Scientists build a big machine in a deep, dark Minnesota hole

"It's dark as a dungeon, way down in the mine" goes the well-worn working class folk ballad. At the long-dormant Soudan mine in the Iron Range--the scene of dramatic strikes and bloody clashes in the early 20th century--physicists from Stanford, MIT and the UofM have been looking for a piece of history that is darker still: the "dark matter" that is said to make up 25% of the universe.

They built the world's most powerful tool to detect dark matter and installed it deep in the mine, where the strange stuff physicists worry about--like interference from cosmic radiation--is not an issue.

The results are in: no stuff-of-the-universe found. Turns out the physicists need a better tool and a deeper hole. So they're packing up their dilution refrigerators and their optical spectrophotometers and moving their Cryogenic Dark Matter Search to Canada. You just can't catch a break on The Range.