Hacker News new | more | comments | ask | show | jobs | submit login

Next, suspend it in a mercury-like globule between two battery-powered magnetic plates, and place it beneath the Vatican...



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.)


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.


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 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_pu...


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.


(Comments like this make me want to stop reading Hacker News.)

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.


No knock on you and your research which seems pretty cool, but it really saddens me that motivation for government spending into this research is to build a bigger, better, more lethal weapon.

I wish the energy supply rationale were the real motivating factor for funding here.


Antimatter munitions scare me personally because they're a fail-deadly weapon. If the positron trap fails it goes kaboom. If a thermonuclear bomb fails in any way except a precisely calculated implosion you at worst you get a fissle, at best a guy in Whateveristan in the year 2040 gets his roof collapsed by a slightly radioactive dud.

I hope, the only thing these are being designed for is some gamma-ray laser for a new ground based Star Wars system and not as an actual munition of any sort. The complications are astronomical, especially given that gamma-rays are the EMP-producing portion of a nuclear reaction. An positron trap light enough to be contained in a weapon going off without a tamper to produce an explosion from the gamma-ray heating could be devastating for a modern society.

I'd never call playing god with this shit, I call playing stupid.


I'm pretty sure I've read somewhere that if you did just dump a quantity of antimatter (e.g. by turning off the containment device) you wouldn't get a nice explosion - more a long drawn out messy fizzle.

I would guess that a antimatter bomb would have to a similar design to fission or multi-stage devices where things are held together long enough by implosion for a significant proportion of the fuel to react.


I've done the math, you get an explosion quite rapidly. In a matter of nanoseconds the reaction of air in contact with the surface of the anti-matter chunk will release enough energy to vaporize the anti-matter and transform it into a growing ball of hot gas/plasma thoroughly mixed with matter, annihilation of the anti-matter completes in a matter of micro-seconds after that. This is if the anti-matter is just sitting in the open air, if it comes into direct contact with solid matter the process would probably proceed faster.


With what purpose? How would such a thing act?


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 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.


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.


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).


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.


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.


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)

If he has one now, he won't have it for much longer at this rate.


Because we need a bigger deterrent that complete loss of life on earth via hydrogen bomb?


Well, we can't allow a positron-trap gap, now can we?


Why?


Cheap literature says so ( http://en.wikipedia.org/wiki/Angels_%26_Demons )


I had hoped that less people on HN are familiar with Dan Brown's books.


Everybody makes bad choices in life, the important thing is to learn from them.


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.


I saw the holes in the plot (and characterization, and writing, etc.) while reading it and recognized the book as the worst sort of hollywood-esque masturbatory dreck. Nevertheless, despite all its defects the book was written well-enough to get me to keep reading it avidly, and for that I'll give Dan Brown a modicum of credit. Realistically, a lot of much more well thought of writers are no better than Brown.


It may be a guilty pleasure like junk food. McDonald's may not be worse for you than lots of other food, but it sure does feel bad.


To play a little devil's advocate, a lot of progress starts out with weapons. If we ever become a space-faring society, having more powerful weapons could possibly be a good thing. Space is big and we have no idea what's out there ( I'm not talking about aliens, but they could be there too. ) Though I do agree that as a terrestrial race, we have no need for weapons like this.




Applications are open for YC Summer 2019

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact

Search: