Page contents not supported in other languages.
From Wikipedia, the free encyclopedia


Don't delete, fictional is useful[edit]

From the content of articles on Neutronium (with many SF references), Neutrium (Nt) a similar but specifically scientific hypothisis, and TetraNeutrons,

  • Disagree. There is nothing scientific about Neutrium. As pointed out below, there isn't even a proposal for what force holds the neutrons together. It's wishful thinking through and through, and wishful thinking is anti-science.JohnAspinall 01:16, 23 September 2007 (UTC)Reply[reply] is clear these serve different communities of interest. Folks following up on Star Treck, Larry Niven's work, etc will find this page useful. Those curious about the concept of neutron-isotopes (polyneutrons, tetraneutrons, etc) as possible (but unconfirmed) particles, the other pages are useful.

  • Disagree again. You can describe the Higgs Boson as "possible but unconfirmed". Neutrium, in contrast, is impossible according to our current understanding.JohnAspinall 01:16, 23 September 2007 (UTC)Reply[reply]

I would like to see more well considered discussion on the Neutrium and related pages about the implications of the neutron-isotope hypothosis. This can yeild some good insight on the nature of matter, even if the particles do not exist. Is this a candidate for Dark Matter? etc.

From a standpoint of the Periodic Table -- should Neutrium be given a seat -- it would seem it must appear above Helium as a noble gas -- with all (zero) electron orbitals filled. 18:47, 21 September 2007 (UTC)JimReply[reply]

Neutronium should have a symbol n (lowercase), as that is the symbol for the neutron. It should have an atomic number of 0, hence 0n. The mononeutron would have mass number 1, 1n. The dineutron would have mass number 2, 2n. And the same goes for tetraneutron and other neutron clusters, if there are x neutrons in the neutron clusters, then the symbol should be xn. Neutronium should have an relative atomic mass of 4.000 temporarily because of the tetraneutron polyneutron cluster. I would say it was a nonmetal. Its group should be 18, appearence unknown, electron configuration none, electrons per shell none, electronegativity undefined as it has no electrons and ionization energy 0. Its place in the table would be above helium as it would most likely be a noble gas with all electron orbitals completely filled up. This seems to show that if a macroscopic quantity of neutronium were ever prepared synthetically, it would be in the gaseous state. I hope given this information you can go ahead and fill in the infobox for neutronium. Oh, and don't forget to ask mav to make a new table image for the element with atomic number zero -- neutronium. -- (talk) 05:52, 2 June 2009 (UTC)Reply[reply]

On account of WP:BB, I will reinsert the infobox. -- (talk) 06:01, 2 June 2009 (UTC)Reply[reply]

You could originally argue that the neutron is not an element, because it's unstable by itself, and it gets to be part of the atom by virtue of its ability to add to the atoms force of attraction as well as its physical rest mass. But now with the standard model, it comes across more as a maverick proton that has lost its positive electrostatic charge, due to an internal change, and which can be changed back under certain circumstances. And the standard model's subdivision if the electrostatic charge unit hasn't helped in determining what an electrostatic charge really is, and sounds more like an accounting gimmick. And since the addition of neutrons to the nucleus winds up adding a variable amount of mass value to the atom, including values of less than 1 Amu, it would be nice to know what the rest mass of the basic particle really is.WFPM (talk) 22:48, 23 October 2010 (UTC)Reply[reply]

Delete, fictional, not real[edit]

Yes, please remove this entry. Please read the last post, by our supernova remnant guest. It's NOT even certain that neutrons exist in the interior of a neutron star. It is almost offensive to my doctorate, which is on, specifically, the interior of neutron stars and equation of state. This entry is degrading my science. Neutron stars should not be the work of Science Fiction novels! Check my IP if you must...

There are plenty of articles in Wikipedia on science fiction concepts, many of which have even less connection to real physics than neutronium does. The article makes the uncertainties and the non-technical usage of this term clear, IMO. Bryan 08:37, 29 Mar 2004 (UTC)
Sure, Bryan, SF topics are great, I see your point, it needs to be in the wikipedia, but I hope you can see my original statement is still somewhat valid. To clear things up *I* think it might be better to clearly state this is an EXCLUSIVELY FICTIONAL term, reference some SF entries on 'neutronium' and then LINK IT to the already existing and sufficient FACTUAL entry on neutron stars, because this entry predominantly, though vaguely, contains factual astrophysics, whereas the fictional term, neutronium, has no basis in neutron star astrophysics whatsoever.
There are only two small lines referring to it as Science Fiction. The last line is particularly irritating, as I am not aware of any accepted astrophysical "theories" that place any limits on a "state of matter" called neutronium, let alone a "state of matter" called neutronium even existing.
I like it, neutronium, it's a cool term in itself, and I wish it could be out there for public consumption, but as the definition here stands it is inextricably linked to the term neutronium, possibly misleading and ultimately disrespectful. To utilise many areas of hard earn astrophysics knowledge in any definition *should* evoke respect of the topics, people and work within... (April 1st 2004)
The first line referring to it as science fiction is the second line of the article, and both lines in the introductory paragraph make it very clear that neutronium is not a technical term. They say this explicitly and specifically, and are the very first lines that anyone reading this article will encounter, so I really don't see how this is inadequate. I can't find the second mention of science fiction you refer to, do you perhaps mean the last paragraph in the article? If so, then it seems to me that there are clearly limits to how much pressure neutron star material can support, since the existance of black holes is widely accepted.
I also can't figure out what you find disrespectful in the current article. Inaccurate perhaps but I don't see why that would evoke such a vehement reaction. At the bottom of this talk page is a comment by someone who did a doctoral thesis on supernovas, presumably someone who's highly educated in astrophisics too, and he seemed pretty sanguine about it. I'll try rewording the last line, let me know if that helps. Bryan 08:42, 1 Apr 2004 (UTC)

Neutron star sizes[edit]

Article says:

The mass of any neutronium body can be no more than 1.4 times the mass of the Sun

I've noticed thats the same as the Chandrasekhar limit. But the Chandrasekhar limit works on the mass of the star pre-collapse, not post-collapse (like a neutron star). Is this a conincedence, has someone got things confused, or is there something deep and meaningful going on here? -- SJK

  • To the point, I believe the original posting you were refering to is now defunct, however it is true that the Chandrasekhar limit governs electron degeneracy pressure AND many recent observational upper limits on neutron star masses are also not much higher than 1.4 solar masses, so yes, it is rather confusing, but all the more interesting at the same time. It must be noted that equation of state estimates that are stiffer can still theoretically have neutron stars well above these limits, and there is some, though currently little observational evidence to support such. (April 1st 2004)

Neutronium in science[edit]

Somebody has thing confused. Actually, I had never heard a reference to neutronium, though is true that neutron stars are supported by neutron degeneracy pressure. But the mass it can suppot is about 3 M_sun (depends on the equation of state, that is not completely certain). I'll try to review it later. AN

thanks. The reference I was working from appeared to have been babelfished at some point, it was a little hard to follow some of it. :)

I made a search and only found the term "neutronium" in a novel "The neutronium alchemist", and sci-fi related pages. The physics of the interior of the core of a neutron star is not well undertood. There is a structure, going from well known iron to unknown superdense matter at the center. Apparently the term "neutronium is used by non experts and sci-fi people to refer to all the unknown physics inside a neutron star. AN

