Air Force Researching Antimatter Weapons

mlmitton writes "The San Francisco Chronicle is reporting that the Air Force is actively pursuing antimatter weapons. Such weapons would easy eclipse nuclear weapons in power, e.g., 1 gram of antimatter would equal 23 space shuttle fuel tanks of energy. Perhaps more interesting, after an initial inquiry by the Chronicle in the summer, the Air Force issued a gag order that prohibits any Air Force employee from discussing antimatter research or funding."

Energy Conversion

[tntguy]

e.g., 1 gram of antimatter would equal 23 space shuttle fuel tanks of energy

How much energy is that in Burning Libraries of Congress? I'm not entirely up to speed on these new-fangled measurements. Rods an' hogsheads, for me!

Re:Energy Conversion

[crayz]

I'd like to get football fields of destruction if possible. It would be nice to have a conversion utility

Re:Because an explosion is 3-d

[ndogg]

What? You have a problem with Footbal Fields Squared?

Weapon research == Power plant research.

[SatanicPuppy]

So yea, woo hoo anti-matter power!

Sure, it's radioactive, just like fission, but hey antimatter is cheap at $62.5 trillion per gram, and it's 10-100 times more powerful!

Not sure what the point would be in antimatter weapons, besides serious coolness. Nukes are at least stable at room temperature, and if you drop a ball of plutonium on your foot, all you get is broken toes. Wouldn't want to have a power failure anywhere NEAR antimatter.

Re:Weapon research == Power plant research.

[gadget junkie]

.....will my tinfoil hat still work?

Re:Weapon research == Power plant research.

[JWW]

no, but your antitinfoil hat might!! ;-)

Re:Weapon research == Power plant research.

[Rosco P. Coltrane]

if you drop a ball of plutonium on your foot, all you get is broken toes.

All 7 of them...

Wrong kind of radioactive

[weedenbc]

Anti-matter weapons are radioactive in the same way as neutron bombs - a burst of gamma radiation. But they are NOT like fission bombs in releasing radioactive particles.

In a fission reaction the fallout comes from two sources. The first is the by-products of the fission reaction. I believe it is radioactive isotopes of Cesium and Potassium. This radioactive particles combine with the uranium/plutonim that did not fission and get distributed as fallout.

A pure fusion bomb, e.g. neutron bomb, has only a fusion reaction and thus theoretically produces no radioactive fallout. However in practice a fission reaction is used to create the pressure and heat needed to start the fusion reaction.

See the Special Weapons Primer at http://www.fas.org/nuke/intro/nuke/index.html [fas.org] for more info.

Re:Wrong kind of radioactive

[Blethrow]

A neutron bomb will also generate a ton of local radioactivity by neutron capture activation of nuclei in the immediate environment. Most of this will be pretty short lived.

Re:Weapon research == Power plant research.

[Joseph Vigneau]

if you drop a ball of plutonium on your foot, all you get is broken toes.

This guy [tripod.com] became the "first peacetime atom bomb" fatality by dropping a brick on a ball of plutonium.

Re:Weapon research == Power plant research.

[grumpygrodyguy]

This guy became the "first peacetime atom bomb" fatality by dropping a brick on a ball of plutonium.

There was a film called "Fat Man and Little Boy" [imdb.com] which included this very incident.

The guy who died of overexposure was played by John Cusack.

Re:Weapon research == Power plant research.

[vsprintf]

The guy who died of overexposure was played by John Cusack.

And another renowned Hollywood nuclear expert, Jane Fonda, was in The China Syndrome. No doubt they will both be testifying before Congress on the dangers of these weapons.

Plutonium

[wowbagger]

Actually, you can hold a chunk of plutonium in your hand with little side effect.

When the plutonium core of the Trinity device was delivered to the site, the commander insisted that the courier open the case containing it - he said something along the lines of "I won't sign for anything unless I have actually seen it".

So, the courier opened the case, the BC took the sphere out, held it briefly (noting the warmth and "feeling of potential"), then returned it and signed for it.

Go read "The Day The Sun Rose Twice" for the details.

Re:Plutonium

[Diamoddavej]

Tell that to Harry Daghlin. During a partial criticality test just after the war, a core slipped during a test and went full critical. Harry had to knock one of the two plutonium hemispheres apart by hand. He saw a blue flash, Harry was that quick but it was not quick enough. He died 25 days later.

Harry's right hand http://www.nmol.com/users/billp/daghlian.jpg [nmol.com]

NASTY PICTURE WARNING

[Anonymous Coward]

Don't look if you ate recently.

Re:Plutonium

[CritterNYC]

Tell that to Harry Daghlin. During a partial criticality test just after the war, a core slipped during a test and went full critical. Harry had to knock one of the two plutonium hemispheres apart by hand. He saw a blue flash, Harry was that quick but it was not quick enough. He died 25 days later.

Actually, it is Harry Dahlian [tripod.com] for those who want to learn more about it.

Re:Plutonium

[Muhammar]

Here you mixed details from 2 related stories: Daghlian accident during the war and Slotin accident after the war. The accidents happened with the same plutonium sphere. Slotin was boss of Daghlian and saw him dying. He had very similar accident and died in the same hospital room 9 months later. This Pu sphere was stored for safety reasons as 2 separate hemispheres and these were put together before experiment. The accidents were caused not by combining the Pu hemispheres but by surrounding them with neutron reflector which turned the system critical.

Daghlian was trying to find the practical (=just barely subcritical) arrangement of cube of tamper material (tungsten carbide) which would be completely surrounding a solid 6.2 kg sphere of delta-phase of Pu239. The carbide bricks functioned as neutron reflector also. Daghlian was working very slowly as he was getting close to critical configuration (neutron reflection increased reactivity). One of the heavy bricks felt out of his hand - on top of the Pu sphere and the system went critical. Daghlian trew the brick quickly away and disasembled the system into more strable configuration, etc. He got just above letal dose so he was dying very slowly.

