Diproton stability vs Dineutron stability edit

Since the dineutron is unstable even in the absence of electromagnetic repulsion, wouldn't the diproton also be unstable no matter how strong the strong force was? Lchiarav 05:23, 27 November 2005 (UTC)Reply

The question is whether the dineutron or diproton would have more binding energy than anti-binding energy. For example, if you stick a proton onto another proton, it would be unstable, because the electromagnetic repulsion would be stronger than the strong attraction. But if you stick a neutron onto a proton, there is no electromagnetic repulsion, and so the strong force can hold them together. EGGS 17:23, 15 January 2006 (UTC)Reply
In the course of my wandering through various physics-related newsgroups searching on this topic, I came across the suggestion that dineutrons are unstable because the degeneracy pressure of neutrons is strong enough to push them apart. Seems reasonable to me considering how strong neutron degeneracy pressure is, though you'd want to ask a real physicist before settling a bet about it. :) Deuterons (a proton and a neutron together) might be more stable because they lack both degeneracy pressure and electrostatic repulsion. Bryan 01:26, 16 January 2006 (UTC)Reply
The lack of a bound state of two protons is due to the spin-spin part of the strong force. The strong force is stronger when the spins of the nucleons are aligned, which can occur for a neutron and a proton in the lowest single particle energy states. For the dineutron and the diproton, aligned spins in the single particle ground states are prevented because of the pauli exclusion principle. This is enough to make the " binding energy" positive and prevent the existence of bound states for these nuclei. On these scales the electromagnetic interaction has a vanishing effect. In some sense, this is due to degeneracy effects. It only becomes important in much more massive nuclei. I have changed the page to reflect this. Luke 134.107.21.200 (talk) 19:44, 19 June 2008 (UTC)Reply

Anti-propaganda edit edit

I have edited this article to try and make it more NPOV. As a quick Google search reveals, the "diproton catastrophe" is mentioned only as a creationist argument and on Wikipedia mirrors- in fact, the external link is to a creationist website. This isn't a problem- what bothers me is that the "diproton catastrophe" is stated as a fact and not a claim, with no source and no alternative arguments. On that note, if the strong force were stronger and the diproton were stable, stars wouldn't simply "burn by the strong force". The entire Periodic Table would be revised, the structure of matter would be different, and nuclear fusion might use Helium-7, or Hydrogen-4, or neutrons, or triprotons, or might just not happen at all. It would take a good deal of research and nuclear physics expertise to figure out just what would happen, and from the sound of the external link, no one has actually bothered to figure it out. EGGS 01:25, 15 January 2006 (UTC)Reply

