I am just an amateur, so go easy on me. I am simply confused about schwarzschild radii and relativity. It seems to me that if you had two observers, one far away from a black hole, and the other just outside the event horizon, and you allow any small amount of time to pass, they would necessarily be travelling at different velocities due to the different gravitational forces. Because of this, their clocks would run differently. The one closest would run slower relative to the one far away. Yet both observers would still measure the speed of light as 'c' (~300,000,000 meters per second, even though each observer's meters and seconds differ from the other's). Given the equation for the schwarzschild radius, wouldn't the two observers measure the schwarzschild radius differently? I mean, their numerical answers would both be the same, but since their meters and seconds differ in relative value, wouldn't their results as well? I am a biologist, and could have just asked some people in the appropriate department, but I figured internet embarrassment would suffice.