Talk:Mirror matter

Mirror light?
The article suggests that there would be "mirror stars" detectable by gravitational lensing. This seems to imply the existence of "mirror light". The problem is, I thought "mirror light" could be obtained at any mirror! For example circularly polarized light changes handedness when reflected in a mirror. Can someone explain? Wnt (talk) 00:09, 17 December 2008 (UTC)


 * The mirror photons would be different particles. It's a bit like the fact that an anti-particle cannot be obtained from an ordinary particle by reflections or rotations. For a detailed discussion of the mirror photon, see here. Count Iblis (talk) 01:11, 17 December 2008 (UTC)


 * Thanks for this intriguing reference... the next ten years of hard sci-fi must be coiled into its few pages. The article doesn't directly address my argument, but I suppose I was thinking in a very antiquated way; photons don't really bounce from hypothetical conductive planes, but from delocalized conduction band electrons that still have their hypothetical chirality.


 * Correct me if I'm wrong: I interpret this article to be saying that the effect of a positive kinetic mixing coefficient between normal and mirror photons is that a small number (1/4ε2) of mirror photons will be observed like ordinary photons... if they don't refract weirdly first.  I assume that these are observed at the same frequency as they were emitted, no chopping photons in half allowed.  So for example if you leave a small lump of ordinary matter at the center of a mirror matter star, it should be bombarded with X-rays more than anything else, because those are the majority of the photons at the core of a star.  And there wouldn't be any way to shield against these X-rays because they're only a tiny fraction of all the mirror X-rays permeating the object.


 * The statement they make about refraction of sterile mirror light produced by reemission of mirror light by normal matter, with a very long focal length, is intriguing. This means that in theory, you could take an ordinary glass lens into space, and you'd get one conventional focus in the right place, and another far, far away from it for the sterile mirror light?  Is it viable to look around for mirror matter mixtures in such a simple way?

Merger proposal
I suggest that the article on mirror photons be merged with this article on mirror matter. Mirror matter and mirror photons are both consitutents of mirror symmetry models. These models, although have attracted some attention from the public, are only advocated by a handful of particle physicists. Unlike, e.g., supersymmetry, they are not studied by the majority of mainstream particle physicists. In my opinion, one WP article devoted to the subject of mirror models is quite sufficient. There is no need for one article per particle of the theory. Puffino (talk) 22:28, 8 February 2009 (UTC)
 * I agree, but before we can merge, the text about mirror photons should be corrected. Count Iblis (talk) 12:26, 9 February 2009 (UTC)


 * I'd like to get this merge proposal resolved soon, it's been on the backlog for over 3 years. I will ask for input on this proposal on WT:PHYSICS. Physics is not my area, but I am willing to assist in the merge if my help is needed. Quasi  human  &#124;  Talk  12:31, 16 March 2012 (UTC)
 * Support - This theory is barely notable, it really doesn't need two separate articles. And otherwise we could end up with an article on each eight type mirror gluon, another for mirror tau neutrinos, etc.  Waleswatcher  ( talk ) 15:16, 16 March 2012 (UTC)

self-mirror
So are any particles considered its own mirror? IIRC, some particles are also their own anti-particles, and others are their own supersymmetric partner... 65.94.252.195 (talk) 07:07, 7 November 2009 (UTC)


 * Yes, it is expected that at the Grand unified scale (GUT scale) there should be very heavy particles with both ordinary and mirror charges. This was in fact the argument by Glashow that mirror matter is already ruled out, but there are some loopholes here. The argument is that because such particles will show up in Feynman diagrams in internal loops, it would also affect the low energy physics in which these heavy particles only appear in internal loops. These are called "radiative corrections", and the effect of this would be to give ordinary electric charges a very small mirror electric charge and vice versa. Or put differently, the ordinary photon als couples very weakly to mirror charges and vice versa.


 * This then leads to the invisible decay of positronium, because yo can draw a Feynman diagram in which the electron and positron annihilate (virtually) into a mirror photon, instead of an ordinary photon, and out comes mirror-positronium which then can annihilate later into two or three mnirror photons. There are strong experimental limts in the invisible decay of ortho-postronium, which is positronium with a total spin 1. This can only decay in 3 photons (you need at least 2 to conserve momentum, but with 2 photons you cannot get a total angular momentum of 1, you need at 3 photons for that). The dacay rate is a lot slower than that of para-positronium (which has total angular momentum of 0) which makes it possible to do sensisitive measurements.


 * Glashow showed that the strength of the coupling of photons to mirror elecrons would have to exeed the experimental limit extracted from orthopositronium decay experiments, despiyte the fact that we don't know a lot about what happens at GUT scale level. This is because the the predicted coupling depends on the logarithm of the mass of the hypothetical particle which would have both charges.


