Mystery over apparent dearth of lithium 7 in universe deepens

Sep 06, 2012 by Bob Yirka report
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 . 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 , low mass bosons called axions, and more recently binary stars that are believed to harbor . 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 , 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.

Explore further: Image: Chandra's view of the Tycho Supernova remnant

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

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User comments : 20

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Dan_K
3.6 / 5 (15) Sep 06, 2012
It's kinda like an ant wondering about the smaller than expected petrolium deposits on planet earth in the 21st century.

Obviously it's because all of the aliens harvest Lithium7 in order to make dilithium crystals - The gasoline of the cosmos.

Dan K
Anda
5 / 5 (1) Sep 06, 2012
Fine. These kind of anomalies lead us to a better understanding of the universe
Torbjorn_Larsson_OM
3.7 / 5 (3) Sep 06, 2012
This is more encouraging than troubling, at least for an outsider.

Having finally tested the predicted the BBN amount, and having sources and sinks for the 7Li, I wouldn't jump to the conclusion that finetuning models are necessary.

For example, CR isn't that well known a process I believe. (Though maybe its outcome on 7LI is.)

Even with apparent finetuning, it happens that those later gets their constraints well predicted by natural mechanisms. The similar amount of water on Earth, Moon, Mars comes to mind, finetuned to give us both oceans and land, now predicted to be the natural result of protoplanetary disk models.
Torbjorn_Larsson_OM
3.7 / 5 (3) Sep 06, 2012
Anda, indeed. If there is a real bottleneck (finetuning), such gives a minimal set of possible pathways.

For example, the proverbial chicken-and-egg observation allows you to propose and test evolution, as the system needs to originate from one without none of those (eg asexual species such as bacteria, their cloning suggesting how evolution of sex came to be).

Similarly the DNA-and-protein bottleneck suggests the RNA world. Bottlenecks/finetuning/anomalies are very fertile grounds.
TheWalrus
2.3 / 5 (3) Sep 06, 2012
"...the amount of lithium 7 in the path between us and a very young star aligns with would have been expected..."

Does anyone else have a problem with this?
antonima
1 / 5 (2) Sep 06, 2012
"...the amount of lithium 7 in the path between us and a very young star aligns with would have been expected..."

Does anyone else have a problem with this?


Yes, thanks for pointing that out. Too many run-on sentences as well. The author should have made the article three or four paragraphs, without trying to pack all the information in as small a space as possible.
Noumenal
1 / 5 (6) Sep 06, 2012
wow, could it be possible, a 21st century theory that, unlike nearly everything else man has thought about existence, might need to be revised. I wonder what the next age of being will bring, I am sad I ended up in this one.
ValeriaT
1 / 5 (7) Sep 06, 2012
I wrote thousands of posts at many forums and which ones were accepted? A very few of them. If I'm right at least a bit, then the contemporary physics must be deeply revised, because the proponents of mainstream physics tend to oppose me in every post.
IronhorseA
5 / 5 (1) Sep 06, 2012
Perhaps Li7 is less abundant for reasons related to the castle bravo incident, where it was assumed the Li7 would be neutral in the reaction but instead amplified a 6 megaton explosion into a 15 megaton explosion. Perhaps it gets used up or converted to something else when compressed in a star. Therefore any new Li7 produced would be short the amount created after the big bang and any previous generation of supernova.
Pressure2
2.4 / 5 (5) Sep 06, 2012
Below is probably the best explanation as to why there is so little lithium in the universe. It probably decays in the stars much more than present theory allows for. Neutrinos are the major source of radioactive decay and they are at their most dense concentration in stars.

Quote from link:
"The nuclei of lithium verge on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides."

http://en.wikiped.../Lithium
wealthychef
not rated yet Sep 06, 2012
"...the amount of lithium 7 in the path between us and a very young star aligns with would have been expected..."

Does anyone else have a problem with this?


Yes, thanks for pointing that out. Too many run-on sentences as well. The author should have made the article three or four paragraphs, without trying to pack all the information in as small a space as possible.


