September 15, 2014 | David F. Coppedge

Big Bang's Lithium Problem Gets More Problematic

There’s no escape; new measurements show far less lithium than predicted by the big bang, and more fine tuning than would be expected by chance.

Measurements made by Italians deep underground confirm an old problem in cosmology: not enough lithium-7, but too much lithium-6.  Science Daily explains:

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.”

National Geographic sums up the problem simply: “That curious deficiency suggests that astrophysicists either don’t fully understand the big bang, they suggest, or else don’t fully understand the way that stars work.”  Such a quandary suggests they could understand neither.  “The most radical solution to the problem is that the big bang theory is incomplete,” said Brian Fields at the University of Illionois.  “But less radical solutions haven’t yet solved the problem.

What lit up the universe?

Happier (or hope-ier) news in cosmology was reported by Science Daily.  Astronomers at University College London believe the Dark Energy Spectroscopic Instrument (DESI) will allow them to map neutral hydrogen throughout the universe—essential for understanding the role of dark energy in the expansion.  The amount of ignorance at this stage of investigation is profound: “It’s amazing how little is known about the objects that bathed the universe in ultraviolet radiation while galaxies assembled into their present form,” the article says.  “This technique gives us a novel handle on the intergalactic environment during this critical time in the universe’s history.”

Cosmic Fine Tuning

PhysOrg presented an update on the subject of fine tuning.  The article begins by re-stating the curious values of fundamental constants that make our universe habitable:

Within physics there are certain physical quantities that play a central role. These are things such as the mass of an electron, or the speed of light, or the universal constant of gravity. We aren’t sure why these constants have the values they do, but their values uniquely determine the way our universe works. For example, if the mass of electrons were smaller, atoms would be smaller. If the gravitational constant were larger, you’d need less mass to create a black hole, and neutron stars might not exist.

The so-called “fine structure constant” called “alpha” is a dimensionless relationship of three fundamental constants, the charge of the electron, Planck’s constant and the speed of light.  Thought to be invariant, there were reports a while back of variations observed between different parts of the universe.  That has been ruled out, the article says: “the mass ratio has changed no more than one part in a billion over the course of seven billion years,” according to another team’s measurements in 2012.  “In other words, they are constant to the limits of our observation.”

Magic in the Universe

Speaking of fine-tuning, there’s an isotope with a remarkable balance that makes it “doubly magic,” PhysOrg reported in another article.  It’s nickel-78, whose “magic numbers” (measures of stability) make it special.  For those interested, here is the explanation:

The magic numbers for isotope stability are well established for isotopes with similar numbers of protons and neutrons. The seven most widely recognized magic numbers are 2, 8, 20, 28, 50, 82 and 126; these correspond to the number of particles needed to completely fill proton or neutron ‘shells’ in the nucleus. The nickel-78 (78Ni) isotope contains 28 protons and 50 neutrons, making it doubly magic according to this series.

Doubts that nickel-78 truly had the two magic numbers have been dismissed, according to the article.  Why does this matter?  It’s a big, cosmic deal:

The experiments confirmed the doubly magic status of 78Ni, providing valuable insights into the behavior of exotic nuclei with large neutron excess. Such neutron-rich nuclei play an important role in the production of elements heavier than the most stable element iron, such as gold and uranium. “We hope to solve one of the biggest mysteries of this century—where and how were the heavy elements created in the Universe?” explains Nishimura.

Higgs Boson: Handle with Care

Meanwhile, those celebrating the Higgs Boson might want to find out why Stephen Hawking thinks the so-called “God particle” could wipe out the universe (Live Science).  The Higgs’ properties are apparently balanced between two destructive possibilities.  If they were to vary, it would be all over for the whole cosmos and those living in it.

Do you get the distinct impression that there’s possibly much more that astronomers do not know about the universe than what is presented in TV documentaries so confidently?  Do you get another distinct impression that the universe appears designed?


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