I can't spot any flaw in the reasoning. But one could sum up the essay as such: "A man from the XXIst century said it it's impossible to leave the solar syste

I can't spot any flaw in the reasoning. But one could sum up the essay as such: "A man from the XXIst century said it it's impossible to leave the solar system" Perhaps we should wait for what the man of the XXIInd century might have to say? We'll need a couple of magic wands, but we've already built a lot of them. Remember that in the early XXth century going into space was still science fiction.