Sujet : Re: Dark matter is the core of stars (minus hydrogen cover)
De : wthyde1953 (at) *nospam* gmail.com (William Hyde)
Groupes : sci.physicsDate : 29. Jun 2025, 21:10:43
Autres entêtes
Organisation : A noiseless patient Spider
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Jim Pennino wrote:
Sorry crackpot, there is no such thing as helium-2.
All kinds of weird isotopes have been created in the lab, though they generally have tiny half lives. Hydrogen-7, for example, has been observed and has a half life of about ten to the minus twenty two seconds.
Helium-2 may have been observed, according to several experiments done in this century. But nobody has claimed certainty yet.
However, theoretical calculations give it a very small half life. How small they are not sure, but much less than a billionth of a second. This is very short compared to Helium-6 or Helium-8.
Not surprising, because helium-2 actually has a negative binding energy.
There is, apparently, a helium-10, also with a tiny (but in this case measured) half life. It can only exist for even that time because this number of nucleons forms a complete shell, adding stability. Helium-9, on the other hand, has never as far as I know been observed, though it must form in the kind of process that results in helium-10.
Of course, none of this supports the crackpottery you were responding to.
William Hyde