10 ms·

Although the cost to create antimatter is very high, our government is actually working on creating antimatter munitions. (I've worked on creating a portable a

by rubypay 16y ago

Although the cost to create antimatter is very high, our government is actually working on creating antimatter munitions. (I've worked on creating a portable antimatter trap, which was funded by the U.S. government.)

aik 16y ago
With what purpose? How would such a thing act?
- rubypay 16y ago
  For its size, it would be many times more powerful than a hydrogen bomb, by several magnitudes.
  - panacea 16y ago
    Because we need a bigger deterrent that complete loss of life on earth via hydrogen bomb?
    - CamperBob 16y ago
      Well, we can't allow a positron-trap gap, now can we?
  - juiceandjuice 16y ago
    Only because the mass to energy conversion is 100%. But, if you factored in the size of whatever object you use to contain the antimatter, then your mass to energy conversion is probably comparable to a hydrogen bomb. Further, factor in the the energy required to contain the antimatter and it seems like it's losing proposition, probably until you start to approach the size of a small house or larger. So then the argument turns into critical mass vs. critical structure mass. Anyways, the technique they used is much more interesting than the fact that it's antimatter. Of course, CERN still has to play the PR game too just like anybody else, and I don't fault them for that.
    - rubypay 16y ago
      The "object you use to contain the antimatter" is not very large, it can be wheeled around in a lab. The "energy required to contain the antimatter" is not very significant, liquid helium cooled inside a liquid nitrogen shell, and some rather ordinary (in terms of power usage) electric and magnetic fields. 100 grams of antimatter has a yield similar to a 4 megaton hydrogen bomb.
      - InclinedPlane 16y ago
        A 4 megaton thermonuclear warhead can be crammed into shockingly little space and weight, the question is whether the antimatter containment device can be smaller and lighter. However, the real benefit to using anti-matter in munitions would be as a catalyst, not necessarily as a primary source of energy. Consider a conventional multi-stage thermonuclear weapon, conventional explosives compress a fission primary bomb which goes off and serves as an x-ray light-bulb inside a radiation channel to provide ablative compression of the fusion secondary which, with the aid of a fission bomb "spark plug" ignites a self-sustaining fusion reaction. If you had significant quantities of anti-matter available you could change this design significantly. In the simplest design you could replace the primary with perhaps a single gram or less of anti-matter. Saving significant amounts of weight and also possibly allowing for much smaller thermonuclear weapons. More so, it may be possible with anti-matter to completely remove the need for fissile components in thermonuclear warheads. This could be useful in civilian applications (in an Orion drive spacecraft, for example).
        jbooth 16y ago
        Actually, the real benefit to using anti-matter in munitions is that it's a hell of a cash cow. Nobody expects it to actually work or ever be used, but you get paid a fortune anyways. Everyone wins -- the air force general gets a staff of 40 to manage the project, and the defense contractor gets several hundred million dollars.
      - juiceandjuice 16y ago
        But the question is what kind of infrastructure is needed to to contain 100 grams of positrons? There's no way you've contained 1/1000th of that amount otherwise you wouldn't be telling us about it on the internet (assuming you have Q/Top Secret clearance) Also, assuming it is positrons, I'd imagine you might also have to worry slightly about relativistic background electrons and gamma rays/pair production, unless you're under 10ft+ of concrete. The extremely rare case that a 10^19 eV cosmic ray hits you head on sounds like an awesome way to possibly produce a spontaneous "detonation", or when some jokester thinks it's awesome to point a LINAC right at you.
RK 16y ago
I call bullshit. The cost is not "very high", it's astronomically high. My advisor also worked on creating antimatter traps at government labs, but none of the projects had any kind of defense related purposes. There are only a handful of interesting research questions about antimatter that exist at reasonable scales. Most of those are either fundamental physics or medical in nature. EDIT: Looks like there has been some Air Force funding for positron traps for defense purposes. Never underestimate the insanity of some generals. I think my physics comments still stand, though.
- rubypay 16y ago
  I call bullshit. The cost is not "very high", it's astronomically high. (Comments like this make me want to stop reading Hacker News.) Just because the "gunpowder" is expensive doesn't stop the production of containment vessels or delivery mechanisms: http://articles.sfgate.com/2004-10-04/news/17447495_1_antimatter-physicists-paul-dirac http://articles.sfgate.com/2004-10-04/news/17447495_1_antima... http://en.wikipedia.org/wiki/Antimatter_weapon http://en.wikipedia.org/wiki/Antimatter_weapon Additionally, "antimatter" can include positrons, which are much cheaper to produce than antiprotons. My advisor also worked on creating antimatter traps at government labs, but none of the projects had any kind of defense related purposes. Your advisor may not have been involved in all imaginable projects related to antimatter. There are only a handful of interesting research questions about antimatter that exist at reasonable scales. Most of those are either fundamental physics or medical in nature. Along with research into directly producing weapons, antimatter can also be used to initiate (micro)fusion, and has been researched for space travel: http://en.wikipedia.org/wiki/Antimatter_catalyzed_nuclear_pulse_propulsion http://en.wikipedia.org/wiki/Antimatter_catalyzed_nuclear_pu...
  - icegreentea 16y ago
    While I kinda agree with the spirit of your comment (we'll get there someday), there's a few problems with the specifics. A pure (or high percentage) positron weapon would be very hard to handle. The repulsive forces would be enormous. As in we have a hard time containing the equivalent mass of electrons. And that's without worrying about annihilation. And really, I think RK's response was spurred on more by rubypay's tone/phrasing. The original phrasing easily sounds like we're on the verge of practical anti-matter weapons. Which we're not.

