The authoritative guide to ensuring science and technology make life on Earth better, not worse.

Watch the 2025 Doomsday Clock announcement on January 28


Daniel Jassby

Daniel Jassby was a principal research physicist at the Princeton Plasma Physics Lab until 1999. For 25 years he worked in areas of plasma physics and neutron production related to fusion energy research and development. He holds a PhD in astrophysical sciences from Princeton University.