A friend sent a PowerPoint presentation about a professor holding a cup. The story goes like this: A professor walked into class one day and held up a cup of water for all to see. The professor asked, “How much do you think this cup weighs?” The students answered, “50g! 100g! 125g!”“I really don’t know unless I weigh it,” the professor said. “But my question is, what would happen if I held the cup like this for a few minutes?” More in this week's post.