Recycling, Courtesy of S.P.Q.R.

In the first century B.C. Roman merchants lost their cargo to the Mediterranean.
In the 21st century we're using that same cargo to study the physical properties of neutrinos.

Because 2,000 year old lead has almost completely lost its natural radioactivity - it can shield a particle detector without adding its own signature.

How freaky is that?

(H/t Neatorama)