Highly recommendable.

The current view of black holes says that for Alice, who crosses the event horizon of a black hole, everything appears to be ok, whereas Bob, who observes her from outside, sees her boiling up in a hot soup on its surface.

Both “realities” are true. This actually is a strong supporter of constructivism, who states that observers construct their own reality. The fundamental questions, then, may not be asked about the reality of observers (which doesn’t make sense as a “reality”), but on the reality between observers.

Ok … constructivism at the level of photons ;)