Um, or they just left out the word "what" between "with" and "would".
ziphead
3 / 5 (10) Sep 06, 2012
Just do what you always do;

1. Invent new property of dark matter that somehow interacts with lithium 7 only.

2. Write lotsa equations to support your point of view. The more dimensions and obscurity, the better.

3. Start calling lithium:the God element

4. Spend another 10bn to build another collider that could prove your gut feel (hoping that you will discover something entirely different in the process of course).

5. Have a bear and laugh at suckers that made it all possible.
code red
1 / 5 (6) Sep 06, 2012
i've been to cambridge a few times nice place. any way i cant see that the binding of lithium would occur unless the forces that bring it into equalibrium, some how have inteligenc,e cause the isotope would still present it self , i just think its time to lift the veil i'm more of a tech mechanic we have only just started realising, the benefits of certain elements,rather than carbon"used for millenea" exscuse my spelling the next step is so near if there is inteligence behind "phenomena?" we are not ants when was the last time there was mind games between, us and ants.. when everyone figures how to get into orbit using frame dragging loop closing and many other ways to skin it; I dont know personally but i have seen a lot of jets and shooting stars that turn ,tight radius' the weather keeps going strange, closed loop cloud banks, time to get real thats fuel for an injection battery make a donation when you market this cause i'm quite broke anyway without proof what can we say thanks.
Shabs42
3.8 / 5 (4) Sep 07, 2012
5. Have a bear and laugh at suckers that made it all possible.


Well I don't see how having a bear in the room with you would help. Unless it's a circus bear maybe...

I like how whether scientists are confirming or refuting a theory it's just a scheme to get more money. Never mind that 90% of the scientists running studies that are published on this site could make a whole lot more money working in private industry.
A2G
2 / 5 (4) Sep 07, 2012
"Never mind that 90% of the scientists running studies that are published on this site could make a whole lot more money working in private industry."

I didn't know that McDonald's was paying that well now.

ziphead
3.4 / 5 (5) Sep 07, 2012
5. Have a bear and laugh at suckers that made it all possible.


Well I don't see how having a bear in the room with you would help. Unless it's a circus bear maybe...

I like how whether scientists are confirming or refuting a theory it's just a scheme to get more money. Never mind that 90% of the scientists running studies that are published on this site could make a whole lot more money working in private industry.


Ah, the grammar and spellcheck; the sharpest tool in the shed of a straw-man practitioner.

As for how much you think you might be worth, could not comment. But let me tell you; it's pretty rough out here in the real world...
Standing Bear
1 / 5 (1) Sep 07, 2012
Any body ever thought of using it for nuclear rocket fuel? Naww, but maybe could amplify combo fission fusion cycles to get appreciable specific impulse gains!?
Torbjorn_Larsson_OM
4.3 / 5 (6) Sep 07, 2012
@ natello:

A failure during test for a theory does not make an alternative pass a test. It is the reasoning of anti-scientists like creationists to propose such a false duality.

Specifically, "the Steady state Universe model" has been buried half a century ago since it was not viable.

@ ziphead:

PhDs and other graduates do very well in industry according to statistics, so no worries there. And science works well, cf the internet this science blogs is housed on, so no worries there either.

The problem is rather, how can people come up with conspiracy theories, even as jokes, since they are the least likely alternatives by construction? (No conspirationist wants to be called out for his bullshit, so makes them as little testable as possible.)

It is a mystery for the mentally healthy part of the population.

And I don't know about you, but I'll never have a bear. I prefer my own species in bed, thank you very much.
Dan_K
not rated yet Sep 07, 2012
It probably decays in the stars much more than present theory allows for.


I Like that explanation, except, wouldn't other radioactive elements do the same? Why just Lithium7?

Dan K
Pressure2
5 / 5 (1) Sep 07, 2012
It probably decays in the stars much more than present theory allows for.


I Like that explanation, except, wouldn't other radioactive elements do the same? Why just Lithium7?

Dan K


It may happen to a lesser degree with some other elements. Lithium 7 is not normally radioactive. But in the pressure cooker of the stars it may be ever so slightly radioactive since it is "on the verge of instability." It may have a half-life of 2 to 3 billion years in stars but be considered stable on the earth.

Quote from link:
"The nuclei of lithium verge on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides."

http://en.wikiped.../Lithium