How Many Spiders Do You Really Swallow in Your Sleep?

iStock
iStock

The “you eat X number of spiders” factoid changes depending on who you ask. Some people says it’s three, others eight, and still others might say as many as several dozen. Ask someone who really knows their spiders, though, and the number of ingested creepy crawlies drops right to zero.

Think about it this way, says Rod Crawford, Curator of Arachnids at Seattle’s Burke Museum and a dedicated buster of spider myths: To swallow even just one spider in your sleep, a number of very unlikely circumstances all have to happen at once.

The first, Crawford says, is that your mouth needs to be open. Sure, some people sleep that way, but not everyone. No open mouth, no swallowed spiders.

Second, the spiders have to get in your bed. “A totally normal, neatly made bed,” Crawford says, “has maybe one or two spiders cross it per year.” Add some humans to the bed, and spiders really don’t want anything to do with it. “Most people roll around in their sleep,” write doctors Aaron Carroll and Rachel Vreeman in their book, Don't Swallow Your Gum!: Myths, Half-Truths, and Outright Lies About Your Body and Health. “This rolling would probably scare the spiders from wandering anywhere close to your face.”

Third and fourth, Crawford says, the spider would have to just happen to cross your body where your mouth is and be so bold as to enter an orifice that’s exhaling warm breath. “Just try blowing on a spider and see how they react to that!” Crawford says. “It’s not attractive to them!”

Finally, you’d have to swallow the spider while sleeping, and Carroll and Vreeman point out that, “we do not automatically swallow every time something goes into our mouths.”

The odds are pretty clearly stacked against you swallowing any one spider, let alone multiple ones over the years. “The chance that all of these things would happen together—that there would be a wandering, potentially suicidal spider in close vicinity to your mouth and that they would actually wander in to the wet dark breathing space and trigger your swallowing reflex,” Carroll and Vreeman write, “is really incredibly small.”

However unlikely, something like this still could happen, but we don’t have any solid proof that it has. Plenty of people watch other people sleep, says Crawford, but he’s never seen or heard a single good eyewitness account of a spider climbing into a sleeping person’s mouth or of someone watching them sleep keeping it from almost happening.

What’s more, says Crawford, “Every time you hear this story, the teller has a different number of spiders and a different length of time in which they are supposed to be swallowed. So even if one version had been correct, nearly all the tellers would still have to be lying!”

But Wait, There’s More!

There might actually be another layer of BS to this urban legend. Many stories that debunk the spider statistic point to an article written in the early 1990s about misinformation on the early World Wide Web as its origin. The article on the spider story at Snopes.com, for example, reads:

Fear not. This "statistic" was not only made up out of whole cloth, it was invented as an example of the absurd things people will believe simply because they come across them on the Internet.

In a 1993 PC Professional article, columnist Lisa Holst wrote about the ubiquitous lists of "facts" that were circulating via e-mail and how readily they were accepted as truthful by gullible recipients. To demonstrate her point, Holst offered her own made-up list of equally ridiculous "facts," among which was the statistic cited above about the average person's swallowing eight spiders per year, which she took from a collection of common misbeliefs printed in a 1954 book on insect folklore. In a delicious irony, Holst's propagation of this false "fact" has spurred it into becoming one of the most widely-circulated bits of misinformation to be found on the Internet.

All well and good, except that a web search doesn’t turn up much of anything about Lisa Holst or PC Professional that isn’t directly related to the genesis of the spider myth and saying pretty much the same thing as Snopes. The columnist, the column and the magazine don’t seem to exist, or were at least lost to history before everyone and everything had some presence on Google. A few people, including a guy named Nick who runs the blog “Eight Spiders,” have gone a little further in search of the source, but to no avail. Even the Library of Congress said they had no record of the magazine when Nick called them up. The story about how the story got made up may itself be made up. Whoa. Meta.

What Would Happen If a Plane Flew Too High?

iStock
iStock

Tom Farrier:

People have done this, and they have died doing it. For example, in October 2004, the crew of Pinnacle Airlines 3701 [PDF]  was taking their aircraft from one airport to another without passengers—a so-called "repositioning" flight.

They were supposed to fly at 33,000 feet, but instead requested and climbed to 41,000 feet, which was the maximum altitude at which the aircraft was supposed to be able to be flown. Both engines failed, the crew couldn't get them restarted, and the aircraft crashed and was destroyed.

