Knowing little factoids makes us feel smart. You store the information away like a squirrel hoarding food for the winter, and then the moment comes when the topic finally arises in casual conversation. You butt in, proudly raising a finger and uttering “did you know...,” but it can all go wrong. The “fun” fact you know may very well be complete nonsense, leaving your shining moment of knowledge ripe for a debunking by a smarmy onlooker. The sad truth is that the reason that many “fun” facts are “fun” is because they’re based on misunderstandings or just outright invented. Learning about some common misconceptions helps you enjoy being the debunker in these situations, rather than the one continuously getting knowledge-owned by well-informed and irritatingly correct pedants. Here are 12 of the most common offenders:
\#1 – You swallow an average of eight spiders per night in your sleep
This is a commonly-repeated “fact,” assumedly due to the profoundly disconcerting idea of a hairy, eight-legged monstrosity clambering around on your tongue while you’re unconscious. However, if you actually pick apart the idea behind it, it’s pretty clear that this is crazy. Spider experts estimate that even without humans in the bed, only one or two spiders would wander across one in a year, so when you throw in a 70 kg hunk of mammal – tossing and turning through the night – it’s clear only a suicidal or insane arachnid would bother risking getting crushed. Plus, the pushing strength of your breath is far from negligible for a small spider – it’d be like walking into the wind. So, you could theoretically swallow a spider in your sleep, if you sleep with your mouth open and have a particularly suicidal spider that’s absolutely determined to crawl into a sleeping giant’s mouth. In other words, you probably don’t swallow any. The idea was actually popularised to show how willing we were to accept nonsense we read on the internet as fact, so in a way it worked too well. We didn't get the message because we were too busy being disgusted by the thought of eating spiders.
Related: Snopes: Spiders inside her
\#2 – Waking a sleepwalker will harm them
Many people claim that if you wake someone when they’re sleepwalking, the shock (or something) of finding themselves not in bed will lead them to suffer a heart attack or otherwise do some serious damage. In actual fact, waking somebody who is sleepwalking does them no harm whatsoever. They might be a little confused and disorientated (so could attack you, if you look like a menacing stranger to their bleary, partially-tired eyes), but they definitely won’t be harmed. In fact, they could hurt themselves by continuing to sleepwalk freely, for obvious reasons. So, it’s better to guide a sleepwalker back to bed without waking, but if you do wake him, it won’t do any harm.
\#3 – Santa Claus wears red because of Coca-Cola
An appealing myth in our consumer society, with our commercialised Christmases and monolithic soft drink corporations, is that Santa Claus wears red because Coca-Cola forcibly adopted him as a mascot and decked him in corporate colours. Although it’s something cynics like to repeat around the holiday period, Santa’s colour scheme (and the modern image of him on the whole) was established before Coca-Cola decided to appropriate him for their advertisements.
Related: Snopes: The Claus that refreshes
\#4 – You lose most of your body heat through your head
This winter-time myth is why you almost always get told off (even as an adult) if you go out in cold weather without a hat on, because apparently, your head has the magical capability to lose more heat than anywhere else in your body. Trying to speculate as to the biological reason for this is hopeless, because the folk-wisdom is yet again completely not true. If it were true, it’d assumedly mean that the majority of our body heat was concentrated in our heads, in which case we’d get frostbite a hell of a lot easier and we’d literally be hot-headed animals. In the real world, we just lose heat from all over our bodies at an equal rate, but since your head is normally uncovered there’s nothing to keep it there in unless you wear a hat.
\#5 – You can see the Great Wall of China from space
This seems right, doesn’t it? The Great Wall of China is massive, after all, and you can see massive things from far away. But even from a low orbit, it’s pretty much invisible to the naked eye, and not exactly easy to pick out with a zooming camera lens. Strangely, this myth existed before we even went into space, so it had the opportunity to become an ingrained “fact” before it could even be checked. There are many other man-made objects visible from space, but because the Great Wall is made from rocks gathered in the surrounding area, it doesn’t stand out against the landscape enough to be visible. How Stuff Works helpfully suggests that China could paint the wall in hot pink to remedy the issue.
