Talk:Primordial element

message: I'm coming at this from an astrophysicist's point of view, and to me -- thinking strictly in the scientific context -- the article's confusing ... suggesting a difference between fields in what "primordial" means.  I'm used to thinking of "primordial elements" being strictly those coming out of Big Bang nucleosynthesis (BBN) ... so thats H, D, the stable isotopes of He and Li, and Be-7.  Everything else is not "primordial" (and actually a great deal of the Li in existance now must be of non-BBN origin).  If in geochemistry "primordial" means "present in the Earth from the time of its formation", then there's a genuine difference in the meaning of the term as used in different fields, and it may take some interdisciplinary attention to hammer this out satisfactorily.
It sounds like at least the distinction between "classical" and "primordial" that is mentioned above is one from philosophy, and that's an entirely different bailiwick.
BSVulturis 15:51, 31 August 2006 (UTC)
thread_title:  Field-dependent meaning? 

message: I don't really think this article has any information that isn't in primordial nuclide, and isn't nearly as clear. Probably this article should just be deleted, but if you can see any info that can be saved, please comment after looking at the other. SBHarris 04:12, 10 December 2010 (UTC)
thread_title:  Merge with [[primordial nuclide]]

message: This article says primordial elements are those "whose half-life must be greater than about 100 million years."  However, Pu-244 has a half-life of 80 million years and the Plutonium article states that Pu-244 is primordial.  —Preceding unsigned comment added by 184.100.195.62 (talk) 20:37, 15 February 2011 (UTC)
replies: text: Well, that's because this article is wrong. In practice, it's 80 million, since Pu-244 is the shortest lived one we've found. Unless somebody objects in the next week, I'm going to be WP:BOLD and carry out the merge. SBHarris 20:49, 15 February 2011 (UTC)
thread_title:  Conflict with the Plutonium article 

message: As this is obviously much less than the age of the Earth, one can assume that the rate of decay beyond this timeframe is still insufficient to eliminate all traces of the isotope by the present day, but this is unclear to me. Is there anyone who can add a little more explanation on how the 100 million year figure was derived?  —Preceding unsigned comment added by 66.134.4.226 (talk) 17:25, 8 April 2011 (UTC)
replies: text: There is no hard and fast time cutoff. It just so happens that we've found some Pu-244 with half life 80 million years, but not yet any of the nuclide with the next shortest half-life, niobium-92, with a half life of 37 million years. So the breakpoint between primorial and non-primordial nuclides is between these two isotopes (it may change as detection equipment becomes better). It's unlikely we'll discover some unknown nuclide with a half-life between these, as all the nucldes anywhere close to the known elements have been synthesized and "accounted for" (characterized) already, and so there's no place for a new one that is THIS stable (> 37 million years) to hide. SBHarris 00:24, 9 April 2011 (UTC)
thread_title:  Half-Life of 100 million years 

message: Note that there was no content worth moving. No licensing issues are involved. I do not see anything on this TALK page worth saving, either, but will leave it for the moment. Feel free to move any section you think needs addressing, to Primordial nuclide. SBHarris 00:49, 9 April 2011 (UTC)
thread_title:  This stub has now been deleted and redirected to Primordial nuclide.