 * Other physicists have shown later that due to certain symmetries the dominant contribution that Glashow considered can be exactly zero, and the leading contribution to the coupling would only arise due to Feynman diagrams with 3 or 4 loops. Then coupling of photons to mirror electrons would be much smaller and mirror matter is then not ruled out. Count Iblis (talk) 14:49, 7 November 2009 (UTC)

popculture refs
FWIW, mirror matter has appeared in popular culture.

There's some theory that the Tunguska event was caused by a collision with a mirror matter meteor.

65.94.252.195 (talk) 06:31, 10 November 2009 (UTC)


 * John G. Cramer's 1989 novel Twistor also references mirror matter - postulating the existence of (at least one) parallel Earth made of shadow matter - along with shadow-trees, shadow-kittens, and very large shadow-bears. Jimw338 (talk) 19:19, 17 February 2015 (UTC)

History of the term
Needs to note when it was coined and who by - David Gerard (talk) 21:14, 19 June 2012 (UTC)

Reference for term 'Alice matter'?
Does anyone know if there is a reference for the term 'Alice matter'? I assume the term is alluding to "Alice in Wonderland", but wonder where the term came from. I don't have an NOR or RS issue with it. But wonder if there is some story about who first came up with the term, how it was received, etc. - even though such a story might only be "referenced" on some string-theorist's web page at some university. Rather like the term 'boojum' in superflidity physics (for a singularity that, like the boojum of Carroll's Hunting of the Snark, causes a supercurrent to ""softly and suddenly vanish away").

PS. I've seen discussions about such terminology (can't think of specific examples right now, sorry) like this in other places, and find them rather silly for something that is 'obviously' a joke. (at least for native English speakers familiar with 'Alice in Wonderland') Jimw338 (talk) 19:14, 17 February 2015 (UTC)


 * Another guess as to Alice terminology would be to the Alice of Alice and Bob fame, although I imagine Wonderland is a better guess.

SME?
Would it be fair to identify this model as a Standard-Model Extension?

Removing text
I'm removing the text below from the article, under the heading Alternate terminology. This is because this text is not really relevant to the article's topic. It has more relevance to the antimatter article, or possibly on a disambiguation page, but I don't feel strongly enough about its merits to add it to either of those. In this article, it is just a distraction, as there is already a hatnote to redirect a user that may be mistaken about the terminology. My feeling is that if further clarification is required, it should be done at the disambiguation level, and should simply include appropriate disambiguation context, such as the author or book mentioned below. 70.247.165.221 (talk) 19:43, 10 September 2016 (UTC)

The phrase "mirror matter" was also introduced by physicist and author Dr. Robert L. Forward as an alternative term for what is commonly called antimatter, in an attempt to emphasize that antimatter is identical to ordinary matter, except reversed in all possible ways (i.e., CPT). (Forward was apparently not aware of the use of the word "mirror particles" by Russian physicists to mean parity reversed matter that does not interact strongly with "ordinary" matter). This is elucidated in his book Mirror Matter: Pioneering Antimatter Physics (1988), and his editing the small review journal Mirror Matter Newsletter (1986–1990). However, this use of the term "mirror matter" for antimatter was never widely picked up by others and is not currently in common use.

Any Update?
Have there been any updates to this theory or its relation to physics experiments since 2006? Or have physicists abandoned it/ruled it out? 2601:441:4102:9010:B5D3:FD7:2650:2FA1 (talk) 22:07, 10 March 2017 (UTC)
 * From searching Google Scholar I have found articles discussing this subject from 2007 to 2017. The references section here stops at 2006. I don't know whether this article needs updating with new information. But from looking at the titles and abstracts of those recent papers, I see several recent experimental results have been taken as evidence for mirror matter, and an upcoming XENON experiment is said in one paper to be capable of proving or ruling out mirror matter. I think this page should be updated. 2601:441:4102:9010:9018:4977:B2A5:F64A (talk) 14:59, 15 March 2017 (UTC)

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Repeating question about how current this is
As others have mentioned on the talk page, this article seems to be in serious need of update. For example: "An experiment to measure this effect is currently being planned.[19]" that reference is 16 years old--is it really "current" any more? I do not have the physics background myself to perform the update. I am adding an Update template to the article in hopes of flagging down a qualified person. IAmNitpicking (talk) 12:09, 26 September 2020 (UTC)
 * I see I was anticipated. IAmNitpicking (talk) 12:10, 26 September 2020 (UTC)

Radiative Correction?
The article uses the phrase "radiative corrections" and links to Effective field theory ... which never uses that phrase. Well, I'm not helped at all by that link, and I probably know more physics than the average person. Like many physics articles on Wikipedia, this one seems to be written for specialists, not the general public. (I did part of a physics major without, as far as I can remember, ever hearing either phrase.) IAmNitpicking (talk) 12:56, 20 September 2022 (UTC)


 * "Radiative corrections" is a synonym for one-loop diagrams. I'll change the wikilink. 67.198.37.16 (talk) 15:43, 4 June 2024 (UTC)