YOU MAY BE relieved to hear that my next guest does not believe in leprechauns. He has an M.D. from Stanford and an undergraduate degree from Yale in chemical engineering, with a special interest in thermodynamics and information theory. Nor does he have a friendly nickname for the soul. He has the opposite of a friendly nickname. He calls it “the (obligatory) negative entropy (i.e., energy/weight equivalent) that is necessary to allow for the nonequilibrium meta-stable physical ‘quasisteady-state’ of a living/conscious biological system.” And he has a plan to weigh it.
Gerry Nahum is a professor at the Duke University School of Medicine who works in an atmospheric old building called Baker House. The building holds an unlikely mix of what I’m guessing is runover from the rest of the medical center. Nahum shares the second floor with the Brain Tumor Center, Dr. C.H. Livengood, Pastoral Services, and the jolly-sounding Endocrine Fellows Office. He himself teaches obstetrics and gynecology. When I first learned this, I thought that perhaps Nahum had been scheming with Donald Gilbert Carpenter, and that any day now, the two of them would be ushering forty-three-days-pregnant women onto extraordinarily sensitive Duke University scales and watching the readout for the arrival of the Mac/(obligatory) negative entropy. Hardly.
Nahum is leaning back in his desk chair, fiddling with his tie, listening to me sputter about what it is I want to know. The tie is patterned with a university logo, very much in keeping with the decor, which is: thirty-one framed diplomas, degrees, and award certificates.
I’ve just described to Nahum the experiments of Duncan Macdougall, hoping to get his professional opinion regarding what might have caused the mysterious weight losses. A flicker of worry crosses Nahum’s brow. Before I arrived, we exchanged a few e-mails, but I failed to fully prepare him for the depths of my ignorance. My ignorance is not merely deep, it is broad; it is a vast ocean that takes in chemistry, physics, information theory, thermodynamics, all the many things a modern soul theorist must know. Nahum pronounces Macdougall’s experiment “silly.” He says you’d need not just a scale, but a completely isolated system.
This system—which Nahum would very much like to build—would be a sort of box, a box completely isolated from the surrounding environment. The box sits atop a mind-blowingly sensitive scale, and all around it are arrays of electromagnetic energy detectors. These detectors measure all the different types of known radiant energy (as opposed to informational, or “soul” energy, for which there are no detectors) that might leave the box. Now let’s say there’s an organism in the box—a paramecium or a wombat or John Tesh; it doesn’t matter. And that organism dies inside the box.[15] If the electromagnetic detectors detect energy leaving the box, there should be a corresponding change in weight. Why? Because of the laws of physics: There is always a weight loss associated with an energy loss. I’m not talking about the listless feeling that besets the overambitious dieter. I’m talking about E = mc2. If the energy changes, then the mass (which is proportionate to weight) must change—in, you know, a teensy, tiny, infinitesimal physics lab way. So if the mass lost when the organism dies is more than what would be expected based on the energy change, then something’s leaving the box in a way that can’t be accounted for. That something being, perhaps, the soul, or consciousness, heading out to some higher dimension—Lew Hollander’s place beyond the open window.
Theorists like Nahum think of the consciousness as information content. And information, to a quantum physicist anyway, has an accepted energy equivalent. And thus a (very very very light) weight. “The change in the heat that has to be liberated per bit of information lost is about three times ten to the minus-twenty-one joules,” Nahum says.
I must have made some sort of face. “I’m making this as simple as I can,” Nahum says. When you’re as brainy as Gerry Nahum is, you lose sight of just how ignorant the rest of us are. Earlier on in our talk, he prefaced the line “Quite a few people look at microtubules as what can be considered almost like an abacus for molecular calculation at a subcellular level” with the phrase “As I’m sure you’re aware.”
For the sake of not completely derailing the explanation, we’re going to accept that the energy lost when one unit of consciousness information is destroyed has been determined by pedigreed physicists to be three times ten to the minus-twenty-one joules, and let Dr. Nahum continue. “And if you use the mass-energy equivalent equation”—the Einstein thing—“then you can say, ‘Well, if that’s true, then that has to represent three times ten to the minus-thirty-eight kilograms.’” So the weight of one bit—the basic unit of information, the stuff that makes up human consciousness—is a billionth billionth billionth of a billionth of a kilogram. “It’s very small,” says Nahum, and that I understand.
But how many bits are there in a consciousness? Or in one thought? When I think to myself, Is this man blowing smoke up my microtubules? how many bits are involved? Not known. “Is a thought one billion bits?” says Nahum. “Ten billion? We don’t know. When we look at consciousness, what is embodied in that? How many bits? We don’t know.” In a way, it doesn’t matter. What’s important for our does-the-soul-exist purposes is that changes can be detected. The energy loss created by a soul heading out the window can, in theory, be detected as a weight loss.
The Fairbanks company does not make a scale for Gerry Nahum’s purposes. Does anyone? Possibly. Scales have traveled a surprising distance since Macdougall’s day. There are scales that easily and accurately measure micrograms, a microgram being a millionth of a gram. Measuring a billionth of a gram—a nanogram—is also possible, though costly. “What about a picogram?” muses Nahum. That’s a trillionth of a gram—10 to the minus-15 kilograms. “Can we measure that? Yeah, we can. Remember I gave you the figure ten to the minus-thirty-eight kilograms?” I remember: in the discussion of the weight of one bit of information. “I’ve just told you I can measure fifteen orders of magnitude of that. The question is, can I measure the next twenty?” Maybe he doesn’t have to. Assuming the consciousness is made up of a vast number of bits, maybe he can get away with the picogram scale.
Nahum says the electromagnetic field arrays around the box are more problematic than the scale. None of these detectors operate over the entire electromagnetic spectrum, so Nahum would have to overlap and improvise. Despite this, he thinks it could be done.
But what if the soul—the residual energy/information that doesn’t register on our electromagnetic energy detectors—doesn’t go somewhere else, but just, you know, snuffs out? Ceases to exist? That has always been my own depressing, humdrum assumption regarding death. No can be, says Nahum. Standing in the way is the First Law of Thermodynamics: Energy is neither created nor destroyed. It has to go somewhere. Nahum says he became convinced that this applied to the consciousness when he was five years old. Around the age you and I were puzzling out the intricacies of the shoelace, Nahum was “thinking about how it had to be conservative, that there’s no way out.” Nahum swivels to face me. “The question then becomes, Where does it go? The question is not, Is it there? It’s there.”
15
Credit for the original seal-a-soul-in-a-box experimental format must go to Frederick II, the thirteenth-century King of Sicily and Emperor of the Holy Roman Empire. In the diaries of the king’s sometime chronicler, the Franciscan monk Salimbene, there is a description of Frederick shutting up “a man alive in a cask until he died therein, wishing thereby to show that the soul perished utterly.” Though Frederick is to be credited for his precocious enthusiasm for scientific method, the cruelty of his experiments invariably outweighed their scientific merit. To wit, the time he “fed two men most excellently at dinner, one of whom he sent forthwith to sleep, and the other to hunt; and that same evening he caused them to be disemboweled in his presence, wishing to know which had digested the better” (the sleeper). At least that one makes some sense.