This segment from the cable TV show: "Universe: Unexplained Mysteries features UC Berkeley's Dr. Richard Muller who has for decades predicted a "Dark Star" binary twin to our Sun, which he calls "Nemesis," whose elliptical orbit he believes it is responsible for the strong cycle of mass extinctions which occur every 26 million years on Earth.
Also featured is UConn's Dr. Ronald Mullet, who hid his obsession with time travel by studying black holes for decades and who is now doing official time travel experiments using lasers and neutron particles.