By Jim Brace-Thompson
In attempting to explain the sources of heavy elements such as gold, silver, and plutonium, scientists have long looked to the sky.
Just as leprechauns gaze upward to follow the towering arcs of colorful rainbows in order to determine where to hide their proverbial pots of gold, scientists once looked to the skies, as well. They believed heavy metals, like gold, were forged when aging stars reached the ends of their lifetimes and their cores collapsed and exploded as supernovas, thus sending heavy elements scattering across the universe. Another theory involves the merger of neutron stars. Yes? No? Maybe so?
Well, maybe not.
Writing in a recent issue of the journal Science, Anton Wallner (Australian National University; Helmholtz-Zentrum Dresden-Rossendorf) and colleagues say that neutron star mergers and supernovas alone cannot explain the quantity of heavy elements residing around we humans and our wee leprechaun kin. Sure, supernovas may be one source of gold. But apparently, there must be others, per analyses of deep-sea crust samples from the Pacific Ocean containing known isotopes delivered by the stars to Mother Earth in the past few million years during, just possibly, two supernova events.
If interested in exploring this conundrum, Wallner and Australian National University partners Michaela Froehlich and Dominik Koll have issued a call for a student project to help in the continuing search for supernova signatures here on Earth. All you need to qualify is to be in a PhD or Masters program with special expertise in astrophysics and to be looking for a third-year special project or honours project. In other words, you need to be a character from the television show The Big Bang Theory. Is that you?
Who knows? If you are qualified, perhaps this might prove to be your pot of gold at the end of the leprechaun rainbow!