Please Explain

'What are the facts? Again and again and again - what are the facts? Shun wishful thinking ... avoid opinion ... facts are your single clue. Get the facts!' - time Enough for Love, Robert Heinlein Does eating celery make you lighter? Do you have to be dying to have a near-death experience? Is a yawn a silent, natural scream for air; and if a little oxygen is good for you is more oxygen better? Can the humble spud kill? Did Galileo drop his balls from the Leaning tower of Pisa? Did a NASA co...