Thanks for the response. If you are still interested in this, there's an useful link on the second page of this thread to a discussion of the same question: ht

Thanks for the response. If you are still interested in this, there's an useful link on the second page of this thread to a discussion of the same question: https://physics.stackexchange.com/questions/370446/is-randall-munroes-what-if-xkcd-correct-that-magnified-moonlight-cant-get-th/370600 https://physics.stackexchange.com/questions/370446/is-randal.... If you expand the comments on the answer, the back and forth presents most of the argument I would make, in a clearer form than I could muster.