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How Far Can You Fall and Still Survive?

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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.

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Big Questions
Why Don't We Eat Turkey Tails?
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Turkey sandwiches. Turkey soup. Roasted turkey. This year, Americans will consume roughly 245 million birds, with 46 million being prepared and presented on Thanksgiving. What we don’t eat will be repurposed into leftovers.

But there’s one part of the turkey that virtually no family will have on their table: the tail.

Despite our country’s obsession with fattening, dissecting, and searing turkeys, we almost inevitably pass up the fat-infused rear portion. According to Michael Carolan, professor of sociology and associate dean for research at the College for Liberal Arts at Colorado State University, that may have something to do with how Americans have traditionally perceived turkeys. Consumption was rare prior to World War II. When the birds were readily available, there was no demand for the tail because it had never been offered in the first place.

"Tails did and do not fit into what has become our culinary fascination with white meat," Carolan tells Mental Floss. "But also from a marketing [and] processor standpoint, if the consumer was just going to throw the tail away, or will not miss it if it was omitted, [suppliers] saw an opportunity to make additional money."

Indeed, the fact that Americans didn't have a taste for tail didn't prevent the poultry industry from moving on. Tails were being routed to Pacific Island consumers in the 1950s. Rich in protein and fat—a turkey tail is really a gland that produces oil used for grooming—suppliers were able to make use of the unwanted portion. And once consumers were exposed to it, they couldn't get enough.

“By 2007,” according to Carolan, “the average Samoan was consuming more than 44 pounds of turkey tails every year.” Perhaps not coincidentally, Samoans also have alarmingly high obesity rates of 75 percent. In an effort to stave off contributing factors, importing tails to the Islands was banned from 2007 until 2013, when it was argued that doing so violated World Trade Organization rules.

With tradition going hand-in-hand with commerce, poultry suppliers don’t really have a reason to try and change domestic consumer appetites for the tails. In preparing his research into the missing treat, Carolan says he had to search high and low before finally finding a source of tails at a Whole Foods that was about to discard them. "[You] can't expect the food to be accepted if people can't even find the piece!"

Unless the meat industry mounts a major campaign to shift American tastes, Thanksgiving will once again be filled with turkeys missing one of their juicier body parts.

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Big Questions
Why Do We Dive With Sharks But Not Crocodiles?
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Why do we dive with sharks but not crocodiles?

Eli Rosenberg:

The issue is the assumption that sharks' instincts are stronger and more basic.

There are a couple of reasons swimming with sharks is safer:

1. Most sharks do not like the way people taste. They expect their prey to taste a certain way, like fish/seal, and we do not taste like that. Sharks also do not like the sensation of eating people. Bigger sharks like great whites enjoy prey with a high fat-bone ratio like seals. Smaller sharks enjoy eating fish, which they can gobble in one bite. So, while they might bite us, they pretty quickly decide “That’s not for me” and swim away. There is only one shark that doesn’t really care about humans tasting icky: that shark is our good friend the tiger shark. He is one of the most dangerous species because of his nondiscriminatory taste (he’s called the garbage can of the sea)!

2. Sharks are not animals that enjoy a fight. Our big friend the great white enjoys ambushing seals. This sneak attack is why it sometimes mistakes people for seals or sea turtles. Sharks do not need to fight for food. The vast majority of sharks species are not territorial (some are, like the blacktip and bull). The ones that are territorial tend to be the more aggressive species that are more dangerous to dive with.

3. Sharks attacked about 81 people in 2016, according to the University of Florida. Only four were fatal. Most were surfers.

4. Meanwhile, this is the saltwater crocodile. The saltwater crocodile is not a big, fishy friend, like the shark. He is an opportunistic, aggressive, giant beast.

5. Crocodiles attack hundreds to thousands of people every single year. Depending on the species, one-third to one-half are fatal. You have a better chance of survival if you played Russian roulette.

6. The Death Roll. When a crocodile wants to kill something big, the crocodile grabs it and rolls. This drowns and disorients the victim (you). Here is a PG video of the death roll. (There is also a video on YouTube in which a man stuck his arm into an alligator’s mouth and he death rolled. You don’t want to see what happened.)

7. Remember how the shark doesn’t want to eat you or fight you? This primordial beast will eat you and enjoy it. There is a crocodile dubbed Gustave, who has allegedly killed around 300 people. (I personally believe 300 is a hyped number and the true number might be around 100, but yikes, that’s a lot). Gustave has reportedly killed people for funsies. He’s killed them and gone back to his business. So maybe they won’t even eat you.

8. Sharks are mostly predictable. Crocodiles are completely unpredictable.

9. Are you in the water or by the edge of the water? You are fair game to a crocodile.

10. Crocodiles have been known to hang out together. The friend group that murders together eats together. Basks of crocodiles have even murdered hippopotamuses, the murder river horse. Do you think you don't look like an appetizer?

11. Wow, look at this. This blacktip swims among the beautiful coral, surrounded by crystal clear waters and staggering biodiversity. I want to swim there!

Oh wow, such mud. I can’t say I feel the urge to take a dip. (Thanks to all who pointed this out!)

12. This is not swimming with the crocodiles. More like a 3D aquarium.

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