Go to Google and make sure you enter "star" as well as "neutronium", else you get the new-age book "The Neutronium Alchemist". Also try this link from a university physics department: [1]
There's an awful lot of crap on the Web about neutronium, which is one of the main reasons I wanted an entry on it in Wikipedia. :) - BD
If you could be so kind to point me to a single peer reviewed journal reference of "neutronium", i'd be glad. Searchs in the web site of the astrophysical jounal gives 0. Search of the NASA ADS abstract service gives one: an unrefereed paper about the capabilities of a telescope. The name of your cosmology book would also be appreciated. AN
I found lecture notes from Penn State's astronomy department [2]. I'm posting to the reputable USEnet groups to try and get some references. MMGB
It's not a peer-reviewed journal, but the book "Cosmic Wormholes" by Paul Halpern discusses neutron stars in chapter 3 and it uses that term. I also found a couple of references to it on some of John Baez's web pages, and he appears to be a researcher in the field [3]. But ultimately, why does the term need to be used in a peer-reviewed journal before it's legitimate to write an encyclopedia article about it? The word "neutronium" is very widely used, people are going to do searches for neutronium and this article is what they'll be looking for.
I'm not telling that there can not be an article about it. The term exist. The peer reviewed journal thing is to see if reputable researchers use the term, or if is it a sci-fi or fringe-science or popular simplification term. The fact that no a single astrophysical paper refers to that term, means it is not widely used in the field.
  • As I read the UQ reference MB gave it seems to imply a neutron star can be no more massive than 2.6 M_sun.

Larry Niven[edit]

Neutronium is also used in many Of Larry Niven's earlier stories. Which is actually why I am researching it. He describes it is being mirror-like. However aren't electrons responsible for the optical properties of a material? Then wouldn't a materail w/o electrons be optically inactive and effectivelt the blackest black you eyes never set upon? -- If you have a convincing answer to this contact me @

You're confusing science with science fiction. Neutronium is a popular term for science fiction writers, often describing an extremely strong, extremely stable form of matter. This usage really has very little to do with the scientific usage.
In actual fact, Niven always refers to neutronium in his stories as the material from pulsars and neutron stars. It's never something extremely strong, just extremely dense. Niven's stories normally have very, very good physics. In the only reference I know where he refers to it as "mirror-like", it is roughly basketball size, and orbiting a roughly earth-sized planet as a moon. It was covered by a shell of degenerate matter and a thinner shell of normal matter, and had a surface gravity of roughly 1 million g. The intense local gravity warps it into a mirror-surface sphere, but there's a thin layer of normal matter on the surface that could reflect light. -garglfluz

Agreed. Whenever Neutronium is encountered in Niven's stories, it's wrapped in a sci-fi stasis field, which, in his Known Space books, produces the mirror effect.

In "There is a Tide" the neutronium blob does not have a slaver stasis feild on it, although they *think* it does. -garglfluz

Neutronium in peer reviewed material[edit]

As someone who wrote a doctoral dissertation on supernova...

I think I've seen the term neutronium used in peer reviewed papers, but it's rare. The reason for this is that it's not known whether or not neutron stars are actually made of pure neutrons. The behavior of matter at these high densities is very poorly understood, and so its perfectly possible that the matter is in some weird form like quark soup or such. Fortunately, you can parameterize your ignorance. The only thing that matters in supernova calculations and the like is equation of state which is

pressure = function (density, temperature)

and you can place limits as to what this function can be.

It's also currently believed that neutron degeneracy limit isn't that much more than the chandesekar limit.

neutronium vs. Neutron star[edit]

I don't get it. Both the discussion and the article claim that the term "neutronium" is not used in science because it's not clear whether neutron stars really consist of neutrons. But apparently this doesn't prevent scientists from using the term "neutron star", which would be equally suspect by the same reasoning. Obviously science fiction writers need a word for the material; they can't keep writing "a gadget made of the stuff that neutron stars are made of". I guess scientists don't have as much need for such a word, since they're dealing mostly with the neutron stars themselves. I don't see any difference in misleading implications of neutron content between the two terms. Joriki 09:58, 25 Jun 2005 (UTC)

P.S.: This is not to say that "neutronium" should be considered a scientific term. One might argue that it carries undue implications of the possibility of this "material" existing in "normal" conditions outside of stars, which is currently entirely fictional. My point was only that the reason for its non-scientificity cannot be that it implies neutron content. Joriki 10:11, 25 Jun 2005 (UTC)

I have heard it referred to as "Neutron star material" which seems to work.

A hypothetical "neutronium" would be composed of neutrons-only bound by the strong force, to be considered an element, while "neutron stars" are believed to be composed of neutrons-mostly bound by gravitation. Scientists don't doubt the existence of "neutrons" but of "neutronium". ... said: Rursus (mbork³) 12:49, 27 October 2009 (UTC)Reply[reply]

Disputed: Periodic table[edit]

{{Elementbox_header2 | number=0 | symbol=Nu | name=neutronium | left=[[electron]] | right=- | above=- | below=[[helium|He]] | color1=#c0ffff | color2=green }}
{{Elementbox_series | none }}
{{Elementbox_groupperiodblock | group=18 | period=0 | block=s }}
{{Elementbox_appearance_img | | unknown }}
{{Elementbox_atomicmass_gpm | ? }}
{{Elementbox_econfig | ''none'' }}
{{Elementbox_epershell | 0 }}
{{Elementbox_section_physicalprop | color1=#c0ffff | color2=green }}
{{Elementbox_phase | unknown }}
{{Elementbox_section_miscellaneous | color1=#c0ffff | color2=green }}
{{Elementbox_isotopes_begin | color1=#c0ffff | color2=green }}
{{Elementbox_isotopes_unstable | mn=1 | sym=n<sup>#</sup> | na=? | n=1 }}
{{Elementbox_isotopes_unstable | mn=2 | sym=n<sup>x</sup> | na=? | n=2 }}
{{Elementbox_isotopes_unstable | mn=4 | sym=n<sup>×</sup> | na=? | n=4 }}
{{Elementbox_isotopes_unstable | mn=? | sym=n<sup>*</sup> | na=? | n=? }}
| colspan="6" align="center" | #<small>[[free neutron]]   x</small>[[dineutron]]   ×<small>[[tetraneutron]]</small>   *<small>[[neutron star]]</small>
{{Elementbox_footer | color1=#c0ffff | color2=green }}

I realy dont think that the periodic table and associated elements should be shown on this page, anyoone agree?

