Alan Alda (January 28, 1936 -)
The trouble with truth is that not only is the notion of eternal, universal truth highly questionable, but simple, local truths are subject to refinement as well. Up is up and down is down, of course. Except under special circumstances. Is the North Pole up and the South Pole down? Is someone standing at one of the poles right-side up or upside-down? Kind of depends on your perspective.
When I studied how to think in school, I was taught that the first rule of logic was that a thing cannot both be and not be at the same time and in the same respect. That last note, “in the same respect,” says a lot. As soon as you change the frame of reference, you’ve changed the truthiness of a once immutable fact.