APOD: Where Your Elements Came From (2016 Jan 25)

[neufer]

The figure claims that lithium comes primarily from cosmic rays, but this is not the case as far as I know. The Wikipedia page on lithium says "According to modern cosmological theory, lithium—as both of its stable isotopes lithium-6 and lithium-7—was among the 3 elements synthesized in the Big Bang." The only mention of cosmic rays on the whole page is in the sentence "Additional small amounts of lithium of both 6Li and 7Li may be generated from solar wind, cosmic rays hitting heavier atoms, and from early solar system 7Be and 10Be radioactive decay." The lithium square should be recolored to Big Bang Purple, as far as I can tell. I didn't attempt to check any other entries, but this one jumped out at me since I remember learning in my physics classes that lithium came primarily from the big bang.

Heehaw brought this up earlier and I gave a knee-jerk response in an attempt to defend the figure... but you are right about lithium & beryllium.

[Chris Peterson]

The figure claims that lithium comes primarily from cosmic rays, but this is not the case as far as I know. The Wikipedia page on lithium says "According to modern cosmological theory, lithium—as both of its stable isotopes lithium-6 and lithium-7—was among the 3 elements synthesized in the Big Bang." The only mention of cosmic rays on the whole page is in the sentence "Additional small amounts of lithium of both 6Li and 7Li may be generated from solar wind, cosmic rays hitting heavier atoms, and from early solar system 7Be and 10Be radioactive decay." The lithium square should be recolored to Big Bang Purple, as far as I can tell. I didn't attempt to check any other entries, but this one jumped out at me since I remember learning in my physics classes that lithium came primarily from the big bang.

The origin of the light (and fragile) elements, Li, Be, and B is not well understood, and remains an area of primary research. The amount of stable Li observed is not consistent with what BB cosmology requires. Several possible explanations have been proposed, but remain poorly tested. Nevertheless, local Li abundances (as in galaxies and stellar systems) are generally attributed to some combination of galactic cosmic rays interacting with CNO in the interstellar medium, with neutrinos interacting with He and C, and by some proposed low-energy cosmic ray interactions (particularly in regions of the early universe). In general, most Li is not assumed to be primordial, so the cell is probably best left as is, at least until ideas are better developed.

[neufer]

In general, most Li is not assumed to be primordial, so the cell is probably best left as is, at least until ideas are better developed.

In general, at least HALF of Li is primordial, so the cell should be changed to reflect that fact.

Measurement at Big Bang conditions confirms lithium problem
August 27, 2014

[b][color=#0000FF]Michael Anders at the LUNA accelerator in Italy. Credit: HZDR/M. Anders[/color][/b]

---

<<The field of astrophysics has a stubborn problem and it's called lithium. The quantities of lithium predicted to have resulted from the Big Bang are not actually present in stars. But the calculations are correct – a fact which has now been confirmed for the first time in experiments conducted at the underground laboratory in the Gran Sasso mountain in Italy. As part of an international team, researchers from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) studied how much lithium forms under Big Bang conditions. The results were published in Physical Review Letters.

Lithium, aside from hydrogen and helium, is one of the three elements that are created before the first stars form. These three elements were – according to the theory – already created early on, through what is known as "primordial nucleosynthesis." That means that when the universe was only a few minutes old, neutrons and protons merged to form the nuclei of the these elements. At the Laboratory for Underground Nuclear Astrophysics (LUNA), the nucleosynthesis of lithium has now been reproduced by an international team of scientists. Michael Anders, who earned his doctorate in the last year at TU Dresden and HZDR on this very topic, took a leading role on the team. Within the framework of a project that was funded by the German Research Foundation, he was supervised by Dr. Daniel Bemmerer, group leader at HZDR.

In the Italian underground laboratory, the scientists fired helium nuclei at heavy hydrogen (known as deuterium) in order to reach energies similar to those just after the Big Bang. The idea was to measure how much lithium forms under similar conditions to those during the early stages of the universe. The result of the experiment: the data confirmed the theoretical predictions, which are incompatible with the observed lithium concentrations found in the universe.

"For the first time, we could actually study the lithium-6 production in one part of the Big Bang energy range with our experiment," explains Daniel Bemmerer. Lithium-6 (three neutrons, three protons) is one of the element's two stable isotopes. The formation of lithium-7, which possesses an additional neutron, was studied in 2006 by Bemmerer at LUNA.