Slotin was demonstrating for his colleagues reactivity of Pu depending on reflection of neutrons from berylium cover (Be holow hemispheric cover surrounding Pu sphere which was sitting half-embeded within another large Be hemispheric stand). The Be cover slipped, enclosed the Pu sphere, the system went critical, there was flash, Slotin took it apart with his bare hands (to save his colleagues) and got huge dose which killed him few days later.

Re:print(Weapon research == basic research);

[museumpeace]

I couldn't think of it when I posted, but I found a very readable article [stanford.edu] from someone at SLAC about the mystery of m/am asymmetry

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:Energy Conversion

[Dyolf Knip]

For those interested in doing the math...

A kilo of antimatter reacting with a kilo of matter releases 2kg x (300,000,000 m/s)^2 = 1.8e17 Joules. The specific combustion energy of TNT is 4.6e6 J/kg, hence 1 kt TNT = 4.6e12 J, 1 Mt TNT = 4.6e15 J. Therefore 1.8e17 J / 4.6e15 J ~= 40 MT of TNT.

You get about 70 times as much energy as you would from fusing 2kg of hydrogen into helium. But then fusion is a viable power source, whereas antimatter is at best a battery. Unless we find a way to make antimatter without having to make matter as well; then the reaction would be a net gain in usable energy (at the expense of matter in the universe, of course)

Re:Energy Conversion

[Rei]

... which points out one of the silly things about this. The headline stated:

"Such weapons would easy eclipse nuclear weapons in power"

No. Such weapons would easily eclipse nuclear weapons in *fuel energy density*. They would not eclipse nuclear weapons in energy, or even overall energy density, without radical breakthroughs. Antimatter is just too expensive to produce, and requires such large containment structures, that you can't get either sizable amounts of raw antimatter energy, nor great energy density. Perhaps antimatter-catylized fusion might produce new, useful weapons (small fusion bombs that don't need a fission bomb to start the reaction), although I personally am not in favor of blurring the line between conventional and nuclear weapons.

Still, I guess there is one good thing that will come of this: I always felt we should spend more money on basic research and less on the military. Here, the military is spending its money on basic research ;)

Re:Energy Conversion

[AoT]

What happens if you make an anti-matter hydrogen bomb?

Re:Energy Conversion

[abb3w]

1 kg antimatter mixed with equal matter yields about 42 megatons, half from matter conversion to energy, half from antimatter conversion to energy. The energy would initially be in the form of gamma rays at the neighborhoods of .5 and 900 MeV, but the latter would self-scatter (? correct term ?) due to electron positron emission/annihilation, and head down REAL fast towards the .5 MeV.

Still a hell of a chest X-ray to give the planet.

Re:Energy Conversion

[NoMoreNicksLeft]

Any self-respecting supervillain uses neutronium/anti-neutronium. Sure, it doesn't weigh any less, but you can pack 50 million tons of it in a suitcase.

Well. A suitcase made of exotic superstring material.

Re:Energy Conversion

[nacturation]

I'm somewhat partial to units involving elephants [slashdot.org]. Can I get this expressed in terms of the potential energy of x elephants dropped from an altitude of 100km?

Re:Energy Conversion

[KillboyPHD]

"I'm somewhat partial to units involving elephants [slashdot.org]. Can I get this expressed in terms of the potential energy of x elephants dropped from an altitude of 100km?"

If I've done the calculations right, the energy released by one kilogram of matter interacting with one gram of antimatter is roughly equivalent to the potential energy of 33 thousand 6 ton elephants [google.com] at a height of 100 kilometers.

Re:Energy Conversion

[Egonis]

How about using this kind of power for POSITIVE purposes? Like low-cost, efficient, and safe energy?

Re:Energy Conversion

[AviLazar]

What are you nuts? Do something useful for our world? We need more WMD's, because after we nuke the planet to hell and back, we want to make sure we get all the cockroaches by using anti-matter weapons on them.
With luck, after we create anti-matter weapons - the vulcans will come here, smack some sense into our leadership and those of us who want can leave on a space ship with warp drive and hot vulcan chicks :D

Laptop Hours, a more useful unit of conversion

[mykepredko]

Rather than equate it to Nuclear Bombs, space shuttle tanks, etc. how about how long a gram of anti-matter could run a laptop?

I would expect that it's on the order of centuries which would make it very desireable, although having a potentially leaking anti-matter device on one's lap would make it very undesireable.

myke

Re:Laptop Hours, a more useful unit of conversion

[winse]

Or imagine buying a motor vehicle that already has enough fuel to run it for the rest of its' usefull life. And then image that car getting into an accident and removing Cleveland.

Re:Energy Conversion

[SeanTobin]

You had to ask didn't you? Well, I asked google how many burning libraries of congress(es?) in one gram of antimatter... And google was stumped :(

So, here we go... 1 gram of antimatter -> burning libraries of congress(es?):

For the sake of argument, lets assume that the Library of Congress is entirely non-flamable and only the books contribute to the heat. Furthermore, lets assume that all the books are made of 100% wood or equivilant.

Now, 1 gram of wood when completely burned produces 3000 calories [cartage.org.lb].

The Library of Congress contains approximately 128 million [loc.gov] items. Again, some of these are recordings of various natures and will not burn as well as books... so to compensate we'll deviate from our initial assumptions and assume that the burning of the 530 miles [loc.gov] of bookshelves compensate for any lack of flamability of the old records.

So... our average paperback weighs under 1lb [schoenhofs.com] and our average hardcover book weighs between 1 and 2lbs [schoenhofs.com]. Seems reasonable enough. Lets assume a distribution between hardcover and paperbacks so as the average book weight in the LOC is 1lb.

Now, Google can help us some more here. Our friendly search engine lets us know that one pound is 453.59237 grams [google.com]. We'll round that off to 453 grams, since we're averaging book weight anyway.

