How shipwrecks and ancient Roman lead help physicists search for dark matter When a 2,000-year-old Roman shipwreck was found off the Sardinian coast in 1988, it didn't just thrill archaeologists — physicists were excited too.

The discovery grabbed the attention of one in particular: Ettore Fiorini, a particle physicist with Italy's Institute for Nuclear Physics (INFN).

He didn't care too much about the ship. He was more interested in its cargo — hundreds of lead bars, each weighing 33 kilograms.

And instead of displaying them in a museum, he planned to melt them down to build an underground observatory. (read on)