Homestake might solve a physics mystery

TwinCities.com : Far below the Black Hills of South Dakota, crews are building the world’s deepest underground science lab called Homestake at a depth equivalent to more than six Empire State buildings—a place uniquely suited to scientists’ quest for mysterious particles known as dark matter.Scientists, politicians, and other officials gathered 22 June for a groundbreaking of sorts at a lab 4850 feet below the surface of an old gold mine that was once the site of Nobel Prize–winning physics research.The site is ideal for experiments because its location is shielded from cosmic rays that could interfere with efforts to prove the existence of dark matter, which is thought to make up nearly a quarter of the mass of the universe.The deepest reaches of the mine plunge to 8000 feet below the surface. Some early geology and hydrology experiments are already under way at 4850 feet. Researchers also hope to build two deeper labs that are still awaiting funding from Congress."The fact that we’re going to be in the Davis Cavern just tickles us pink,” said Tom Shutt of Case Western Reserve University in Cleveland, referring to a portion of the mine named after scientist Ray Davis Jr, who used it in the 1960s to demonstrate the existence of particles called solar neutrinos.