Doctor Who and Black Holes

My kids and I love watching Doctor Who.  We recently watched the 9th and 10th episodes of the first season of the 10th Doctor and I must say the physics of black holes was horribly botched.  Still a fun couple of episodes to watch, but horrible science.  In these episodes, there is a ship on a planet about to be sucked into a black hole, but isn't sucked in because the planet is in orbit.  Everyone is shocked by how a planet can orbit a black hole.  Um...shocked?  This is exactly what is taking place with our current Solar System.  Okay, Earth itself is not orbiting a black hole, but the Solar System is orbiting the center of our galaxy which contains a super massive black hole!

The above image is straight from these episodes.  Ug...horrible representation of a black hole.  If the Sun were suddenly replaced by a black hole of equal mass, nothing happens to the orbit of the Earth.  The Earth continues to orbit as normal.  Mercury continues to orbit as normal.  Venus continues to orbit as normal.  You see the pattern.  Will Earth be sucked in?  No.  Gravity hasn't changed.  The first of these two episodes makes a big deal of a planet orbiting a black hole.  Orbiting is normal!  They should have made the planet NOT orbit the black hole.  Now that would be a big deal!

Again, despite the horrible science, Doctor Who is a wonderful show that everyone should watch.  If you have kids, watch it with your kids!