On 12/26/2012 10:56 PM, Abd ul-Rahman Lomax wrote: > At 05:56 PM 12/26/2012, Craig wrote: >> Isn't it a calculated location? Isn't it the radius from the center >> of the black hole at which a theoretical object at a great distance >> would reach the speed of light when falling into the black hole from >> its gravity? > > No. Mass doesn't ever reach the speed of light. Light only travels at > the speed of light....
Black holes defy the laws of physics. The escape velocity of a black hole is greater than the speed of light. The escape velocity is the same speed at which an object, falling from infinity, would reach when it hit the center of mass. Einstein's General Theory of Relativity treats gravity in a similar way to objects travelling very fast. Objects in a strong gravitational field appear to slow down from an observer in a lesser gravitational field. As the ship neared the event horizon, its clock would slow down. An outside observer would never see it reach the event horizon because at that point, the clock would stop. The formulas are similar to that of a ship speeding away at an ever increasing speed. Craig > > I'm puzzled here. > > In fact, I'm seriously starting to smell a rat. > > There is one somewhere around here, and I don't know if it's only in > my thinking, or in how event horizons and the like are being explained. > > The event horizon is being described as the boundary around a black > hole where the gravity is so intense that light cannot travel away > from the hole at all. > > Yet it's also being stated that the event horizon is generally between > the observer and the singularity, that if you cross the event horizon, > the singularity is still in front of you. > > I'm having a bit of trouble wrapping my mind about both ideas at the > same time. > > It's also being said that a spaceship approaching the event horizon > from an observer's direction would appear to slow down, and redshift, > until it disappears. The slowing down, why? The ship is actually, as > it approaches the horizon, accelerating. Light leaving it, before it > reaches the horizon, will be redshifted, but that light will still > travel at the speed of light. Why would the ship appear to slow down?
