Comet Enthusiast

Despite a decade spent searching for dark matter with experiments costing tens of millions of dollars from experiments at the bottom of iron mines in Minnesota to the Ice Cube project in Antarctica, nobody has laid eyes on the stuff.  It's hard to escape the conclusion that some other explanation for the missing mass is needed.

Cosmologist Paul Frampton at the University of North Carolina and colleagues propose that the missing 23% of mass of the universe is made up of black holes that are too small to see directly but too big to have evaporated away due to Hawking radiation.