4. People used to sleep in segments.
Before the invention of electricity, rather than sleeping through the night many people would sleep for a few hours, wake up, read, write, socialize, pray, or reflect, and then got back to sleep for another few hours before waking up for the day (Photo Credit:: iStock).
5. All-nighters are never good.
If you're awake for 16 hours in a row, your mind's ability to function is impaired, similar to the feeling when you have a blood alcohol level of .05% (photo: iStock).
6. Color TV has changed the way we dream.
Prior to color film, only 15% percent of people dreamed in color. These days, 75% of people dream in color (Photo Credit: iStock).