Recent Forum Topics › Forums › The Public House › not enuff anti-matter?
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July 29, 2018 at 4:48 pm #88682wvParticipantJuly 29, 2018 at 6:32 pm #88689AgamemnonParticipantJuly 29, 2018 at 7:24 pm #88690wvParticipant
Well he didnt say how we know there is such a thing as anti-matter. If we dont see any in the universe why do we believe there is such a thing?
Also, if there are anti-rams-fans, then why dont they just explode and be done with it?
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vJuly 29, 2018 at 10:40 pm #88711znModeratorWell he didnt say how we know there is such a thing as anti-matter. If we dont see any in the universe why do we believe there is such a thing?
Also, if there are anti-rams-fans, then why dont they just explode and be done with it?
w
vWell they discovered it through a mathematical equation, and that’s a great story. I’ll tell it later.
But particle colliders regularly create it. Just at the subatomic level.
All he was saying in the vid is that there are not huge masses of it. BUT yes it can be encountered at the subatomic level. It’s not just theoretical.
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Making antimatter
https://angelsanddemons.web.cern.ch/antimatter/making-antimatter
We don’t find antimatter around us; in order to study antimatter it has to be made.Transforming energy into mass
When enough energy is squeezed into a very small space, such as during high-energy particle collisions at CERN, particle-antiparticle pairs are produced spontaneously. The energy given to the accelerated particles has to be at least equivalent to the mass of the new particles in order for this to occur; the more energy that is put into particle collisions, the more massive the particles and antiparticles that can be produced.
When energy transforms into mass, both matter and antimatter are created in equal amounts.
Antimatter at CERN
Antimatter is produced in many experiments at CERN. In collisions at the Large Hadron Collider the antiparticles that are produced cannot be trapped because of their very high energy – they annihilate harmlessly in the detectors. The Antiproton Decelerator at CERN produces much slower antiprotons that can be trapped. These antiprotons can then be studied to explore questions such as: do antiparticles fall upwards?
Antimatter production in practice
At CERN, protons with an energy of 26 GeV (about 30 times their mass at rest) collide with nuclei inside a metal cylinder called a target. About four proton-antiproton pairs are produced in every million collisions. The antiprotons are separated from other particles using magnetic fields and are guided to the Antiproton Decelerator, where they are slowed down from 96% to 10% of the speed of light. They are ejected and run through beam pipes into experiments to be trapped and stored.
Small, very small quantities
Even if CERN used its accelerators only for making antimatter, it could produce no more than about 1 billionth of a gram per year. To make 1 g of antimatter would therefore take about 1 billion years.
The total amount of antimatter produced in CERN’s history is less than 10 nanograms – containing only enough energy to power a 60 W light bulb for 4 hours.
July 29, 2018 at 11:09 pm #88712znModeratorWell they discovered it through a mathematical equation, and that’s a great story. I’ll tell it later.
Your second vid mentions Dirac, who discovered anti-matter, but theoretically. How he did it is really interesting.
Dirac’s equation predicts antiparticles
2 January 1928In 1928, British physicist Paul Dirac wrote down an equation that combined quantum theory and special relativity to describe the behaviour of an electron moving at a relativistic speed. The equation would allow whole atoms to be treated in a manner consistent with Einstein’s relativity theory. Dirac’s equation appeared in his paper The quantum theory of the electron, received by the journal Proceedings of the Royal Society A on 2 January 1928. It won Dirac the Nobel prize in physics in 1933. This equation provided a natural explanation of one of the electron’s intrinsic properties – its spin.
But the equation posed a problem: just as the equation x2=4 can have two possible solutions (x=2 or x=-2), so Dirac’s equation could have two solutions, one for an electron with positive energy, and one for an electron with negative energy. But classical physics (and common sense) dictated that the energy of a particle must always be a positive number.
Most people would have said that this means that something was wrong with the equation, but Dirac seemed to think otherwise. He thought this was the case because of the symmetry between positive and negative charges. In other words, Dirac thought every positive particle should have a negative partner and vice-versa. He remarked that his equation was more intelligent than its author. By taking the equation seriously, Dirac interpreted it to mean that for every particle there exists a corresponding antiparticle, exactly matching the particle but with opposite charge. For the electron there should be an “antielectron” identical in every way but with a positive electric charge.
July 29, 2018 at 11:55 pm #88713znModeratorJuly 29, 2018 at 11:55 pm #88714znModerator -
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