Recently, scientists may have found a plausible biological explanation for the collection of phenomena known popularly as "Near Death Experiences (NDE)." According to the study, people who have died and experienced the common elements associated with near death experiences like white light, a tunnel, floating above their body are actually dreaming.

"I see it as an activation of certain brain regions that are also active during the dream state," explains Dr. Kevin R. Nelson of the University of Kentucky in Louisville, in a prepared statement for a study just published in Neurology.

There’s a great little article in last week’s New York Times, Down For The Count which overviews recent scientific research on sleep.

“Sleep has attracted a tremendous amount of attention in science, but we really don’t know what sleep is.”