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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."
Just in time now that Texas can't get Sodium Thiopental.
It only takes NSA to vaporize your freedom
It's gonna take a mighty big shark to carry around that kind of firepower . . .
I read TFA and all I got was this lousy cookie
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.
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.
Seven puppies were harmed during the making of this post.
Texas should consider the method.
The phasers I remember just made their target clutch their chest and fall to the ground dramatically.
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.
And if you're going to say that the death ray isn't the lightning bolt, then I challenge you to prove you can make a 100% electrically efficient death ray.
*turns knob up to 8*
Ready Player One...
They're called "Phasers". I like to think that they don't disintegration or vaporize people, they just phase them into another dimension, a dimension where all the other folks who got zapped are hanging out, bitching about the Federation in some kind of distributed cosmic basement...
Depends on how quickly you want it done.
If you wanted it done in 2.5 seconds, 1.21 gigawatts would be perfect.
upon the advice of my lawyer, i have no sig at this time
around the same energy that a 2,000-pound car going 70 miles per hour on the highway has in potential.
Wouldn't that be kinetic?
systemd is Roko's Basilisk.
Jiggawatts is just jiggagoules over time.
Scientists point out problems, engineers fix them
altslashdot.org: The future of slashdot.
It just doesn't have the same ring to it, Doc.
What's that it JiggaWatts? I'll be freaked out if it's 1.21!
Hmm, let's see...
$ units 2.99gigajoules jiggawatts
Unknown unit 'jiggawatts'
Great Scott!
...do to the immediate environment? I suspect the poor soul that god disintegrated would be the lucky one.
Doesn't that depend on the weight of the person? Its gonna take a lot more energy to vaporize a 200 Kg american than sn 85 Kg asian.
With a bit of plutonium borrowed from terrorists, or a lightning bolt, you could vaporize someone in 2.47 seconds.
Vaporization isn't needed to kill. I assume that's what death rays are all about. I suppose it would take a little extra to make the remains difficult to identify. If you've gone the death ray route, using lots of power is part of the "send a message" image thing anyway. For an eco-friendly kill, it is still best to club the victim and let hungry pigs dispose of the corpse.
My son has been asking me how someone would get disintegrated. He's been obsessed after I let him watch Mar's Attacks. He keeps asking me how the Martian guns work and I try to explain to him it's Science Ficition. Maybe I'll show this too him and then I'll have to explain what a Joule is. Thank you for submitting this now I have a good point of refrence when dealing with a 6 year old's imagination.
They simplified this too much. Anyone could have plugged in the numbers for water. I want to see them take into account the non-water content of the human body. And maybe assume a non-uniform heating model, since presumably the energy would be transferred via a ray from a phaser.
"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."
First, it's 1.21 gigawatts, not 2.99 gigajoules.
Second, it's 88 miles per hour, not 70 miles per hour.
You're forgetting to account the DeLorean surrounding surrounding the person. An orange vest should probably be thrown in there too.
In debates about Christianity, there are two groups: those looking for answers, and those looking to just ask questions.
Most 911 victims were vaporized. If you believe the official story.
Like all victims on American Airlines Flight 77 Pentagon Crash - Sept. 11, 2001
Doesn't take gigajoules, just what is commonly done in crematoriums, but done at much faster speed for cinematic effect. I am sure most people will not mind a small puddle of calcium-based ashes, but if they do we can focus on sublimating that and still save lots of juice. For even more savings, add corrosive acid that would produce residue with lower sublimation point.
If successful we can work our way down list with future kickstarters:
Ashton Kutcher
Miley Cyrus
Kate Perry
Guy from Verizon Wireless commericals
Congress
On things I've never wondered about, this would be pretty much right at the top of the list...now how much energy is required on the 'stun' setting?
Must be Friday the 13th or something. :)
"I love animals! Some are cute, others are tasty, what's not to like?" - Betsy Schroeder, Jeopardy contestant
Apply 1.21 GW of power for 2.47 seconds and you will have done 2.99 GJ of work.
Who says the phaser vaporizes them?
I do remember some 'hard' numbers being mentioned on Enterprise once.
