71–80 of 95 posts
"antimatter seems to have disappeared" This is not very mysterious. If there was lots of antimatter lying about nearby, we could not be alive to see it. So, any antimatter must be a long way away or otherwise separated from us.
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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 s…
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_antima... http://en.wikipedia.org/wiki/Antimatter_weapon Additionally, "antimatter" can include positrons, which a…
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.
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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 s…
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_antima... http://en.wikipedia.org/wiki/Antimatter_weapon Additionally, "antimatter" can include positrons, which a…
I wish the energy supply rationale were the real motivating factor for funding here.
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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 s…
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_antima... http://en.wikipedia.org/wiki/Antimatter_weapon Additionally, "antimatter" can include positrons, which a…
If that's not trolling, I don't know what is. I will remind the gentle readers that I even edited my post (with a tag) for correctness almost immediately.
Just because the "gunpowder" is expensive doesn't stop the production of containment vessels or delivery mechanisms:
Actually that's exactly why such a project doesn't make sense. Kind of like building a fancy castle to put your Holy Grail in before you've found it. Read any of the articles or commentaries based on actual science, they say that such a weapon is so far fetched from an engineering stand point, that it's not worth pursuing.
Ref.: http://public.web.cern.ch/public/en/Spotlight/SpotlightAandD...
Or the same wikipedia article you linked:
http://en.wikipedia.org/wiki/Antimatter_weapon
Your advisor may not have been involved in all imaginable projects related to antimatter.
Thank you for ignoring my edit.
I'm not saying that any of this is impossible, just that it's horribly impractical, needing probably an order(s?) of magnitude more than Manhattan Project level of effort.
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For its size, it would be many times more powerful than a hydrogen bomb, by several magnitudes.
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 argu…
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As has been alluded to, gravity is an extremely weak force, so any gravitational effect is easily masked by electroweak forces until you accumulate a very significant mass. There's no way they can measure this on a single atom.
But easy to test with 2 atoms! Smash them together at a high enough speed where e=mc^2 says they would create a black hole. If they are destroyed in a blip of Hawking radiation, they had gravity!
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I had hoped that less people on HN are familiar with Dan Brown's books.
Off topic but I had a very interesting experience reading Dan Brown. I read 'The da Vinci Code' without knowing anything about it or Brown, and I really enjoyed reading it. Then I saw the movie and I immediately recognized the massive holes in the plot, holes that I never saw while reading it. It surprised me.
The article doesn't spell it out, and I know practically nothing about the subject, but... what happens at the end of the 0.2s? Do the antimatter atoms drift out of the magnetic fields used to contain them? Do matter atoms drift in? Or is it some property of the atoms or magnetic fields? Basically, what needs to change to increase the 0.2s?
Just based on what the article says, I suspect that even at the vacuum pressures they can achieve, there's enough normal matter around that eventually one of them penetrates the field and annihilates it.
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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 argu…
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.
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).