So, the LOC has (453*128,000,000) or 57,984,000,000 grams worth of books. At 3000 calories per gram, burning down the LOC would produce 173,952,000,000,000 calories of energy. For the sake of sanity, lets convert that to joules. Google says that 173 952 000 000 000 calories = 7.27815168 × 10^14 Joules [google.com]

Now, our space shuttle main tank (and engines, NOT including boosters which are more powerful) produce 1,987,500,000 Watts [hypertextbook.com] of energy, and burn for 8.5 minutes [daviddarling.info]. That's (510*1,987,500,000) 1013625000000 Watt/seconds of energy. Converted to joules, that is remarkably 1013625000000 Joules [google.com].

So.. One space shuttle fuel tank of energy is 1013625000000 Joules. 23 space shuttle tanks of energy is 23313375000000 Joules. For convienence, one space shuttle tank is 0.23313375x10^14 joules.

So... it comes down to one burning LOC is 7.27815168 × 10^14 joules. 23 space shuttle fuel tanks are 0.23313375*10^14 joules. So, one gram of antimatter combining with one gram of matter is approximately 0.032 Burning Libraries of Congress(es?). I actually expected it to be more.

Now how do I get Google to include space shuttle fuel tanks and burning libraries of Congress(es?) as acceptable measurements?

Re:Energy Conversion

[Oliver Wendell Jones]

What anti-matter weapons?

Re:Energy Conversion

[Martin Blank]

See? They were successful!

Re:Dr Strangelove, I presume?

[chris_mahan]

What I meant was 1 burning library of congress should be enough to satisfy the current administration.

Re:Anti-Matter Resch.

[Durandal64]

A particle of anti-matter colliding with its matter counterpart will produce an annihilation of 100% efficiency. And yes, there will be resulting gamma-ray photons. But this reaction will not produce radioactive materials, like a nuclear fission reaction would.

And the article didn't mention the chief problem with storing anti-matter. You can't allow it to touch anything. At all. It has to be in a vacuum container and make no contact with the edges. Otherwise, you'll get an explosion.

Re:Anti-Matter Resch.

[jfdawes]

Or course, the following quote is from the article that only some people who click the link actually get:

Another problem is the terribly unruly behavior of positrons whenever physicists try to corral them into a special container. Inside these containers, known as Penning traps, magnetic fields prevent the antiparticles from contacting the material wall of the container -- lest they annihilate on contact. Unfortunately, because like-charged particles repel each other, the positrons push each other apart and quickly squirt out of the trap.

If positrons can't be stored for long periods, they're as useless to the military as an armored personnel carrier without a gas tank. So Edwards is funding investigations of ways to make positrons last longer in storage.

Re:Anti-Matter Resch.

[Charvak]

Here is the math..
E = 2mc^2
E = h*frequency
Frequency of the photon = 2 m*c*c/h
where m = mass of electron c = speed of light
h = planck constant
Now according to google
m = 9.109*10^-31 c= 3*10^8 h = 6.63 *10-34
frequency comes out to be 2.47*10^20 hertz
which comes under gamma rays.
So indeed the positron+electron will produce gamma rays

Space Shuttle Fuel Tanks?

[Wizzy Wig]

SSFTs are now units of energy?

Re:Space Shuttle Fuel Tanks?

[TFGeditor]

In Texas, "shitload" is an official unit of measurement. I suspect this technology will yield energy on a scale several orders of shitload greater than any other to date this side of the sun.

A shitload?

[FirstNoel]

A co-worker's husband runs a Septic Tank clearing business. When we asked what a shitload was we were told "1600 gallons".

Sean D.

Oooops

[Anonymous Coward]

In other news... The air force research center suddenly dissappeared along with 200.000 square kilometers of land. Nobody from the research center was available for comment.

Really...

[jsoffron]

isn't this a tremendous waste of money? I'm generally pretty high on national defense, but is our biggest national security threat really that nuclear bombs aren't powerful enough?

We can not afford a mine shaft gap!

Re:Really...

[Mr. Bad Example]

> I'm generally pretty high on national defense

Careful...it's a gateway policy. Before you know it, you'll be mainlining the hard stuff like trade agreements.

Re:Really...

[jsoffron]

Too late...I've been freebasing Nafta all day... Sweet, sweet NAFTA.

Probably useless

[PIPBoy3000]

It's probably a big waste of money. The efficiencies in creating antimatter are incredibly low. Nuclear power is far cheaper for virtually all applications. From the article:

With present techniques, the price tag for 100-billionths of a gram of antimatter would be $6 billion

The only reason I could see it being useful is if you needed an extremely high energy density. "Bullets" with a magnetically suspended speck of antimatter might be handy. They would be virtually undetectable by radar and pack a huge punch. Perhaps the low weights would be useful for space warfare?

Re:Probably useless

[AKAImBatman]

Considering that I have no idea where they'd get the required amounts of antimatter from, I think the military is having fun blowing smoke up our collective asses. (And those of our enemies.) However, the military *may* be looking into Antimatter catalyzed fission [wikipedia.org]weapons. Such weapons would need only a few particles of antimatter to fuel a fission warhead that could fit in the palm of your hand.

Re:Really...

[Mysticalfruit]

Here's the thing.

We've got the bomb. In fact we've got nuclear submarines so fucking quiet you wouldn't even know their in your harbor just chuck full of the little bastards. However, much like spitting into the wind, using said weapons means we get to glow in the dark as well.

Anti-matter weapons don't have this spit in face problem. We could drop a anti-matter bomb on Iran and flatten the whole country to within an inch of sea level and nobody is going to be dying of cancer from the nuclear fallout.

It's like the bomb, only much better.

Re:Really...

[carpe_noctem]

This isn't the thing that's kept us from using nuclear weapons in the past. The thing that has is mutually assured destruction (or MAD, if you will).

Nuclear weapons were successful in ending the second world war because we were the only country that had them at the time. We couldn't use them in any cold war conflicts because our enemies could use them on us.

