Different religions throughout the world claim to understand what happens to us after we die. Scientists are not as certain. They can explain, of course, what happens in and to our bodies at the moment of death and just after. To doctors, clinical death comes when the heart goes into cardiac arrest, which can occur from a variety of causes—from a car accident to illness. In effect, most of us die from cardiac arrest. The heart stops beating, cutting off the flow of blood, and thus oxygen, to the brain. Next comes biological death, as the brain, other organs, and cells stop functioning because of a lack of oxygen.
Before reaching that point, however, in the window between clinical and biological death, doctors have been able to start the heart beating again, thus preventing death, or irreversible brain damage due to lack of oxygen. Thanks to research over the past several decades, doctors can now revive people whose hearts have stopped beating for as long as two hours, without any brain damage.
Sam Parnia, who studies heart resuscitation at the State University of New York at Stony Brook, says doctors now know that some cells, including brain cells, can function without oxygen for longer periods than once thought. After cardiac arrest, Parnia says, people enter a “gray zone, where death can be reversed.” The key is chilling the body by about seven degrees as quickly as possible, so doctors can begin the resuscitation process.
Parnia’s work has convinced him that even after cardiac arrest has led the brain to shutdown, a person’s consciousness can remain intact for up to several hours, though in what Parnia calls a hibernated state. That fact could explain the “neardeath experiences” (NDEs) some revived patients report. But beyond those few hours, most researchers believe, consciousness disappears, since, as scientist Richard Dawkins has said, the brain creates consciousness. Without a functioning brain, there can be no consciousness.
Not all scientists, though, share this view. Dr. Robert Lanza believes that quantum physics allows for the possibility that human consciousness is separate from the brain, and that consciousness continues after the body dies. Space and time are not external realities, he argues, but products of our consciousness. The world, in reality, has no space or time, and “death does not exist in a timeless, spaceless world.”
Whatever religions teach about life after death, it’s clear science is still trying to solve the mystery of what happens after we die. David Wilde, a British research scientist studying NDEs said in 2014, “We are still very much in the dark about what happens when you die ….”