# Anti-Matter **URL:** \ **Category:** Factual Questions\ **Created:** [June 27, 2009, 5:12am UTC](https://boards.straightdope.com/t/anti-matter/501149 "2009-06-27T05:12:09Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 27, 2009, 11:43pm UTC](https://boards.straightdope.com/t/anti-matter/501149/21 "2009-06-27T23:43:40Z")
> [@Rigamarole](#): > > Why can’t this enormous release of energy from a matter / anti-matter reaction be harnessed for productive uses (that is, besides making bombs)? I mean, it did power the Enterprise’s warp engines after all. > > Is it because the energy necessary to _create_ the anti-matter is equally huge? If you have a source of existing antimatter to “mine” and use for reaction with matter then the cost is small. But if you have produce antimatter, and especially by the conventional means of sifting through the residue of a high speed particle impact, the cost (in terms of energy efficiency) is grossly prohibitive. I don’t have any idea how they supposedly produced the antimatter used to power the _Enterprise_ on _Star Trek_, but that process itself would require enormous energy. And although the physics of “warp drive” are just so much handwaving, if we assume that it takes at least a comparable amount of energy to move a spaceship through subspace as it would conventional propulsion, it would actually take years of the Sun’s output to send a bag of peanuts to put a bag of peanuts around orbit of the nearest star. So science fiction probably isn’t your best guide to technological feasibility. Stranger ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 27, 2009, 11:47pm UTC](https://boards.straightdope.com/t/anti-matter/501149/22 "2009-06-27T23:47:45Z")
> [@Stranger\_On\_A\_Train](#): > > We’ve produced somewhere on the order of a microgram. Storing antimatter in small quantities is easier than you would think, at least, as long as the antimatter is charged; the matter can be contained by a magnetic field, as in a Penning trap. This takes surprisingly little energy–a trap could be powered by a 9v battery–although you’d also have to keep the chamber evacuated and cryogenic… Can you refer me to any information on antimatter actually being stored and accounted for any significant length of time? There is a reason that I ask. _If_ one assumes that space actually consists of some greater than three spatial dimensions, _then_ it is not reasonable to \*assume \*that antimatter is oriented in and moves about that n-dimensional space exactly as matter does. What would an n-dimensional universe which contained equal amounts of two sets of materials, each of which were oriented in that n-dimensional space slightly differently and moved about some of the smaller n-dimensions slightly differently look like from the POV of observers made of one or the other sort of material? Pertinent to this thread, one way it would look is that an antimatter trap would experience loss of material in excess of that loss caused by contact with matter and measurable by energy released into the system - loss as the particles simply traveled in a direction that magnetic fields produced by matter could not contain it. I know that [ATHENA](http://ad-startup.web.cern.ch/AD-Startup/Science/Athena.html) is planned to trap and study antimatter, but even there I do not think that they intend on measuring whether the loss of material is consistent with the energy released. The assumption is so entrenched that the possibility is not even considered. ---
**Author:** ![Rigamarole](https://avatars.discourse-cdn.com/v4/letter/r/77aa72/32.png) [@Rigamarole](https://boards.straightdope.com/u/Rigamarole)\ **Post date:** [June 27, 2009, 11:49pm UTC](https://boards.straightdope.com/t/anti-matter/501149/23 "2009-06-27T23:49:20Z")
> [@Stranger\_On\_A\_Train](#): > > If you have a source of existing antimatter to “mine” and use for reaction with matter then the cost is small. Could such a thing exist, somewhere? It sure would be a neat solution to our energy problems. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 27, 2009, 11:53pm UTC](https://boards.straightdope.com/t/anti-matter/501149/24 "2009-06-27T23:53:50Z")
> [@Rigamarole](#): > > Could such a thing exist, somewhere? It sure would be a neat solution to our energy problems. [Yes.](http://www.abc.net.au/science/news/space/SpaceRepublish_794693.htm) But inconveniently located. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 28, 2009, 5:13am UTC](https://boards.straightdope.com/t/anti-matter/501149/25 "2009-06-28T05:13:16Z")
> [@](#): > > There is a reason that I ask. If one assumes that space actually consists of some greater than three spatial dimensions, then it is not reasonable to assume that antimatter is oriented in and moves about that n-dimensional space exactly as matter does. Of course it’s reasonable to assume that. Antimatter acts just like matter, except with the charge and a few other quantities reversed. Why not assume that normal matter would leak out into the extra dimensions, if you’re going that route? Antimatter is not some weird, exotic thing that ignores all we know of physics. To put things into perspective, the photon is its own antiparticle, so you could fairly say that you produce antimatter every time you turn on a lamp. And we’re as sure as we can be of anything that light doesn’t leak off into extra dimensions. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 28, 2009, 7:38pm UTC](https://boards.straightdope.com/t/anti-matter/501149/26 "2009-06-28T19:38:29Z")