\#6 – Some of your blood is blue
Now this just isn’t fair. A simple look at your wrist shows you that yes, the deoxygenated blood is blue! You can see it, and it’s portrayed as blue in text-books, so how could it possibly not be true? Well in this case, it’s the light you’re detecting that’s misleading you. The deoxygenated blood is just dark red, but different colours of light (being different wavelengths) can penetrate your skin with differing degrees of success, and we only pick up the more energetic blue light when we look at deoxygenated blood through our skin. If you don’t believe it, find some way to extract blood from your veins without exposing it to oxygen and have a look. It’ll just be boring old red (but slightly darker).
\#7 – You only use ten percent of your brain
This is the type of “fact” often used to justify belief in extra-sensory perception or psychic abilities, but again, a bit of basic critique reveals that it’s pretty ridiculous. Why would an animal produce such a large amount of matter and not even use it? Surely it would be a criminal waste of energy to build a complex internal machine and not get some evolutionary advantage out of it? Of course we use all of our brains – we might not use every bit at the same time (just like you don’t simultaneously use all of your muscles), but we do definitely use all of it, as fMRI and PET scans clearly demonstrate.
\#8 – Einstein failed at school
Einstein – the modern archetypal genius – failing at school is a “fact” which serves as consolation to under-performing schoolchildren and is repeated by motivational speakers wanting to make some convoluted point about failure and success. It would be fairly comforting if true, but reality doesn’t tend to care about how comfortable you are. There are versions of this myth focusing on maths, but in either case, it’s just not true. He was studying calculus at age 12, three years ahead of his peers. The myth seems to stem from the fact that the grading system used in his school was reversed the year after he left – from 1 being the highest mark to 6 being the highest. Einstein got 1s (because, you know, he was a genius), but to anybody looking back at his grades, it would seem like that meant he’d failed.
Related: ABC Science: Einstein failed school
\#9 – Sharks don’t get cancer
This fact has gained acceptance despite having merely been invented as a justification for selling people shark cartilage pills as a cancer cure. Firstly, even if it was true that sharks didn’t get cancer, that wouldn’t mean that consuming a part of it was a cure or treatment for cancer, just like I wouldn’t become a genius if I ate Einstein’s brain. There were some initial positive results (if cartilage was directly inserted at the site of the tumour), but they were also obtained with other animal cartilages and didn’t translate into a reliable treatment. In short, eating shark cartilage pills does nothing for cancer patients. And to pile more stupidity on top of it, sharks demonstrably do get cancer. They don’t get it as often as we do, but they do get it. Regardless, the fun fact persists and sharks are still needlessly slaughtered for ineffective medicines which offer nothing besides false, hollow hope.
\#10 – Walt Disney was cryogenically frozen
Contrary to popular opinion, Walt Disney is not the real-world equivalent of Fry from Futurama, and is not currently locked up in a super-cold chamber under the Pirates of the Caribbean ride. In fact, he was cremated, as his death certificate confirms; the polar opposite of being frozen. Although it’s possible, there is no evidence that he even knew about cryonics, and most of the myth can be traced back to two poorly-researched biographies. Needless to say, we won’t be able to reanimate him, and nor will our hyper-technological futuristic equivalents.
Related: Snopes: Suspended animation
Much of this myth’s prevalence can undoubtedly be traced back to the Simpsons. Towards the beginning of the episode Bart vs. Australia, Lisa makes the claim and Bart sets about to prove her wrong. Since Lisa said it (and Bart proves her correct in the episode) it seems like it must be true, after all, she’s the smart one. In real life (where the only yellow people are the ones who have jaundice and those with four fingers are probably just accident-prone), the Coriolis effect only has an impact on large scale systems: things like the weather and ocean currents. Which way the water drains around a plughole is unaffected, as you can prove by forcing it in the opposite direction.
\#12 – Some people have a photographic memory
There’s something appealing about the notion that some people have super-human abilities, but it’s pretty much confined to the pages of comic books. There are people that claim to have photographic memories, but there is nobody that actually has a photograph-quality memory. Some people have much better memories than others, and may even make intuitive use of mnemonics or other memory techniques, but it’s never photographic. Up to 15 percent of children and some (rare) adults have eidetic memory, which is more like a mental “afterimage” they recall for a few minutes before it disappears, but it’s nowhere near perfect. Even somebody with this condition in adulthood couldn’t immediately memorise a page of writing, for example, but if you took a good enough picture of it you could read the whole thing.