  • According to this article and this site apparently there is an alternate periodic table of the elements, created by an Oxford prof (!) of ecology (?) featuring neutronium. That's actually what brought me to this page, because I had no idea what that word meant. I'm no expert on the topic, but to me that implies that at least some people are starting to interpret neutronium as "element zero", and this is not just a science fiction concept. --Arcadian 18:57, 19 July 2005 (UTC)Reply[reply]
  • Agree with not placing it on the periodic table. Neutronium is not a real element under any definition of "real" I can think of. Not everything belongs on the periodic table. A reasonable definition of what belongs on the periodic table is things that do chemistry. Chemistry is done by electron shells. No electron shell, no chemistry. A single neutron does not appear on the periodic table, and the (individual) neutron's existence is well established. JohnAspinall 17:26, 24 September 2007 (UTC)Reply[reply]
  • Agree. Regardless of whether there are alternative tables in use, this article certainly shouldn't show the periodic table position of Nitrogen - that's just wrong. I'm not very familiar with how these boxes work - can the picture be removed, but the other info left in? MyNameIsClare talk 14:52, 11 August 2005 (UTC)Reply[reply]
  • Ah, I think I understand the issue now. Here's what's going on (I think). Someone created all the graphics needed, and there is a template used to create the links to those images. For example, on the Oxygen Wikipedia page, there is a link to Image:O-TableImage.png. So, the format for these appears to be: use the element name, and then add "-TableImage.png". So, what's the element name for Neutronium, assuming it is an element? The infobox implies that it is "n", lowercase. However, Wikipedia always capitalizes the first character of a link. In the template linking to the table of the elements, there is a "symbol=n". But when the template combines this with the path, it ends up linking to the Nitrogen page, because the "n" becomes a "N". I still don't know what the answer is to fix the problem, but it would probably be a good start to find out what the real abbreviation for neutronium is. It can't really be a lowercase n, can it? No other element starts with a lowercase letter. --Arcadian 15:21, 11 August 2005 (UTC)Reply[reply]
  • All right, in the spirit of Be bold, for now I've renamed the abbreviation to "Nt", along with a disclaimer on the page that this is not an actual consensus abbrevation, but just for consistency. Now there's a missing graphic, but I feel that's better than a misleading graphic. But this is just my two cents, and if anybody has a better idea I wouldn't object. --Arcadian 15:32, 11 August 2005 (UTC)Reply[reply]
  • I don't think it is a chemical element. For instance, the ratio of electron–positive barion pairs to neutrons depends on the temperature and pressure. Assuming we are talking about something physical, and not a simplified model without electons.--David R. Ingham 22:50, 11 August 2005 (UTC)Reply[reply]
  • The periodic table shows the proper place, and the valence shell of Nitrogen.
Good luck to physicists in fixing this one... this article is pretty FUBAR.
    • I've replaced Element Header with Element Header 2, it'll now show a generic periodic table.
  • I've revised the table from Nt to Nnn, as it's element 0, it's also element 000, and using IUPAC naming for trans-uranics, this gives Nilnilnilium, or Nnn. 19:15, 20 August 2005 (UTC)Reply[reply]
Does anyone actually use that term anywhere other than here? IMO Wikipedia:No original research would come into play on this if there are no references to back this up, I somehow doubt IUPAC had this in mind. Bryan 21:50, 20 August 2005 (UTC)Reply[reply]
I think it's a close call, but I like the Nnn solution, at least until/unless something better is provided. It is arguably not original research. It is compliant with the IUPAC standard for atoms explained Systematic element name. By analogy, the IUPAC standard for molecules explained at Systematic name can lead to names of molecules that are not currently referenced in the literature, but that does not mean that the names themselves are original research. --Arcadian 21:59, 20 August 2005 (UTC)Reply[reply]
I still don't like it, myself. The IUPAC system is for naming elements, but I doubt IUPAC recognizes neutronium to be an element at all. It's a little different, then, from using IUPAC molecule-naming standards to name molecules that haven't been referenced in literature. It's more like using IUPAC molecule-naming standards to name new types of footwear. Bryan 15:58, 5 October 2005 (UTC)Reply[reply]
Not only that, but the IUPAC systematic names were explicitly declared on introduction to be only for Z ≥ 101, so this would simply be a completely OR and utterly unofficial extrapolation of the system to a case it was never intended to be used for. (Almost ten years late, but since nobody brought this up...) Double sharp (talk) 04:27, 29 September 2015 (UTC)Reply[reply]
  • I am outraged at the fact that someone is trying to fit it in with the periodic table of elements, or the same table template! Where it says "Neutronium is considered element zero," is completely false, and unjustifiable. I'm wondering what crackpot or science fiction author made that up. Anyways, to be an element on the periodic table, it must have electrons orbiting the atom. Neutronium is not an atom, and has no orbiting electrons. -Mac Davis 07:53, 5 December 2005 (UTC)Reply[reply]
0 -neutroniumH


Name, Symbol, Number neutronium, Nnn, 0
{{Elementbox_footer | color1=#c0ffff | color2=green }}
I'd like to see some real journal articles or papers that mention the "Chemical Galaxy" periodic table
That's not a "Chemical Galaxy" periodic table template, though. It's a Mendeleevian periodic table, on which neutronium doesn't appear. Perhaps you could come up with a diagram depicting neutronium's place on the Chemical Galaxy chart instead? I suspect the Chemical Galaxy approach is not widely used enough that you'd be able to get consensus to add it to all the other existing element articles, so amending the template itself is unlikely to be a solution. Bryan 00:16, 4 October 2005 (UTC)Reply[reply]
  • Chemicals have chemical properties, which are created by a nucleus' orbiting electrons. Neutronium is not a chemical. Neutronium should not be on the "Chemical Galaxy" periodic table. --Mac Davis 11:24, 7 December 2005 (UTC)Reply[reply]

Why not just use the symbol n as that's the symbol for the neutron (as a subatomic particle), as I mentioned earlier. -- (talk) 05:54, 2 June 2009 (UTC)Reply[reply]

When it appears in a college text book for Chemistry 101 I say it should be on a periodic chart. Until then, keep it off. Manticore55 (talk) 22:02, 16 December 2009 (UTC)Reply[reply]

neutron matter[edit]

  • Before reading much here, the science fiction story I read when I was a kid called it neutron matter.
  • I heard four of these from UCLA professor Steven Moszkowski in a seminar he gave in Jülich in the early 1970s, but I can't remember all.

The first is that the first four pulsars or neutron stars are called LGM 1–4, for "little green man". (You see, they give off regular radio signals like we do.)

He considered adding the Science fiction story I described above with "little sliver men". He was working on the stability of neutron matter. For there to be "little silver men" their would have to be a phase transition. For them to have space travel, it would have to be stable without gravity.

Condensed rewrite[edit]

I've rewritten the article into a more condensed form that attempts to take into account the comments on this page, as well as providing links to relevant articles rather than duplicating their contents. The old version of the article is preserved at Talk:Neutronium/OldPage2005Nov for comparison and in case anyone feels there is more information in it that should be salvaged for the new page.

A few more references at the bottom would be nice, too.

