate and other sweets aren't aphrodisiacs.

Wikimedia Commons | Woodlot

No, that heart-shaped box of chocolates isn't likely to make anyone more amorous.

The long-held myth never needed to be debunked, because there was never really any scientific evidence to support it in the first place.

8. Cats and dogs aren't actually colorblind.

Wikimedia Commons | Rufus Sarsparilla

We've been conditioned to think that our pets see in black and white, but that isn't exactly true.

Both cats and dogs see better in low-light situations, and also see in different spectrums, with colors appearing differently than they do to us.

9. You can't see the Great Wall of China from the moon.

Wikimedia Commons | Ofol

There's an old myth that the Wall is the only human-made object visible from the moon.

You can see it from low-orbiting satellites like the International Space Station, but the same is true of many objects. From the moon, the narrow wall is completely invisible, however.

10. We use way more than 10% of our brain.

Wikimedia Commons | Royonx

There's a popular myth that humans only use a certain, small percentage of their brain.

Different parts of the brain are used for different things, but we still use all of our brain. Brain stuff uses up a fifth of the body's energy.

11. Mount Everest isn't the tallest mountain on Earth.

Wikimedia Commons | Luca Galuzzi

The mountain is definitely the tallest above sea level, but it isn't technically the tallest mountain on Earth.

That honor goes to the Hawaiian island of Mauna Kea. Factoring in the submerged section of the volcanic island, it's 33,500 feet tall — about a mile taller than Everest.

12. Organic food isn't always better for you.

Wikimedia Commons | Alanthebox

It may cost more, but that doesn't mean it's pesticide-free or even better for you. Organic crops are often sprayed with "natural" pesticides.

What's more, experts have found that organic food doesn't have any nutritional benefits that non-organic doesn't.

13. The Sahara isn't Earth's biggest desert.

Wikimedia Commons | Sanasouna

The vast Sahara may be our planet's most famous desert, but it isn't the biggest.

The biggest desert actually spans a whole continent. Antarctica, at 5.4 million square miles, is just as dry and much bigger than the 3.6 million square mile Sahara.

14. Vitamins aren't as important as they may seem.

Wikimedia Commons | Mike1024

Vitamins can be helpful for people who have nutritional deficiencies, but their benefits are overblown.

Multivitamins in particular don't necessarily provide any benefits to a person with a balanced diet, and they're not recommended by the U.S. Preventive Services Task Force.

15. Being in orbit doesn't mean you're weightless.

Wikimedia Commons | NASA

Sure, spacewalking astronauts may appear to float, but their body weight is still real.

Being in orbit basically means an object is falling forever around an object, and that object's gravity continually slingshots them around it, causing them to continue "falling."

16. You don't need to wait after eating to go swimming.

Wikimedia Commons | Wikimedia Commons

No, swimming after eating isn't going to make anyone cramp up and drown.

It's unclear where this myth came from, but there's absolutely zero evidence to support it. Swim away!