A testbed phaser being overcharged to ten megajoules output(per second, presumably) burning a hole through some unidentified metal target.
Given that's about equivalent to five pounds of tnt in the same room as you, I doubt they had any actual physicists advising them on the show.
Also seems to indicate phasers have a pretty beefy reactor in them...
So if 2.99 GJ is enough to vaporize a person, and enough to simulate a lightning bolt, then shouldn't people hit by lightning get vaporized?
But the phasers had three settings.
Stun
Kill
Disintegrate
TFA sounds like it's referring to #3
So does this also give an indication of how much energy an transporter(Star Trek like) would consume(assuming 100% efficiency of course)?
I've always wondered how much energy would be needed for transportation like that. Always wanted to see if its more/less efficient than driving your SUV to work.
Or we could line them up in order of annoyance in front of a rail gun and demonstrate the effectiveness of a tungsten projectile fired at 1600 m/s.
I'm going to do some rough calculations - the paper's computation is also pretty rough - just to get the right order of magnitude.
First of all, to vaporize water, you don't even need to boil it. Spill some water on the floor and it vaporizes pretty darn quick just from the ambient environment - it changes from liquid water at room temperature to water vapor at room temperature. The only heat that needs to be added is the "Enthalpy of vaporization" which is 2260 kJ/Kg. For the 78kg human described in the paper, if it were all water, that would only be 176 Megajoules. Given that a human is normally at about 37C and room temperature about 25C, you can also take away 4kJ/Kg*78Kg*(37-25) = 4 Megajoules that the water vapor releases as you cool it from 37C to 25C. The net result is that with 172 Megajoules, you can turn a human body's mass of water to vapor.
However, as the paper suggests, the body isn't all water - it's about 85% water and 15% "dried pork." That means 172MJ*0.7 for the water, 146MJ, and the 11.7Kg of pork releases about 4KCal/g when oxidized (4 dietary Calories/g), 1 Kcal=4.2KJ, so burning the "dried pork" releases 196MJ. Assuming the "dried pork" gets fully oxidized (i.e burned) into CO2, the result is a gas. So overall, vaporizing a human body (in the sense of turning all the body into a gas) can release more energy than you started with - about 50MJ.
The paper estimates the energy required to break every molecular bond. However, all those bonds are going to reassemble into something else, whether into H2, O2, or H2O, or including the "dried pork," CO2, releasing much of the energy back.
The laser in "Real Genius" was 5 megawatts (sustained), so it would take about 10 minutes to vaporize a person with that thing.
Holocaust deniers keep prattling on about how hard it would be to incinerate 6 million Jews. They full of sh*t because, as Nazis, Holocaust deniers know about the secret Nazi weapon that could vaporize entire cities and boil oceans. With such a super Nazi death ray it was a sinch to vaporize millions of human bodies.
Seastead this.
To turn 75kg of water (165lbs) starting at 37C to steam at 100C requires 190 megajoules. Wouldn't that be enough to vaporize a human body? I suppose the bones would be left behind.
Hang on a moment... TFA isn't talking about vaporizing - turning water to steam. It's talking about ionizing, which is clearly going to require a much bigger quantity of energy.
For actual vaporization, making a very rough calculation - 60kg person, 2,270 kJ/kg latent heat of vaporization of water = 136 MJ,
Sure there's specific heat to add in there too, but the vaporization of water is the dominant term, so it's at least out by an order of magnitude.
Lesson learned - don't try and be 'all sciency' and use the wrong jargon!
It is ridiculous to use "roughly" and "2.99" in the same measurement. Seriously?!? A professor informed my engineering class that adding extra decimal places implied that that level of precision was known and/or required. It is at all plausible that the variability in the "average" human body is less than a one part per thousand?
Sounds a lot like Karl Marx when he took material costs in "round numbers", "assumed" costs for spindles and rates of waste, arbitrarily "put" wear and tear at 10% and "supposed" a value for rent then somehow, miraculously, calculated that surplus value equaled 153-11/13%
Kudos to Scientific American for being sensible enough to say "about three."
~~~~~~~
"You are not remembered for doing what is expected of you." - Atul Chitnis
what happens when you use that at 88MPH?
when i saw the word mole i was thinking of the animal http://en.wikipedia.org/wiki/Mole_%28animal%29
Am I the only person who instantly thought of that line from Back to the Future?
