Most of the atoms in the world are either hydrogen or helium. Hydrogen, of course, is the simplest of atoms. One electron circling one proton. The Ockham's razor of atoms.
Helium is what you get when a lot of hydrogen atoms are tightly compressed together in a star. It is the consequence of the process of fusion in that context.
What about all the other elements? Most of them can be explained as themselves also the products of nuclear fusion in the stars, increasingly rare as they get heavier. But there are a few elements that scientists think require a more complicated explanation, and gold is one of these.
These problem elements are neutron heavy and they could only have come into existence in an environment that allows rapid neutron capture, known as "the r process." The usual theory has been, for decades now, that the r-process is created when neutron stars merge with each other, since a dense soup of neutrons, is the most plausible source for gold and like metals.
But the numbers don't add up. The universe seems to contain too much gold and too few neutron star collisions. ["How do we know how much gold the universe contains, outside of Earth?" "Spectral analysis, dude."]
Anyway: something else has to be happening.
This year, a team of scientists led by Brian Metzger of Columbia University, has proposed another origin. This also involves neutron stars but it doesn't require them to collide with each other. A magnetar is a neutron star with an extremely strong magnetic field, prone to throwing off giant flares. These flares, the team proposes, have the right environment for the p process to take place.
Is this a full explanation at last of where the universe's gold comes from?
I would expect other astrophysicists will want to be heard from on the subject before all is said and done. But Metzger presents empirical evidence, and the whole matter is a valuable bit of meta-evidence that (a) the universe still has surprises for us and (b) science still makes progress.
As regular readers of this blog may know, I have long been interested in the matter of whether gold ought to be restored to a place of importance in the (Earth's) monetary system, a place akin to that it lost when President Nixon destroyed the old Bretton Woods system.
Metzger's findings have no very direct bearing on that question, but they do leave me thinking, "now THAT is an origin story that suits the preciousness of a precious metal!"
Comments
Post a Comment