In this talk-show with the popular astrophysicist Neil deGrasse Tyson, Bill explores a variety of topics, including the nature of an expanding, accelerating universe (and how it might end), the difference between “dark energy” and “dark matter,” the concept of God in cosmology and why science matters.
Today on Crash Course Astronomy, Phil explains comets. Comets are chunks of ice and rock that orbit the Sun. When they get near the Sun the ice turns into gas, forming the long tail, and also releases dust that forms a different tail. We’ve visited comets up close and found them to be lumpy, with vents in the surface that release the gas as ice sublimates. Eons ago, comets (and asteroids) may have brought a lot of water to Earth -- as well as the ingredients for life.
More than three decades after the debut of Carl Sagan's ground-breaking and iconic series, "Cosmos: A Personal Voyage," it's time once again to set sail for the stars. Host and astrophysicist Neil deGrasse Tyson sets off on the Ship of the Imagination to discover Earth's Cosmic Address and its coordinates in space and time. Viewers meet Renaissance Italy's Giordano Bruno, who had an epiphany about the infinite expanse of the universe. Then, Tyson walks across the Cosmic Calendar, on which all of time has been compressed into a year-at-a-glance calendar, from the Big Bang to the moment humans first make their appearance on the planet.