I am hardly one to be using Wikipedia as a creationist soapbox. :) The external link is not a primary source but fortunately it does list its own sources; the disputed claim apparently comes from Davies, "The Anthropic Principle," p. 8, and I.L. Rozental, Elementary Particles and the Structure of the Universe (Moscow: 1984, in Russian), p. 85. Do you have evidence suggesting that Davies and Rozental in particular are creationists? It's common for creationists to use real science out of context to support their arguments. I remember creating this article because I'd come across discussion of the diproton catastrophe in a science fiction newsgroup which was quite thoroughly non-creationist-oriented. Bryan 04:42, 15 January 2006 (UTC)Reply
Is it some sort of tradition in creationist or scientific writings to list sources that are almost impossible to track down? The second source is listed at link, but there is no actual text, and it's written in Russian anyway. The first source is even worse: "The Anthropic Principle" is a general term in use everywhere, and there are over two dozen people on Wikipedia alone named "Davies" (Davies). As to the authors, Rozental isn't listed anywhere except as an author of papers, and I suspect "Davies" may be Paul Davies, who, although not a strict creationist, purports the "diproton catastrophe" argument himself. So, to be honest, I have no idea whether these claims are reliable. EGGS 17:19, 15 January 2006 (UTC)Reply
I'm just about to leave the house right now so I don't have time, but when I get back this evening I'll try to dig up the Usenet postings that sparked my writing of the article in the first place. I suppose in hindsight Usenet would have been a more reliable source to cite than a creationist site, but at the time I doubt I realized it was a creationst site - it's just the first one to come up in Google that used plain language to discuss the matter. Hopefully that'll at least establish it's not something creationists made up whole-cloth. Bryan 18:08, 15 January 2006 (UTC)Reply
Well, this is annoying - I can't find any Usenet postings in Google Groups that even vaguely resemble my memory of the discussion (it was on one of the rec.arts.sf heirarchy on the topic of alternate universes). But I'm quite sure I didn't use that external link as my only source since "diproton catastrophe" doesn't appear there and I know I wouldn't just dream up a phrase like that out of thin air. I did notice diprotons brought up in both serious particle physics newsgroups and occasionally in talk.origins or alt.atheism as part of creationism arguments, though, so I'm willing to compromise. I'll edit the article again, let me know what you think of it. Bryan 01:14, 16 January 2006 (UTC)Reply
Oh, I think you've got the author of that reference right. Earlier on in the references section is a reference to "P.C.W. Davies' "The Anthropic Principle," in Particle and Nuclear Physics 10 (1983)" - the later references to the same work are just trimmed a bit. Paul Davies' middle names are Charles Williams, so this matches. Bryan 01:14, 16 January 2006 (UTC)Reply
What would happen assuming the diproton were stable is a valid and interesting question, and I have a pet theory- there was a paper or two on the diproton or the effects of the strong force, with stars burning quicker listed as a consequence. Someone stumbled across the paper, thought of another example of the "fine-tuning" argument, and then looked up the relative strengths of the strong and weak forces or a similar figure, for numerical effect. In reality, the diproton probably couldn't fuse with itself to form tetraprotons, which would be unstable even in a diproton universe. Any neutrons would be mopped up in helium-3, which would be far more stable and less prone to fusion, or conventional helium-4. Tritium would probably decay quicker and with more power, and deuterium might not be stable. Diproton fusion into helium-4, lithium-4, helium-3 and a proton, and such could proceed much as regular fusion does. Elements with high masses would be more stable, and low neutron numbers would be favored relative to now, because of the neutron's higher mass. All of which is irrelevant anyway, because any fusion reaction as fast as the link claims would have gone to completion during the first few minutes of the universe, leaving the products to form stars. EGGS 21:45, 17 January 2006 (UTC)Reply
And the creationists of that universe would be talking about the "monoproton catastrophe", where if the strong nuclear force were 2% weaker, monoprotons could never have fused to form diproton, the basis of all fusion reactions. ;-) Nik42 20:40, 5 May 2007 (UTC)Reply

The article explains,

diprotons are not stable under the existing laws of physics…

The phrase in italics evokes various 'funny' responses, but is in fact meaningless. I removed it.
Herbee 21:25, 6 July 2006 (UTC)Reply

Diproton catastrophe edit

I think the term "diproton catastrophe" needs some work, for two reasons -

• Is this a catastrophe in the sense that it is something that has happened (or could happen)?

• Is this a catastrophe in the sense that the result would be "bad" (either bad for us and/or bad for whomever ends up populating that universe)?

The term seems to me to be misleading - surely "diproton-capable alternative universe" is more accurate? Chrisobyrne 17:39, 1 November 2006 (UTC)Reply

I'm also having difficulty understanding the creationist argument here. The suggestion seems to be that humanity cannot live in a diproton universe, and hence God created the universe in such a way that diprotons cannot exist. So what is the catastrophe? Did God leave the door open for humanity to change the physical constants so that diprotons could exist? If so, then he is a very silly God, for not only did He leave the door open, He also left only a 2% gap that humanity has to cross!