Likewise, the development of anti-matter weapons is useless too, because even if we develop the technology to use them, long-range nuclear weapons from our enemies can still be used against us.

Creating more powerful weapons in an arms race is kind of like seeing who can count to the biggest number faster... I doubt we'll ever reach a largest number, and eventually both people will shout out "infinity plus one!".

Re:Really...

[Jacer]

If you can have a weapon more powerful than a nuke, without the fallout, they'll be more prone to use them.

Re:Really...

[ViolentGreen]

But storage is EXTREMELY tricky. If the antimatter ever contacts the edges of its container, boom.

Simple solution: store the anti-matter in an anti-matter container. Duh.

How to detonate it?

[FTL]

One of the potential problems with antimatter is how to use it. If one just removes it from its isolation container, it may just glow, spit and fizzle for an extended period of time, rather than explode properly. As the first particles of matter comes in contact with it, that matter (and the corresponding amount of anti-matter) will annihilate, causing a blast that may separate the two objects for a while. So to detonate properly one might need some very fancy geometries or implosion schemes that make an atomic bomb look like child's play.

Alternatively antimatter may blow up just fine without any assistance. It's all theory just now. We'll have to drop a gram of it to be sure.

Re:How to detonate it?

[imkonen]

You don't need a matched piece of matter to detonate antimatter. Wherever that antimatter goes it will find matter with which to detonate unless you take immense precautions to keep it isolated (which is what much of the article is about). Especially with positrons: What you percieve as mechanical resistance...two solid objects that push against each other rather than just mixing like a gas...is electron-electron repulsion between the atoms on the outsides of those objects. Electrons orbiting an iron atom are just as likely to annihilate with positrons orbiting an anti-iron nucleus, an anti-proton nucleus, or nothing at all.

Schweet!

[idontgno]

F-22 Raptors with photon torpedoes on multiple-ejector racks.

How many megatons yield per aircraft?

OK, now I'm scared.

1 gram of anti matter?

[ackthpt]

Shouldn't that be -1 gram of anti matter?

Re:1 gram of anti matter?

[idontgno]

Where's my +1 anti-overrated moderation?

Re:1 gram of anti matter?

[identity0]

Yes, I read all about it on AntiSlashdot: News for Nerds. Stuff that AntiMatters.

Unfortunately some Slashdotters got onto AntiSlashdot, and the resulting reaction with the thoughtful, intelligent and polite women there caused an explosive reaction which destroyed the AntiSlashdot server. A shame, really, since AntiSlashdottings gave the affected server a tremendous amount of free bandwidth, their site design was colorful yet tasteful, and I always loved Joan Dogz's thoughtful articles.

Oh well, I guess I'm stuck with regular 'ol Slashdot now. It's just as good, right?

Re:1 gram of anti matter?

[RyuuzakiTetsuya]

quick. someone call alton brown. let's find out if we can use this stuff for antipasto.

[little john] WHAT? [/little john]

[kippy]

This is insane. A gram of antimatter would cost almost more money than exists on earth if I recall. You thought nukes were expensive? wait till you see the military budget if this gets taken seriously.

I'd love to see their containment schemes so that the anti matter doesn't bump the bomb casing wall and annihilate in storage or in transit.

On a funny note this nut [antimatterenergy.com] whom I've met in person, claims that comets are made of pure antimatter. Riiiight. That should bring production costs down :)

1gm antimatter = 39 kT TNT

[wowbagger]

units
1948 units, 71 prefixes, 28 functions

You have: grams*c^2
You want: tonnes-tnt
* 19487.022
/ 5.1316205e-05

So 1 gram antimatter + 1 gram matter is about 39 kT of TNT. Hiroshima was about 20 kT, Nagasaki was 13 kT, so one gram antimatter would release just a scosh more than both devices.

So let us use a bit more sensible units than "shuttle fuel tanks".

However, the costs of manufacturing the antimatter, and the size of the containment system, and the fail-null mode of antimatter vs. the fail-safe mode of a nuke (a nuke may leak, but it will not detonate without everything going just right), would lead me to wonder about the utility of an antimatter weapon.

Some things I don't understand about anti-matter..

[halivar]

- Would you have to store the anti-matter, or create it as you need it? The first seems impossible, unless you has some kind of containment where the anti-matter doesn't actually touch anything. The other requires a massive amount of energy. Is this even plausible?

- What about the radiation involved? We've measured the rays that result from minor, single-atom collisions, but what happens when the collision is actually big enough to damage something?

- How do you propel something like this? Magnets? Or am I wrong in assuming anti-matter can't touch anything?

Anyways, maybe some smarter /.'ers than I can tell me where to find this info (it's hard to filter reliable sources out of Google).

Re:Some things I don't understand about anti-matte

[Mr. Bad Example]

> The first seems impossible, unless you has some kind of containment where the anti-matter doesn't actually touch anything.

Clearly our containment systems must be made of antimatter cats with pieces of antimatter buttered toast strapped to their backs.

Re:Some things I don't understand about anti-matte

[Trespass]

The most common sci-fi containment system is holding the antimatter in a vacuum while suspending it in a powerful magnetic field to keep it from contacting the walls of vessel holding it. I understand something similiar is done with plasma in experimental fusion reactors. It doesn't sound very portable.

Re:Some things I don't understand about anti-matte

[egomaniac]

Would you have to store the anti-matter, or create it as you need it? The first seems impossible, unless you has some kind of containment where the anti-matter doesn't actually touch anything. The other requires a massive amount of energy. Is this even plausible?

The only mechanisms we know of to create antimatter are UNBELIEVABLY power-hungry. The technology to manufacture even a mere gram of antimatter does not exist. So, the answer to your question -- we really have no idea. We can't manufacture meaningful amounts of antimatter at all, so the question of when it would get manufactured is something of a moot point.

What about the radiation involved? We've measured the rays that result from minor, single-atom collisions, but what happens when the collision is actually big enough to damage something?

