Talk:Antimatter

Uses - hypothetical weapons

I feel the hypothetical possibility of weapons should be included. This is my suggested wording, others can probably improve it:

Less positively, antimatter has been considered as a trigger mechanism for nuclear weapons. A major obstacle is the difficulty of producing antimatter in large enough quantities. However, the U.S. Air Force funded studies of the physics of antimatter in the Cold War, and began considering its possible use in weapons, not just as a trigger, but as the explosive itself. Switchcraft (talk) 10:33, 26 February 2013 (UTC)

That wording would way overstate the plausibility of the idea. Currently, making a single atom of antimatter (as opposed to isolated particles) is a major achievement. Putting together enough to make a weapon is nowhere on the horizon, and even then you would have the problem of safely confining it. Looie496 (talk) 16:34, 26 February 2013 (UTC)

I included it but with "there is no evidence that it will ever be feasible" (I hope). Switchcraft (talk) 10:34, 9 March 2013 (UTC)

References

Standard model

I think the words standard model need to be in here someplace. Student7 (talk) 22:57, 28 March 2013 (UTC)

Gravity Experiments at Cern

Are current experiments with antihydrogen at Cern to determine the effect of gravity on antimatter worth a mention here? News outlets are reporting on "antigravity" experiments on the off-chance antimatter responds negatively to the Earth's pull, which is rather silly, but even a modest gravity asymmetry could be a potential part of a solution to the baryogenesis problem (hard to rule out since we really have no idea why non-anti particles have the random-ass gravity charges they do). TricksterWolf (talk) 19:09, 30 April 2013 (UTC)

Something sourced (preferably from a scientific source) could certainly go in. SpinningSpark 20:15, 30 April 2013 (UTC)

The problem, if the BBC story I read can be relied on, is that the results thus far are so weak that they hardly say anything at all. If the experiment yielded any meaningful information it would be worth discussing, but so far there doesn't seem to be any. Looie496 (talk) 22:51, 30 April 2013 (UTC)

The fact that they are looking is the thing worthy of note here. After all, we have a wide selection of articles on grand unified theories, string theories and supersymmetry without any experimental evidence at all that any of these things even exist. SpinningSpark 23:53, 30 April 2013 (UTC)

To say nothing of Dark matter and dark energy which they are "pretty sure" exist, but have no basis in exact particle analysis just yet. Anyway, they are spending billions of euros on the project. That alone should count for something!  :) Student7 (talk) 17:54, 5 May 2013 (UTC)

Terrible and misleading

This article goes out of its way to talk about the properties of (atomic) antimatter as if more than a couple of atoms have been observed, ever. This is wrong headed and misleading. 99.999% of the references in the Scientific literature to antimatter are to the elementary particles. Only in the popular press and especially science fiction is antimatter meant to be atomic antimatter. This has not been made clear here, instead the article goes out of its way to confuse the two types of antimatter. This is pragmatically harmless, since atomic antimatter is almost a null set, but confuses the difference between the two at a higher level of abstraction. I recommend a rewrite to depreciate atomic antimatter, and to clearly differentiate between the antimatter we use everyday (positrons, for example) and the antimatter that just a couple of atoms have been confirmed ever to have existed, and those only for a fraction of a second.173.189.75.67 (talk) 22:00, 7 May 2013 (UTC)

If you can see specifically how to improve the article in this respect, I encourage you to take a shot at it. Regards, Looie496 (talk) 22:42, 7 May 2013 (UTC)

Alkahest?

The article does speak of the difficulty of containing anti-matter. I think this difficulty should be "repeated" or reworded for the subsection which contains "fuel" and "weapons." There is an uncomfortable alchemy feel for suggesting that a container might be readily available for what is, essentially, an alkahest, once (or if) the production of anti-matter becomes possible. Student7 (talk) 20:15, 19 July 2013 (UTC)

Add a Footnote

In the section Origin where it reads as follows:

Almost all matter observable from the Earth seems to be made of matter rather than antimatter. If antimatter-dominated regions of space existed, the gamma rays produced in annihilation reactions along the boundary between matter and antimatter regions would be detectable.[9]

It should be changed to read as follows:

Almost all matter observable from the Earth seems to be made of matter rather than antimatter. If antimatter-dominated regions of space existed, the gamma rays produced in annihilation reactions along the boundary between matter and antimatter regions would be detectable.[9] A minority view holds that gamma ray bursts do reflect such annihilation between such boundaries. Footnote

There with this Footnote D.L. Mamas (2011) An explanation for quasars and gamma ray bursts. Physics Essays: December 2011, Vol. 24, No. 4, pp. 475-476. http://physicsessays.org/browse-journal-2/product/199-3-pdf-dean-l-mamas-an-explanation-for-quasars-and-gamma-ray-bursts.html.

