Artificial selection is one example, eyes another, of the well-documented and inescapable process of evolution--change in a population of species over time--by natural selection. These are some of the things that molecules do.
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.
NASA is sizing up a new but familiar challenge: how to transport humans back into deep space - to the moon, to Mars, to asteroids, and beyond. New destinations require new hardware - more powerful rockets and radical new landing modules. Venture back to our early space adventures with Buzz Aldrin, Jim Lovell and NASA experts and learn about the successes and failures of the Apollo missions. Follow today's technicians as they reach for the stars by learning from these lessons of the past. The programme also looks at the extreme power created by an SLS rocket during a test at the Stennis Space Centre in Mississippi, along with NASA’s latest multi-purpose crew vehicle
MARS: Inside SpaceX will go inside SpaceX's plan to get humanity to Mars, providing an unprecedented glimpse into one of the world's most revolutionary companies. Filmed over the course of three years - this journey will take us behind the scenes with Elon Musk and his engineers - as they persevere amidst both disheartening setbacks and huge triumphs to advance the space industry faster than we ever thought possible.
Carl Sagan teaches students in a classroom in his childhood home in Brooklyn, New York, which leads into a history of the different mythologies about stars and the gradual revelation of their true nature. In ancient Greece, some philosophers (Aristarchus of Samos, Thales of Miletus, Anaximander, Theodorus of Samos, Empedocles, Democritus) freely pursue scientific knowledge, while others (Plato, Aristotle, and the Pythagoreans) advocate slavery and epistemic secrecy.