Talk:Neutronium
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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)
To the point below, 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)
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
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] (http://www.physics.uq.edu.au/people/ross/ph227/evolve/whitey.htm)
- 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
- 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] (http://www.google.com/search?hl=en&q=+site:math.ucr.edu+neutronium). 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.
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 @ http://pthbb.org
- 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.
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.