# How Far Can You Fall and Still Survive?

IStock

You’re on a plane. You’re bored. You stare out the window at the clouds. You wonder what would happen if you couldn’t resist the urge to open the emergency exit and plummet to the earth below. Is death certain? Or would you pick yourself up, set a broken bone or two, and proceed directly to a mental institution with a great story?

Let’s first toss out some variables that often bog down this fair—albeit morbid—question. Forget Felix Baumgartner, the man who filmed himself jumping from 128,100 feet. He had a cool pressurized suit and a parachute. And let’s set aside what free-fall experts have coined “wreckage riders,” those who have fallen while trapped inside a portion of broken aircraft. (The larger surface area increases air drag, slowing their descent. Still likely fatal, but the odds improve somewhat: Serbian flight attendant Vesna Vulovic fell 33,000 feet this way in 1972 and lived to tell her tale—once she woke up from her coma.)

Let’s instead restrict the question to a single individual without any equipment, encasement, or premeditation. You’ve ripped the exit door open like a lunatic. You begin to fall. What now?

We know for certain a person can survive a fall of at least 20,000 feet. That’s how far up World War II pilot Alan Magee was when he had to abandon his plane without a parachute. He crashed through a glass roof that likely helped spread out the impact. According to James Kakalios, Ph.D., a professor at the School of Physics and Astronomy at the University of Minnesota, how and where you land is one of the major factors in whether you get up from the ground or go 6 feet further into it.

“If you can make the time [landing] longer, the force needed to stop you is smaller,” he says. “Think of punching a wall or a mattress. The wall is rigid and the time of interaction is short so the force is large. People who have survived falls, they’ve managed to increase that time, even if it’s in milliseconds. From one millisecond to three, that’s three times longer, three times less force needed for the same change in momentum.” Magee’s glass landing likely reduced the impact; other survivors have plummeted into snow, trees, or something that can better absorb your landing than, say, concrete.

The other major factor? Slowing your descent. Increasing surface area means more energy is required to push air out of your way, slowing you down. The “flying squirrel” position, body splayed out, is preferred over falling feet or head first. “Increasing that drag is the biggest factor in keeping you alive,” Kakalios says. A parachute’s large surface area is best, obviously. Without one, fall belly down or try tumbling. “Drop a pen off the Empire State Building straight down and it might kill someone. But if it drops sideways, spinning end over end, it probably wouldn’t.”

You’re increasing air drag. You’re trying to land in snow or something absorbent. If you’ve passed out from lack of oxygen at high altitudes, you’ve woken up in time to orient yourself. Magee traveled 20,000 feet—nearly four miles—so you know survival is possible from there. What about going higher?

Kakalios stops short of offering a prediction, citing the numerous variables involved. (“Even how much clothing is fluttering behind you can affect surface profile,” he says.) So we pestered someone else: Paul Doherty, Ph.D., a physicist and Co-Director of the Exploratorium, a learning center in San Francisco, California.

“As you get higher up, the air gets thinner and thinner,” he says. “You can spin so fast the blood can rush into your head and kill you. Or the friction with the elevation will burn you up. That’s why space shuttles have heat insulating tiles.”

Once terminal velocity (maximum acceleration, usually 120 miles per hour for average-sized humans) is reached, Doherty says, it doesn’t really matter whether you throw another 5000 or 10,000 feet on top of Magee’s 20,000: You’re not going to fall any faster. But start too high up and the lower atmospheric pressure means your blood might start to boil. That’s believed to happen around 63,000 feet, though data is obviously limited, and Doherty thinks it might be as high as 100,000. (NASA mandates pressure suits starting at 50,000 feet just to be on the safe side.)

So falling just under 63,000 feet is survivable, in theory? “Let’s say 60,000, Doherty says. Up to 100,000 if you wake up after passing out. And if your blood doesn’t boil. And if you can impact something.”

Stay on the plane.