by rubypay 16y ago

aik 16y ago

With what purpose? How would such a thing act?

rubypay 16y ago
For its size, it would be many times more powerful than a hydrogen bomb, by several magnitudes.
- panacea 16y ago
  Because we need a bigger deterrent that complete loss of life on earth via hydrogen bomb?
  - CamperBob 16y ago
    Well, we can't allow a positron-trap gap, now can we?
- juiceandjuice 16y ago
  Only because the mass to energy conversion is 100%. But, if you factored in the size of whatever object you use to contain the antimatter, then your mass to energy conversion is probably comparable to a hydrogen bomb. Further, factor in the the energy required to contain the antimatter and it seems like it's losing proposition, probably until you start to approach the size of a small house or larger. So then the argument turns into critical mass vs. critical structure mass. Anyways, the technique they used is much more interesting than the fact that it's antimatter. Of course, CERN still has to play the PR game too just like anybody else, and I don't fault them for that.
  - rubypay 16y ago
    The "object you use to contain the antimatter" is not very large, it can be wheeled around in a lab. The "energy required to contain the antimatter" is not very significant, liquid helium cooled inside a liquid nitrogen shell, and some rather ordinary (in terms of power usage) electric and magnetic fields. 100 grams of antimatter has a yield similar to a 4 megaton hydrogen bomb.
    - InclinedPlane 16y ago
      A 4 megaton thermonuclear warhead can be crammed into shockingly little space and weight, the question is whether the antimatter containment device can be smaller and lighter. However, the real benefit to using anti-matter in munitions would be as a catalyst, not necessarily as a primary source of energy. Consider a conventional multi-stage thermonuclear weapon, conventional explosives compress a fission primary bomb which goes off and serves as an x-ray light-bulb inside a radiation channel to provide ablative compression of the fusion secondary which, with the aid of a fission bomb "spark plug" ignites a self-sustaining fusion reaction. If you had significant quantities of anti-matter available you could change this design significantly. In the simplest design you could replace the primary with perhaps a single gram or less of anti-matter. Saving significant amounts of weight and also possibly allowing for much smaller thermonuclear weapons. More so, it may be possible with anti-matter to completely remove the need for fissile components in thermonuclear warheads. This could be useful in civilian applications (in an Orion drive spacecraft, for example).
      - jbooth 16y ago
        Actually, the real benefit to using anti-matter in munitions is that it's a hell of a cash cow. Nobody expects it to actually work or ever be used, but you get paid a fortune anyways. Everyone wins -- the air force general gets a staff of 40 to manage the project, and the defense contractor gets several hundred million dollars.
    - juiceandjuice 16y ago
      But the question is what kind of infrastructure is needed to to contain 100 grams of positrons? There's no way you've contained 1/1000th of that amount otherwise you wouldn't be telling us about it on the internet (assuming you have Q/Top Secret clearance) Also, assuming it is positrons, I'd imagine you might also have to worry slightly about relativistic background electrons and gamma rays/pair production, unless you're under 10ft+ of concrete. The extremely rare case that a 10^19 eV cosmic ray hits you head on sounds like an awesome way to possibly produce a spontaneous "detonation", or when some jokester thinks it's awesome to point a LINAC right at you.

RK 16y ago

I call bullshit. The cost is not "very high", it's astronomically high. My advisor also worked on creating antimatter traps at government labs, but none of the projects had any kind of defense related purposes. There are only a handful of interesting research questions about antimatter that exist at reasonable scales. Most of those are either fundamental physics or medical in nature. EDIT: Looks like there has been some Air Force funding for positron traps for defense purposes. Never underestimate the insanity of some generals. I think my physics comments still stand, though.

rubypay 16y ago
I call bullshit. The cost is not "very high", it's astronomically high. (Comments like this make me want to stop reading Hacker News.) Just because the "gunpowder" is expensive doesn't stop the production of containment vessels or delivery mechanisms: http://articles.sfgate.com/2004-10-04/news/17447495_1_antimatter-physicists-paul-dirac http://articles.sfgate.com/2004-10-04/news/17447495_1_antima... http://en.wikipedia.org/wiki/Antimatter_weapon http://en.wikipedia.org/wiki/Antimatter_weapon Additionally, "antimatter" can include positrons, which are much cheaper to produce than antiprotons. My advisor also worked on creating antimatter traps at government labs, but none of the projects had any kind of defense related purposes. Your advisor may not have been involved in all imaginable projects related to antimatter. There are only a handful of interesting research questions about antimatter that exist at reasonable scales. Most of those are either fundamental physics or medical in nature. Along with research into directly producing weapons, antimatter can also be used to initiate (micro)fusion, and has been researched for space travel: http://en.wikipedia.org/wiki/Antimatter_catalyzed_nuclear_pulse_propulsion http://en.wikipedia.org/wiki/Antimatter_catalyzed_nuclear_pu...
- icegreentea 16y ago
  While I kinda agree with the spirit of your comment (we'll get there someday), there's a few problems with the specifics. A pure (or high percentage) positron weapon would be very hard to handle. The repulsive forces would be enormous. As in we have a hard time containing the equivalent mass of electrons. And that's without worrying about annihilation. And really, I think RK's response was spurred on more by rubypay's tone/phrasing. The original phrasing easily sounds like we're on the verge of practical anti-matter weapons. Which we're not.