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: What makes a theory a scientific one? (Synopsis) - “I cannot help fearing that men may reach a point where they look on every new theory as a danger, every innovation as a toilsome trouble, every social adv...
21 hours ago