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It Takes 2.99 Gigajoules To Vaporize a Human Body

Have you ever wondered how much energy is needed to power a phaser set to kill? A trio of researchers at the University of Leicester did, so they ran some tests and found out it would take roughly 2.99 GJ to vaporize an average-sized adult human body. Quoting: "First, consider the true vaporization – the complete separation of all atoms within a molecule – of water. With a simple molecular structure containing an oxygen atom bonded to two hydrogen atoms, it takes serious energy to break these bonds. In fact, it takes 460 kilojoules of energy to break just one mole of oxygen-hydrogen bonds — around the same energy that a 2,000-pound car going 70 miles per hour on the highway has in potential. And that's just 18 grams of water! So as you can see, it would take a gargantuan amount of energy to separate all the atoms in even a small glass of water — especially if that glass of water is your analog for a person. The human body is a bit more complicated than a glass of water, but it still vaporizes like one. And thanks to our spies spread across scientific organizations, we now have the energy required to turn a human into an atomic soup, to break all the atomic bonds in a body. According to the captured study, it takes around three gigajoules of death-ray to entirely vaporize a person — enough to completely melt 5,000 pounds of steel or simulate a lightning bolt."

5 of 272 comments (clear)

  1. Disintegration by BasilBrush · · Score: 4, Interesting

    Phasers don't vaporise a person. They disintegrate them.

    Since we don't yet know the physics behind this phenomenon we can't say how much energy it needs.

  2. Bad science by Dunbal · · Score: 5, Interesting

    Since when does "vaporization" involve breaking chemical bonds inside a molecule? When you boil water you're not turning it into hydrogen and oxygen, you're just overcoming the vanderWaals bonds keeping the liquid together and giving them enough energy to float away. Likewise if you "vaporize" someone. You need enough energy to turn them from a solid/colloid state to a gaseous state, not the energy required to reduce the person to elemental atoms.

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    Seven puppies were harmed during the making of this post.
    1. Re:Bad science by mysidia · · Score: 4, Interesting

      You need enough energy to turn them from a solid/colloid state to a gaseous state, not the energy required to reduce the person to elemental atoms.

      I can't wait to see how much energy people say the transporter requires.

      I assume it is a similar principle.... except the phaser set to disintegrate just has to scramble and disperse their molecules, so that the person or thing no longer exists in a recognizable form; the transporter has to reassemble people.

  3. Self Bootstrapping Death Ray by Zan+Lynx · · Score: 4, Interesting

    Directly providing the power to vaporize a person is not the elegant way to do it. The correct, elegant mad scientist method is to use the power contained in the vaporized mass to power the vaporization.

    Consider if you develop a means to "program" a plasma such that it generates a contracting magnetic field that causes fusion inside the vaporizing object and then absorbs some of the energy from this fusion reaction to power itself.

    Now you're talking! Now you've got an effect that can vaporize any object provided you can provide the initial energy requirement.

    There could be variants on this. Perhaps you've got an effect that flips matter into antimatter and absorbs some of the released energy to continue the effect.

    If this is an expanding effect instead of a collapsing effect you've got a world killer like the weapons in Ender's Game.

  4. 3 GJ to vaporize? by fyngyrz · · Score: 2, Interesting

    Well, another way to look at this is that the human body contains 3 GJ of constrained energy, and that if you released that energy -- like an atom bomb -- rather than trying to match energy for energy, you'd *get* 3 GJ, which you would then have to put somewhere, or you'd be vaporized along with it.

    Remember: A good sized atom or fusion bomb contains (and will release) more than 3GJ of energy, but it takes one hell of a lot less than 3 GJ as a trigger to let that energy free.

    And given that there are at least those two ways to approach bounded energy release, odds are reasonable that there are others, as well. Yes, yes, fissionables sort of *like* to be let free, but that's kind of the point. Perhaps there are other mechanisms.

    And therefore, I'm just going to go with "Phasers don't have to deliver 3 GJ to vaporize a Klingon."

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    I've fallen off your lawn, and I can't get up.