Scientific Facts That Aren’t Actually True

Bambi Turner

Image: krisanapong detraphiphat / Moment / Getty Images

About This Quiz

In 1998, a British doctor published a groundbreaking study linking vaccines and autism. Terrified parents quickly took note, questioning their children's pediatricians or even skipping vaccines altogether. Just two decades later, this reluctance to vaccinate has negated years of vaccination progress and caused nearly eradicated illnesses like measles or whooping cough to threaten the lives of a whole new generation of children. But here's the kicker -- no one has been able to replicate the results of the study. The doctor who published the initial study has lost his license to practice medicine and the medical journal that published his work has issued a retraction -- but that hasn't stopped the fact that many people still accept his initial work as fact. 

And that's just one example of this phenomenon. Despite the fact that science and medicine are continuously reaching new heights, far too many people cling to folk remedies, old wives' tales, disproved facts and plain old bad science. It's why turkey "makes you so sleepy," a goldfish "has no memory," and a penny dropped from the Empire State Building is "deadlier than a speeding bullet." Think you can know the truth about some of the most commonly repeated scientific "facts?" Prove it with this quiz!

What color is blood when it's still inside your veins?

Running through your veins, pumping into your heart or oozing from a wound, blood is always the same color -- red. Well, unless you happen to be an octopus or a horseshoe crab. Both of these critters are among the rare species running around with blue blood.

What happens if you cut an earthworm in half?

No, cutting an earthworm in half will not result in two thriving worms. While some flatworms can regenerate when cut in half, earthworms cannot. The best case scenario is that the head end of the cut earthworm will survive, but the tail end is a goner.

When do hair and fingernails stop growing?

Ever heard that fingernails and hair continue to grow after you die? Creepy, but not true. When you die, body processes stop -- including nail and hair growth. This rumor likely reflects the fact that dehydration after death causes skin to shrink, which can make hair and nails appear to have grown.

Which of these has been scientifically proven to help cure a cold the fastest?

No, antibiotics won't cure a cold. They are designed to attack bacteria, but a cold is caused by a virus, so antibiotics will have zero effect. Orange juice and soup can't really hurt, but also won't help. Want to get that cold out of your system more quickly? Get plenty of rest and relaxation to speed healing.

Which of these is true regarding water and electricity?

Contrary to rumor, pure water -- such as distilled -- is actually an insulator, not a conductor. When you are warned to steer clear of water during a lighning storm, it's because all of the minerals in the water are excellent conductors. The threat doesn't come from the water itself.

Did humans ever have to worry about being eaten by dinosaurs?

The closest any human has ever came to a dinosaur was when you saw that T. rex skeleton at the museum. Dinosaurs died out around 65 million years before humans came into the picture, so the two species never cohabited.

Why are you so darn sleepy after chowing down on a big Thanksgiving dinner?

The enzyme tryptophan is involved in sleep, but no one eats enough turkey on Thanksgiving to ingest any meaningful amount of this amino acid. Instead, that after-dinner crash comes because your body is so busy digesting all that food, leaving you little energy for other activities.

What exactly causes embarrassing acne?

It's safe to finish that candy bar -- chocolate does not cause acne like you might have heard. Instead, pimples come from overactive sebaceous glands, but scientists aren't exactly sure what gets these glands so worked up.

What happens if you eat ice cream to soothe a painful sore throat when you have a cold?

The old wives tale that dairy consumption increases mucus production has caused many people to steer clear of ice cream or milk when nursing a cold. Today, scientists know that there's no connection between dairy and mucus, so it's safe to enjoy that ice cream when your throat is too sore for anything else.

What's the worst thing that can happen if you crack your knuckles all the time?

Contrary to rumor, cracking your knuckles does not contribute to arthritis or any other long-term health effects. Dr. Donald Unger proved this when he spent 50 years only cracking the knuckles in one hand, but not in the other. After half a century, he had no difference in physical health between the two hands.

What determines the direction that liquid will take when it affects the drains in your home?

