Enlarge / IceCube is actually under the ice, pointing downward. The Earth is a big filter to remove all the other stuff the Universe throws at us. (credit: Eli Duke)

I’ve largely given up writing stories about new dark-matter candidates. Theoretical physicists keep coming up with more elaborate scenarios to make dark matter more interesting and less inert. It all seems a bit forced. About the only thing that dark matter has to do is provide mass. A particle that doesn’t interact with electromagnetism at all fits the bill almost perfectly (and does practically nothing else).

Still, when there is experimental data to support it, I get interested in dark-matter candidates again. My cynicism aside, there are actually a few results hanging around that seem hard to explain. For instance, the hydrogen in the early Universe seems to have absorbed less light than expected. The center of the galaxy emits an unexpected amount of gamma rays (though they might be due to ordinary matter). And the neutrinos observed by the IceCube Neutrino Observatory in the Antarctic seem to be a bit weird, too.

Neutrinos on ice

Out of all of these, a recent explanation for the IceCube data has caught my attention because it is reasonably simple. This is in contrast to a recent proposal for a Bose-Einstein condensate of dark matter to explain the lack of hydrogen absorption, which seems hideously complex.