Dear Cecil:
I've often read that if you jump off the Golden Gate Bridge, you will accelerate to the point where hitting the water will be like hitting concrete. But my little brain keeps saying, "Yeah, but it's WATER!" Could you jump off a bridge like the Golden Gate and contort your body in such a way that you'd survive? --Paul, Ann Arbor
Dear Cecil:
I've heard that if you jump off a tall enough building, you'll pass out before you hit the ground due to falling so fast. My friend tells me this is not true. He argues that skydivers free-fall and hit terminal velocity and are just fine. I told him that they haven't fallen long enough. Can you help me prove him wrong? --Katie, Bellingham, Washington
Cecil replies:
Of course not, numbskull. Your friend is right. Skydivers in free fall routinely reach terminal velocity, i.e., the speed at which air resistance and weight balance out and acceleration stops, which often exceeds 120 mph. During a typical plunge they may drop 10,000 feet in 60 seconds, remaining conscious throughout. (The free-fall speed record, incidentally, is 614 mph, set in 1960 by Joseph Kittinger, who stepped out of a balloon gondola into the exceedingly thin air at 103,000 feet.) Nonetheless the belief persists that anyone leaping or falling from a great height blacks out, has the breath sucked out of them, etc. Fact is, some pass out, but not all. We know this because--you knew we'd get around to your question eventually, Paul--people have in fact survived a leap off the Golden Gate Bridge, and staying alert is one reason they did.
Scientists have long been fascinated by what happens to people who fall from great heights without a parachute. Unsurprisingly, most of them get killed; perhaps surprisingly, a few don't. A prime example of the latter was a 17-year-old male who in 1979 leaped off the Golden Gate Bridge from a height of 250 feet. According to one report, "he recount[ed] a slowing of time initially, and mid-fall, when fully realizing the oncoming impact, strove to adjust his attitude to the vertical feet-first position. An almost perfect entry was achieved. Although dazed, he swam to shore" and checked into a hospital, where his worst injury turned out to be several cracked vertebrae.
Walking away from something like that is rare. The Golden Gate Bridge is said to be the most popular suicide location in the world--at least 1,200 people had jumped as of 2003, of whom fewer than 20 survived. A more typical outcome was that of a stuntman calling himself Kid Courage, who jumped off the bridge in 1980 trying to set a free-fall record. He landed flat on his back and was dead when pulled from the water with massive internal injuries.
The key to survival appears to be vertical entry. Your little brain is right, Paul--there's a difference between landing on water and landing on concrete, namely you can't dive into concrete. The 17-year-old male survivor said he may have touched bottom, perhaps 20 to 25 feet down--plenty of room to disperse the force of impact. In contrast, Kid Courage's body never sank beneath the surface, meaning he'd gone from 75 mph (a Golden Gate leaper's peak speed) to zero in maybe six inches.
Beyond a certain point even Olympic form won't save you. One expert claims the upper limit for surviving water entry is around 80 mph. Presumably it's less if you're hitting something solid. Still, the literature teems with spectacular exceptions:
In a 1942 paper, physiologist Hugh De Haven told of eight people who survived falls of 50 to 150 feet on dry land, many with only minor injuries. The common denominator: something to break the fall or soften the impact, such as loose dirt, the hood of a car, or, in one astonishing but verified case, an iron bar, metal screens, a skylight, and a metal-lath ceiling.
In 1963, U.S. Marine pilot Cliff Judkins's chute didn't open after he bailed out of his crippled fighter. He fell 15,000 feet into the Pacific, suffered numerous broken bones and a collapsed lung, but lived.
U.S. Army air force sergeant Alan Magee fell 20,000 feet from an exploding B-17 in 1943 and crashed through the skylight of a French train station. (A lesson emerges: Aim for the skylight.) Though his arm was shattered, he lived too.
When his bomber was shot down in 1942, Soviet lieutenant I.M. Chisov fell 22,000 feet into a snowy ravine. He was badly injured but recovered.
Luckiest of all was RAF flight sergeant Nicholas Alkemade, who leaped from his burning bomber in 1944 without a parachute at 18,000 feet. After a 90-second plunge, he crashed through tree branches in a pine forest and landed in 18 inches of snow. His only injuries: scratches, bruises, burns, and, in some accounts, a twisted knee.
--CECIL ADAMS
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