Since my co-blogger Adam Frank posted yesterday that hilarious Monty Python video examining whether there is life after death, and Mark Memmott of The Two-Way blog wrote Monday on Hawking's pronouncements on the same topic quoting me, I couldn't resist contributing to this valuable debate with a few remarks on life-after-death experiments.
I quote from my book A Tear at the Edge of Creation, where I described both my teenage fantasy of measuring the weight of the soul and a "serious" attempt from early in the twentieth century that got a lot of press at the time:
Reading Frankenstein as a teenager incited even more my fantasy of becoming a Victorian natural philosopher lost in the late twentieth century. When I joined the physics department at the Catholic University at Rio in 1979, I was the perfect incarnation of the Romantic scientist, beard, pipe and all. I remember, to my embarrassment, my experiment to "investigate the existence of the soul." If there was a soul, I reasoned, it had to have some sort of electromagnetic nature so as to be able to animate the brain. Well, what if I convinced a medical facility to let me surround a dying patient with instruments capable of measuring electromagnetic activity, voltmeters, magnetometers, etc.? Would I be able to detect the cessation of life's imbalance, the arrival of death's final equilibrium? Of course, the instruments had to be extremely sensitive so as to capture any minute change right at the moment of death. Also, for good measure, the dying patient should be on a very accurate scale, in case the soul had some weight. I remember explaining my idea to a professor [...] I can't remember exactly what he said, but I do remember his expression of muted incredulity.
Of course, I was only half serious in my excursion into "experimental theology." But my crackpot Victorian half, I am happy to say, had at least one predecessor. In 1907, Dr. Duncan MacDougall of Haverhill, Massachusetts, conducted a series of experiments to weigh the soul. Although his methodology was highly suspicious, his results were quoted in The New York Times: "Soul has weight, physician thinks," read the headline. The weight came out at three quarters of an ounce (21.3 grams), albeit there were variations among the good doctor's handful of dying patients. For his control group, MacDougall weighed fifteen dying dogs and showed that there was no weight loss at the moment of death. The result did not surprise him. After all, only humans had souls.
Those interested in more details of this and other stories, should read Mary Roach's hilarious and informative Stiff: The Curious Lives of Human Cadavers and consult this site. Dr. MacDougall's measurements inspired the 2003 Hollywood hit movie 21 Grams, which featured Sean Penn playing the role of an ailing mathematician.
Back to Hawking, I must agree with him. Although from a strictly scientific viewpoint we haven't proven that there is no life after death, everything that we know about how nature works indicates that life is an emergent biochemical phenomenon that has a beginning and an end. From a scientific perspective, life after death doesn't make sense: there is life, a state when an organism is actively interacting with its environment, and there is death, when this interaction becomes passive. (Even viruses can only truly be considered alive when inside a host cell. But that's really not what we are taking about here, which is human life after death.) We may hope for more, and it's quite understandably that many of us would, but our focus should be on the here and now, not on the beyond. It's what we do while we are alive that matters. Beyond life there is only memories for those who remain.