And for the unit nazis in the audience who'd point out that joules and watts are different, 2.99GW is what you will need for a TRUE VAPORIZATION of a person in ONE SECOND!! Which sounds a lot more evil than a simple boring vaporization. So there.
When stun is no fun.
And lethal is so primeval,
There's only one true eliminator,
The ACME disintegrator!
Now, for only 99.95$
VAT not included.
How does that energy compares to what is needed to send a human body in the sun? That get the same result in the end.
"First, consider the true vaporization â" the complete separation of all atoms within a molecule"
That's not what vaporization is.
Why the are pounds and miles per hour used here and in the "Scientific" American article? Correctly describing energy but not and speed or weight in the same paragraph is fucked. Grams are mixed in as well! WTF?
Everybody knows that when set to kill the phaser emits high energy polarized tachyons that send most of the mass into other dimensions. From the PoV of the infinite other universes a harmless burst of neutrinos occurs at several random locations. The matter that doesn't get transferred by the tachyons may remain as a dusty residue, but that's only if the phase correlator is poorly adjusted. Properly maintained phasers set to kill won't do that.
And yes, I just made all that up, and some of it is mumbo-jumbo. That's how Star Trek technology works. Dammit Jim, I'm a Slashdot poster, not a phaser technician. Why do I have to explain this?
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Our local utility is subsidizing the replacement of inefficient incandescent death rays with the more efficient LED ones.
They tried CFL death rays, but one was better off just getting the subject to break them and inhale the mercury.
Have gnu, will travel.
The only "reasonable" explanation within the Star Trek canon (if the term applies) is that the corpses are pushed "out of phase" or into subspace or something. Otherwise, there really is no place for the mass to go.
I hate it when they make up these numbers to show they're accurate. 2.99 GJ, 50.00001%, 1 billion and 3 grams.
It's just ridiculous.It'd drop down by 20 MJ if I take a shit.
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion. -- Spazmania (174582)
While some folks choose to pronounce giga as jigga, it always makes me cringe and think less of them. Ugh.
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."
I've fallen off your lawn, and I can't get up.
I think this puts to rest the myth of "flash vaporized humans" that supposedly left behind the shadows in the concrete in hiroshima and nagasaki.
One ton TNT equivalent is 4.184 gigajoules. So it takes ~ 0.72 tons of TNT to completely vaporize one human.
Hiroshima and Nagasaki were each about 10Kilotons TNT equiv. Now, that is the TOTAL energy radiated by the devices.
1) they were a few thousand feet in the air.
2) the energy would be radiated in all directions from a sperical point of detionation
3) the total energy to flash vaporize a human has to be delivered across that human body area
4) http://en.wikipedia.org/wiki/Inverse-square_law
The weapon detonated at about 2000 ft altitute.
Initial sphere's radius lets say is 10 ft. Area of such sphere is: 1257.1429 square feet. the energy radiated is 10kt, giving
Let's calculate even distribution of energy at a sphere 2000 ft from point of detonation. It's roughly the total energy (I am being generous to ignore losses in atmosphere and for vaporizing the heavy steel case) divided by surface area of that imaginary sphere:
1 ton equivalent in joules: /50285714.2857 square feet =
4181000000
so 10KT = 4.181e+13 J
4.181e+13 J
831449 J/SqFT AT BEST
Say the square foot cross section of a human is 10 square foot, then
8314490/2990000000 = 0.00278076588
Ok, now that means that AT BEST, there would only be 2% of the energy density needed to "flash vaporize" a human like the claims are made in propaganda
(radiation shadow on the steps of that one building, etc)
You've been sold a lie, folks
Might explain some of those missing persons.
The pronunciation represent how it is pronunced in french (the origin of the metric system...), think of it like the historical pronunciation.
Tomorrow is another day...
I know where we are heading with this.
https://www.youtube.com/c/BrendaEM
Phasers set on stun probably is the green way to go for energy savings! :)
That means a fully equipped DeLorean could vaporize you in 1.35 seconds of time travel.