— Preceding unsigned comment added by 96.228.244.95 (talk) 02:29, 18 June 2014 (UTC)

Semi-protected edit request on 1 July 2014

Hertzian radiation studies cast serious doubt on the antimatter theory. In the hertzian radiation mechanism, the antiparticle is nothing else than an electron flowing back in the opposite direction to the one it was initially injected from. The radio-electric transduction mechanism is fully consistent with Prof. John Archibald Wheeler's own intuition as aknowledged by Richard Feynman in his Nobel lecture. Moreover, evidence shows that the law of conservation of energy holds true, while leaves no room for keeping on theorizing about the positrone and the antimatter.

194.242.230.21 (talk) 07:17, 1 July 2014 (UTC)

That seems to me to be a) original research, b) not a reliable source, and c) a fringe theory. To say nothing of the serious cleanup needed for grammar, spelling and style issues. SpinningSpark 07:50, 1 July 2014 (UTC)

Agreed  Not done - Arjayay (talk) 08:23, 1 July 2014 (UTC)

Antimatter

We all know E=mc² therefore c=±sq root(E/m). Is the -sq root(E/m) a physical property/value from antimatter?197.245.92.84 (talk) 19:49, 19 September 2014 (UTC)SF Chang 19 Sep 2014

No, it just means that light can travel forwards or backwards along any given path. SpinningSpark 20:17, 19 September 2014 (UTC)

Maybe more understandable and applicable diagrams could be added? It would help people understand the structural composite of antimatter and maybe add in some more on experiements that are being conducted to elborate on this theory (Including how it is being done {i.e. CERN}). — Preceding unsigned comment added by JammyCoDmaster (talk • contribs) 13:51, 5 December 2014 (UTC)

Jun 2015

I have made several edits that I feel are constructive to this page that have been reverted by user:Epigogue. I am a professional scientist in this field and a native English speaker, so I am confident when I say that many of this user's additions make the article less accessible. Can a third party take a look? cannywizard (talk) 12:40, 16 June 2015 (UTC).

The edits made by cannywizard were incorrect in terms of macroeconomics and nuclear physics. This interjection into my original words was undone on that basis.

Cannywizard's reversion to describing the rate of inflation as a change in price makes the article less accessible to people with backgrounds in economics or finance.

A simple explanation of why you are right and presentation of sources backing that up would be far more productive than making comments about the user who has challenged you. By the way, we don't require that editors should "add original clauses" in their contributions. Copyediting others is a perfectly acceptable activity. SpinningSpark 17:35, 16 June 2015 (UTC)

The main issue is that Cannywizard is factually wrong, as dollars cannot have prices in legal or economic terms. Here is the quote about inflation-"Eventually, the Manhattan Project employed more than 130,000 people and cost nearly US$ 2 billion (equivalent to US$ 23 billion in 2007 dollars)." Clearly, it does not reference the price of goods, which is a different measurement in economics. Copyediting is not appropriate when the copyeditor introduces an error by failing to read the reference.Epigogue (talk) 19:55, 16 June 2015 (UTC)

If I have understood cannywizard's issue correctly, he thought that the date (2007) should be stated after you had removed it, rather than disputing the nature of the figures. I agree with that, if the date is not stated the article will eventually go out of date and be inaccurate. I'm pretty sure it says exactly that in the guidelines somewhere but can't be bothered to look it up. However, since your latest edit has retained the date everyone should now be happy, no? SpinningSpark 20:10, 16 June 2015 (UTC)

The current figure should be about 27 billion adjusted for inflation over the past 8 years. It is not an accurate estimate, anyway; Since the demand for raw materials used in the Manhattan Project has risen faster than the rate of inflation. I would have been happy from the start if cannywizard had simply added the date, because the word 'prices' implicates a much more inaccurate estimate- the metals used in the project are pricier by a factor of 40. It would cost about 100 billion to re-do the Manhattan Project.Epigogue (talk) 00:58, 17 June 2015 (UTC)

If Epigogue trying to extrapolate the costs to present day, then we're entering the realm of original research. It's factual to stick with the dollar value in 2007 prices as in the article. cannywizard (talk) 08:57, 17 June 2015 (UTC)

It is not factual to do so because the article is estimating by gross inflation, not budgetary costs; so the estimate is not in terms of any 'prices'Epigogue (talk) 10:29, 17 June 2015 (UTC)

Spinningspark has interpreted my issue with this edit, correctly, but I also have issues with other edits of mine that have been reverted - https://en.wikipedia.org/w/index.php?title=Antimatter&oldid=666030550 and https://en.wikipedia.org/w/index.php?title=Antimatter&oldid=667161869. Both add over-technical, near-impenetrable language to the article. Neither "ionically unstable" nor "cyclic processes" nor a long description of neutron star processes helps the article in any way. I'm a professional particle physicist, and I don't understand what it means. To the averaged wikipedia reader it's not going to add anything. cannywizard (talk) 08:57, 17 June 2015 (UTC)