IANANP (I am not a nuclear physicist), but I don't believe it would be significant. Nuclear weapons have two major sources of residual radiation (fallout): fission byproducts and induced radioactivity caused by neutron bombardment. Antimatter bombs wouldn't produce either. The radiation produced by a matter-antimatter reaction is high-energy gamma rays -- the explosion's extreme energy levels would probably manage to split or fuse a few atoms, and probably create very small amounts of radioactive material, but without fission byproducts or neutron flux you shouldn't see any large-scale radioactivity. The explosion would essentially look and behave just like a nuclear explosion (thermal pulse, mushroom cloud, shock wave, etc.) but without the fallout.

How do you propel something like this? Magnets? Or am I wrong in assuming anti-matter can't touch anything?

You are correct -- matter-antimatter collisions are bad news, and you can't allow the antimatter to touch any matter until the desired moment of explosion. Fortunately, antiprotons and antielectrons (positrons) are both electrically charged, and can therefore be magnetically contained in a vacuum to keep them from contacting any matter. A (very simple and dangerous) bomb design might be as simple as a containment shell with antimatter inside. You drop it on the target, the bomb ruptures and releases antimatter, BOOM.

The real problem is that the failure mode of antimatter weapons (at least ones that relied on pre-manufactured antimatter) is so damned dangerous. If the circuitry in a nuclear weapon fails, no biggie -- the bomb just doesn't detonate. Even in the worst case all that happens with a nuke is leakage of radioactive material. In fact, even an accidental critical mass isn't enough to produce a large-scale explosion -- unless you contain everything just right it just doesn't give you a big blast.

With an antimatter bomb, the opposite is true. You have to contain everything just right, because the second you don't, BOOM.

Re:Some things I don't understand about anti-matte

[WillWare]

...seems impossible, unless you has some kind of containment where the anti-matter doesn't actually touch anything.

Don't worry, we've got it covered. You ever see one of those aerodynamic trick gadgets where a balloon is suspended in an updraft from a fan? You push the balloon to one side, it recenters itself over the fan.

Now take out the balloon and put in a blob of antimatter. If the antimatter is too heavy to float in the breeze, duct-tape the antimatter to the balloon.

Funny the way the article is worded...

[Weaselmancer]

The San Francisco Chronicle is reporting that the Air Force is actively pursuing antimatter weapons. Such weapons would easy eclipse nuclear weapons in power, e.g., 1 gram of antimatter would equal 23 space shuttle fuel tanks of energy.

Are we sure they're pursuing weapons? We are talking about the Air Force, and it's funny how they'd compare the relative energy to a spaceship fuel tank, of all things...

Ding!

[mikeee]

I think you've got it. Consider that space shuttle.

It's something like 95% fuel by weight on takeoff. Now, if your engines are burning antimatter, you can replace all that weight with payload and still reach orbit!

If the antimatter could be manufactured for a reasonable multiple of the energy cost, it would cause the cost of getting stuff into space to drop dramatically.

"23 space shuttle fuel tanks" and the "gag order"

[sczimme]

1 gram of antimatter would equal 23 space shuttle fuel tanks of energy.

I thought the standard unit of explosive power was the ton of dynamite...

Perhaps more interesting, after an initial inquiry by the Chronicle in the summer, the Air Force issued a gag order that prohibits any Air Force employee from discussing antimatter research or funding

This isn't really that interesting or even unusual: Uncle Sam frequently limits what military folks can say about ongoing projects. There is a classification called "Sensitive But Unclassified", or SBU, whcih means the info is not classified as such (Secret, TS, etc.) but it is still not for public disclosure. (Years ago SBU was called "For Official Use Only" or FOUO.) Budgets are generally considered at least SBU, so it should be no suprise that the budget is not publicized.

/spent six years in the Air Force

Classification acronyms

[halivar]

This isn't really that interesting or even unusual: Uncle Sam frequently limits what military folks can say about ongoing projects. There is a classification called "Sensitive But Unclassified", or SBU, whcih means the info is not classified as such (Secret, TS, etc.) but it is still not for public disclosure. (Years ago SBU was called "For Official Use Only" or FOUO.) Budgets are generally considered at least SBU, so it should be no suprise that the budget is not publicized.

Well, since they just telling employees not to talk about it, the proper designation is Sensitive Topic For the Uninitiated, or STFU.

Not as spectacular as you think.

[techno-vampire]

During a panel at LACon II in '84, Dr. Forward mentioned that calculations showed that an anti-matter bowling ball wouldn't go up in a blaze of light and gamma, it'd sit on the floor sizzling like a drop of water on a griddle for several minutes. From what I gathered, the matter and anti-matter only interact as they come into contact with each other, and even in a normal Earth atmosphere there's a limit as to how many particles touch at any given time. Also, of course, the reaction heats the air up, causing convection currents that lower the pressure. Thinking about it, I guess you'd get the fastest reaction with an anti-dust so that there's as much surface as possible.

Pretty darned spectacular if you ask me...

[Dr. Zowie]

Hmmm... "sit on the floor sizzling like a drop of water on a griddle" conjures up positively, er, gentle images.

But you have to think about what's doing the holding up. In this case, it wouldn't be steam, it would be radiation pressure keeping the atmosphere from rushing in and annihilating. The actual momentum carried by gamma ray photons from the annihilation would deflect air molecules out of the way to prevent a rapid inrush.

You can calculate how much power that is per square centimeter of "exposed" antimatter.
Each photon carries a certain amount of momentum, momentum per unit time is force. So to sustain a certain pressure a certain number of photons have to be absorbed by the air per square centimeter.

The momentum carried by a photon is just E/c, where E is its energy and c is the speed of light. So to hold out 15 psi (10 Newtons per cm^2), you have to transmit 10^9 Newton-meters/second of power through that square centimeter.

So a golf ball of antimatter, sitting in the atmosphere, would emit about 4*pi*10^9 Watts, or about 10^10 Watts. The surface of the golf ball would be 10^11 times brighter than the surface of the Sun -- though of course most of that radiation would be in the form of gamma rays.

