Can someone adjudicate the conflicting answers to "what is the velocity when falling at the event horizon of a black hole"?
I personally like <PERSON> answer at https://physics.stackexchange.com/q/255281/. It makes sense to me. I would just add that plugging in the numbers, <PERSON>'s math leads to the interesting result that the fall velocity across the event horizon from a very far away distance is 0.75c.
But others say that the speed cannot be defined at all becasue there is no meaningful reference frame to use, which seems inconsistent to me. After all, we have a physical length for the event horizon radius. Does not the specification of a length imply a reference frame?
And yet others say that the fall velocity is the same as the escape velocity at https://physics.stackexchange.com/q/515739/.
Is there some sort of officiating body at Physics Stack Exchange who can pick one of these three answers as the "conventionally accepted" answer? That is, to that question about throwing a ball at a black hole, is the velocity as it crossed the event horizon (a) slower than lightspeed, (b) undefinable, or (c) lightspeed? Or is this a question with no conventionally accepted answer?
To clarify: at least at wikipedia, I can see a description of the black hole at the center of the Milky Way as being at a distance of 25,000 lightyears and having a radius of 118 million meters. 275
So the reference frame I am using is the one defined by those lengths (which, in turn, implies that time is passing as measured by my wrist watch here on Earth, since length can always be measured as ct, so the 25,000 lightyears implies time passes as I measure it). So I am postulating a falling ball that is currently at some definable position, say 118 million meters + 300 meters from the black hole center, at time = noon. My definition of velocity will be the (distance 300 meters)/(time to reach the event horizon). So if the object fell at light speed of 300 m per microsecond, it would arrive at 1 microsecond past noon, as I would calculate it (not as I would see it, I understand that I cannot see it ever). I think that I would calculate it arriving at noon + 1/0.745 microseconds by my watch based on the final equation at <PERSON> answer at https://physics.stackexchange.com/questions/255281/why-can-an-object-not-reach-the-speed-of-light-by-falling-in-a-gravitational-fie?rq=1 plugging in an initial distance of very large and a final distance of the black hole radius. 275