A: Your brain

WHY YOU SHOULDN’T MAKE DECISIONS WHILE FLYING: One British scientist says that your brain doesn’t work as well at 40-thousand feet as it does on the ground. Professor David Gradwell explains that the pressure on board planes is lower than it is at sea level, which makes it harder for the brain to use the oxygen in the air, and therefore harder to perform tasks. Gradwell says the cabin pressure inside an airplane is the same at about eight-thousand feet as it is at 40-thousand feet, and that learning at either height is a bit impaired. He doesn’t advise making big decisions while flying, but says that if you regularly do crossword puzzles on the ground, you’ll have no issue doing them in the air, but if you attempt to do one for the first time, you’ll find that you probably won’t do as well as you would on the ground. (Daily Mail)