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Antimatter atoms produced and trapped at CERN

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81–90 of 95 posts

Re: Antimatter atoms produced and trapped at CERN

#81
post #48

I, for one, am just glad that CERN didn't create a black hole or otherwise destroy spacetime before they managed to do the kind of thing we normally have to turn to science fiction to read about.

Yet... Their developments are so fascinating to read about I can't wait to hear more.

For now, they seem happy enough to annihilate the world one atom at a time.

Re: Antimatter atoms produced and trapped at CERN

#82
post #53

Earlier quoted context omitted.

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…

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 n…

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.

Re: Antimatter atoms produced and trapped at CERN

#83

Earlier quoted context omitted.

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.

Re: Antimatter atoms produced and trapped at CERN

#84
post #29

Earlier quoted context omitted.

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.

Isn't the annihilation supposed to cause an explosion? How much energy is generated?

Just take the resting mass of an hydrogen atom and multiply it by c^2. Try feeding Wolfram Alpha with "(mass of hydrogen) * (speed of light ^ 2)" or something, if you are lazy.

It's not very much in everyday units.

Re: Antimatter atoms produced and trapped at CERN

#85
post #6

So far they have 38 atoms. I wonder what the price per kilo or pound of antimatter is... :)

Yet another substance cheaper than printer ink, whatever its price.

I actually once bought a new printer (and ink for it) because the combo was cheaper that replacement ink for the printer a family member had bought...

Re: Antimatter atoms produced and trapped at CERN

#86
post #50
post #14

I hope they will finally definitely answer if anti-matter also has anti-gravity. Not a single scientist thinks it does, but it's one of those things you just want confirmed.

Antimatter has opposite charge, not opposite mass. It has the exact same magnitude and sign of gravitational interaction as normal matter. It's never been directly observed, but I'm not aware of any models that predict otherwise. http://en.wikipedia.org/wiki/Gravitational_interaction_of_an... Maybe you're thinking of exotic matter? http://en.wikipedia.org/wiki/Exotic_matter

Isn't that why we have experiments, to check the predictions of models?

Re: Antimatter atoms produced and trapped at CERN

#87
post #29

Earlier quoted context omitted.

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.

Isn't the annihilation supposed to cause an explosion? How much energy is generated?

Isn't the annihilation supposed to cause an explosion?

It releases lots of energy proportional to the mass, yes, but one proton + one anti-proton annihilating at a time, it's a very small explosion. And they only had 38 anti-protons.

I believe that one of the the articles quotes one of the Physicists saying that it "wouldn't even warm up a cup of coffee"

Edit here you go:

Prof Rob Thompson, head of physics and astronomy at the University of Calgary, one of the 42 Alpha investigators, said: 'This is a major discovery. ... We've been able to trap about 38 atoms, which is an incredibly small amount, nothing like what we would need to power Star Trek's Starship Enterprise or even to heat a cup of coffee.'

Re: Antimatter atoms produced and trapped at CERN

#89
post #75

Earlier quoted context omitted.

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…

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.

Re: Antimatter atoms produced and trapped at CERN

#90
post #60

Earlier quoted context omitted.

If I remember correctly, Feynman quickly suggested to Wheeler that this is probably wrong, as it would imply that there are as many positrons as electrons. At least in our little piece of the universe, this is definitely not the case.

Maybe we haven't seen the positrons yet because they're still traveling back in time from the future!

Showing that this makes no sense is left as an exercise to the reader.
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