William Broad is the author of several books, including “The Oracle: The Lost Secrets and Hidden Message of Ancient Delphi.” He tells Steve Paulson how a multi-disciplinary scientific team recently proved that the secret of the ancient sisterhood of mystics in Greece was that the Temple of Apollo was sitting on top of soil saturated by petrochemical fumes that caused the Oracles to go into trance. And they’re finding geological bases to other sacred sites all over the world.