Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then dives into what we know. Bursts come in two rough varieties: Long and short. Long ones are from hypernovae, massive stars exploding, sending out twin beams of matter and energy. Short ones are from merging neutron stars. Both kinds are so energetic they are visible for billions of light years, and both are also the birth announcements of black holes.
On the 15th Dec 2015, Tim Peake will launch into space to be Britain's first astronaut on board the International Space Station. For the past two years, Tim has been filming a video diary for Horizon showing the risks, pressures and rigorous training required to launch into space. Horizon also talks exclusively to his wife and two children as they prepare to wave him goodbye on his voyage to space. From training in the Soyuz capsule, centrifuges, space station mockups, virtual reality and a huge pool to replicate spacewalks, to dealing with the physical dangers of weightlessness, witnessing his first launch and spending time away from his wife Rebecca and his two sons, this is an intimate portrait and remarkable insight into the world of an astronaut.
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.
Worried about black holes? Consider this: Every time you accelerate - you generate an event horizon behind you. The more you accelerate away from it the closer it gets. Don’t worry, it can never catch up to you, but the Unruh radiation it generates sure can.