Quite simply, antimatter is the opposite of normal, everyday matter. Thanks Dirac.
If a is any particle and this particle has no attributes other than linear and angular momentum (which include energy and spin), then a is its own anti-particle--one of the constituents of antimatter. For example, the photon is its own anti-particle. Any other quantities, such as magnetic spin or electric charge, are opposite for matter-antimatter pairs.
Usefulness
Mostly present in fiction lore, weapons using the interaction physics of matter-antimatter collisions are predicted to be a massive source of devastation. Supposedly word got around about the US Air Force spending millions of dollars secretly on the research of antimatter for weapons application. Going beyond the ethics of not talking to media as an employee, the USAF instructed employees not to even discuss the subject of antimatter.
What's the real interest? Well, the energy from colliding positrons and antielectrons "is 10 billion times ... that of high explosives," moreover, 1 gram of antimatter would equal "23 space shuttle fuel tanks of energy." Thus positron energy conversion would be a novel, revolutionary source of large amounts of energy. Antimatter at lower energies is used in Positron Emission Tomography. It has captured public interest mainly as fuel for the fictional starship Enterprise on Star Trek. In fact, NASA is paying attention to antimatter as a possible fuel for interstellar propulsion. CERN studies the ratio of matter to antimatter in the universe to understand its origins.
References
http://science.howstuffworks.com/antimatter1.htm
http://home.cern/topics/antimatter
http://www.scientificamerican.com/article/what-is-antimatter-2002-01-24/
http://www.sfgate.com/science/article/Air-Force-pursuing-antimatter-weapons-Program-2689674.php
Would an antimatter bomb be more devastating than a fusion bomb? It sounds like it would, but I haven't found any sources on the matter.
ReplyDeleteIf you mean a bomb that releases a large amount of antimatter, yes I think it would be more devastating. A fusion bomb is a huge explosion, but an antimatter bomb would cause anything it interacted with to basically cease to exist, while still releasing a large amount of radiation to the surroundings.
DeleteA positron moving forward in time is mathematically equivalent to an electron moving back in time. That's an extremely fascinating concept to think about, at least for me. If I thought I could make a living out of it, particle physics and physical cosmology would have been 100% my educational background. I'm absolutely dumbfounded thinking about the Universe.
ReplyDeleteI can never read enough about what we know about the Universe, how we know it, and what we know we don't know, and why we don't know it. Then there's the extremely terrifying category: things we don't know that we don't know.
Great post! I wish we'd spent more time on the antimatter side of nuclear interactions during our degree. There's been way too much "And this reaction makes a positron, but it's just gonna disappear so we won't worry about it".
ReplyDeleteHow would anti-matter be contained to provide 1 anti-gram? Maybe positron "batteries" functioning similarly to regular batteries, but all of it's components being anti-particles> At some point, the anti-matter reaction would have to be contained to within some non-antimatter device in order to harness the reaction at an appropriate time.
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