In this episode of the Voices from DARPA podcast, Dr. Michael Fiddy, a program manager since 2016 in the agency’s Defense Sciences Office (DSO), takes listeners on a whirlwind tour of his programs. They all share a common thread, which stems from Fiddy's lifelong interest in how light — electromagnetic (EM) energy, more generally — interacts with matter. At DARPA, he has expressed that interest by challenging researchers to investigate whether cells interact with one another via EM signals; how it might be possible to use low-frequency EM radiation to see through just about anything (including metal); and how precisely engineered surfaces might tap into quantum mechanical phenomena (Casimir forces) in the vacuum of space in a quest for fuel-less propulsion technology. As Fiddy points out in the podcast, “We have been doing science for a few hundred years and there still is an awful lot that we don’t know.”