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!
2015 • Astronomy
The expanding universe is a complicated place. During inflation the universe expanded faster than light, but that's something that actually happens all the time, it's happening right now. This doesn't violate Einstein's theory of relativity since nothing is moving through space faster than light, it's just that space itself is expanding such that far away objects are receding rapidly from each other. Common sense would dictate that objects moving away from us faster than light should be invisible, but they aren't. This is because light can travel from regions of space which are superluminal relative to us into regions that are subluminal. So our observable universe is bigger than our Hubble sphere - it's limited by the particle horizon, the distance light could travel to us since the beginning of time as we know it.
In the Orion constellation, Betelgeuse, a red star 1,000 times the size of the Sun, is an old star that scientists predict will soon come to a violent end. Will we see a supernova explosion 100 times brighter than a full moon in our lifetimes? Will the explosion release rays harming life on Earth?
Asteroids have a bad reputation as deadly rocks from space. They wiped out the dinosaurs and will be back for us. But that's only half the story. Ancient asteroids built the Earth. And they may have brought life to its barren surface. Asteroids will shape our future as much as our past. They are the perfect location for deep space colonies and could be the stepping stones that eventually send humans out into the cosmos. From icy worlds with more fresh water than Earth to flying mountains of pure metal, a hundred miles wide, scientists are striving to unlock their secrets. Could these enigmatic space rocks hold the key to how life in the Universe arises and is extinguished?