In another thread, which I don't want to derail, the issue came up as to whether or not the event horizon of a black hole is physical. Some contend that it is physical but I contend that it is merely a set of coordinates (most easily represented by the spherical coordinate R). I DO recognize that any photon emitted exactly at the EH, and trying to propagate away from the singularity, is just going to stay right there at the EH, but somehow I just don't "get" that that makes the EH physical. One argument that I found particularly unacceptable was that just because you can say whether or not a coordinate-specified point is on or off of the EH, THAT makes the EH physical. I see that as nonsense. You could equally well say that any point exactly 50,000 miles from the center of the Earth is automatically a physical point BECAUSE it is exactly 50,000 miles from the center of the Earth. Using this definition there is no such thing as a set of coordinates that do not represent a physical place, and I just can't see that. Comments appreciated.