Energy required to vaporize a human

[Rich Jordan]

Or perhaps more accurately to totally disintegrate one.

Three researchers from the University of Leicester wondered what it would take so they ran some tests....

[PawPaw]

I guess it depends on what your definition of 'disintegrate' might be. The Telegraph reported some months ago that North Korea had 'obliterated' a government minister by forcing him to stand on a spot targeted with a mortar.

On the orders of Kim Jong-un to leave "no trace of him behind, down to his hair," according to South Korean media, Kim Chol was forced to stand on a spot that had been zeroed in for a mortar round and "obliterated."

I know that mortars are notoriously inaccurate, but I bet that a battery with a TOT calculator could obliterate somebody.

[Steamforger]

I seem to remember soviet era mortars in the 150 mm range. I'll have to check that when its more convenient. A simple pre-sighting by firing one test round and placing the offending general officer in the smoking crater would have a very high chance.of success, I think. Also given that mortars are more explodey that similar caliber arty rounds owing to their not having to survive revolutions and other extreme physical forces... I'd day he was kaboomed quite completely.

ETA- It looks like the Soviet and Eastern Bloc stuff topped out at 120mm. The Japanese fielded some 150mm mortars in WWII. 120 or 150, I really don't think it will matter much when its basically hitting you.

[MarkD]

That's a surprisingly easy calculation to make, and doesn't take extensive research.

I haven't looked at the link yet, but let's see what I come up with.

To instantly vaporize a human, one need only multiply the specific vaporization energy of water (1 joule per gram x 100), times the latent heat of water vapor (x7 for instantaneous vaporization), divided by the efficiency of energy transfer (anywhere from less than 1% maxing out around 20%)... Let's say we can achieve 10%.

Given the average human weighs appx 80 kilos, and accounting for 6 standard deviations (the relative realistic extreme of human body mass)... call it a maximum of 240 kilos.

(24,000,000*7)/.1=1,700 megajoules or 1.7 gigajoules.

1.7 gigajoules of energy, at 10% energy efficiency transfer, will instantly vaporize any reasonable human body.

There are 4100 joules of energy in a gram of TNT, meaning it takes the energy of about half a ton of TNT to instantly vaporize any reasonable human, at 10% energy transfer.

In reality, wouldn't you need considerably more TNT than that because most of the energy would be directed away from the victim unless you used a cylindrical charge with the energy directed inward (with the victim inside the cylinder)? If a bomb goes off next to someone (even if it's in contact with him when it goes off) most of the energy of the explosion would be directed in a direction other than pointed directly at the vaporizee (if I can coin a word).

[Aglifter]

A more interesting calculation would be microwave energy - you might be able to get a more complete... And WHY am I worried about this???

[Aglifter]

Relevant journal article

[Rich Jordan]

A more interesting calculation would be microwave energy - you might be able to get a more complete... And WHY am I worried about this???

'Cause death rays are cool? Set phaser to "Kill"...

[Greg]

Thus why I said "the energy of".

Though of course, in actually, a half ton of TNT will absolutely vaporize a human body... By rapidly turning it into very very tiny pieces which then burn and boil off...

... but there will be a few big chunks that fly off first... Feet covered by shoes, that sort of thing.

Indeed. The energy would need to be applied evenly everywhere at once. Try to apply the energy at once at one spot, and most of the body would turn into steam-driven chunks flying everywhere.

Like when a tree 'blows apart' when it's hit by lightning, the water in the part hit by lighting turns to steam and expands outward. Similar things have happened to people. Being hit in the chest by the jet of a HEAT warhead... makes a person explode. (I only read about it, thank goodness.)

[Aglifter]

Hmm... One of those ultra short wave microwaves - like they use to strip search us in airports - with quite a bit more power...

In theory, might be able to do the whole Sci-Fi thing of incineration with leaving the clothes behind...

[308Mike]

[Being hit in the chest by the jet of a HEAT warhead... makes a person explode. (I only read about it, thank goodness.)

Never seen that, but I have seen a couple examples of extreme energy applied to the human body... it's never pretty.

Or the results of a civilian vehicle hit head-on by an Abrams SABOT round (the DU type of round). I've seen reports on the TV that the kinetic energy of that round simply (essentially) liquidates the occupants of the vehicle as it blows through the vehicle's engine area and the rest of the target - throwing extremely hot metal fragments throughout the inside of the vehicle and decimating anyone/anything inside. They've actually said you could simply hose out the inside of the vehicle to clear the remains of the former passengers/inhabitants. They're nothing but a bunch of liquified goo.

I can imagine getting hit in the chest by an AT4, Carl Gustav, LAAW, 40mm grenade, or even RPG (once all them have traveled enough distance to arm), would do much the same thing - BUT the head is actually a fairly robust structure (unless hit directly), so it's not unusual to find a head rolling around even with almost nothing left from the rest of the body (except perhaps the feet IF they were wearing boots). If you hit the head directly, it frequently is the ONLY thing that gets vaporized leaving much of the rest of the body intact (providing the rest of the body is not hit also).

HOWEVER, there's the UNIVERSAL caveat: "IT DEPENDS......"