The National Transportation Safety Board determined that the probable causes of this accident were: (1) the pilots’ unprofessional behavior, deviation from standard operating procedures, and poor airmanship, which resulted in an in-flight emergency from which they were unable to recover, in part because of the pilots’ inadequate training; (2) the pilots’ failure to prepare for an emergency landing in a timely manner, including communicating with air traffic controllers immediately after the emergency about the loss of both engines and the availability of landing sites; and (3) the pilots’ improper management of the double engine failure checklist, which allowed the engine cores to stop rotating and resulted in the core lock engine condition.

Contributing to this accident were: (1) the core lock engine condition, which prevented at least one engine from being restarted, and (2) the airplane flight manuals that did not communicate to pilots the importance of maintaining a minimum airspeed to keep the engine cores rotating.

Accidents also happen when the "density altitude"—a combination of the temperature and atmospheric pressure at a given location—is too high. At high altitude on a hot day, some types of aircraft simply can't climb. They might get off the ground after attempting a takeoff, but then they can't gain altitude and they crash because they run out of room in front of them or because they try to turn back to the airport and stall the aircraft in doing so. An example of this scenario is described in WPR12LA283.

There's a helicopter version of this problem as well. Helicopter crews calculate the "power available" at a given pressure altitude and temperature, and then compare that to the "power required" under those same conditions. The latter are different for hovering "in ground effect" (IGE, with the benefit of a level surface against which their rotor system can push) and "out of ground effect" (OGE, where the rotor system supports the full weight of the aircraft).

It's kind of unnerving to take off from, say, a helipad on top of a building and go from hovering in ground effect and moving forward to suddenly find yourself in an OGE situation, not having enough power to keep hovering as you slide out over the edge of the roof. This is why helicopter pilots always will establish a positive rate of climb from such environments as quickly as possible—when you get moving forward at around 15 to 20 knots, the movement of air through the rotor system provides some extra ("translational") lift.

It also feels ugly to drop below that translational lift airspeed too high above the surface and abruptly be in a power deficit situation—maybe you have IGE power, but you don't have OGE power. In such cases, you may not have enough power to cushion your landing as you don't so much fly as plummet. (Any Monty Python fans?)

Finally, for some insight into the pure aerodynamics at play when airplanes fly too high, I'd recommend reading the responses to "What happens to aircraft that depart controlled flight at the coffin corner?"

This post originally appeared on Quora. Click here to view.

Why Are Some Men's Beards a Different Color Than Their Hair?

iStock
iStock

Throughout civilization, beards have acted as a silent communicator. For some, it's a symbol of virility and power. For others, being hirsute is mandated by religion, marital status, or both. (Amish single men are clean-shaven; husbands are not.) Seeing an unkempt, scraggly beard could be an indication of a person's economic status or their lack of vanity. One man, Hans Langseth, sprouted a 17-foot-long chin warmer for the unique identity it afforded him. (He kept it neatly rolled over a corn cob when he wasn't busy showing it off.)

Langseth's whiskers, which wound up in the Smithsonian, present a curious timeline of his life. The furthest end of the beard was a vibrant brown, grown out when he was younger. The ends closer to his face—and to the end of his life in 1927—were yellowed.

While age can certainly influence hair and beard color, it doesn't explain why a younger man can sport a decidedly different beard tone than what's on the rest of his head. Other follicular forces are at work.

By default, scalp hair is white. It gets its color from melanin, turning it everything from jet black to dirty blonde. Pheomelanin infuses hair with red and yellow pigmentation; eumelanin influences brown and black. Like shades of paint, the two can mix within the same hair shaft. (Melanin production decreases as we age, which is why hairs start to appear gray.) But not all follicles get the same dose in the same combination. While you might sport a light brown top, your beard could be predominantly dark brown, or sport patches of lighter hairs in spots. Eyebrow hair will probably appear darker because those follicles tend to produce more eumelanin.

If you're wondering why these two-toned heads often have a red beard but not red hair, there's an answer for that, too. While all hair color is genetic, one gene in particular, MC1R, is responsible for a red hue. If you inherit a mutated version of the gene from both parents, you're likely to have red hair from head to toe. (Hopefully not too much toe hair.) But if you inherit MC1R from just one parent, it might only affect a portion of your follicles. If that swatch of color annoys you for whatever reason? There’s always beard dye.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER