It is no good getting furious if you get stuck. What I do is keep thinking about the problem but work on something else. Sometimes it is years before I see the way forward. In the case of information loss and black holes, it was 29 years.
“The most important and urgent appeal we have to make is for an immediate cease-fire. Initial reports from the cease-fire talks being held in N'Djamena in Chad are not very encouraging.”