I think that's about how long it took Captain Terrell to commit suicide between the length of the phaser firing and his body disintegrating.
You can never go home again... but I guess you can shop there.
We need to try it and see.
Not roughly 3 GJ, but roughly 2.99!!!!! Clearly not written by anyone who understands engineering!
Unicorn Setu. "Eagles may soar, but weasels don't get sucked into jet engines".
I'll leave my phasor set to "stun" in future. It will help extend the battery life.
www.nazigassings.com
The public might found out that it was impossible to cremate 6 million bodies in the time the so-called 'Holocaust' occurred...
> found out it would take roughly 2.99 GJ to vaporize an average-sized adult human body
How much for a fat, sedentary human body, of the type that contemplates things like this?
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
This could make for an interesting subthread in a dark scifi-novel.
"-Sarge! We are pinned down in this foxhole, said private Foo
-We have no option but to charge, answered Bar
-But! We are running low on power in our Vapz.
The entire unit are glancing at an increasingly panicked crowd of wounded.
Bar sighs and say:
-I have a charge left, hook up the chargers to the wounded and let's make this quick
"
What, what... what does it mean?
I'll agree with Miley Cyrus, but there are many others that are more deserving than the rest of your list, like:
Kim Kardashian
Justin Beiber
Paris Hilton
Piers Morgan
Rachel Maddow
etc.
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
If you added that much energy, preferbly in a short amount of time, then every thing is changed to a gas(136Mj) or even a plasma(2,99Gj). That will take a lot more space than that same mass in solid form. Thus it will explode because of that thermal effect alone. The chemical reaction is not the biggest of your worries.
But yes, the explosion surely will be there if you do this in a short period of time.
Megane we do not use disintegrators against people we disagree with, thats what mod points and flaming are for.
Article would have more credibility if the author new that vaporization is the process of converting liquid to gas. What they discribe - breaking a molecule into its atoms is call 'dissasociation'.
For a practical phaser you'd have to add an incredibly larger amount of energy to the budget to power a force field that surrounds the victim to prevent wall splattering by surface tissue that manages to escape during the 'conversion process' from thermodynamic expansion and propulsion at the edge of the field.
And since you've already allocated the budget for a force field, why not skip vaporizing the victim, just have the force field close in and compress them into a dense little cube? Then once that is done, expand the cube until it flash freezes.
Cleanup is still a breeze. And after a major battle you can make Stew.
<blink>down the rabbit hole</blink>
2.99 GJ is 830 kWh. My home burns about 12 to 25 a day, depending on the season. It would really take three months of power to burn a body? That seems high.
I really don't think a phaser would be practical working as a heat beam. You also never see the vaporized matter precipitating back out of the air. Plus the energy release would be like a bomb going off.
To disrupt someone the way it's shown on the show the phaser would have to destabilize their subatomic structure at the quantum level. Maybe disrupting their waveform causing the matter to be canceled out and they just cease to exist.
Another possible way is for the phaser to create a subspace displacement sending the target into subspace. Stun could be just a low level field effect of these two, not enough to disrupt but enough to shock their nervous system.
*It's not what you can do for the Dark Side but what the Dark Side can do for you!*
So that makes you an expert in being wrong?
It only takes 1.21 GIGAWATTS to go back in time with Doc Brown and another 1.21 GIGAWATTS to fry Billy Rae Cyrus's penis off to prevent the abomination that is Milly and another 1.21 GIGAWATTS to come back to the future! WEEEEEEEEEEEEEEE
Look it up, that is a perfectly correct pronunciation. In fact it is the first one meriam-webster gives.
It's not like you need to separate the structure to the atomic level. Molecular is fine, and probably more appropriate. You just know those hydrogen and oxygen atoms are going to recombine...
Being disintegrated makes me very angry.
Very angry indeed.
where do i sign up?
I was pretty bummed at the last NIST seminar I attended. Not only did the speakers pronounce giga as "jigga," but they prounced pico as "pie-co."
It's still gig-a and peek-o to me, dammit.
You forgot to address the obvious question: where the hell does the resulting 100 to 200 cubic meter cloud of water vapor go?
"Politicians and diapers must be changed often, and for the same reason."
