It was a near-death experience -- like those reported by thousands of others. But Alexander was determined to prove scientifically that it happened.
In his new book, "Proof of Heaven," he raises and then strikes down various hypotheses on how his journey could not happen.
Alexander said he is scientifically certain that his stricken brain could never have produced the images and ideas he experienced -- or remembered them.
"If you would have asked me before my coma, How much will someone who is in coma for a week with a severe bacterial meningitis -- so severe that the sugar level ... around my brain, normally around 60-80 and in a bad meningitis maybe down to 20; in my case it went down to 1 -- to me, that's just one piece of evidence of how severe this was. If you'd ask me how much would that patient remember, I'd say nothing," he said. "They wouldn't remember a single thing. ...The severity of the meningitis would have prevented dreams, hallucinations, confabulations, because those things all require a fairly coordinated amount of cortex."
Alexander isn't fazed at all by the skeptics. He was one, too.
Now he has "proof of Heaven," he said.
"For me, it's become clear that the best way to look at it is to turn it around and realize that consciousness exists in a much richer form, free and independent of the brain, which has everything to do with the eternity of our souls and the fact that our awareness, our consciousness, our soul, our spirit, does not depend on the existence of the brain in the physical universe. In fact, it's freed up to a much richer knowing when we're outside."