Sorry Simpsons; the Coriolis Effect does determine wind patterns, but has no effect on the way water flows out of your toilet when you flush. Toilets in both hemispheres can drain clockwise or counterclockwise depending on the fixtures and how they were installed.

How much of the brain is the average human using on a given day?

No, humans don't limit themselves to using 10 percent of their brains, leaving the rest of that gray matter to rot. In fact, the brain uses around 20 percent of all the energy used by the body, which means you're using pretty much every part of your brain at almost all times.

What happens when kids consume sugar?

A 1994 double-blind, peer-reviewed study found that sugar does not make kids hyper or lead to bad behavior. What it does is impact the way parents think; parents told their kids are given sugar rate the child as more hyper than parents who are told the child was given no sugar -- even if neither group had any sweets.

Which of these are vaccines scientifically proven to cause?

Every major medical institution on the planet recommends basic vaccines to prevent illness and allow people to live healthy lives. That MMR/Autism study by Andrew Wakefield that spurred the whole anti-vaxxer movement? It was based on a sample size of 12 and rife with fraud. Wakefield lost his license to practice medicine and no other study has ever come close to replicating his results.

How long does swallowed gum hang around in your stomach?

Humans have been chewing on gum for fun since the first version of the product -- made from spruce resin -- came out in the 1840s. Rest assured that swallowed gum doesn't linger for 7 years; it's processed just like other food and sent out with other waste products.

Astronaut Neil Armstrong was asked about the Great Wall of China shortly after his trip to the moon. What was his response?

In perfect conditions, flying at 100 miles above the Earth, it's sometimes possible to see portions of the Great Wall of China. Far from being the only manmade object visible from outer space, however, Neil Armstrong himself specifically said he couldn't see it at all -- and could only distinguish the continents and water bodies.

How long is a goldfish's memory?

Forget everything you've heard about goldfish and their sad, three-second memories. Even wild goldfish can be trained to remember things -- and some of those memories can endure three months or more.

What would happen if a penny dropped off the Empire State Building hit you on the head?

A penny dropped from the top of the Empire State Building wouldn't kill anyone. Instead, its flatness would slow it enough that it would only be traveling at around 25 mph when it reached the ground. That might be annoying if it hit you, but it certainly wouldn't cause any real injury.

Does an apple a day keep the doctor away?

It's great marketing for apple sellers, but there is no scientific link between eating an apple each day and time spent at the doctor. For real -- it's actually been studied. A 2015 study published in "JAMA Internal Medicine" found that apple eaters visit the doctor about as much as non-indulgers.

Why does that ostrich have her head hidden in the sand?

Forget the rumors; ostriches don't stick their heads in the sand because they are scared or shy. They do bury their eggs underground, so mom might duck her head down at times to take a peek -- which might make it appear she's gone into hiding for a minute.

When did most educated people understand that the world was a sphere?

No, people did not think Columbus was going to sail off the edge of the Earth in 1492. Most educated people have understood that the Earth is round since the ancient Greeks figured it out starting around 350 BC.

Which of these gives you a cold?

Forget the old wives' tales; you don't get a cold because it's cold outside, or you went out with a wet head or forgot your jacket -- colds come from viruses, period. If it seems like you get more colds in the winter, it's probably because you're spending more time indoors sharing close quarters with other people, who are sharing their germs with you.

What happens to your eyes if you sit too close to the TV?

No matter what your mother may have told you, sitting too close to the TV does not permanently damage eyes. The worst it can do is cause temporary eye strain, which resolves itself with a bit of R&R.

How many human years is the first year of a dog's life equivalent to?

According to the American Kennel Club, the first year of a dog's life is equivalent to about 15 human years. Year 2 for a dog is another 9 human years, and every year after that is about 5 human years.

Which of these is true about gravity in space?

When you exit the Earth's gravitational field, it can seem like gravity in space is really weak, but in fact, outer space gravity is super strong. It's what keeps all the planets where they are, slinging them around an orbit to circle the sun.

Which of these is true about the moon?