# Why is Friday the 13th Considered Unlucky?

iStock

Today, people around the globe will feel uneasy about getting out of bed, leaving their homes, or going about their normal daily routines, all because of a superstition. These unfortunate folks suffer from paraskavedekatriaphobia, a common neurosis familiar to us all: the fear of Friday the 13th. But just where did this superstitious association come from, and how did it catch on?

The truth is that no one is absolutely sure where the idea that Friday the 13th is unlucky originated. Donald Dossey, the founder of the Stress Management Center and Phobia Institute in Asheville, North Carolina, suspects the fear can be traced back to a Norse myth about 12 gods who had a dinner at Valhalla—the fabled hall where legendary Norse heroes feasted for eternity after they died—that was interrupted by a 13th guest, the evil and mischievous god Loki.

According to legend, Loki tricked Höðr (the blind god of winter and son of Odin, the supreme god in Norse mythology) into shooting his brother Baldr (the benevolent god of summer who was also a son of Odin) with a magical spear tipped with mistletoe—the only substance that could defeat him. Thus the number 13 was branded as unlucky because of the ominous period of mourning following the loss of such powerful gods by this unwanted 13th guest.

For whatever reason, among many cultures, the number 12 emerged throughout history as a "complete" number: There are 12 months in a year, 12 signs of the zodiac, 12 Gods of Olympus, 12 sons of Odin, 12 labors of Hercules, 12 Jyotirlingas or Hindu shrines where Shiva is worshipped, 12 successors of Muhammad in Shia Islam, and 12 tribes of Israel. In Christianity, Jesus was betrayed by one of his 12 Apostles—Judas—who was the 13th guest to arrive for the Last Supper. Surpassing the number 12 ostensibly unbalances the ideal nature of things; because it is seen as irregular and disrespectful of a sense of perfection, the number 13 bears the stigma of misfortune and bad luck we know today.

## WHY FRIDAY?

Friday joins in the mix mostly because all of the early accounts of Jesus’s crucifixion agree that it took place on Friday—the standard day for crucifixions in Rome. As Chaucer noted in The Canterbury Tales, "And on a Friday fell all this mischance." Yet perpetuating Friday as an unlucky day in America came from the late 19th-century American tradition of holding all executions on Fridays; Friday the 13th became the unluckiest of days simply because it combined two distinct superstitions into one. According to the Oxford University Press Dictionary of Superstitions, the first reference to Friday the 13th itself wasn’t until 1913. (So despite actually occurring on Friday, October 13, 1307, the popular notion that the Friday the 13th stigma comes from the date on which the famed order of the Knights Templar were wiped out by King Philip of France is just a coincidence.)

The repercussions of these phobias reverberated through American culture, particularly in the 20th century. Most skyscrapers and hotels lack a 13th floor, which specifically comes from the tendency in the early 1900s for buildings in New York City to omit the unlucky number (though the Empire State Building has a 13th floor). Some street addresses also skip from 12 to 14, while airports may skip the 13th gate. Allegedly, the popular Friday the 13th films were so-named just to cash in on this menacing date recognition, not because the filmmakers actually believed the date to be unlucky.

So, is Friday the 13th actually unlucky? Despite centuries of superstitious behavior, it largely seems like psychological mumbo jumbo. One 1993 study seemed to reveal that, statistically speaking, Friday the 13th is unlucky, but the study's authors told LiveScience that though the data was accurate, "the paper was just a bit of fun and not to be taken seriously." Other studies have shown no correlation between things like increased accidents or injuries and Friday the 13th.

And Friday the 13th isn't a big deal in other cultures, which have their own unlucky days: Greeks and Spanish-speaking countries consider Tuesday the 13th to be the unluckiest day, while Italians steer clear of Friday the 17th. So today, try to rest a little easy—Friday the 13th may not be so unlucky after all.

Additional Source: 13: The Story of the World’s Most Popular Superstition.

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

# Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception: in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

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

arrow
LIVE SMARTER
arrow
LIVE SMARTER