Despite the gigantic leaps made by science in the last few decades, a comprehensive explanation of what exactly happens to us when we die is yet to emerge. Simultaneously, more research than ever before has now been done on near-death experiences -- those fleeting, almost supernatural experiences that hundreds of thousands of people have reported feeling on the brink of death.
This oxymoronic combination of progress and the lack of it has meant that a variety of theories on death have emerged in the last several years. Here's a quick look at some of them.
Dr. Eben Alexander III has been a neurosurgeon and an associate professor at Harvard Medical School for 25 years. In 2008, he contracted an extremely rare form of bacterial meningitis and fell into a deep coma. After seven days of virtual brain death, Dr. Alexander emerged from the coma, virtually unscathed. His recollection of the coma varies from a vision of murky brown, to a journey through "the core", where he was faced with the vision of God. Waking up, he realized there was another existence beyond the one he knew and had studied. Most scientists conclude that "when the brain actually dies, so does the mind/soul/self." But Dr. Alexander's experience shows that this isn't the whole truth -- how can the soul die with the brain if, in the midst of being brain-dead, one had a rich spiritual experience?
Dr. Bruce Greyson, a psychiatrist at the University of Virginia, is one of the foremost experts of near-death experiences, having studied more than 100 cases on incidents of near-death. From his work, he has learned that several patients have recounted experiencing a sense of peace, love and a feeling of "leaving the physical." Sometimes they even encountered deities or deceased loved ones. Although most scientists dismiss such "experiences" as nothing more than hallucinations triggered by a brain undergoing tremendous stress, Greyson believes that these near-death experiences suggest that your mind can actually function without the physical body. Like Dr Alexander, he says that this "incredibly lucid" experience happens often when the brain is clinically non-functioning.
Biocentrism expert and Huffington Post blogger Robert Lanza argues that since space and time only exist as tools for us to understand the world around us -- i.e. without consciousness, space and time don't actually exist -- we don't really ever die. Without the concrete existence of time, you can take any moment of time -- whether past or future -- as your new frame of reference. "Death is a reboot that leads to all potentialities," he says in one article.
Like much of the scientific community, Dr. Wendy Wright, a neurologist from Emory University, believes that near-death experiences are purely a function of endorphin release in the brain. "So when these chemicals are released, these different type of phenomena can occur: a person might see a light, or experience a sense of peace or calming. Feel that they're surrounded by loved ones." Such visions, although potentially comforting to the individual, are little more than tricks of the brain," she says.