[el_draco (Rom)]

Briefly, Its all about gravity and inertia. The earth stays in orbit around the sun because the pull of gravity exactly matches the tendency of the planet to want to go in a straight line and "leave" so to speak.

The source of the gravitational field is not really relevant in this context. The "you'll never escape" concept comes from the reality that if you can not travel fast enough to atleast balance the gravitational attraction of the object, star or black hole, you will inevitably get drawn in to it.

Frizzle either way because of the radiation and temperature around either type of object. Black holes generate nasty amounts of most things that will obliterate your DNA in a flash; a star will fry you just as nicely.

Nothing in theory can escape the black hole once it passes the event horizon because the speed required would exceed the speed of light, which is probably about as fast as we can go in this universe. Hence, the hole is "black" because you cant see anything beyond the Event Horizon.

BBC is correct in that if a black hole of any appreciable mass approached our solar system, it would disrupt the gravitational balance and could happily gobble us up.

So would another star....

Now, the physics is somewhat flexible when the hole gets really big, like at a galactic core. The big buggers may be able to be "played with a bit" but rest assured, the ultimate result would be the same for a planet or entire star. Get to close and you are gonna get eaten.

Hope this, "really simplified" answer helps.

Rom