The expansion of the mixed gases isothermally releases even more energy, making the net energy balance even "better."
AC: ++! The next sci-fi show should have a recycler instead of a vaporizer - otherwise you'd be wasting your enemies.
[NB: there's a typo in my previous calculation: the 85% water is 172MJ*0.85=146MJ - it doesn't affect the other results]
I obsessively calculated the energy from expansion of the gases, working it out for 78kg of water. I'm not going to bother working out the "dried pork" factors....
The expansion of the gas: assume 78kg of water is changed to gas at STP. Water vapor is 18g/mol (O=16,H=1*2), and each mol is 22.4l, so 78kg of water vapor takes up 78kg/(18g/mol)=4.3kmol, 4.3kmol*(22.4l/mol)=97kl=97m^3. The original volume is 78 liters, so the volume ratio is 1244. W=p*v*ln(ratio)=(0.1MPa*97m^3)*ln(1244)=69MJ.
So in addition to the 50MJ net energy calculated earlier, you can add 69MJ from expansion of the gas, a total net of 120MJ. This is about -4% of the 2.99GJ figure (i.e. one twenty-fifth and opposite sign).
your link is not relevant at all, did you read it? one ounce to two lbs. of TNT, and survival of "heavily protected explosive ordinance technician, supplied with a rigid enclosed thoraco-adominal protector, MAY be able to survive the air blast at those distances".
We are talking of a steam blast with 160 cubic meters of steam, maybe in your average meeting room of 36 cubic meters.That won't go well for the remaining occupants of the room.
That's assuming all the power comes from the phaser. The chemical bonds inside the human body contain quite a bit of fuel themselves. One need only kick start a chain reaction. One need only dehydrate the subject body to trigger an exothermic reaction resulting in a body that could burn as well as coal, poof no more body, just carbon dioxide and a little ash. For instance if you dehydrate sugar in sulphuric acid it is an exothermic reaction that make the carbon rich byproducts easily combustable.
Another way this might be done is if the phaser array doesn't destroy anything, if it merely re-arranged some of the molecules say converting the water in your body to sulpuric, hydrochloric, or nitric acid. It certainly doesn't take gigajoules of energy for acid to disintegrate a body.
Now thinking outside the box, the most important thing this article should hold for a Trekkie is that it takes gigajoules of energy to disintegrate a body but they don't say how many it would take to re-integrate it. That's right, if you can take a body apart molecule by molecule that is the basis of the outbound loop of a teleporter, The idea being that the information about where those molecules were is transmitted to another location where a matter re-integrator either re-assembles the stream of molecules, or creates new ones.
FYI: Phasers could be set to kill which leave a corpse and they could be set to disintegrate which is what the "research" is about. Of course Kirk and never ordered the use of the latter setting.
01/01/01
Um... there is an assumption that one would disassociate all the atoms in the body in this disintegration -- but disintegration isn't an exact synonym for disassociation. If you think of items taking up a certain amount of space / mole (6.02x10^23 "things") -- gasses are fairly similar, so converting water to 2xH2+O2 would take up a large amount of space -- i.e. big explosion. That was never the case in a phaser set to disintegrate (or vaporize -- which is a closer synonym to disassociate).
Instead, it would be more efficient to annihilate part of the matter to power the conversion and ensure that there was no left over matter to expand in the space as well as converting no MORE matter than necessary to do the job, so no excess energy is released. A miniature computer in the phaser would likely do the trick.
With E=mass x light^2, only a tiny amount of the body's mass would need to be converted to energy to power the whole reaction.
3*10^8 squared, = 9 * 10^16. A gigajoule = 10^9 joules. So, we'd only
need 10^(-7)* of the mass units... ?? grams? kg? moles? But that's
an awfully small amount. The phaser just has to control the fusion conversion. Considering in the star-trek era, fusion was considered an old tech, I would guess they'd have it fairly well controllable.
(forgive any math errors, as I didn't look everything up, but hopefully people get the general idea)....
1.21 Gigawatts to time travel (if you have the flux capacitor that is).
The day Microsoft creates a product that doesn't suck, it will be known as the Microsoft Vaccuum Cleaner!