Note that different people have different research approaches. The two old ladies check that none of them can see herself and the problem is solved! ;-)
The other older lady makes an experiment with motion and rigorously determines that she is ... well ... unsichtbar. :-)
Ask Ethan #33: A Flight Without Stars (Synopsis) - “Don’t get involved in partial problems, but always take flight to where there is a free view over the whole single great problem, even if this view is sti...
3 hours ago