Double stars are stars that appear to be near each other in the sky, but if they’re gravitationally bound together we call them binary stars. Many stars are actually part of binary or multiple systems. If they are close enough together they can actually touch other, merging into one peanut-shaped star. In some close binaries matter can flow from one star to the other, changing the way it ages. If one star is a white dwarf, this can cause periodic explosions, and possibly even lead to blowing up the entire star.
Ideas about time and space are explored in the changes that constellations undergo over time, the redshift and blue shift measured in interstellar objects, time dilation in Albert Einstein's theory of relativity, the designs of both Leonardo da Vinci and spacecraft that could travel near light speed, time travel and its hypothetical effects on human history, the origins of the Solar System, the history of life, and the immensity of space. In Cosmos Update, the idea of faster-than-light travel by wormholes (researched by Kip Thorne and shown in Sagan’s novel Contact) is discussed.
Brian Cox explores the ingredients needed for an intelligent civilisation to evolve in the universe - the need for a benign star, for a habitable planet, for life to spontaneously arise on such a planet and the time required for intelligent life to evolve and build a civilisation. Brian weighs the evidence and arrives at his own provocative answer to the puzzle of our apparent solitude.
Black holes! From Stephen Hawking to Interstellar, black holes are mammoths in the world of science AND sci-fi. But what exactly IS a black hole? Do events happen inside black holes? Are black holes really a hole? Are black holes really black?! Join Gabe on this week’s episode of PBS Space Time as he debunks popular black hole misconceptions, and rethinks what the term, ‘black hole’, even means. Thought you knew what a black hole was? Think again!