Lenny Susskind’s Humour

I stumbled upon one of Lenny Susskind’s old arXiv papers titled “Rebuttal to a Paper on Wormholes“. In the abstract, he wrote a pretty harsh criticism on another arXiv paper by saying “the author of that paper demonstrated that he didn’t know what he was talking about. In this paper I correct the author’s naive erroneous misconceptions.” I was thinking whoever wrote the other paper must have been stunned and discouraged a lot considering Susskind being a pretty big guy in physics community. It turns out that the author of the other paper is Susskind himself! So after all, it was a harsh self-criticism:). In the other paper, he argued that time travel using a traversable wormhole is not likely possible because (he thought) it would violate two fundamental principles of physics. Apparently, he changed his mind in his rebuttal to himself. It’s funny.