--Christopher Thomas 20:30, 12 November 2005 (UTC)Reply[reply]

not necessary...[edit]

no deletion is necessary, But if it wants to be in the same place it was in, the title of the article should be changed. But if it wants to retain it name, then All we have to do is not to place it under the physics section. 22:11, 21 December 2005 (UTC)Reply[reply]


Re-raising a question I raised back when element templates were being considered for this article, does anyone know if the "nilnilnilium" or "Nnn" IUPACish names are actually used anywhere except here? A Google search produces only Wikipedia itself and one Wikipedia mirror. If no references exist then I think coming up with this application of IUPAC rules is well over into the field of original research and should be removed. Bryan 07:45, 16 January 2006 (UTC)Reply[reply]

I've now removed all references to nilnilnilium, including two redirects, a copy of the same paragraph at systematic element name, and a disambiguation at NNN. Bryan 02:17, 22 January 2006 (UTC)Reply[reply]

Can I just point out that Nilnilnilium is a readily observed element? One isotope is called Vacuum, another is Neutronium in the form of a single neutron. Of course it's a noble gas, and it would be interesting to readers to provide some philosophical information on the topic.
I've with never held with the view that Wikipedia should just be a "lowest common denominator" summary of what the established textbooks say. On that basis, what would contributors (including deletionists) think about an article on the theoretical properties of Nnn? Neuralwarp (talk) 18:17, 21 May 2015 (UTC)Reply[reply]
Under different names, there is already plenty of material on the topic, under names such as neutron. After all, IUPAC has not banished all the standard names of elements. Besides, it would probably just be called nilium, not nilnilnilium. Whatever you might like, unsourced essays are not what WP is about. —Quondum 03:42, 22 May 2015 (UTC)Reply[reply]

Subject Matter[edit]

The article features more on sci fi and postulates and very little scientific matter. This should be reconsidered as this article is supposedly scientific. For this I'm seeking expert guidance. --Soumyasch 14:45, 22 February 2006 (UTC)Reply[reply]

As is spelled out in the article's introduction, "neutronium" is not a scientific term. It's a popular-literature term for what scientists would refer to as neutron-degenerate matter. There isn't any significant scientific information to _add_; that would be at degenerate matter and neutron star. --Christopher Thomas 17:41, 22 February 2006 (UTC)Reply[reply]
In that case, should it not be deleted from the "Phases of Matter" template? --Soumyasch 06:54, 23 February 2006 (UTC)Reply[reply]
That depends on whether you think readers will look for information about it there. I'd lean towards keeping it, as I'd think a layman would consider it a phase of matter, but I don't feel strongly either way. My main concern was about the "expert attention" template that got added, as I don't think there's much in the topic to be an expert on. --Christopher Thomas 17:32, 23 February 2006 (UTC)Reply[reply]
I do feel that its inclusion in the template confuses users. And as for the expert attention template, I also feel it is not necessary. --Soumyasch 05:51, 24 February 2006 (UTC)Reply[reply]
Done and done. I've also added the "fictional material" categorization. --Christopher Thomas 06:39, 24 February 2006 (UTC)Reply[reply]

Schlock Mercenary[edit]

My point about notability isn't whether neutronium is featured prominently in Schlock Mercenary - it's about whether the Schlock Mercenary webcomic is well-known enough to be an example listed in this article. The list of examples here should be the handful that are most important; an exhaustive list would be at something like "list of occurrences of neutronium in fiction". --Christopher Thomas 07:13, 26 February 2006 (UTC)Reply[reply]

Schlock Mercenary is one of the "top" webcomics out there as far as I'm aware. It's been running daily for five and a half years now (over 2000 strips) and is being published in book form, the author quit his reasonably lucrative day job at Novell to work on it full-time. Some of the other "in fiction" sources are far more trivial, IMO - that VGA Planets reference for example. Fortunately there aren't a lot of them, maybe once the list grows longer it might be worth splitting off but right now it's only half a page (on my monitor). Bryan 18:17, 26 February 2006 (UTC)Reply[reply]
I am very familiar with Schlock Mercenary (I've been reading it for years). I just don't think that the average Wikipedia reader will be familiar with it, while they'll likely at least have heard of Star Trek, Dr. Who, and Stargate, with Civ and MOO being borderline cases. I think that many of the other references should also be moved to a separate list page, but I'm willing to wait until the list becomes long enough to be a problem (see Time travel for an example of what an out of control list looks like; that article badly needs an overhaul on several fronts, but I'm not in a position to do it until summer). --Christopher Thomas 20:21, 26 February 2006 (UTC)Reply[reply]
I would think that if the average Wikipedia reader isn't familiar with it then that's all the more reason to include it here. The point of an encyclopedia article is to inform and it wouldn't do much of that if everything in it was already stuff the reader was familiar with. :) Bryan 06:30, 27 February 2006 (UTC)Reply[reply]
This is a great argument for including it in list of occurrences of neutronium in fiction, but not a good argument for including it in neutronium, as content in neutronium should mostly be aimed at telling the reader what neutronium is. Without a (fairly high) notability threshold for examples cited _in the neutronium article_, you end up with a list a mile long that detracts from the article's usefulness (as with time travel). --Christopher Thomas 07:19, 27 February 2006 (UTC)Reply[reply]
However, I maintain that there isn't sufficient material to warrant a separate article for that list. The list isn't a mile long. So it's currently a moot point. Bryan 07:30, 27 February 2006 (UTC)Reply[reply]
There aren't enough in the neutronium article, yet, but give it 6 months and there will be. I'll probably end up doing the move myself when it gets to that point. Alternatively, I'm sure either of us is capable of starting a half-decent stub list in its own article right now, though it isn't a terribly urgent matter. --Christopher Thomas 18:11, 27 February 2006 (UTC)Reply[reply]

To Merge or Not to Merge (Neutronium and Neutrium)[edit]

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.
  • Opposer. I don't think there's enough in the neutrium article to merit a merge. In my opinion, it would be better off to redirect that article to polyneutron, which itself could use more references establishing notability (it appears to be the work of a single scientist, on a subject that's controversial). --Christopher Thomas 19:08, 19 April 2007 (UTC)Reply[reply]
  • Neutral perhaps not a merge, but it can and should be mentioned here, and linked to, along with polyneutron. 02:28, 12 June 2007 (UTC)Reply[reply]
  • Opposer I do not think that the two articles should be merged, because it will be easier to track with seperate articles. Please join the opposers and try to prevent the merging.
  • Opposed No matter how science-fiction-y the existence of neutronium may be, at least it is bound by a known force — gravity. Both polyneutrons, and their composite, neutrium, are one step farther from the standard models of physics, being bound by as-yet unknown force or forces. JohnAspinall 20:41, 14 September 2007 (UTC)Reply[reply]
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Neutronium: The Uncommon Element[edit]

The Symbol for Neutronium

Okay, now. It should be a little clean-up for the symbol of neutronium (element zero; a bare neutron). I have noticed some of you said it was n. I understand that commotion. I noticed nitrogen had a capital N, so it might be kind of confusing.

One person commented that the symbol should be Nnn. I noticed that only when you reach the Unun- elements that three letters are in the symbol. It seems kind of weird to me having a three-letter symbol followed by around a hundred one/two-lettered symbols in a row, then having some three-letter symbols. So, that idea does not seem so good.

Other people decided that neutronium’s symbol should be Nu. I totally agree with this. I think that it makes sense, it seems to fit, hey… speaking of fit… where should it be on the periodic table?

The Space of Neutronium

I know that the element of neutronium is already in the newer version of the periodic table (which I will refer to as the Chemical Galaxy). In the older version (that shall be referred as the Block Elements), neutronium does not have a place in the periodic table. Now, here are some things about it I have to say.

I think I understand the problem. Some of you are putting neutronium on a big bar on top of the Block Elements. I understand you do not see its place, but it seems, hmmm… how should I put it----unfair. It seems unfair that one element has this big bar floating above the others and the others have small blocks.