> [@Chronos](#): > > Of course it’s reasonable to assume that. Antimatter acts just like matter, except with the charge and a few other quantities reversed. Now that is just plain wrong. It was initially thought that antimatter and matter were the same but in sort of mirror images of each other but differences in observed behaviors were noted - the much vaunted [CP violation](http://en.wikipedia.org/wiki/CP-symmetry). We do not observe the exact same behaviors with just a few quantities reversed. The three spatial answer to explaining CP violations is that there are fundamental asymmetries between matter and antimatter. OTOH higher dimensional space (three extended spatial and some n of smaller curled up ones) could leave open the option that antimatter and matter have no CP violation if we were only able to view them both from the n-dimemensional POV - that the apparent CP violation is actually a result of the fact that we are only viewing a smaller n-dimensional slices of a larger n-dimensional objects that are differentially oriented in the higher dimensional space and which each can move somewhat differently within it. > [@](#): > > Why not assume that normal matter would leak out into the extra dimensions, if you’re going that route? Well other than that I am not “assuming” that it “leaks” just that it can move about in those curled up spaces a bit differently, I do. That is that this model would say that matter would look the same way from the POV of antimatter. Neither leaks; they are both just both oriented differently than each other in the space and therefore able to move differently than each other. Separate questions, these about the [quantum foam](http://en.wikipedia.org/wiki/Quantum_foam). So particles and antiparticle pop into existence and annilihate each constantly within a vacuum. The net energy is zero. But didn’t some energy need to occur to create the particles which was then canceled out by the energy released upon annilihation? If one part of that pair is caught in a Black hole then isn’t there some energy loss to the universe (until the hole evaporates)? And don’t those particles have some mass for those brief periods of time they exist? Is that accounted for in calculations of dark matter? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 28, 2009, 8:10pm UTC](https://boards.straightdope.com/t/anti-matter/501149/27 "2009-06-28T20:10:51Z")
> [@](#): > > Separate questions, these about the quantum foam. So particles and antiparticle pop into existence and annilihate each constantly within a vacuum. The net energy is zero. > > But didn’t some energy need to occur to create the particles which was then canceled out by the energy released upon annilihation? If one part of that pair is caught in a Black hole then isn’t there some energy loss to the universe (until the hole evaporates)? > > And don’t those particles have some mass for those brief periods of time they exist? Is that accounted for in calculations of dark matter? The nature of the way such virtual particles come into being is such that they should behave as dark energy, not dark matter (this is in fact the reason why folks nowadays usually talk in terms of a “dark energy” stress-energy term rather than in terms of a “cosmological constant” field term). The problem is the magnitude of the dark energy: Current particle physics theories are not yet sufficient to calculate the energy density of the vacuum energy, but we can make a rough, order-of-magnitude estimate. Which is all well and good, except that order-of-magnitude estimate ends up disagreeing with the actual cosmological observations by 120 orders of magnitude (do note that that’s orders of magnitude, not a factor of 120). It’s presumed that the various terms that go into that calculation cancel out instead of adding, but even so, it’s frankly bizarre that they should cancel out so close to exactly, but still leave a nonzero remainder. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 28, 2009, 9:57pm UTC](https://boards.straightdope.com/t/anti-matter/501149/28 "2009-06-28T21:57:14Z")
Sorry that I don’t follow that as an answer. Meanwhile [here](http://cerncourier.com/cws/article/cern/30577) is some information about antimatter traps at ATHENA. > [@](#): > > So let’s look at what is possible in experiments with antimatter today, leaving the speculation to aficionados of sci-fi and NASA. If you wanted to take antimatter to the offices of your national funding agency, you might consider taking some antiprotons, since most of the mass-energy of an antihydrogen atom is in the nucleus. This might be tempting, since our charged-particle traps are certainly deeper than those for neutral matter or antimatter. ATRAP and ALPHA initially capture antiprotons in traps with depths of a few kilo-electron-volts, corresponding to tens of millions of kelvin. But, density is an issue. A good charged-particle trap for cold positrons has a particle density of about 109 cm–3. Antiproton density is much smaller, but we’ll be optimistic and use this number. So to transport a milligram of antiprotons – of the order of 1021 particles – you would need a trap volume of 1012 cm3, or 106 m3. That means a cube 100 m wide, which will not fit in your luggage. Incidentally, a milligram of antimatter, annihilating on matter, would yield an energy equivalent to about 50 tonnes of TNT… > > … How many anti-atoms can we trap? The Japanese-led ASACUSA experiment, using an extra stage of deceleration after the AD, can trap around a million of the 30 million decelerated anti-protons that the AD delivers every 100 s or so (CERN Courier March 2005 p8). Suppose we could make all of these into antihydrogen (in comparison, ATHENA achieved about 15%). The trapping efficiency for neutral anti-hydrogen is anybody’s guess at this point – we would be grateful for 1%. This is why the very notion of having a dense cloud of interacting antihydrogen atoms will bring a weary smile to the face of anyone working in the AD zone. Using the above figures, it would take us 1019 s – about 300 billion years – to accumulate just one milligram. … > > … Back down to the sober reality here at CERN, we would be happy just to demonstrate trapping of antihydrogen in principle. This means initially trapping just a few anti-atoms – not making a BEC or antihydrogen ice. The future of our emerging field seems to depend on this, although ASACUSA is developing a plan to do spectroscopy on antihydrogen in flight. Time will tell which approach proves more promising. Not quite “easier than you would think” I think **Stranger** , unless you think it is really pretty damn difficult. [Previous page](https://boards.straightdope.com/t/anti-matter/501149.md?page=1)