If the golf ball massed about 5 grams, it would
release 5x10^15 Joules in total, so it would indeed last a long time -- but you wouldn't want to classify it as a gentle sizzle...

You could do much better by applying more pressure to the golf ball. Putting it in the imploding shock wave of a thermonuclear bomb trigger could increase the output by something like eight orders of magnitude if you got lucky enough (it scales linearly with pressure).

slight correction...

[Dr. Zowie]

whoops -- I mistyped the comparison with the Sun. That should read "The surface of the golf ball would appear 10^11 times brighter than sunlight". The surface of the golf ball would "only" be 2 million times brighter than the surface of the Sun.

change the department

[Naikrovek]

this should be "from the stuff-that-antimatters dept."

If you're dropping The Bomb anyway...

[RobertB-DC]

Unlike regular nuclear bombs, positron bombs wouldn't eject plumes of radioactive debris. When large numbers of positrons and antielectrons collide, the primary product is an invisible but extremely dangerous burst of gamma radiation. Thus, in principle, a positron bomb could be a step toward one of the military's dreams from the early Cold War: a so-called "clean" superbomb that could kill large numbers of soldiers without ejecting radioactive contaminants over the countryside.

As depressing as it sounds, this is probably a Good Thing.

If we take as fact that militaries exist to kill, then it follows logically that they will develop tools to kill as effectively as possible. That's how we've ended up with uranium fission bombs, then plutonium fission bombs, then hydrogen fusion bombs.

Someone, somewhere, will eventually decide that they need to neutralize their enemy bad enough to accept the consequences of a nuke. It may even be us -- if Bush hadn't restarted research on nuclear bunker-busters, someone else would have eventually.

So if you accept the depressing notion that use of massively destructive weapons is inevitable, you *want* this research to go forward. At least, this way, you *can* go back home.

Kind of ironic... for all the talk about "WMD"s, this would be a real Weapon of *Mass* Destruction... or at least, a Weapon of Mass Conversion Directly To Energy.

Re:If you're dropping The Bomb anyway...

[Greyfox]

They say soldiers, but hasn't the only use of nuclear weapons in a wartime scenario been against civilians? Oh and our own guys in testing, of course. I was not under the impression that nuclear weapons have ever been used against anyone else's army. And during the cold war, I'm pretty sure that the vast majority of the targets on either side were not military.

So lets not decieve each other about who such a weapon will be used on, nor its ultimate purpose. Such a bomb would be a weapon designed to kill off the civilian population of a country while leaving their oil fields standing. OK, maybe I'm a little cynical, but I grew up during the height of the cold war at what would have been ground 0 had there been a war. I think I've earned the right to be a bit cynical.

It's been a while, but I believe I heard about several treaties back in the day banning the research on the "Neutron Bomb." No one particularly liked the idea of a clean weapon that could kill off a large population. All you'd have to do is bomb a region, send some guys in to clear the bodies out and then start moving your own people in. I wouldn't trust the most saintly of governments with a power like that, much less my own.

I would not, however, object to a particle/beam weapon that could cut an enemy tank or missile up like a big piece of cheese.

Dear US Air Force

[dchamp]

Dear US Air Force. Please don't blow up the planet.

Thank You,

A Concerned Citizen

Interviewer : Do you have the power to destroy the Earth?
The Tick : Egads! I hope not. That's where I keep all my stuff!

My guess is this has been going on for a long time

[davidwr]

I'd be shocked if this research hasn't been going on since the early days of the Cold War.

Like any technology, antimatter can be used for good or evil. Ever get a PET scan [unimelb.edu.au]? That's antimatter right in the middle of your body. Don't worry, you won't grow a third leg or anything from it.

I'm sure the DoD is aware of this, but gamma-ray bursts can cause nuclear changes, which can create radioactive particles that linger. It's not nearly the problem of traditional fallout, and is even be "negligible" for a sufficiently large value of "negligible." Much more likely is ionization which can kill living tissue and cause chemical changes to non-living materials. This can cause buildings to become less structurally sound, for example. However, absent the "negligible" secondary radiation I mentioned above, a conquering army can roll in without wearing radiation suits.

Medical (Peaceful) Uses of Positron

[abcho]

For a balanced view, it is important to realize that anti-matter physics have yielded substantial medical and non-military benefits already. Many people probably already encountered various applications of this technology without realizing it.

For example, Positron Emission Tomography (PET) is a very useful clinical and medical research tool for brain and cardiac functional imaging. See: Positron Emission Tomography [triumf.ca]

Pointless.

[Jaywalk]

Exactly what military threat do they envision where they need a bigger "boom" than what they have now? Every current military threat isn't a matter of having insufficient explosive power, but having difficulty ascertaining the target. This stuff may have practical use as a non-military explosive (e.g., asteroid deflection) but the U.S. military already has the necessary force to blow up anything on earth using existing technology.

Re:Pointless.

[Gulik]

Exactly what military threat do they envision where they need a bigger "boom" than what they have now?

Actually, as others have posted, it seems to be more that it's a different kind of boom -- one which doesn't throw lots of radioactive contaminants into the atmosphere, for one. It just, you know, kills everybody nearby with X-rays (I believe).

I can't help but assume that half the impetus behind this research are the Trek geeks in the Air Force wanting to be the first one to say "We've got an antimatter containment breach." They know they'll be dead shortly afterwards, but they're okay with that. Kind of like the geek equivalent of dying for the glory of God.

This is long term research, folks

[Michael Woodhams]

Don't panic/celebrate in anticipation of antimatter weapons being deployed 15 years from now.

From the article:
"about 50-millionths of a gram could generate a blast equal to the explosion (roughly 4,000 pounds of TNT, according to the FBI) at the Alfred P. Murrah Federal Building in Oklahoma City in 1995."

and

"With present techniques, the price tag for 100-billionths of a gram of antimatter would be $6 billion"

from which we can calculate that blowing up a building with antimatter will cost about 3 trillion dollars. (And tens or hundreds of millions for the equipment to confine the antimatter until you want it to detonate, but that is negligible in comparison.)

