D. L. Helis

Ancient lead that lay on the seafloor for two thousand years has become the heart of a detector searching for the most elusive substance in the universe. From it, researchers grew a transparent lead tungstate crystal weighing 13 grams and cooled it to near absolute zero.

Deep underground, in the silence of a cryostat (a cooled container), lie crystals of lead that once belonged to an ancient Roman ship. This material barely emits background radiation — over two thousand years, unstable isotopes have decayed, leaving it perfectly clean for hunting the rarest events.