If you've ever been up all night, you may have found that staying awake becomes a lot easier after five or six a.m. Why?
You are exposed to relatively high doses of radiation from the time you go through security to the moment your plane lands.
Chances are you've heard a description of what's called a near death, out-of-body experience. For a lot of people, it's a powerful, even mystical experience.
For people with REM sleep behavior disorder, or RBD, the action in the dream is acted out in reality!
Almost all mammals, in fact, have REM sleep; birds do too, although only in the early parts of their lives. It seems that sleep and REM are required by a particularly complex kind of brain.