I have decided a reasonable solution. I think that on top of the block for hydrogen, there should be the neutronium block. It will be arranged like the other elements. If anybody decides to create a periodic table showing what it should look like, just send a periodic table showing only the area around neutronium They can be sent to 313 Karas Road.

I couldn't of done this presentation without the help of the other comments about neutronium. Please post your own comments on this discussion page. And thank you for taking your time reading this.

I agree and think that Neutronium is a noble gas above Helium in the periodic table, but the outside sources listing neutrons alongside charged nuclide use n or 0n. We can hint IUPAC of this. Otherwise we are bound to refer to what outside sources say preferrably primary outside sources. Said: Rursus 07:11, 4 June 2008 (UTC)Reply[reply]
It would be odd having neutronium in group 1, as it doesn't have any electrons so it can't form positive ions. If the neutron dipole moment is non-0, I think that that would make an n- ion possible at extremely low temperatures, but this would be highly unstable, sort of like ions of noble gases, so I agree that it would make more sense to put it above He. (talk) 12:35, 5 May 2013 (UTC)Reply[reply]
I think that any decision made here is pointless, as it is unencyclopedic information, and thereby is not addable to Wikipedia. For what it's worth, I think that neutronium, hydrogen and helium, each deserve their very own column, just like the transition metals. That is each column would have one member. I like the cylindrical table, I will contruct one today just for fun. Plasmic Physics (talk) 21:54, 5 May 2013 (UTC)Reply[reply]

Don't forget Vacuum, which is the no-neutron isotope of Nilium. I'd agree with the other author who noted that N was nitrogen, and n is not capitalised so cannot be a proper element acronym. Two-letter acronyms are reserved for permanently named elements, so we can only consider Nilnilnilium, Nnn. Neuralwarp (talk) 18:30, 21 May 2015 (UTC)Reply[reply]

Polyneutron References[edit]

Here are some legitimate polyneutron[4] refs in case anyone wants to work them into the article.

  1. Band, W., Origin of the lighter elements. Physical Review 1950, 80, 813-18.
  2. Peierls, R. E.; Singwi, K. S.; Wroe, D., The polyneutron theory of the origin of the elements. Physical Review 1952, 87, 46-50.
  3. Turkevich, A.; Cadieux, J. R.; Warren, J.; Economou, T.; La Rosa, J.; Heydegger, H. R., Search for particle-bound polyneutron systems. Physical Review Letters 1977, 38, 1129-31.
  4. Nayak, R.; Satpathy, L., Existence of bound neutral nuclei. Proceedings of the Nuclear Physics and Solid State Physics Symposium 1978, 21B, 54.
  5. Satpathy, L.; Nayak, R., On the existence of bound neutral nuclei. Journal of Physics G: Nuclear Physics 1978, 4, L161-L164.
  6. Baba, C. V. K.; Datar, V. M.; Bhargava, V. K.; Rao, V. K.; Marathe, S. G.; Iyer, R. H. Search for bound polyneutron nuclei in the fission of uranium-236; Bhabha At. Res. Cent.,Bombay,India.: 1979; pp 73-5.
  7. Rao, V. K.; Bhargava, V. K.; Marathe, S. G.; Iyer, R. H.; Datar, V. M.; Baba, C. V. K., A radiochemical investigation on the existence of polyneutron nuclei in the thermal neutron fission of uranium-235. Journal of Inorganic and Nuclear Chemistry 1981, 43, 1-3.
  8. Zaitseva, N. G.; Kuznetsova, M. Y.; Knotek, O.; Kovalev, A.; Novikov, S. A.; Khalkin, V. A., A radiochemical search for polyneutron nuclei in the interaction of 10 GeV protons with sodium iodide. Radiochimica Acta 1983, 34, 159-61.

--Kkmurray (talk) 04:26, 12 December 2007 (UTC)Reply[reply]

Neutrality issue?[edit]

Someone put the neutrality tag on the article. ? I think the article is doubly neutral :) ... and enlighting ... and valuable ... and valid. It should remain intact. But it seems that it is original research, since (seemingly) the article states that the various polyneutrons are to be regarded as isotopes of Neutronium, a conclusion that by my mind is an obvious and uncontroversial conclusion. I say this because I think there should be some precise criteria in WP:OR that allows obvious and uncontroversial conclusions, and that the text in WP:OR is too social science oriented. Said: Rursus 07:06, 4 June 2008 (UTC)Reply[reply]

I'm going to have to second your feelings. There was no reason given for adding the neutrality tag, and I don't see any significant (or insignificant) issues as far as neutrality goes. Would the editor who did add the neutrality tag please explain to us why? 3Juno3 (talk) 20:19, 24 August 2008 (UTC)Reply[reply]
The tag was added in this edit, without any explanation, in violation of the NPOV dispute guidelines. Since that editor has only made a total of three edits (with the two others on entirely unrelated topics), and the last was one more than two months ago, it's unlikely that an explanation is forthcoming in the foreseeable future. I'm going to remove the {{POV}} tag; if anyone disagrees, feel free to put it back with a proper justification. Hqb (talk) 19:27, 1 October 2008 (UTC)Reply[reply]

Citation(s) needed in "Neutronium in Fiction"[edit]

An erroneously-place note in the main article brought something to my attention: citations or links to releveant articles are required in the Neutronium in Fiction section. Namely, the role it plays in the Mass Effect universe. Perhaps a quote from offical game text? 3Juno3 (talk) 00:24, 24 August 2008 (UTC)Reply[reply]

Terry Pratchett[edit]

Terry Pratchett's "Strata" contains references to "neutronium" as a material you could coat the underside of a planet-sized disc with in order to get "artificial" gravity.

Pratchett is certainly pretty notable, but "Strata" may not be (it's not part of the Discworld series, but it does feature a disc world - whether it is coated with neutronium is not firmly established).

-- (talk) 23:06, 14 October 2008 (UTC)Reply[reply]


FIX THE INFOBOX! -- (talk) 06:31, 2 June 2009 (UTC)Reply[reply]

Don't worry, I've fixed it myself because of WP:BB. -- (talk) 09:35, 2 June 2009 (UTC)Reply[reply]

cluster merge[edit]

There's not enough to be set about the resonance 2Nt or the hypothetical quasi-nucleus 4Nt to be worthy of separate articles, and most of what there is to say in those articles doesn't have tracable sources. — Arthur Rubin (talk) 16:23, 25 July 2009 (UTC)Reply[reply]

Perhaps for tetraneutrons, but I'm pretty sure dineutrons are noteworthy enough to have a standalone article. I'll investigate.Headbomb {ταλκκοντριβς – WP Physics} 16:42, 25 July 2009 (UTC)Reply[reply]
Upon reading the references in both articles, I would be against such a merge. The physics involved in both cases are different enough, these articles should be expanded not merged.Headbomb {ταλκκοντριβς – WP Physics} 17:00, 25 July 2009 (UTC)Reply[reply]


I have to check the three following articles for neutronium und Andreas von Antropoff

  • Antropoff, A. (1926). "Über einen möglichen Zusammenhang zwischen der abnorm hohen Dichte einiger Fixsterne, der Hess schen Weltraumstrahlung und der Entstehung der Elemente". Naturwissenschaften. 14 (21): 493. doi:10.1007/BF01507535.
  • Stewart, Philip J. (2007). "A century on from Dmitrii Mendeleev: tables and spirals, noble gases and Nobel prizes". Foundations of Chemistry. 9 (3): 235. doi:10.1007/s10698-007-9038-x.
  • Stewart, Philip J. (2009). "Charles Janet: unrecognized genius of the periodic system". Foundations of Chemistry. 12: 5. doi:10.1007/s10698-008-9062-5.