With these new results, what is known as the "lithium problem" remains a hard nut to crack: on the one hand, now all laboratory results of the astrophysicists suggest that the theory of primordial nucleosynthesis is correct. On the other hand, many observations of astronomers show that the oldest stars in our Milky Way contain only half as much lithium-7 as predicted. Sensational reports by Swedish researchers, who discovered clearly more lithium-6 in such stars than predicted, must also likely be checked again based on the new LUNA data. Bemmerer says, "Should unusual lithium concentrations be observed in the future, we know, thanks to the new measurements, that it cannot be due to the primordial nucleosynthesis.">>

[Chris Peterson]

In general, most Li is not assumed to be primordial, so the cell is probably best left as is, at least until ideas are better developed.

In general, at least HALF of Li is primordial, so the cell should be changed to reflect that fact.

I don't think that's the conclusion of the referenced work. Furthermore, the situation is complicated by the fact that the origin of Li in old stars may be quite different from that found locally, which means we have to decide what is meant by where "our" elements came from.

[neufer]

In general, most Li is not assumed to be primordial,
so the cell is probably best left as is, at least until ideas are better developed.

In general, at least HALF of Li is primordial, so the cell should be changed to reflect that fact.

I don't think that's the conclusion of the referenced work.

Theoretically, virtually ALL Li is primordial.

Experimentally, HALF of Li can be confirmed to be primordial.

Hence: at least HALF of Li must be primordial, and the cell should be adjusted to reflect that fact.

Furthermore, the situation is complicated by the fact that the origin of Li in old stars may be quite different from that found locally, which means we have to decide what is meant by where "our" elements came from.

Originally, I bent over backwards by giving the APOD diagram the benefit of the doubt that it seemed to specifically refer to elements of humans/animals/Earth.

However, since ALL Earth Helium comes from radioactivity the diagram must refer to Solar System/Universe instead.

Hence, there is absolutely no reason to credit cosmic rays with the bulk of Li or Be.

[Chris Peterson]

Theoretically, virtually ALL Li is primordial.

Well... no.

Experimentally, HALF of Li can be confirmed to be primordial.

Possibly. Not certainly, though.

Originally, I bent over backwards by giving the APOD diagram the benefit of the doubt that it seemed to specifically refer to elements of humans/animals/Earth.

However, since ALL Earth Helium comes from radioactivity the diagram must refer to Solar System/Universe instead.

Certainly, that matter could use some clarification.

Hence, there is absolutely no reason to credit cosmic rays with the bulk of Li or Be.

You mean outside of a large body of respectable, reviewed literature?

[Chris Peterson]

Why aren't photonic molecules shown on your table?

http://phys.org/news/2013-09-scientists ... -seen.html

Because they aren't elements.

[Ron-Astro Pharmacist]

Why aren't photonic molecules shown on your table?

http://phys.org/news/2013-09-scientists ... -seen.html

Because they aren't elements.

I thought photons were bosons that easily interacted.

What's up with the statement in that link, ""...Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other," Lukin said. "What we have done is create a special type of medium in which photons interact with each other so strongly..."?

[neufer]

Hence, there is absolutely no reason to credit cosmic rays with the bulk of Li or Be.

You mean outside of a large body of respectable, reviewed literature?

• Example

[Starobs]

Two other examples of periodic table pointing to origin of the elements:
Didn't found the source for this one, at least from 2010:
http://www.universetoday.com/70646/astr ... supernova/
This is a more recent one, mixing origin and "use":
http://astrobiology.com/2015/07/the-ast ... table.html

[messier.palette]

Thanks Starobs. I've added both of these to my Element Charts Collection. I love the colors of the first and expanded reach of the second.

But wow, even the newest one is still going with the same origin legend icons and excluding neutron star collisions as the best candidate for the origin of things like gold (Au). I would have thought by now....

Oh well, maybe they're waiting for visits to the actual crash site of two neutron stars to prove it beyond any shadow of a doubt. After all, neutron stars are small. What could go wrong!!! Let's just mosey on over there and mine us some gold!!! Easy

Just kidding. I love element charts. I'll just keep editing them in my head.

[Ron-Astro Pharmacist]

I couldn't figure out why our helium supply seemed -all of a sudden- better. It's not like we are going to start making it helium from fusion any time soon.

Then I read this.

But then again maybe there's a new source?

Sun Canadian Pipeline.jpg

Those Canucks are ambitious!!

I just didn't remember where in Canada the pipeline's end was located.