From a 1999 Nasa page
Kinda puts that mint condition Spiderman #1 in it’s place, don’t it.
Oh, and the link.
They make antimatter? Antimatter is commercially available? You live and learn.
Antimatter has been made, and used, at particle accelerators for years. Antimatter is produced in energetic collisions of certain particles. Some colliders even collide matter and antimatter beams (electrons with positrons, protons with antiprotons). From the point of view of a particle physicist, antimatter is not really exotic. Explaining why so little of it survived the Big Bang, is another matter. If you’ll pardon the pun.
It is only recently, however, that actual antimatter atoms could be made. It is one thing to send beams of antiparticles in circles; it is quite another to slow down antiprotons and positrons so that they can interact and form antiatoms. A big part of the trick, of course, is to manipulate and contain the antimatter without actually touching it. It is easy to see how magnetic fields might control charged antimatter, but once you’ve created a neutral antiHydrogen molecule you must have to get pretty clever.
I knew there were plans to sell antimatter; I was unaware that that it was commercially available, however. Fortunately, we are a long way from casually mailing the stuff - talk about your letter bombs!
To expand on SlowMindThinking’s last paragraph, commercial applications of antiproton production have been considered, as in this paper (a pdf) or this seminar. There’s also this outfit, who seem rather enthusiastic about the prospects, but don’t actually seem to be shipping the stuff yet.
Applications where antimatter is involved along the way, like in PET scanning, are very commonplace.
Antimatter isn’t something theorized like “dark matter.” It’s actually a comparitively boring term for positrons etc., positive particles that at the beginning of the universe were roughly equal to negative ones but due to some miniscule imbalance were largely cancelled out.
(compare Dark Matter, which is indeed theoretical)
I wouldn’t say that. We may not know all the properties of dark matter, but we’re pretty sure it exists. We have as much evidence for it as we do “black holes”.
- We have as much evidence for it as we do “black holes”.*
Except that there’s a pretty obvious logical sequence as to how black holes come to be: Every massive object has an escape velocity, or how fast something must travel to get off of it. If the thing is heavy enough, then its escape velocity is greater than the universe’s maximum speed limit. Thus, a black hole.
I’ve never heard of any such obvious explanations for how dark matter could come into existence. Not that I really believe or disbelieve the existence of dark matter; it could be that there’s heavy stuff out there we can’t see, or it could be that our conception of gravity isn’t quite right. Time will tell, I’m sure.
If our conception of gravity isn’t quite right, then that pretty obvious logical sequence you used as evidence for black holes falls apart.
I liked the answer about californium and the thread about anti matter but t5hink they are contenders for the most expensive stuff. What do you think is the most expensive thing? Perhaps cost to build or cost to buy would both be reasonable tests. Would it be something like the space station or the Hoover dam?
While I was wondering about the mental age of cinnamonfin based on his wonderous posts on the board I came across another question.
How exactly would someone go about giving antimatter to someone once they had bought some.
What I it contained in?
Well you can’t say he was wrong, but the article does need updating! 
I don’t believe him but my brother who is a bio medical/chemical engineer says anti matter cannot be transported. It is only created… and when it is, it’s use is accomplished. Antimatter is created for a sole purpose in the event it is needed. It cannot exist on it’s own as “anti-matter.” In order to transport anti matter, we need billions of dollars AND energy to contain it. It’s just not worth it to transport it…it’s cheaper to create it.
P.S. He’s lying on my couch right now playing The Getwaway on my PS2.
You’re right not to believe him.
Granted, the traditional method of moving antimatter from A to B has been accelerator beamlines - though, even then, they rarely even approach billions of dollars to build. But people are already developing relatively simple devices to port antiprotons. That PSU scheme is based on Penning traps, which are already common laboratory equipment. There are no doubt some engineering challenges to overcome to make it practical technology, but I see no fundamental physical obstacles.