Hi all,
Forgive me if this is rudimentary, but I have just been enlightened by the fact that it IS possible for a planet (or anything) to orbit a black hole. My prior knowledge was not only informed by Science Fiction, but by documentaries such as BBC Space (with Sam Neill) which consistently imply that NOTHING can escape from a black hole. Giving it the status of some sort of monster that can eat whole Solar Systems.
Now I have learnt that (hypothetically) if the Sun were to magically turn into a black hole (minus the fireworks), the Earth's orbit would continue unchanged.
So when BBC Space says something like "there are millions of black holes that could potentially swallow our planet" - they are leaving out the fact that there are billions of stars that would have exactly the same devastation if they wandered nearby.
I understand (very vaguely) that you have to pass the "event horizon" of a black hole, or in other words, be really close to it to not be able to escape. But if you were that close to a star, you would be on fire anyway, so black holes are no more dangerous than stars.
Please somebody correct me if I'm wrong, but more importantly, can anyone explain why SciFi gets this so wrong? Is this only a new development in the study of black holes, or has it always been known? As a Doctor Who fan, I am particularly dissapointed that the premise of "The Impossible Planet" episode is a complete fail.