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Does this actually prove that antimatter necessarily exists? Does this prove that antimatter is necessary for theories of gravity to concur with other observat

Does this actually prove that antimatter necessarily exists? Does this prove that antimatter is necessary for theories of gravity to concur with other observations? Do the observed properties of antimatter particles correspond with antimatter as the or a necessary nonuniform correction factor to theories of gravity?

ranger207 2y ago
Antimatter has been used in medical PET (positron emission tomography) scans since the 60s
pvg 2y ago
Antimatter detection is not the new thing here, being nearly a century old: https://timeline.web.cern.ch/carl-anderson-discovers-positron https://timeline.web.cern.ch/carl-anderson-discovers-positro...
OscarCunningham 2y ago
You're confusing antimatter with dark matter.
- nsxwolf 2y ago
  With a splash of antimass in that confusion too
  - westurner 2y ago
    My mistake, my mistake. It seems I had my Antimatter confused with mah Dark matter. Antimatter: https://en.wikipedia.org/wiki/Antimatter https://en.wikipedia.org/wiki/Antimatter Dark matter: https://en.wikipedia.org/wiki/Dark_matter https://en.wikipedia.org/wiki/Dark_matter Antimass: I and the Internet have never heard of antimass. Negative mass: https://en.wikipedia.org/wiki/Negative_mass https://en.wikipedia.org/wiki/Negative_mass Dark energy: https://en.wikipedia.org/wiki/Dark_energy https://en.wikipedia.org/wiki/Dark_energy Dark fluid: https://en.wikipedia.org/wiki/Dark_fluid https://en.wikipedia.org/wiki/Dark_fluid : > Dark fluid goes beyond dark matter and dark energy in that it predicts a continuous range of attractive and repulsive qualities under various matter density cases. Indeed, special cases of various other gravitational theories are reproduced by dark fluid, e.g. inflation, quintessence, k-essence, f(R), Generalized Einstein-Aether f(K), MOND, TeVeS, BSTV, etc. Dark fluid theory also suggests new models, such as a certain f(K+R) model that suggests interesting corrections to MOND that depend on redshift and density
    - nsxwolf 2y ago
      Negative mass was what I was going for with "antimass". For some reason I thought that was a common term but I guess it is not.
      - westurner 2y ago
        Not sure why I confused the terms. FWIU this Superfluid Quantum Gravity rejects dark matter and/or negative mass in favor of supervaucuous supervacuum, but I don't think it attempts to predict other phases and interactions like Dark fluid theory? From "Show HN: Physically accurate black hole simulation using your iPhone camera" https://news.ycombinator.com/item?id=42191692 https://news.ycombinator.com/item?id=42191692 : > Ctrl-F Fedi , Bernoulli, Gross-Pitaevskii: >> "Gravity as a fluid dynamic phenomenon in a superfluid quantum space. Fluid quantum gravity and relativity." (2015) https://hal.science/hal-01248015/ https://hal.science/hal-01248015/ There's a newer paper on it. Alternatives to general relativity > Testing of alternatives to general relativity: https://en.wikipedia.org/wiki/Alternatives_to_general_relativity#Testing_of_alternatives_to_general_relativity https://en.wikipedia.org/wiki/Alternatives_to_general_relati... The new Sagittarius* black hole image with phase might help with discarding models unsupported by evidence. Are those knots or braids or fields around a vortical superfluidic attractor system? There doesn't at all appear to be a hard boundary Schwarzschild radius. But that's about not dark matter not antimatter.
deleted 2y ago
[deleted]
dragonwriter 2y ago
> Does this actually prove that antimatter necessarily exists? Antimatter definitely exists, it is detectable, and used; e.g, PET scans use positrons (anti-electrons), and there have been experiments (only in animal models last I knew) with anti-proton radiotherapy for cancers. This is the first evidence of a particular configuration of antimatter, not the first evidence of antimatter.
- benbayard 2y ago
  To be more specific this is the first time we have detected hyper-antimatter of Helium where one of the quarks in the nucleus is an anti-strange quark (an anti-lambda from the article)
  - westurner 2y ago
    Thank you all for corrections and clarifications. I had confused Antimatter in particle theory (where there is no gravity) and Dark matter, which has no explanation in particle theory and maybe probably shouldn't be necessary for a unified model that describes n-body gravity at astrophysical and particle scales.
    - westurner 2y ago
      > [dark matter] has no explanation in particle theory From https://news.ycombinator.com/item?id=42369294#42371561 https://news.ycombinator.com/item?id=42369294#42371561 : > One theory of dark matter is that it's strange quark antimatter.
gus_massa 2y ago
My guess is that you are confusing "antimatter" and "dark matter". If you want some antimmater, you can go to your nearby physics suply store and buy some radioactive material that produce positrons. It's quite easy. (Radioactive material may be dangerous. Don't fool with that!) If you want antiprotons or antihydrogen, you need a huge particle acelerator. They make plenty of antiprotons in the CERN, to make colisions. They are very difficult to store, so they survive a very short time on Earth. Dark matter is very different. We have some experimental resuls that don't match the current physics theories. The current best guess is that there is some matter that we can't see for some reason. Nobody is sure what it is. Perhaps it's made of very dark big objects or perhaps it's made of tiny particles that don't interact with light. (I'm not sure the current favorite version in the area.) Anyway, some people don't like "dark matter" and prefer to change the theories, but the proposed new theories also don't match the experimental results.
- orwin 2y ago
  > Anyway, some people don't like "dark matter" and prefer to change the theories It seems a bit more complicated than that, mostly because the vulgarization often available too is quite bad to explain the issue. My understanding: - Our current theories fail to predict/match an array of observations, as if more matter than what we can detect exist. Some scientists called that the "dark matter problem", that's what most physicists working on the subject refer to when they talk about "dark matter". - Every theory you talked about: dark matter big objects, dark matter particles AND the "change the theories" (i guess you talk about the Modified Newtonian dynamics, where you alter Newton's second law at low speed to match some observations) are dark matter theories: theories that tries to explain why the universe act as it is, not matching our current theories, either by adding new things, or by modifying our discovered laws to match our observations. Each of those theories have multiple branch investigated. - the "dark matter particle theory" is sometime vulgarized as "dark matter" on podcasts or in books/articles. This is because more scientists work on particle physics than on gravity or astrophysics (my country present like 3 astrophysics thesis each year, and dozens of particle physics thesis). I think this caused a huge misunderstanding. - Some people with a common understanding (like mine, i meant non-physicists, it's absolutely not derogatory) like MOND because philosophically it is quite nice, and also tend to draw in people with minority/anti-etablishment habitus[0] (cf: most physicists working on those subjects are particle physicists). I'm not saying this theory is worse than the others at all, i'm just saying that the kind of layperson drawn to it can be _really_ sure they're right and profess their beliefs everywhere, and sometime claim that "MOND isn't dark matter", when they really confuse dark matter as a problem to be solved with "dark matter particle theory". Misunderstanding happen to everyone btw, it's really not a big issue. In case you did not talk about MOND but about theories that claim that the issue are with our tools to observe at a distance, some theories include that to explain some of the inconsistencies, never all of them, and those theories seems to really be a minority atm, so hopefull it wasn't about that. [0] Also, those habitus seems to draw in grifters who know they can make quick bucks by selling books/conferences if they look convincing enough, which is why MOND has a weird reputation now, but absolutely serious physicists and mathematicians work on the subject very, very seriously.