The whole "dark side of the moon" thing isn't really true. Sure, we can only see one side of the moon from Earth, but both "sides" of the moon spend time in the light. Each side is light for about two weeks, then dark for a few weeks, so no area of the rocky surface is ever in permanent darkness.

Is Earth the only planet in our solar system with water?

While Earth is the only planet with consistent supplies of liquid water, it isn't the only planet with water. Scientists know that Mars has water, which even flows at times, while moons of Saturn and Jupiter have subterranean seas.

How long does it take for bacteria to contaminate food once you drop it on the floor?

Forget the 5 second rule. Bacteria starts to contaminate food the second the food hits the floor. The longer the food stays down, the more bacteria climbs on board to threaten your gastrointestinal health if you decide to pick up the food and eat it.

How long did Galileo spend in jail for insisting that the sun, not the Earth was the center of the universe?

Italian astronomer Galileo raised eyebrows when he claimed that the sun, not the Earth, was the center of the universe. While history leads us to believe he was persecuted for his ideas, he actually only spent one day in prison. The church actually sponsored his research, and only put him on trial because he was teaching his theories as facts without proof -- not because they were heretical.

What happens to dead brain cells?

No, dead brain cells aren't gone forever. Scientists have known since the '60s that just like many other cells in the body, brain cells damaged by disease or injury can regenerate and restore themselves over time. Isn't the body amazing?

What happened to Ben Franklin when lightning struck his kite?

Yes, Benjamin Franklin flew a kite in a lightning storm in 1752 to experiment with electricity, but lightning never struck the kite. Instead, Franklin used a metal wire to attract ambient electrical charges in the air -- not huge, dangerous bolts of lightning,

Which of these is true of frozen vegetables?

On a budget but trying to get your greens? Flash-frozen veggies are about equal to fresh veggies in terms of nutritional value. If you can't afford fresh vegetables or can't find them off-season, frozen veggies can give you all the nutrients and fiber you're looking for.

When are people in the United States closest to the sun?

Contrary to what you might have heard, seasons on Earth are determined by the tilt of the planet's axis, not by its distance from the sun. In fact, people in the U.S. and other parts of the northern hemisphere are actually closest to the sun in the winter when temperatures are the lowest.

How long should you wait to swim after you finish eating?

The whole idea of waiting 30 minutes after eating before you swim is an old wives' tale with no scientific basis. It's perfectly safe to swim right after chowing down, so feel free to jump in with both feet.

How many times can lightning strike and hit a single spot?

Yes, lightning can strike the same spot more than once. In fact, a Virginia park ranger named Roy Sullivan was struck 7 times over a 30-year period, and tall buildings like the Empire State Building get struck all the time.

What happens to a person of average health if they eat lots of carrots?

Back in WWII, British pilots blamed carrots for their awesome eyesight, when in fact it was a little trick called radar that was allowing them to hit their targets. The rumors stuck, and carrots are still associated with good vision. For people who aren't malnourished, however, chowing down on these veggies will have little to no effect on vision.

How do babies with pets at home fare in terms of lifetime allergies?

Believe it or not, babies who grow up with a pet in the house are less likely than those without pets to suffer allergies over time. This effect only works if the baby is under a year old, and getting a pet later in life has no impact on allergy occurrence.

What is most likely to happen if you take antioxidant supplements?

According to the National Cancer Institute, antioxidant supplements don't prevent cancer, and if you take them when you already have cancer, you may end up with a worse outcome. Some supplements actually cause tumors to grow, rather than shrink.

When can a flu shot give you the flu?

Flu shots contain a dead flu virus and absolutely, positively cannot give you the flu. Around 1 to 2 percent of people who get this shot may have mild symptoms like a fever, but that's just a sign that the immune system is responding to the vaccine and gearing the body up to fight off future flu infections.

Which of these is scientifically proven to cause stomach ulcers?

Since 1982, scientists have known that helicobacter pylori, a type of bacteria, causes peptic ulcers. Spicy food might aggravate an existing ulcer, but it won't cause one to form.

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