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Why is it so hard to study anti-matter?
- M_Grey 10y agoIt's much harder to come by then traditional "incredibly hard to come by" substances like precious metals or coral snake venom; harder to store, harder to study, and consequently much more expensive. Keep in mind that something like a coral snake's venom goes for more than $1000 a gram (Platinum being ~$30), but antimatter according to NASA estimates? $62.5 trillion USD per gram.
- Twisol 10y agoGosh, I can only imagine how terrifying a whole gram of antimatter would be. It's kind of a good thing we can only generate it in such minuscule quantities.
- ben_w 10y agoOne gram would be about as bad as the Nagasaki nuke, so not that terrifying. Sure, it's bad, but I only sometimes lose sleep over all the nukes, so…
- eganist 10y ago> One gram would be about as bad as the Nagasaki nuke, so not that terrifying. There's something fascinating about this sentence, but I can't quite put my finger on what it is.
- eternalban 10y agosomething to do with anti- ...
- eganist 10y agoIs it something material?
- eternalban 10y agoIn a continental sense.
- M_Grey 10y agoI just want to say how much I appreciate you leaving the ~50% of energy released as neutrinos out of your explosive yield estimate, you almost never see that.
- ufmace 10y agoAt least nuclear weapons only go off when the detonation explosives are triggered in exactly the right way. Anti-matter goes boom if anything goes wrong with the confinement system.
- ben_w 10y agoI do not recommend spending a large percentage of Gross World Product on antimatter weapons. Or even a small percentage, if antimatter becomes cheaper. In fact, I'd go as far as to suggest that — if you can figure out how to make and keep it — world peace is much better than having any military.
- M_Grey 10y agoOf course this leads into the realistic aspect of science fiction... sufficiently advanced drive technology is indistinguishable from a weapon of mass destruction. We love to talk about fusion drives or antimatter reactions propelling us beyond Earth, but the truth is that such technology has a very dark side and one we're historically likely to exploit.
- danbruc 10y agoLittle Boy was 0.7 gram mass equivalent, Fat Man was 1.0 gram. So you are looking at almost three times Hiroshima or two times Nagasaki.
- nickpsecurity 10y agoSeveral militaries are looing into making it happen anyway: http://cui.unige.ch/isi/sscr/phys/anti-BPP-3.html http://cui.unige.ch/isi/sscr/phys/anti-BPP-3.html https://arxiv.org/abs/physics/0507125 https://arxiv.org/abs/physics/0507125 Note: The second one has very interesting implications for safety of citizens in countries possessing such devices. Especially given the number of accidents in nuclear transportation and command/control. ;)
- itchyjunk 10y agoI always wonder why photon is its own anti matter. If it was not so, we wouldn't be able to study anti matter with lasers for example. Also, why is the anti particle pair of a charged particle the opposite charge, but neutral particle/anti particle pair are both chargless? Though it does make sense that in order to cancel each other out, it must be so.. I would say we live in a strange world but I don't know if a non strange world would even exist.
- danbruc 10y agoAlso, why is the anti particle pair of a charged particle the opposite charge, but neutral particle/anti particle pair are both chargless? That's just the definition of an antiparticle - same as the particle put opposite charges. Though it does make sense that in order to cancel each other out, it must be so.. That's right, this is required to maintain charge conservation in annihilation processes.
- MereInterest 10y ago> That's just the definition of an antiparticle - same as the particle put opposite charges. Well, a bit more is needed. If a particle has no charge, then it is possible for it to be its own antiparticle, but it is not necessarily so. The photon is neutral and is its own antiparticle. The neutron, on the other hand, is neutral but is distinct from the antineutron. It is still an open question whether the neutrino is its own antiparticle.
- danbruc 10y agoIf a particle has no charge, then it is possible for it to be its own antiparticle, but it is not necessarily so. [....] The neutron, on the other hand, is neutral but is distinct from the antineutron. The neutron is only electrically neutral, there are also weak isospin and color charge. Antimatter is not only concerned with electrical charge but with charges in general. In case of the neutron and antineutron this becomes obvious if you compare the quark content of both.
- mschuster91 10y agoRegarding that suspended frog... is being suspended in magnetic levitation painful for the frog? Or could this, one day, be used to create artificial gravity in space for humans?
