Near-death experiences aren't just a Hollywood trope. From Plato's Republic to 18th-century medical texts, history is filled with testimonials from people who've nearly met their end and lived to tell the tale. Typical details including blinding white lights, an out-of-body floating sensation, a blurred montage of loved ones, and a feeling of deep peace. Are these experiences proof of a mythical afterlife, or does science have another explanation?

According to the SciShow's Hank Green, it's not that easy to study near-death experiences, as scientists have a hard time recruiting a large and reliable pool of participants. They think, however, that it's possible people may report seeing similar things during their brushes with death because they expect to see them. Other theories are that near-death experiences are biological and the result of the brain protectively flooding itself with neurochemicals, a psychological response to the threat of death, or a combination of all of the above.

Hear Green's full explanation below: