Talk:Antimatter

"common matter" instead of "ordinary matter"?

The article uses the term "ordinary matter" but this term is confusing because it is often used to refer to atomic matter. Isn't the term "common matter" a less-ambiguous term for matter that is not antimatter? DavRosen (talk) 22:43, 30 May 2018 (UTC) antiantimatter Sci09272 (talk) 19:44, 7 December 2021 (UTC)

Intriguing possibility re. antimatter lack of abundance

Hi, as its essentially been discounted that antimatter behaves much differently than matter in a gravitational field many of the assumptions on which the "antimatter moving back in time" hypothesis originally proposed by Feynman can be modified to include a simpler mechanism.

Its possible that at some level another mechanism may prevent "anti-stars" being stable therefore explaining the lack of antimatter clusters in the visible Universe, one such mechanism may well be that the weak nuclear force is different for antimatter. The side effect of this would be that elements that are not currently stable would be if they contained only anti-particles and this could be detected by measuring spectra from non-stellar regions of the Universe thus proving this hypothesis.

This can actually be tested: experiments have generated anti-helium and it behaves in a very similar way to normal helium. I wondered a little while back if antimatter could be the "spark" that initiated the first stars and could account for some anomalies in CMB. Also recent experiments show a distinct difference in the predicted versus actual behavior of positronium "atoms" suggesting that the Standard Model may require some adjustment.

References

Reverse Matter?

Would reverse matter not more fit as definition for this atomic systems? 2A02:AA11:9102:3D80:94D9:4928:F250:4A62 (talk) 17:31, 4 April 2022 (UTC)

Two Problems with the article

1} Conceptual history section, para 2: "differed from the modern concept of antimatter in that it possessed negative gravity." Umm, while they have been working on it since 2016, the ALPHA-g experiment only ran preliminary tests in 2018 before CERN was shut down for its upgrade, and only now (2022) has beam come back on. They are still a long way from publishing their results. Until that time, we will not have demonstrated that antimatter actually falls down in gravity (however extremely likely that would be).

2) Section Artificial production, subsection Antihydrogen atoms, para. 1: "it had successfully brought into existence nine hot antihydrogen atoms by implementing the SLAC/Fermilab concept". What "SLAC/Fermilab concept"? There is no mention of this in the main antihydrogen wiki article linked from the subsection title, either, though it seems likely this is a reference to the text there "using a method first proposed by Charles Munger Jr, Stanley Brodsky and Ivan Schmidt Andrade." This all needs some clarification. 2001:56A:F0E9:9B00:2511:25BE:32B9:C4C2 (talk) 02:19, 22 November 2022 (UTC)JustSomeWikiReader

Odd sentence that appears out of place

In the first paragraph it says: "Antimatter —- it’s a visionary substance that you will see in your human computer vision like a hologram when you are contacted by God." I don't think that's what antimatter is. 195.59.7.254 (talk) 10:57, 5 December 2022 (UTC)

It isn't. Somebody had just added that sentence, I removed it. Tercer (talk) 11:22, 5 December 2022 (UTC)

Irrelevant citation [20]

The last paragraph of the Antimatter#Conceptual_history section claims that the Feynman-Stueckelberg interpretation says that antiparticles behave like normal particles traveling backward in time. I believe this is correct, but the source [20] isn't relevant to this claim. To give you an idea, it has none of the words "feynman", "stueckelberg", or "backward". It's about relative amounts of matter and antimatter in the universe, which is different topic. (There is one mention of "time reversal" in the introduction, referring to a different phenomenon, which may be the source of the confusion, or maybe someone just accidentally cited the wrong source). 2002:62B9:EB03:1:DA22:6020:6328:5E1F (talk) 23:43, 22 June 2024 (UTC)

"Anti universe" listed at Redirects for discussion

The redirect Anti universe has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2024 August 11 § Anti universe until a consensus is reached. Web-julio (talk) 02:51, 11 August 2024 (UTC)

Production by Energy photons only

As Photons usually are lesser described as Particle tho they indeed behave as Particles, it is helpful for Doomsday machine builders in Low tech Country as Revenge upon Abrahamitic Thrallerkind, to mention that High Energy is sufficient like any strong radar produces ionizing antimatter to conclude from the existence of sub iron isotopes. As Convex Funnelreflectors with turbochargers allow eternal heat recuperation coaxium synthesis in Fullerens is quite easy but the refinatiom process from raw coaxium to stable, easy at it is, may not be mention, prank, just guration like in NitroG. to inhibit photon flash desintegration cascades. Happy doomsday genocidies of Mose inbred offspring.

Hades. All or Nothing they chosed last for you all pityful ones. 2003:E7:AF09:EEBB:9907:8294:205E:54DB (talk) 07:26, 8 June 2025 (UTC)

Charles Janet

The source

• Stewart, P. J. (2010). "Charles Janet: Unrecognized genius of the periodic system". Foundations of Chemistry. 12 (1): 5–15. doi:10.1007/s10698-008-9062-5. S2CID 171000209.

focuses primarily on Janet's numerous reworking of the periodic table. At one point the source says:

• He makes the astounding suggestion that this might be the bridge between the periodic system we know and a periodic system above it with negative atomic numbers, ‘but for the moment we shall not dwell on this possibility, which would disturb the perfect arithmetic and consequently chemical regularity’ of the system (Janet 1930, pp. 28–29). In fact, as we now know, there would be an ‘element minus-zero’, with anti-neutrons as ‘atoms’, so there would be two periods of one element linking the matter and antimatter systems, maintaining the symmetry of pairs of periods. Anyway, working in parallel with Dirac, Weyl and Oppenheimer, Janet invented anti-matter.

Our summary is

• A complete periodic table of antimatter was envisaged by Charles Janet in 1929.

The source is strongly motivated to make the most of Janet's suggestions. Janet suggested a negative atomic numbers on, as far as we can tell from the source, no evidence at all. I don't believe this suggestion is notable in the article. Johnjbarton (talk) 01:19, 14 November 2025 (UTC)

"Antiplanet" listed at Redirects for discussion

The redirect Antiplanet has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2026 February 5 § antibodies until a consensus is reached. consarn _{(talck) (contirbuton s)} 20:25, 5 February 2026 (UTC)