> How is it possible to both detect a photon and then allow it to travel to the human eye?
Leonard Susskind explained it like this in one of his lectures (they are on YouTube, he's an excellent explainer):
From the moment the photon is emitted, to the moment it's detected, the photon exists in entanglement with all the intermediary things it "touched". Only at the final location it's "absorbed" (with a probability). At the intermediary locations the probability ended on the low side so it passed through.
Leonard Susskind explained it like this in one of his lectures (they are on YouTube, he's an excellent explainer):
From the moment the photon is emitted, to the moment it's detected, the photon exists in entanglement with all the intermediary things it "touched". Only at the final location it's "absorbed" (with a probability). At the intermediary locations the probability ended on the low side so it passed through.