ranger207 2y ago

Antimatter has been used in medical PET (positron emission tomography) scans since the 60s

pvg 2y ago

Antimatter detection is not the new thing here, being nearly a century old: https://timeline.web.cern.ch/carl-anderson-discovers-positron https://timeline.web.cern.ch/carl-anderson-discovers-positro...

OscarCunningham 2y ago

You're confusing antimatter with dark matter.

nsxwolf 2y ago
With a splash of antimass in that confusion too
- westurner 2y ago
  My mistake, my mistake. It seems I had my Antimatter confused with mah Dark matter. Antimatter: https://en.wikipedia.org/wiki/Antimatter https://en.wikipedia.org/wiki/Antimatter Dark matter: https://en.wikipedia.org/wiki/Dark_matter https://en.wikipedia.org/wiki/Dark_matter Antimass: I and the Internet have never heard of antimass. Negative mass: https://en.wikipedia.org/wiki/Negative_mass https://en.wikipedia.org/wiki/Negative_mass Dark energy: https://en.wikipedia.org/wiki/Dark_energy https://en.wikipedia.org/wiki/Dark_energy Dark fluid: https://en.wikipedia.org/wiki/Dark_fluid https://en.wikipedia.org/wiki/Dark_fluid : > Dark fluid goes beyond dark matter and dark energy in that it predicts a continuous range of attractive and repulsive qualities under various matter density cases. Indeed, special cases of various other gravitational theories are reproduced by dark fluid, e.g. inflation, quintessence, k-essence, f(R), Generalized Einstein-Aether f(K), MOND, TeVeS, BSTV, etc. Dark fluid theory also suggests new models, such as a certain f(K+R) model that suggests interesting corrections to MOND that depend on redshift and density
  - nsxwolf 2y ago
    Negative mass was what I was going for with "antimass". For some reason I thought that was a common term but I guess it is not.
    - westurner 2y ago
      Not sure why I confused the terms. FWIU this Superfluid Quantum Gravity rejects dark matter and/or negative mass in favor of supervaucuous supervacuum, but I don't think it attempts to predict other phases and interactions like Dark fluid theory? From "Show HN: Physically accurate black hole simulation using your iPhone camera" https://news.ycombinator.com/item?id=42191692 https://news.ycombinator.com/item?id=42191692 : > Ctrl-F Fedi , Bernoulli, Gross-Pitaevskii: >> "Gravity as a fluid dynamic phenomenon in a superfluid quantum space. Fluid quantum gravity and relativity." (2015) https://hal.science/hal-01248015/ https://hal.science/hal-01248015/ There's a newer paper on it. Alternatives to general relativity > Testing of alternatives to general relativity: https://en.wikipedia.org/wiki/Alternatives_to_general_relativity#Testing_of_alternatives_to_general_relativity https://en.wikipedia.org/wiki/Alternatives_to_general_relati... The new Sagittarius* black hole image with phase might help with discarding models unsupported by evidence. Are those knots or braids or fields around a vortical superfluidic attractor system? There doesn't at all appear to be a hard boundary Schwarzschild radius. But that's about not dark matter not antimatter.

