If I were looking at Earth from a distance, I would be pretty disappointed,” theoretical physicist Avi Loeb says. “Most of ...

His job was to uncover secrets from the unknown. But his curiosity opened doors that the government preferred to keep closed.

Russia and Ukraine have accused each other of violating a Kremlin-declared Easter ceasefire as Orthodox Christians gathered ...

China, the U.S., Russia and others have ramped up their contest over artificial-intelligence-backed weapons and military ...