I think we should do creationists a favour and get rid of the "diproton catastrophe" bit - unless someone is able to explain what is actually going on here. Chrisobyrne 10:32, 2 November 2006 (UTC)Reply

As I recall back when I was reading up on this stuff, the "catastrophe" refers to the situation where diprotons are able to form, since they would then do so with wild abandon. It results in the extremely rapid fusion of all hydrogen in the universe so that stars burn out in only a matter of years and chemical life as we know it would be impossible, which is pretty catastrophic. I recall not being able to find a whole lot of examples of that particular word being used for this situation (though since any discussion of diprotons at all was hard to find that may not be so bad proportionately speaking), but if you feel you must remove the phrase for some reason there should still be mention of how drastically such a difference in physical law would affect the universe. I don't see how it would do anyone any "favors" to remove it, it's not like this article is brimming over with massive amounts of information and needs trimming. Bryan 16:55, 2 November 2006 (UTC)Reply
I agree with you that the article isn't brimming over with massive amounts of information - that isn't my motivation for wanting to change it. My motivation is one of accuracy - I'm still left with the sense that the phrase "diproton catastrophe" is inaccurate, and I fear it is a phrase invented by someone with an agenda. I don't suppose you have a source for your very interesting story about the "catastrophe"? Is it a truly possible scenario, or is it just speculation? And, are there dissenting opinions on what would happen in such a situation? I think it is entirely possible to include that information (if it is accurate) without being alarmist (unless we should be!). Chrisobyrne 13:37, 3 November 2006 (UTC)Reply

Structure of matter edit

Now my curiosity is piqued. So if this physical constant were slightly different, all protons would bind together, and the fundamental nuclear charge would be a diproton. Would they then be like quarks are to us? Is it safe to say that, no matter how strong the strong force is, repulsion of like charges will result in some set of stable building blocks?

Are we fortunate that protons are so well held together? If stable nuclei were made with diprotons, but protons could be freed readily, then it would seem there would be a richer set of nuclear reactions. But it's hard to say if that would benefit or hinder life.

I guess this is where group theory gives hints about how many possibilities there "really" are. Still no hint as to whether there's a "smallest wave" though. 74.134.236.69 09:01, 13 November 2006 (UTC)Reply

The answer to all your questions is quite possibly "no-one knows". As far as I can see, all of this is speculation (which makes me a bit uneasy about having it in Wikipedia - however, the fact that it is speculation seems to be fairly well covered by the language of the article). Somehow, I think the people with the skills and knowledge to answer those questions probably consider that there are more productive questions for them to answer than "how different would the universe be if the fundamental physical constants were different"! They are probably far more concerned with the effects of the physical constants that we are actually subject to... Chrisobyrne 14:07, 13 November 2006 (UTC)Reply
True that. It does seem a reasonable question whether we can extrapolate a continuum of alternative periodic tables based on the particles we do know (and making assumptions they don't change... meh). Next time I run into a physicist here I'll ask. (They love that.) It would be an interesting tidbit to put in this article.74.134.236.69 22:35, 13 November 2006 (UTC)Reply

Diproton Disaster, Diproton Catastrophe edit

I think both these pages should exist and should link here. They are important concetps in cosmology. The fact that they did not, and could not occur under current physical laws is not sufficient reason to delete them. It is a well-known fact that the current laws of physics did not apply during the very early part of the big bang.

64.142.13.174 20:25, 10 August 2007 (UTC)Steve P.Reply

Dineutron : A New Form of Artificial Radioactivity edit

Article in progress

Source: http://www.aip.org/pnu/2008/split/865-2.html

Figure: http://www.aip.org/png/2008/302.htm —Preceding unsigned comment added by 76.69.155.191 (talk) 22:51, 7 August 2008 (UTC)Reply

Note, article refers to He-2 not dineutrons. Potatoswatter (talk) 17:22, 8 August 2008 (UTC)Reply
But 76.69.155.191:s links point to articles about He-2/diprotons, not dineutrons! Those links are relevant here! ... said: Rursus (mbork³) 12:40, 27 October 2009 (UTC)Reply
Found some other that also supported the unsourced section. Guys! WP:BEBOLD! ... said: Rursus (mbork³) 12:37, 27 October 2009 (UTC)Reply

Citations added edit

The AIP link marked Source above describes the Italian research mentioned in the article, so I have now added it as a reference. The AIP link marked Figure is mentioned in the one marked Source so I have not included it separately.

I also used the information in the AIP link to find the original Physical Review Letter which I have added as a second reference. It is much harder to read than the first popularized reference, so the first reference is still necessary.

Finally the Japanese and Russian research is still unsourced so I have added a citation needed tag. Dirac66 (talk) 14:48, 3 January 2012 (UTC)Reply