deleted 2y ago

[deleted]

dragonwriter 2y ago

> Does this actually prove that antimatter necessarily exists? Antimatter definitely exists, it is detectable, and used; e.g, PET scans use positrons (anti-electrons), and there have been experiments (only in animal models last I knew) with anti-proton radiotherapy for cancers. This is the first evidence of a particular configuration of antimatter, not the first evidence of antimatter.

benbayard 2y ago
To be more specific this is the first time we have detected hyper-antimatter of Helium where one of the quarks in the nucleus is an anti-strange quark (an anti-lambda from the article)
- westurner 2y ago
  Thank you all for corrections and clarifications. I had confused Antimatter in particle theory (where there is no gravity) and Dark matter, which has no explanation in particle theory and maybe probably shouldn't be necessary for a unified model that describes n-body gravity at astrophysical and particle scales.
  - westurner 2y ago
    > [dark matter] has no explanation in particle theory From https://news.ycombinator.com/item?id=42369294#42371561 https://news.ycombinator.com/item?id=42369294#42371561 : > One theory of dark matter is that it's strange quark antimatter.

gus_massa 2y ago

My guess is that you are confusing "antimatter" and "dark matter". If you want some antimmater, you can go to your nearby physics suply store and buy some radioactive material that produce positrons. It's quite easy. (Radioactive material may be dangerous. Don't fool with that!) If you want antiprotons or antihydrogen, you need a huge particle acelerator. They make plenty of antiprotons in the CERN, to make colisions. They are very difficult to store, so they survive a very short time on Earth. Dark matter is very different. We have some experimental resuls that don't match the current physics theories. The current best guess is that there is some matter that we can't see for some reason. Nobody is sure what it is. Perhaps it's made of very dark big objects or perhaps it's made of tiny particles that don't interact with light. (I'm not sure the current favorite version in the area.) Anyway, some people don't like "dark matter" and prefer to change the theories, but the proposed new theories also don't match the experimental results.

orwin 2y ago
> Anyway, some people don't like "dark matter" and prefer to change the theories It seems a bit more complicated than that, mostly because the vulgarization often available too is quite bad to explain the issue. My understanding: - Our current theories fail to predict/match an array of observations, as if more matter than what we can detect exist. Some scientists called that the "dark matter problem", that's what most physicists working on the subject refer to when they talk about "dark matter". - Every theory you talked about: dark matter big objects, dark matter particles AND the "change the theories" (i guess you talk about the Modified Newtonian dynamics, where you alter Newton's second law at low speed to match some observations) are dark matter theories: theories that tries to explain why the universe act as it is, not matching our current theories, either by adding new things, or by modifying our discovered laws to match our observations. Each of those theories have multiple branch investigated. - the "dark matter particle theory" is sometime vulgarized as "dark matter" on podcasts or in books/articles. This is because more scientists work on particle physics than on gravity or astrophysics (my country present like 3 astrophysics thesis each year, and dozens of particle physics thesis). I think this caused a huge misunderstanding. - Some people with a common understanding (like mine, i meant non-physicists, it's absolutely not derogatory) like MOND because philosophically it is quite nice, and also tend to draw in people with minority/anti-etablishment habitus[0] (cf: most physicists working on those subjects are particle physicists). I'm not saying this theory is worse than the others at all, i'm just saying that the kind of layperson drawn to it can be _really_ sure they're right and profess their beliefs everywhere, and sometime claim that "MOND isn't dark matter", when they really confuse dark matter as a problem to be solved with "dark matter particle theory". Misunderstanding happen to everyone btw, it's really not a big issue. In case you did not talk about MOND but about theories that claim that the issue are with our tools to observe at a distance, some theories include that to explain some of the inconsistencies, never all of them, and those theories seems to really be a minority atm, so hopefull it wasn't about that. [0] Also, those habitus seems to draw in grifters who know they can make quick bucks by selling books/conferences if they look convincing enough, which is why MOND has a weird reputation now, but absolutely serious physicists and mathematicians work on the subject very, very seriously.