IceCube [here’s my own description of the experiment], the big high-energy neutrino experiment cleverly embedded into the ice at the South Pole, announced a very interesting result yesterday, following on an already interesting result from a few weeks ago, one that I failed to cover properly. They have seen the highest-energy neutrinos ever observed, ones that, unlike previously observed high-energy neutrinos, appear not to be generated by cosmic rays hitting the top of the atmosphere. Instead, they apparently come from new sources far out in space. And as such, it tentatively appears that they’ve opened up, as long anticipated, a new era in neutrino astronomy, in which high-energy neutrinos will be used to understand astrophysical phenomena!
[The only previous example of neutrinos being used in astrophysics occurred with the discovery of neutrinos from the relatively nearby supernova, visible with the naked eye, that occurred in 1987. But those neutrinos had energies millions of times smaller than the ones discussed here. And there was hope that IceCube might see neutrinos specifically from gamma-ray bursts, including the one that occurred just two weeks ago; but that appears not to have happened.]
I don’t understand certain details well enough yet to give you a careful explanation — that will probably come next week — but here’s an early description (and expert readers are strongly encouraged to correct any errors.)