--Stone (talk) 20:24, 25 July 2009 (UTC)Reply[reply]


At least, for the past few months, the infobox had been stable, except for occasional periods when Plasmic Physics (talk · contribs) removed it. Comments? — Arthur Rubin (talk) 06:20, 17 July 2010 (UTC)Reply[reply]

That infobox is a disgrace. Unsourced, prominently displaying a made-up symbol, and with virtually all entries consisting of "—", "undefined", etc. We might as well have a box for 0Nt, aka. the vacuum. Even worse, the "Isotopes" section gives the decay properties of free neutrons, which are irrelevant for neutronium/neutron-degenerate matter as a bulk material: with the "most stable isotope" having a half-life of less than 15 minutes, even the largest neutron star would decay away in a manner of days. Delete. Hqb (talk) 06:51, 17 July 2010 (UTC)Reply[reply]
Neutron degenerate matter is essentially the same as free neutrons, just neutrons under extreme pressure from gravity. Element infoboxes primarily consider elements in their standard state.
In any case, I also vote for the prohibition of an element infobox in this article. Element infoboxes should be reserved for elements only. Element status can only be assigned by the IUPAC. Neutronium or any other pure substance composed of neutrons only, is not considered an element by the IUPAC thusfar. Hence, presenting Neutronium in an element infobox is a false representation of fact, which is in breach of Wikipedia policy.
The only information presented in the current element infobox pertains solely to neutrons, and can already be found in the respective article on the neutron.--Plasmic Physics (talk) 08:05, 17 July 2010 (UTC)Reply[reply]

The information on the hypothetical states 2Nt and 4Nt used to be in the infobox. It's in the "isotopes" section now, and probably should be in the infoxbox. As for "standard state"...., well, perhaps, the infobox, along with references to 2n and 4n, should be in neutron , rather than here. — Arthur Rubin (talk) 09:37, 17 July 2010 (UTC)Reply[reply]

The infoxbox should be there, as well as the information for 2Nt and 4Nt. It is a neat summary of their properties, fullly compliant with WP:V and all other policies and guidelines we have. Headbomb {talk / contribs / physics / books} 16:41, 17 July 2010 (UTC)Reply[reply]
Come on. We do not put information about "hypothetical isotopes" in infoboxes for any other elements. As for "fully compliant with WP:V", please cite a reliable source for the symbol "Nt", which (apart from the free-neutron decay properties) is just about the only piece of information in that infobox that doesn't boil down to "undefined". The fact that there doesn't even exist an IUPAC-approved element symbol for neutronium should be a strong hint that mainstream scientific consensus does not consider it an element, and hence it's directly misleading to use {{infobox element}} to describe it. Hqb (talk) 18:28, 17 July 2010 (UTC)Reply[reply]
I agree that {{infobox element}} is inappropriate for this article. I think it is more likely to mislead than to inform. -- Ed (Edgar181) 13:04, 18 July 2010 (UTC)Reply[reply]
It's time that this discussion be concluded; 3 for and 2 against the removal of an element infobox.--Plasmic Physics (talk) 22:01, 22 July 2010 (UTC)Reply[reply]

Removing the infobox seems to be slightly favored, so I have gone ahead and removed it. -- Ed (Edgar181) 12:33, 29 July 2010 (UTC)Reply[reply]

I see it's removed already, and I agree. "Neutronium" is not an element. If this article needs an infobox, then create an ad-hoc one instead of pretending it is an element. --Itub (talk) 13:22, 7 August 2010 (UTC)Reply[reply]

Stability of lone neutrons?[edit]

Lone neutrons (not found in close proximity to a proton in a nucleus) decay into proton - electron pairs in less than 14 minutes. Has anyone proposed a mechanism by which a neutron star's strong gravity might overcome this instability? If not, the whole concept of neutron stars -- as widespread as it is -- is on shaky ground. (talk) 23:59, 26 August 2010 (UTC)Reply[reply]

Try Neutron-degenerate matter#Neutron degeneracy. Here neutrons do actually decay into protons, but due to the enormous gravitational pressure, the produced electron is crushed right back into the proton it came from within an unimaginably short space of time. This length of time is so short that the persistence of a single neutron can be considered as continuous.--Plasmic Physics (talk) 00:07, 27 August 2010 (UTC)Reply[reply]
Actually, that isn't quite correct. What happens is that the neutron star is dense enough that any electrons produced by decaying neutrons would have to be at extremely high energy (due to electron degeneracy). This makes the decay energetically unfavourable, so it doesn't happen. --Christopher Thomas (talk) 17:18, 7 September 2010 (UTC)Reply[reply]
Well, I'm pretty sure that quantumn statistics come into play - even though it is energetically unfavourable, there is a non-zero statistical probability of decay occuring. If aslo take into consideration the sheer size of the statistical population in a neutron star, then even a relatively tiny propability should show up.--Plasmic Physics (talk) 03:12, 11 September 2010 (UTC)Reply[reply]

States of matter navbox[edit]

Neutronium is listed in the navbox Template:States of matter. Additions of that template to this page have been (re-)reverted a few times. However no corresponding edit has been made to the navbox. As I see it, that navbox is a broad collection of articles related to states of matter, and the hypothetical nature of neutronium should not necessarily be an impediment to its inclusion. There are other types of "exotic" matter in the navbox as well. David Hollman (Talk) 10:12, 2 September 2010 (UTC)Reply[reply]

(I see the navbox is edited now too; they should, at least, be consistent. David Hollman (Talk) 10:15, 2 September 2010 (UTC))Reply[reply]

Neutronium was erroneously added to the navbox template. As stated in this article, Neutronium has many definitions, one of which defines it under degenerate matter. Degenerate matter is already in the navbox. The notion that neutronium is a state of matter, is not verifiable in any reputable sources.--Plasmic Physics (talk) 10:22, 2 September 2010 (UTC)Reply[reply]
Thanks for clarifying that and updating it in both places. David Hollman (Talk) 11:58, 2 September 2010 (UTC)Reply[reply]
I don't see how that helps either way, since as a form of degenerate matter, it's appropo to have the template here, as it is a form of degenerate matter, it need not occur on the template itself. This doesn't show why or why not the template should or should not appear on the article. (talk) 03:46, 13 September 2010 (UTC)Reply[reply]
If it is not verifiable that it is a state of matter, it seemed prudent to leave off the navbox, as its presence might imply otherwise. However there is a (just added) link to states of matter (as well as degenerate matter) in the article, and that seems to provide a good balance. (If there were some good sources which suggest that it really is a state of matter, then that would be a different story). David Hollman (Talk) 07:28, 13 September 2010 (UTC)Reply[reply]
Degenerate matter is not the only definition for neutronium, neutronium is an ambiguous term.--Plasmic Physics (talk) 06:17, 13 September 2010 (UTC)Reply[reply]
Neutron-degenerate matter is already covered by the template.--Plasmic Physics (talk) 06:19, 13 September 2010 (UTC)Reply[reply]
Your claim that "the notion that neutronium is a state of matter, is not verifiable in any reputable sources" is just plain nonsense. Neutron stars are, by definition, composed of neutronium. Neutrons stars exist. Therefore, neutronium exists. Azidothymizeal (talk) 07:21, 21 September 2010 (UTC)Reply[reply]
That doesn't make "neutronium" a state of matter, it makes "neutron-degenerate matter" a "state of matter". Although I don't agree with much of Plasmic Physics's editing of the article, he's absolutely correct about the template. — Arthur Rubin (talk) 08:37, 21 September 2010 (UTC)Reply[reply]
I'm intrigued, what does much of my editing of the article include? As far as I'm aware, I was only involved with the removal of the element infobox.--Plasmic Physics (talk) 08:53, 21 September 2010 (UTC)Reply[reply]

