Don't know if you're familiar with the character Ali G? He was the creation of English actor and comedian, Sacha Baron Cohen. Anyway, he did a series of spoof interviews with famous people, where he would wrong foot them with his bizarre line of questioning.
Anyway, he asked astronaut Buzz Aldrin, "does the moon exist?" Buzz, commendably, took the question in his stride, replying that not only did the moon exist, but he and his crew went there. Thing is though, this is almost the identical question Einstein (to illustrate a point) asked Niels Bohr - "does the moon exist, when no one is looking at it?" Immanuel Kant, as you probably know, was asking similar questions 100 years previously; does any phenomena or object exist objectively beyond the act of observation, and in what form? These questions aren't as absurd as they first appear, not only to philosophers, but also to physicists.