- pythonistic 10y agoA very strong magnetic field has bad health (neurological and intracellular) consequences. I can't find a good citation, but this blog post should help explain the risks. https://gravityandlevity.wordpress.com/2015/01/12/how-strong-would-a-magnetic-field-have-to-be-to-kill-you/ https://gravityandlevity.wordpress.com/2015/01/12/how-strong...
- adrianN 10y agoThe frog levitates at 16 tesla. That's a long way from the fields the article talks about. Nevertheless, given that our brain reacts to magnetic stimulation, I'd be wary of using it as artificial gravity.
- M_Grey 10y ago...Plus anything metal on/in you would be violently ripped out. This would make the fields used for a typical MRI look mild by comparison.
- hwillis 10y agoInside a homogeneous magnetic field there is no force. It's kind of like being under very high pressure- humans can survive many hundreds of psi as long as the pressure is equal inside and outside the body. The danger comes when there is a gradient to the field, as happens outside the coil. Then ferromagnetic material wants to move from the low to high field, like high pressure water will want to move to low pressure. As long as you're inside the high field area, you're okay. This is part of the reason why people can be MRI'd even with shrapnel in their bodies. When the shrapnel is in the center of the volume being imaged, the field is relatively homogeneous except for the small induced gradient field. The shrapnel is already "touching the magnet", so it doesn't feel much more pull.
- lngnmn 10y agoBecause it does not exist outside of the minds of the "scientists" "studying" it? Proof of its existence before down-voting would be appreciated. Update: a quick overview of how easily sectarian beliefs could be held with support of nothing but opinions of the followers could be found a in my older comments.
- adrianN 10y agoPlease argue why you disagree with mainstream physics before requesting links to Wikipedia.
- lngnmn 10y agoWhy, the very same distinction as between a science and a religion - a proposition which lack empirical verification cannot be used as a valid premise. One single logical flaw (assumption of existence of a mere abstraction) is enough to discard the whole mental construction or a model. Most of so called modern science is based on a sectarian consensus of ignoring the logical inconsistencies.
- adrianN 10y agoPlease cite the exact flaws of the experiments that claim to show the existence of antimatter.
- lngnmn 10y agoSimulation is not an experiment. Everything which involves a probabilistic calculation is not an experiment but a simulation. But go ahead, which experiment confirms existence of antimatter?
- jerf 10y agoPetabytes of data from particle accelerators that only make sense if anti-particles exist. You seem to be operating under the assumption that anti-matter is something weird and exotic. It's not. It's engineering. We use anti-matter in medical devices at your local hospital: https://en.m.wikipedia.org/wiki/Positron_emission_tomography https://en.m.wikipedia.org/wiki/Positron_emission_tomography We're checking to see if our predictions are correct because that is proper science, and it's hard to have a lot of antimatter, but there is basically no reason to doubt it's existence, unless you want to write off all of particle physics. As that is arguably the most solid science we have, you'd basically be writing off all science.
- Sir_Cmpwn 10y agoIf antimatter has an indistinguishable spectrum from regular matter, maybe there is more of it in the universe than we thought.
- danbruc 10y agoIf there were regions of antimatter in the universe, then there would be boundaries with regions of matter. And on those boundaries a lot of matter antimatter annihilation would happen, we would see those boundaries glow in energetic gamma light. We don't see something like that, therefore there are probably no large region of antimatter in the universe.
- Sir_Cmpwn 10y agoGotcha, makes sense. Are we sure the density of the intergalactic medium is high enough to make interactions between matter and antimatter produce light visible from long distances, though?
- danbruc 10y agoWe have bounds on the density near such boundaries and their distance from Earth above which they would become visible. [1] [1] https://en.wikipedia.org/wiki/Baryon_asymmetry#Regions_of_the_universe_where_antimatter_dominates https://en.wikipedia.org/wiki/Baryon_asymmetry#Regions_of_th...
- johnfn 10y agoIsn't space mostly empty? Aren't galaxies like millions of light years apart, and don't they collide only incredibly rarely? If some galaxies were antimatter and some matter, how would we know?
- danbruc 10y agoThe space between galaxies is not completely empty, there is still about one atom per cubic meter. Boundaries in outer space would stretch across billions of square light years, enough space to generate noticeable signals even at such low densities.
- lutusp 10y agoQuote: "At the same time, atomic spectra is generated by ..." s/is/are/
- erikb 10y agoBecause it is anti and most scientists are pros.