We should we add Eezo from Mass Effect to the use in fiction section.[edit]

Element Zero or eezo atomic number 0 chemical symbol Ez fits the description of Neutronium, just with a different name. — Preceding unsigned comment added by (talk) 05:39, 16 July 2011 (UTC)Reply[reply]

It may fit the description of neutronium, but it is not called neutronium. Plasmic Physics (talk) 05:59, 16 July 2011 (UTC)Reply[reply]

Recovered text deleted with the mention of original research[edit]

The following text was recently removed (see here) with the mention of original research (WP:NOR), but it seems this is perhaps not an appropriate argument and that part of this text was useful:

If one accepts neutronium to be an element, the above mentioned neutron clusters would be the isotopes of that element,{{Tl:Whom?|date=}} if their existence can be confirmed. Also, if neutronium is accepted to be an element, it would not be a noble gas,{{Tl:Citation needed|date=}} for it would have no electrons, in fact, it would have no electron shells. All electron shells and their electrons have been squeezed out of the material by pressure.{{Tl:Citation needed|date=}} The material would, thus, like noble gasses be unreactive{{Tl:Citation needed|date=}}, but for different reasons. Neutronium would not fit anywhere in the periodic table.{{Tl:Citation needed|date=}}

Any comment or argument to reinsert it at least partly? Best regards, Shinkolobwe (talk) 12:14, 1 April 2012 (UTC)Reply[reply]

It would need to be cited. Without proper sources, the text appears like conjecture/speculation. Plasmic Physics (talk) 13:13, 1 April 2012 (UTC)Reply[reply]
Treating free neutrons (even disregarding the more controvertial larger clusters) as element with atomic number 0 (at least hypothetically for the purpose of the statement) is not not technically controvertial. However, essentially only the first 20 words has merit.
The rest is largely patent nonsense:
  • "if their existence can be confirmed": the existence of free neutrons is well-established
  • "it would not be a noble gas": no relevance, speculation
  • "it would have no electron shells": true (obviously so), may have merit
  • "...have been squeezed out of the material by pressure": seems to be confusing two completely different uses of the term "neutronium"
  • "Neutronium would not fit anywhere in the periodic table": an invalid statement; the periodic table is in any event not entirely regular (e.g. hydrogen and helium do not fit very well either), and there are tables that include it.
The concept that free neutrons (and neutron clusters) can be regarded as an element in the periodic table is already covered by the section as it stands. — Quondum 17:17, 1 April 2012 (UTC)Reply[reply]

A completely clear superfluid[edit]

First of all, liquid neutronium (at least 1
) does not exist under the normal pressure. It is possible that it is a superfluid under very high pressures, but the substantiation “due to its incredible density and its inability to form rigid structure” is a complete rubbish. Second, neutronuim-1 interacts with electromagnetic field if only because it has a magnetic dipole. It is likely that its even isotopes have not, but 2
is extremely unstable and 4
is hypothetical (and also, unlikely is stable enough under reasonable pressures). Hence, it is plausible that neutronium, even in the gaseous phase, would have a noticeable refractive index comparable with one of “ordinary” gases. Hence, “completely clear” is an baseless speculation. Incnis Mrsi (talk) 13:12, 31 March 2013 (UTC)Reply[reply]

I know properties of neutronium is not completely known, but two cites in properties section deals about people's ideas about the appearance of neutronium. In order for mainstream scientists to study actual properties of neutronium, neutronium would have to be made in the labratory. Did scientist ever make or even attempt to make neutronium? Alternatively, scientists could study neutron stars since they made of neutronium. PlanetStar 19:48, 31 March 2013 (UTC)Reply[reply]
Neutron stars? For neutrino-related, mechanical and magnetic properties, we could (and in fact there are some evidences that their interior is liquid). But their crust does not contain neutronium at all, so even landing on a neutron star will not give any answer about neutronium’s visual appearance. Also, I repeat, the article does not contain a reasonably substantiated claim about superfluidity and there are no supporting astrophysical evidences. Why not just remove it? Incnis Mrsi (talk) 08:26, 1 April 2013 (UTC)Reply[reply]
Do we make neutronium? Yes, the gaseous neutronium-1, and in quite large quantities. Incnis Mrsi (talk) 08:35, 1 April 2013 (UTC)Reply[reply]
'Clear' and 'colourless' are synonomous, so I'll give him credit for that. Something can have a refraction index and be colourless. Unless, you know for a fact that neutronium may be coloured in theory. Plasmic Physics (talk) 20:21, 31 March 2013 (UTC)Reply[reply]
I think, it depends on conditions. In a magnetic field of an appropriate strength 1
will be coloured for an obvious reason, for example, and neutron stars (see above) suggest that a magnetic field can penetrate the neutronium to a large depth. I repeat: it is a reckless speculation and should be removed from article’s body. I even am not sure that is WP:EL-worthy. Also, “completely clear” implies “colourless”, but certainly not versa. If a media scatters the light noticeably, but does not absorb it, then it is unclear and colourless. They are not synonymous. Incnis Mrsi (talk) 08:26, 1 April 2013 (UTC)Reply[reply]
That depends strongly on the definition chosen for 'colour', hence 'colourless'. In optics, points on the greyscale are not considered to be colours, thus you be correct. However, according to common verbiage, points on the greyscale are considered to be colours, thus 'clear' is synonymous with 'colourless'.
Yes, I agree that that is an unreliable source. Plasmic Physics (talk) 08:42, 1 April 2013 (UTC)Reply[reply]

Element 0 vs degenerate matter[edit]

May I suggest a new name for neutronium for the purposes of this discussion, to distinguish the element from the degenerate matter: nihilogen, with symbol Nh. Plasmic Physics (talk) 09:03, 1 April 2013 (UTC)Reply[reply]

