In the column “How does a bullet or knife kill somebody?”, Cecil claims that rifle bullets inflict hydrostatic shock. As far as I know, this theory was proven bunk long ago. The Wikipedia article on Hydrostatic Shock confirms this (yes, I know, it’s Wikipedia, but their sources check out). Plus it makes sense, since even an M-16 bullet travels only 930-772 m/s, well below the 1500 m/s needed to exceed the speed of sound in water.
To my knowledge, the only way to effectively kill someone instantly is a shot directly to the brain/certain areas of the spine. Even tearing out someone’s heart leaves them 10-15 seconds of voluntary movement. (see hangun wounding factors, a 1987 FBI Report) Well, that or you could blow them to pieces, that would be instantaneous. :smack:
IANAExpert, but I think I take issue with the statement in your link that says:
Surely there’s another mechanism - damage (in the form of stretching, tearing, crushing) caused by the pressure gradient in the shock wave front. Am I just reading it wrong, or are they overimplifying?
Well, don’t forget tissue has memory and will return to its original shape after being stretched. Even so, tissue will also dissipate energy while stretching (energy of deformation or something; been a while since I took my projectile physics course).
A sonic pressure wave CAN be generated by a bullet, but the pressure wave generates only about 100 atm at most. When kidney stones are eliminated using a lithotriptor, nearly 2000 waves at 500 atm waves can be used, without any soft tissue damage. See what’s wrong with wound ballistics.
So the gist of it is, the pressure wave really isn’t a big deal. Your body can withstand much more without damage.
Yeah, “hydrostatic shock” is bunk. Bullets cause damage the same way a stabbing wound would - damage to internal organs, bleeding, and all that good stuff.