Also notice that while the antimatter may be the ultimately compact explosive, the containment equipment required will increase the size of a warhead by many orders of magnitude. No antimatter rifle bullets anytime soon.

Frickin "Anti-Matter"

[neuro.slug]

So what I've done is taken this .."anti-matter" and mounted it in a giant conical cannon. I shall call it.. The "Anti-Matter Horn".

Mwa ha ha ha!

Orion

[Scott Laird]

I think everyone's spinning it wrong. The most useful thing you can do with lots of positrons would be to build an antimater-catalyzed nuclear pulse propulsion [wikipedia.org] engine. With a good source for lots of positrons, you should be able to build nukes small enough to be useful.

Units of measure conversion?

[erroneus]

Okay I'm just as confused as the next person about that unit of measure. But I am sure there are real much smarter people here that could enlighten us.

Could someone convert that into units of "can of whoop-ass?"

Other uses...

[Hamster Of Death]

I know next to nothing about this, but I'll toss this out there anyway.
How efficiently is this stuff converted to energy once it contacts matter? Could it be used to say generate electricity (or whatever, heat/light etc..)?
It would make a great way to clean up current nuclear waste if you could get the costs of production down. Just dump some antimatter on some nuclear waste (in a controlled manner of course), and voila, energy AND less waste .

Just a thought...

One reason for the gag order:

[museumpeace]

.yaw ralucatceps yllear a ni lla ti dne ot detnaw ew sselnu retemirep tnemenifnoc eht evael reven dna pu tuhs ot su dlot yehT !bal eht ta ereh tnempiuqe retupmoc ruo htiw elbuort fo stros lla gnivah erew ew deciton neht tub gninnur retrevnoc rettamitan eht tog eW

Cheap irony alert

[Strange_Attractor]

The end of the article:

Besides, Lynn is enthusiastic about antimatter because he believes it could propel futuristic space rockets. "I think," he said, "we need to get off this planet, because I'm afraid we're going to destroy it."

Maybe if we lay off building the antimatter bombs...

Wrong warriors, wrong workplace, wrong spacetime

[Doc Ruby]

Antimatter research is extremely valuable science. Insight into the mechanisms of anti/matter annihilation, and its total (or nearly) conversion to energy, will inform science from nuclear energy to nano (femto?) tech and beyond. It's best performed in space, away from the rest of the world which it can contaminate with either annihilable (anti)material or radiation from the reaction. But budgeting the Air Force to make bombs out of it is insane. We've already got expensive ginormous bombs that scare everyone silly, and send the craziest of us into terrorism to compete. How about we just shift that Pentagon budget across to NASA? That will satisfy the aerospace bribers^Wlobbyists who are pushing this stuff, but keep them serving a sustainable market.

fantasy and unimaginable budget plans

[kc_cyrus]

Actually, antimatter does not make good bombs. Even more ordinary nuclear bombs can "fizzle" unless carefully designed: the reaction gets going but too slowly, so the bomb blows itself apart before the reaction can proceed very far.

With antimatter this problem is far worse, because while fission and fusion occur throughout the reaction volume, the matter-antimatter reaction occurs only on a contact surface.

It's exceedingly difficult to get a major explosion with antimatter.(Tiny ones are not hard, since the square-cube law gives you more surface area per volume as the scale shrinks.)

Also, with production technology we can reasonably foresee, antimatter is impossibly expensive for weapons applications.
Even the US military has finite budgets. The cost of burning a city down with conventional weapons is large but not infinite. We won't get the price down below US$ 60.e6/mg using foreseeable Earth-based technologies and, at 43 kT/gm of antimatter, we're talking roughly US$ 1.4e9 per kiloton !!!!!!!!! Even the Pentagon's budget isn't THAT large...

Thank goodness

[Tom7]

Such weapons would easy eclipse nuclear weapons in power

Thank goodness. One of the biggest problems with nuclear weapons is their lack of power.

Re:So when...

[Bowling Moses]

No no you're thinking of naquadria.

Re:Why, cause nuclear bombs aren't sCary enough?

[Skye16]

That kind of depends on what scares you more... a higher propensity to use these weapons due to low radiation or a great fear of using these weapons due to high radiation.

I'm scared shitless either way.

Re:Why, cause nuclear bombs aren't sCary enough?

[NoMoreNicksLeft]

Less radioactive. Alot of what you see in a fission bomb is the "unburnt" materials being dispersed by the explosion, the fallout. This just won't exist with anti-hydrogen (I'm assuming this is the most synthesizable element). However, even with fission, not all of it exists beforehand, when you have neutrons flying fuckfast all over the place, some stick in a nucleus here and there producing what are usually small halflife radioactive elements. A m/am would produce lots of all different sorts of radiation and fast particles... there is sure to be something created that lasts longer than a split second. And of course, immediately after the explosion, everything far enough away to avoid being vaporized will be dosed heavily.

It might very well be more scary, and not just from a power perspective... assume something as big as a nuke, but as (nearly) clean as a conventional explosive. The temptation to use it might be greater, the inhibitions even less.

BTW, anyone want to speculate on H/anti-H bombs? No neutrons to shoot all over the place, but at least a few protons (I'm assuming less than 100% perfect mix). And what happens when an anti-H atom hits oxygen or nitrogen, how does that work exactly?

Re:How about research them...

[nacturation]

But destructe research wins over constructive alternatives hands down.

Given that matter + anti-matter is a purely destructive process to begin with, it isn't surprising that this is a key area of military research. On the brighter side, tons of everyday inventions funnel down from military funded projects, so it's not all doom and gloom.

Re:How about research them...

[koreth]

As energy storage, maybe. But right now it takes millions of times more energy [wikipedia.org] to produce a unit of antimatter than you get by annihilating that unit afterwards.

