I have been semi-baffled about this for some time. Is it the impact with the water? Seems unlikely, since cliff divers have been high-diving for centuries. Unless you do a spectacular belly-flop, perhaps? Would this cause such damage to your heart, lungs, and other internals that death would result?
Or, is it because you end up so deep in the water that you would drown before you could resurface? This also seems unlikely, unless you somehow resisted any efforts by your body of returning to the surface (which also seems like it would be extremely difficult to do).
I’m not about to take a flying leap or anything, I’m simply curious about this.
mmm
Water is so dense it doesn’t ‘move out of the way’ fast enough. It’s like jumping on to concrete. Well, not concrete, but a surface hard enough to kill you.
Whenever I hear about this I always wonder about the cliff diving thing. I always assumed there’s a big difference between someone that’s purposely jumping off a cliff with the intent of surviving (proper formation, knows how to swim, knows they can get to land, knows the water isn’t too cold etc) and someone who’s, well, trying to kill themselves (or falls by accident).
Usually impact with the water. When divers jump from heights they have to be very careful that they pierce the water correctly (hands first, or feet first) to minimize the impact. If you hit the water just a little bit off, it will be much like hitting solid ground. You’ll do a lot of physical damage, as well as be stunned so you’ll drown.
There are some survivors from Golden Gate Bridge jumpers including a teen this year that was barely injured from it. Don’t let anyone tell you this a dumb question. I have wondered it myself many times before. Water is not the same as concrete although the end result (death) is the same for most people that make a really high jump. You can be in good enough shape and have a jumping or diving form good enough to let you swim away from something that instantly kills most jumpers but I am not exactly sure what that is.
Do any of the physics types know the speed a person reaches from a 220 foot jump (take air drag into account)? I would like to know what organs are most prone to failure under such circumstances. I don’t think it literally breaks every bone in their body so that must be some weak points and a jumping form that can compensate for that if executed perfectly. I assume cliff diving is a good model for much higher heights but I don’t know that for sure.
Long, long ago, when I was in high school (and Hubert Humphrey was a big name in U.S. politics…and sliced bread hadn’t been invented…) we were shown an educational film on the subject, that had charming little animations showing the leg bones being shoved up into the abdominal cavity. (The subject jumped into the water feet-first…) Death was ultimately due to the massive disruption of these organs. I would imagine that there would also be a lot of internal bleeding – what’s the term, hematoma? The film ultimately showed the femurs jabbing up into the lungs…
I don’t know if the film was accurate or not. This was in the same time period as anti-drug and anti-VD films where the scientific accuracy was…um…impeachable.
It’s typically massive trauma. Ruptured internal organs, broken bones, etc.
As noted it’s possible in rare circumstances to survive a long fall into water but you can also survive a long fall onto a solid surface, it’s just really rare.
My friends dad was a park ranger at a place with a 200 foot high bridge, he said that in many cases the structural damage to the body was severe, as in legs being pushed up, probably out of socket, into very unnatural places.
But he also said 1 person basically survived with just a broken back.
I read a Reader’s Digest article years ago about a man who lept off a bridge (The Golden Gate?) trying to rescue a suicidal jumper. The man, who survived, reported that the impact of hitting the water was so powerful that he was only semi-conscious and almost drowned himself. I think the only reason he survived was because he’d called for help before diving in after the suicide, and rescuers plucked him from the water shortly thereafter.
I remember watching cliff divers in Acapulco and they would stand there, sometimes for what seemed like forever (probably really about 2 to 5 minutes) before finally jumping. They watched the tide, the speed and height of the waves, wind speed, etc. and picked their moments to jump very carefully.
Some of it could be showmanship, but I think a lot of it is as stated above. They are able to slice into the water with the least possible impact by positioning themselves perfectly based on all those factors.
At the 225 foot height of the Golden Gate Bridge, a dropped object that was not subject to drag would accelerate to around 82 mph (120 ft/s). Terminal speed for a human body in free fall (assuming stable flight with the arms and legs out) is about 120 mph (176 ft/s). It depends upon what the assumption of C[SUB]d[SUB] is, but someone in free-fall from a jump that high should be at or very near terminal speed unless they have oriented themselves for minimum drag (diving position).
As for damage, it is a matter of speed on impact and how much aspect of the falling body the water sees instantaneously upon impact. For a body that is spread-eagled, there is a very large surface area and the water is pressurized normal to the surface of the body, i.e. down. Since water is fairly viscous (compared to air) and essentially incompressible, it responds with an equal but opposite a force that would be similar to that of a solid continuum such as concrete, and the deceleration will be in the hundreds of Gs. The combination of hydraulic force of the water on the body, and the inertial force from deceleration will cause massive damage to both the surface of the body and dislocation of the internal organs, as well as rupture of the lungs if the thoracic diaphragm is held rigid. However, if the body falls in an orientation such that the aspect is minimal and tends to part the water, pushing it sideways (diving position) the water is pressurized in a largely lateral direction where it can move without compressing. The force normal to the direction of travel is small and the diver will experience significantly less force and a much more gentle deceleration. It is entirely possible for someone to survive these forces with minimal injury; however, it does require a perfectly oriented impact and that the head be held as rigidly as possible (chin tucked into the chest) to prevent neck injury.
A side remark by a poster led to a discussion on suicide, which was not appropriate for GQ. I have removed the posts in question. This subject is best dealt with through professional help, not from advice by posters on an anonymous message board.
I heard somewhere that one mechanism causing death is that water may part the buttocks and enter the anus, creating a sudden enormous enema powerful enough to rupture the colon and spread its contents everywhere. This sounds to me like it could lead to a death by infection in a day or so, but I don’t see why this should be especially fatal over the course of the first hours. No cite, sorry.
I watched summer Olympic training for the aerialist skiiers at Park City, Utah once, and they skiied down a ramp and over the kicker jump, did their backflip spin things, then landed in the big pool which was being specifically aerated with bubble generators at the bottom to cushion the landing.
