alfa015 Posted April 14, 2019 Share Posted April 14, 2019 Hi! I would like to share with you guys some facts you might not know about antimatter: 1º - Recent studies suggest that an antimatter spacecraft could achieve up to 70% the speed of light, reaching Proxima b in just about 6 years. 2º - The maximum time that antimatter has been stored is 405 days. 3º - According to the former Fermilab physicist Gerald Jackson, antimatter rockets could become a reality by 2050. SPAM DELETED What are your thoughts about antimatter propulsion? Link to comment Share on other sites More sharing options...
beecee Posted April 14, 2019 Share Posted April 14, 2019 On 4/14/2019 at 2:44 AM, alfa015 said: Hi! I would like to share with you guys some facts you might not know about antimatter: 1º - Recent studies suggest that an antimatter spacecraft could achieve up to 70% the speed of light, reaching Proxima b in just about 6 years. 2º - The maximum time that antimatter has been stored is 405 days. 3º - According to the former Fermilab physicist Gerald Jackson, antimatter rockets could become a reality by 2050. SPAM DELETED What are your thoughts about antimatter propulsion? From what little I know, we just can not, and do not possess or make anti matter in sufficient quantities to be put to any use. Link to comment Share on other sites More sharing options...
John Cuthber Posted April 14, 2019 Share Posted April 14, 2019 The same OP seems to have been posted on at least half a dozen websites. 3 hours ago, beecee said: The maximum time that antimatter has been stored is 405 days. As far as I can tell, that result comes from here https://iopscience.iop.org/article/10.1088/1367-2630/aa7e73 where they report on having 30,000,000 antiprotons stored If you reacted those with normal protons you would get energy equivalent to the destruction of twice that mass of matter. If I have done the maths right (and not lost track of all the zeroes) it's 5.4 mJ Roughly the energy released if I drop a paracetamol (acetaminophen) tablet as I take it out of the package (while standing up). We are not launching spaceships with it any time soon. On a tangentially related not, that paper also wins the understatement of the year award. " the lifetime of the proton has been one of the subjects of investigation. In direct measurements stringent limits up to a have been derived, .... However, experimental limits on the antiproton lifetime are much lower. " Yes. The estimated life of the proton is at least 210000000000000000000000000000 years The estimate they have published based on this work is 10 years, two months and ten days. which is indeed, "much lower". Link to comment Share on other sites More sharing options...
Sensei Posted April 14, 2019 Share Posted April 14, 2019 14 minutes ago, John Cuthber said: If I have done the maths right (and not lost track of all the zeroes) it's 5.4 mJ 30*10^6 * 2 * 938.272 MeV * 1.6021766*10^-19 J/eV = ~ 0.00902 J https://www.google.com/search?q=938.272+MeV+*+2+*+30*10^6 13 hours ago, alfa015 said: What are your thoughts about antimatter propulsion? The problem here is such that annihilation of proton-antiproton does not lead to 100% efficiency.. Newly created e.g. pions+ can decay to muon+ (and further decay chain) with muonic and electronic neutrinos and antineutrinos, which take part of mass-energy with them. Link to comment Share on other sites More sharing options...
Janus Posted April 14, 2019 Share Posted April 14, 2019 54 minutes ago, Sensei said: 30*10^6 * 2 * 938.272 MeV * 1.6021766*10^-19 J/eV = ~ 0.00902 J https://www.google.com/search?q=938.272+MeV+*+2+*+30*10^6 The problem here is such that annihilation of proton-antiproton does not lead to 100% efficiency.. Newly created e.g. pions+ can decay to muon+ (and further decay chain) with muonic and electronic neutrinos and antineutrinos, which take part of mass-energy with them. Right, which mean that the annihilation will produce an exhaust of these particles, traveling at moderate fractions of the speed of light. If we take "moderate" to mean ~50%, then we can work out the efficiency of the rocket in terms of mass-ratio. It would work out that for a craft to reach 70% of c and then reduce speed at the end of the trip, you would need ~31 kg of matter-antimatter "fuel" per kg of ship of which 15.5 kg would need to be anti-protons. The ship would have to be almost entirely fuel and antimatter containment systems. Link to comment Share on other sites More sharing options...
The Shadow Posted July 10, 2019 Share Posted July 10, 2019 On 4/14/2019 at 5:51 AM, beecee said: From what little I know, we just can not, and do not possess or make anti matter in sufficient quantities to be put to any use. I concur and have read this countless times (admittedly in forums). Also, do you agree (also my understanding) that containment (or storage) methods remain challenging? That is my belief. Since, obviously, segregation of matter and antimatter is crucial prior to it's intended use. Or else..Boom! Link to comment Share on other sites More sharing options...
Mordred Posted July 10, 2019 Share Posted July 10, 2019 A very crucial part indeed Link to comment Share on other sites More sharing options...
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