First of all, the new name is redundant: you ever can speak specifically about degenerate neutronium (vs ordinary matter), just like one speaks about other cases of degenerate matter. I do not see that a clear-cut distinction between the two meanings can be established. Degenerate or not, but neutrons have a magnetic dipole and will interact with an EM field. All of them in an ordinary gas, or only some of them near the Fermi level in a degenerate 1
, but they will. Transition from one to another will change the strength of interaction, but not its mechanism. But if a portion of neutronium converted to 2
(I expect that it will convert under an elevated pressure), then its EM interaction (for reasonable energies) will almost disappear together with spin. Probably, it is the reason why (degenerate) neutronium is a preferred term over (degenerate) neutrons – electrons do not form bound pairs, at least under conditions of a high-pressure electronic degenerate matter, for a comparison. So, isotopic consideration are relevant both for degenerate and non-degenerate case, and you can’t forget about isotopes until neutronium’s density reaches values comparable to the density of atomic nuclei. Incnis Mrsi (talk) 17:44, 1 April 2013 (UTC)Reply[reply]
The symbol Nh is now used for nihonium (element 113), though Nl would still be possible for "nihilogen". This is of course just OR and shouldn't be in the article. Double sharp (talk) 02:15, 6 April 2018 (UTC)Reply[reply]

Well, a symbol Nn for neutronium has been used... Double sharp (talk) 02:02, 13 November 2022 (UTC)Reply[reply]

Irrelevant reference[edit]

I don't think, that a reference to "Wookiepedia" is what should be used. Could we get it from a more reliable source?--Mr.23 (talk) 19:47, 18 April 2013 (UTC)Reply[reply]

Bound neutrons[edit]

The article states that the two neutrons in the dineutron are not bound but are nearly bound. OBVIOUSLY, the definition of "bound" (along with an explanation, if necessary) is needed. They either do exist as a bound system (state) or do not. If they are not bound, isn't the quantum mechanics very different? They aren't free, so the artificial dichotomy between bound and unbound that this article suggests is IMHO incorrect. I guess that the author confuses stability with "bondedness". Can someone please fix? (talk) 14:27, 8 June 2013 (UTC)Reply[reply]

Do not search for contradiction where it does not exist. In some systems where an actual energy level (i.e. a point spectrum element a.k.a. eigenvalue) does not exist, but the Hamiltonian is so close to having it that the difference can be, in short time intervals, neglected. It is called a (narrow) resonance (particle physics) – unfortunately, this important article is underdeveloped. Incnis Mrsi (talk) 15:11, 8 June 2013 (UTC)Reply[reply]
I had the same concern as the above poster. The article is not clear. If this is in fact a resonance (seems quite reasonable), the article should do a better job pointing this out. I'll see if I can help. — Preceding unsigned comment added by (talk) 20:03, 3 June 2020 (UTC)Reply[reply]
It seems to me that with trineutrons and beyond, one shouldn't be talking about bound states but possible short-lived resonances. The phrase, "even for a short time", suggests that what's discussed is the possible existence or nonexistence of resonances.Johnm307 (talk) 14:47, 6 April 2021 (UTC)Reply[reply]

Mass Effect version of neutronium[edit]

If we are to have a complete listing of all uses of the word "neutronium" in this article, we'd need mention of the use of the term in the Mass effect series. Per WP:TRIVIA we shouldn't include the list at all, let alone this marginal component of the list. At this edit I have removed the list. Please don't reinsert trivia without policy-backed consensus. Richard Keatinge (talk) 16:21, 18 August 2016 (UTC)Reply[reply]

I am familiar with WP:TRIVIA and vehemently disagree with your categorical removal of this section, per WP:TRIVIA. Notably:
  • "This guideline does not suggest removing trivia sections, or moving them to the talk page. If information is otherwise suitable, it is better that it be poorly presented than not presented at all."
  • "This guideline does not suggest always avoiding lists in favor of prose. Some information is better presented in list format."
  • "A large number of articles contain a section on media references to, and other popular culture coverage or portrayal of, the subject of the Wikipedia article in which the section is written. [...] This material is not categorically trivial. Media coverage of a topic is generally encyclopedic information, helps establish the topic's notability, and helps readers understand the subject's influence on the public (and often vice versa)."
You have effectively gutted the "In fiction" section by removing all specific references to neutronium within fiction. I agree that per WP:TRIVIA the list should be reworked into prose if at all possible, and only some examples need to be given rather than a miscellaneous, unreferenced, list. But removing all examples so that only large generalities remain weakens the article. (As for the Mass Effect reference: I see no reason it needs to remain. We don't need EVERY reference that was on the original list.) Jtrevor99 (talk) 14:35, 19 August 2016 (UTC)Reply[reply]
The other problem is that fictional neutronium has nothing in common with the (possibly) real stuff. Perhaps a separate article on the sci-fi versions of neutronium would be useful, would you like to write one? I can't see anything more than a brief generalization being justifiable here. Richard Keatinge (talk) 15:32, 19 August 2016 (UTC)Reply[reply]
Part of the problem is that, we don't fully know what neutronium's properties would be in environments outside of e.g. neutron star cores - or if that would even be possible using technologies that don't exist yet. Fictional "practical" applications or manipulations of neutronium have to assume technologies beyond our current understanding, which conceivably could alter neutronium's properties beyond those we currently understand. Besides, I think we're both missing the point here...we are talking about the "In fiction" section of the article, after all, and there is no WP policy that states a fictional representation of something must be accurate - its impact on fiction, regardless of the representation, is what is notable.
Frankly, I don't think the "fictional" topic is important enough to warrant a separate article; and, that article might just devolve into a WP:TRIVIA-violating list again. A couple of the more prevalent mentions from the previous list would be sufficient - I'd suggest perhaps Bear as the "best" representation of literature and Star Trek as a representation of media, though feel free to pick your own. If these two examples were included, I think that would be sufficient to illustrate for the reader the sorts of impact "neutronium" has in fiction. Jtrevor99 (talk) 23:02, 19 August 2016 (UTC)Reply[reply]
@Jtrevor99 IMHO the biggest problem with the section was not the list rather than prose format, but that the examples were trivial and it's not clear that the subject has any significant "influence on the public". I agree with the essay WP:IPCEXAMPLES that we should ask if reliable sources have pointed out the reference. If you want a reference to a policy rather than to an essay, WP:PRIMARY applies: "Wikipedia articles usually rely on material from reliable secondary sources". If no reliable secondary sources have ever talked about the influence of neutronium on the public, there probably isn't any significant influence that we can say anything meaningful about. Rolf H Nelson (talk) 04:01, 26 August 2016 (UTC)Reply[reply]
Let's see what other people think. I agree, the separate article would inevitably devolve into a list of unrealistic plot devices based on primary references, but at least it'd be out of our way here. How about making it a subsection of Unobtainium? Personally I'm left with a mild, but definite feeling that we're better off here with just the generalization. 18:22, 22 August 2016 (UTC)Richard Keatinge (talk)
I've had some more time to think about this, and now agree that there probably isn't sufficient need for such a list, or even specific examples. Unless anyone else speaks up, I'm content to leave it as is. Thanks for the good edit. Jtrevor99 (talk) 16:48, 24 August 2016 (UTC)Reply[reply]
I have been thinking about this for a few days and the more I think the more convinced I am that removing the list was a good idea. Jonathan A Jones (talk) 17:08, 24 August 2016 (UTC)Reply[reply]

Bound neutronium[edit]

How many neutrons do you have to pack together for the strong nuclear force to take over and finally hold the neutrons together? Six? Ten? One hundred? One billion? Is it not possible? 02:51, 9 December 2016 (UTC)02:51, 9 December 2016 (UTC)~~ 32ieww (talk) 02:51, 9 December 2016 (UTC)Reply[reply]