From a past Ray Murry post as follows:
anomaly re Lithium 7 dearth in universe, as not enough formed after
Big Bang to fit current theories -- any relevance to Widom-Larsen
theory of weak interaction beta decay chains? Rich Murray 2012.09.09
just asking... Allan Widom and Lewis Larsen ?
http://phys.org/news/2012-09-mystery-apparent-dearth-lithium-universe.html#jCp
Mystery over apparent dearth of lithium 7 in universe deepens
September 6, 2012 by Bob Yirka
Enlarge
Estimates of the lithium abundance in the SMC interstellar medium and
in other environments.
Credit: Nature, 489, 121–123. (Phys.org) -- Researchers studying the
cosmos have been stumped by an observation first made by Monique and
François Spite of the Paris Observatory some thirty years ago;
they noted that in studying the halos of older stars, that there
should be more lithium 7 than there appeared to be in the universe.
Since that time many studies have been conducted in trying to explain
this apparent anomaly, but thus far no one has been able to come up
with a reasonable explanation.
And now, new research has deepened the mystery further by finding that
the amount of lithium 7 in the path between us and a very young star
aligns with would have been expected shortly after the Big Bang, but
doesn't take into account the creation of new amounts since that time.
In their paper published in the journal Nature, Christopher Howk and
colleagues suggest the discrepancy is troubling because it can't be
explained with normal astrophysics models.
What's really bothering all the scientists working on the lithium
problem is the fact that it's the only element that doesn't fit with
models of how things should have come to exist right after the Big
Bang.
All known elements occur in amounts predicted, except for lithium 7;
there's just a third as much as theorists think there should be.
In trying to understand why, researchers have looked at old stars that
surround the Milky Way galaxy, low mass bosons called axions, and more
recently binary stars that are believed to harbor black holes.
Unfortunately, such studies have only made the problem worse by
suggesting that even more lithium 7 ought to be hanging around
somewhere than was predicted earlier.
In this new research the team looked at one single huge young star in
the Small Magellanic Cloud, or more precisely, at the spectrum
measured of gas and dust through which light must travel to get from
there to here, and found that the amount of lithium 7 is consistent
with theories that suggest how much of the element there should have
been shortly after the Big Bang, which is unsettling because
scientists know that more of it should have been created between then
and now.
Thus, these new results only add to the mystery of where all the rest
of it is, or worse, why it wasn't created in the first place as models
suggest.
More information:
Observation of interstellar lithium in the low-metallicity Small
Magellanic Cloud, Nature, 489, 121–123 (06 September 2012)
doi:10.1038/nature11407
Abstract
The primordial abundances of light elements produced in the standard
theory of Big Bang nucleosynthesis (BBN) depend only on the cosmic
ratio of baryons to photons, a quantity inferred from observations of
the microwave background.
The predicted primordial 7Li abundance is four times that measured in
the atmospheres of Galactic halo stars.
This discrepancy could be caused by modification of surface lithium
abundances during the stars' lifetimes or by physics beyond the
Standard Model that affects early nucleosynthesis.
The lithium abundance of low-metallicity gas provides an alternative
constraint on the primordial abundance and cosmic evolution of lithium
that is not susceptible to the in situ modifications that may affect
stellar atmospheres.
Here we report observations of interstellar 7Li in the low-metallicity
gas of the Small Magellanic Cloud, a nearby galaxy with a quarter the
Sun's metallicity.
The present-day 7Li abundance of the Small Magellanic Cloud is nearly
equal to the BBN predictions, severely constraining the amount of
possible subsequent enrichment of the gas by stellar and cosmic-ray
nucleosynthesis.
Our measurements can be reconciled with standard BBN with an extremely
fine-tuned depletion of stellar Li with metallicity.
They are also consistent with non-standard BBN.
Press release Journal reference: Nature © 2012 Phys.org
Read more at:
http://phys.org/news/2012-09-mystery-apparent-dearth-lithium-universe.html#jCp
My answer addressing this issue as follows:
http://www.newscientist.com/article/mg20327246.700-13-more-things-the-lithium-problem.html#.U8mmbXlOU0k
Snip
So what is going on? The lithium-6 problem might just be an accounting
issue: it is hard to discern lithium-6 abundances by looking at the light
from stars. The lithium-7 shortfall might be due to destructive processes
within stars, but there is no consensus as to what these processes might
be. *Others suggest the lithium-7
