B Possibility of Black Hole research

[timmdeeg]

I see, but I thought the diagram is only schematic.

Altogether the 17 diagrams in this Book are very instructive. The first one shows just light cones with decreasing r getting increasingly tilted while their width decreases. There are various scenarios with one and two observers, with a rope going in, etc. The only scenario missing is the one discussed here.

 

[PAllen]

I see, but I thought the diagram is only schematic.

At least in this case, had the diagram been a little more precise with angles, and perhaps shown light cones along the infaller, it would have been less misleading.

I also just noticed some bad wording in the captions:

"The global time direction is in the direction of the axis of the cylinder". Taken literally, this is problematic, as the vertical direction is spacelike inside the horizon. But better wordings might sound pedantic, e.g. "the upper light cones are future pointing".