I do not know if Cannywizard can fathom physical chemistry, but there is a spectrum of readers between that user and the average; and at least some of them get it. As a scientist, if one does not understand something, then one should always ask a question. If anyone disagrees with me on the basis of fact, then I welcome the argument.Epigogue (talk) 10:29, 17 June 2015 (UTC)

The majority of readers of this article are not scientists (and I would be horrified if nuclear scientists were coming here to get their information). Encyclopaedia articles should be written primarily with the general reader in mind. It's fine to use technical terms in an article, but readers should be given some hope of understanding what the terms mean. Wikilinking, in-article explanantion, or footnote glossing are all acceptable means of achieving this. SpinningSpark 19:02, 17 June 2015 (UTC)

Feynman interpretation and Canetti

I still have doubts about the New Journal of Physics, but a minority view on the gravitational properties of antimatter should be noted as such. According to my understanding, and our article on the gravitational properties of antimatter, the predominant view is that the inertial mass is equal to the gravitational mass, and is positive. The last paragraph (which I'll copy when I get home) seems to have the opposite POV. (If it's "open access", there should be a URL for the article.) — Arthur Rubin (talk) 23:36, 1 July 2015 (UTC)

Not quite sure what you're talking about with the minority view of the gravitational properties of matter. The FS interpretation certainly says no such thing, and from a cursory glance at http://iopscience.iop.org/1367-2630/14/9/095012/pdf/1367-2630_14_9_095012.pdf, I can't find anything in there (on in our article) which supports that inertial != gravitational, or that mass is negative. Headbomb {talk / contribs / physics / books} 01:53, 2 July 2015 (UTC)

No, but what you DO find in there is a primary source masquerading as a review. The review part is okay, but not the rest. The authors do not go on to say that in their new theory "antimatter falls apart" which is the statement the cite references. That whole sentence should go. Canetti et al. admit that what they are floating in this paper, at the end, is a new "testable hypothesis" beyond the standard model, which has something to do with baryogenesis by means of Big Bang oscillations of a hypothesized sterile neutrino which has not been detected, but which the authors are going to use, to explain dark matter, too! All Nobel Prize stuff if it works. Meanwhile, it is just some beyond-Standard Model hypothesizing, like a thousand string theory papers. By definition it has not yet been tested and is not standard or accepted. Such things have no place explaining anything so basic as antimatter, in Wikipedia. Feynman and Stuckelberg are fine. The rest is not. SBHarris 03:05, 2 July 2015 (UTC)

I'll agree on that point. Headbomb {talk / contribs / physics / books} 05:32, 2 July 2015 (UTC)

That's what I meant by my comment. The source is provides a (as they put it) "testable hypothesis" which might lead to a new theory. Even if "antimatter falls apart" was a consequence of their their theory, it shouldn't be in the "history" section, but in a separate "speculations" section. It is noted in the Gravitational interaction of antimatter article that some speculate that antimatter would have antigravity; if it repelled itself, then it would "fall apart" on large scales. — Arthur Rubin (talk) 00:55, 3 July 2015 (UTC)

Question about the webm nasa video

The video states that when an electron can create gamma ray when it hits an atom and in return when that gamma ray hits an atom it creates another electron and a positron. Is this energy conversion from speed/force of impact? 2601:280:C301:215D:0:0:0:32BF (talk) 19:01, 31 October 2015 (UTC)

New Measurement of Antihydrogen Electric Charge

Phys.org report on M. Ahmadi et al. An improved limit on the charge of antihydrogen from stochastic acceleration, Nature (2016). DOI: 10.1038/nature16491, which reports on the most precise measurement yet of the electric charge of antihydrogen. — Preceding unsigned comment added by Ecwiebe (talk • contribs) 23:02, 20 January 2016 (UTC)

References

I found this surprising paragraph in the article: "In 2016 a new antiproton decelerator and cooler called ELENA (E Low ENergy Antiproton decelerator) was built. It takes the antiprotons from the antiproton decelerator and cools them to 90 KeV which is "cold" enough to study. More than a hundred antiprotons can be captured per second, a huge improvement, but it would still take several thousand years to make a gram of antimatter." I refer to the final sentence, in particular.

If you replaced "years" with "lifetimes of the universe", the statement would be more accurate. For comparison: at one million (10^6) particles per second, it would take about the lifetime of the universe (over 10^10 years, one year is 3*10^7 seconds) to produce an Avogadro's number (6*10^23) of particles -- a gram of antiprotons.

I should probably fix this myself. However, I'm still uncertain enough (not about the facts, but about proper editing) to ask someone else to change this. --Johnm307 (talk) 01:41, 2 October 2016 (UTC)

You see one reason I didn't change it myself. I meant to create a new section, rather than tack it on the end of this section. --Johnm307 (talk) 01:48, 2 October 2016 (UTC)