Re:How about research them...

[pz]

Uh, basic physics, people. The Universe is comprised of matter, not anti-matter. You can make anti-matter, but it takes a heapload of energy (recall that E=mc^2 applies to anything that has mass), and you cannot go out and mine anti-matter. Why? Mostly because if there were any antimatter around, it would have a nasty tendency to interact with all that matter and be converted to energy.

So, you can use it to create a nice bomb, but it's equivalent to pumping up a pressurized bottle with a lot of air -- the only energy that's going to come out is the energy that you've put in to create the anti-matter. You make some anti-matter, find a way to confine it and later release it in a controlled fasion and you get a very nice bomb which is incredibly powerful given the mass of the active ingredients. But you cannot use it as an energy source because unlike coal, oil, natural gas and uranium, it isn't freely available: you have to make it.

This is in stark contrast with nuclear fusion and fission: there is lots of available material lying around in the ground and in the seas, just waiting to be extracted and used. While you can find ways of generating anti-matter without putting too much energy into the process (eg, by triggering nuclear decay) you just don't get that much mass very quickly. Unless, of course, you've got a right raging nuclear reaction going, and, then, well, your problems of bomb making are pretty well solved.

Re:How about research them...

[Tassach]

Hence the question of 5.56mm vs. 7.62mm, etc.

Urban legend. The downward trend in military rifle cartidge power ( .30-06 to 7.62NATO to 5.56NATO ) has nothing (or very little) to do with the propensity to kill or wound.

During WWII we found that the standard-issue rifle round (.30-06 at the time) was a lot more powerful than it needed to be. Going into the war, they expected infantrymen to be able to conduct aimed fire out to 600 - 1000 yards, so they adopted a rifle (M-1) and cartidge which was effective at these ranges. However, once they actually looked at real-world performance they found that soldiers were doing very little aimed fire and that most targets more than 250 yards away were engaged with heavy weapons.

In keeping with these findings, they redesigned the primary infantry weapon to have a less powerful cartridge that had full-auto capability to provide suppressive fire vs aimed fire. A smaller cartridge means that an infantryman can carry more rounds for the same weight. This gave us the M-14. The problem with the M-14 was that it was still too powerful for an average soldier to fire it on full auto. So, they went to an even lighter rifle & cartidge and got the M-16.

Re:How about research them...Big Wrong!!

[Nom du Keyboard]

they redesigned the primary infantry weapon to have a less powerful cartridge that had full-auto capability to provide suppressive fire vs aimed fire. A smaller cartridge means that an infantryman can carry more rounds for the same weight. This gave us the M-14.

Sorry, Big Wrong here. The M14 fires the .308 (7.62 x 51mm) cartridge, which provides virtually identical ballistics to the .30-06 (7.62 x 61mm) round in the M-1. All the .308 proved was that you could put a .30-06 into a case about a half inch shorter.

It was from that mis-step that we went to the 5.56 (.223) cartridge in the M-16 that wasn't even initially intended for the U.S. Army. We were giving AR-15 (civilian model of the M16) to our more slightly statured (shorter & lighter) South Vietmese allies when some one realized that a heavy rifle with heavy ammunition that nobody could control on full-auto fire didn't make nearly as much sense in the jungle where visibility was often 15 yards or less, as did this toy rifle we were giving to everyone else.

As a result, the M16 and its derivations have now served for as long as any other service rifle in the U.S. Military.

And btw, it was the Germans back in 1941-1942 who realized that it didn't make sense for their soliders to carry 1000 metre rifles when most battles were fought at under 400 metres. A smaller, lighter, cheaper rifle with ammunition only effective out to 400 metres that allowed selective fire as well made the individual foot solider a much more effective fighter. Too bad that the USA had to learn that lesson TWICE!! (M14, before M16.)

Re:I'm curious as to why Matter + Antimatter = Ene

[sexylicious]

It's a bit more than -1 + 1 = 0. In terms of net charge, you're correct. If you start with a particle and an anti-particle and get them to collide, you'll have no net charge left over.


Now, there's that other part of matter called mass. There's the rest mass of a particle (the particle has NO kinetic energy). And there's the mass associated with velocity (E=mc^2 comes from this... Kinetec Energy = 1/2 * m * v^2).

All the stuff that makes up the particles mass has an equivalent energy via E=mc^2. When you bring a particle and an anti-particle close enough that they react with each other, then the net charge of the two becomes neutral and the mass becomes so great that the new mass wants to find a more stable state. In order for the new mass to find a more stable state, it has to decay. (Now, the mass doesn't "know" or "think" about this, there are physical limits to the amount of mass that you can put into one particle.)

Since the super-particle isn't stable, it breaks up into smaller particles. It just so happens that when you bring an electron and a positron (anti-electron) just close enough that they barely touch with no excess kinetic energy beyond what is needed to make them react, then you'll get a super-particle that instantly decays into two high energy photons (gamma rays).

Re:This is only a small part of weapons research.

[NerveGas]

If you think that 3 million deaths over 60 years makes the US government the worst in history, you should go back to the history books.

In African history, there were plenty of times when 3 million over 60 years would pale in comparison. Then, look into the colonial period of England, France, Spain, Portugal, and Belgium. Between the numbers of natives murdered, worked to death, killed by disease, and the slaves brought in to replace them, 3 million over 60 years wouldn't look so bad at all. In fact, one particularly dark period of Belgian rule in the Congo brought about 10 million deaths over 40 years.

Germany, of course, slaughtered far more than 3 million (perhaps as high as 11 million) during WW2. The Russian gulag system would rival the 3 million mark, and that was perpetrated against it's own citizens.

I'm not in any way taking any side on any part - American or otherwise. I'm just saying that your statement of the US government being the worst in the history of the world would take an awfully skewed, narrow viewpoint to accept.

steve

Re:This is only a small part of weapons research.

[tsm_sf]

"America, we're not quite as bad as Stalin or the Nazis"