by Jim Holt
“No, Jim, I’m being philosophically elastic,” he said. “I’m not necessarily siding with Leibniz. Maybe one can imagine time flowing in a Null World, as Newton did. But that’s not how the Big Bang model works! The model itself says that the initial singularity marks a temporal boundary. If you take the model to be physically true, then that’s where time begins.”
So was he saying that the very idea of a world coming into existence out of nothingness was nonsensical?
“Yes, because it implies a process taking place in time. To ask how the universe came into existence in the first place presupposes that there were earlier moments of time when nothing at all existed. If the theory allowed us to talk about such earlier moments—time before the Big Bang—then we could ask what was going on then. But it doesn’t. There is no ‘before.’ So there’s no gap for God to sneak into. You might just as well say that the universe came out of nirvana!”
But it’s not just religious believers who dwell on the gap between Nothingness and Being, I objected. Plenty of atheist philosophers are also on record professing astonishment that there should be a cosmos. I mentioned one in particular, J. J. C. “Jack” Smart—a tough-minded Australian philosopher of science and, like Grünbaum, an uncompromising materialist and atheist. Smart said that Why does anything exist at all? struck him as the “profoundest” of all questions.
“Well, I’ll tell you something about Jack,” Grünbaum replied. “He had a very religious upbringing. He may be an atheist now, but he once told me he’d be glad if someone could refute his arguments against religion, because he missed his old beliefs. People like him have a deep-seated tendency to be awed or amazed by the existence of the world. Like I say, they absorb it with their mother’s milk.”
I could not resist bringing up Ludwig Wittgenstein, who was also obsessed with the mystery of existence. Many philosophers deem Wittgenstein the greatest philosophical figure of the twentieth century. But Grünbaum, I quickly learned, was not among them.
“I’m sorry,” he said, rolling his eyes, “but the paper where Wittgenstein talks about that is just dreadful. It’s an unbelievably sick paper, semi-psychotic. He gets to the end of his lecture and says he’s in ‘awe’ of the question Why is there something rather than nothing? But he also claimed that the question had no sense! Then why is he still in awe of it if he’d debunked it? He needed to see a psychiatrist and not inflict his ‘awe’ on us.”
I began to wonder whether Grünbaum might not be the most unflappable philosopher I had ever met. Clearly he did not suffer from any dread of Nothingness—what he derisively called the “ontopathological syndrome.” Clearly he was unastonished by a world of Being. Did anything astonish the man? Was there any philosophical problem he found awesome and bewildering? What about, for example, the problem of how consciousness arises from brute matter?
“I’m amazed by the variety of consciousness and the kinds of things that the human mind can come up with,” he said. “It’s all very splendiferous! But I don’t find the existence of consciousness puzzling.”
I noted how different his attitude was from that of the philosopher Thomas Nagel, one of my intellectual heroes. In his book The View from Nowhere, Nagel pondered at length the mystery of how the mind’s irreducibly subjective character could fit into the objective physical world.
“I’ve never read that book,” Grünbaum said.
But it’s such an important book! I stammered. The Oxford philosopher Derek Parfit declared Nagel’s book the greatest philosophical work of the postwar era.
“Did he?” Grünbaum replied. “Well good for him! But as for me, why should I be puzzled that I’m put together the way I am? I know that many things have shaped my personal history. And there are many things about myself that I don’t understand—why I have certain habits and tendencies, for example. But these are biological or bio-psychological questions. With enough evolutionary theory and genetics and what-have-you, they become potentially interesting. But I don’t sit around wondering why I’m the way I am. I don’t live in a limbo of dubiety.”
If, as Aristotle remarked, philosophy begins with wonder, then it ends with Grünbaum.
Still, the scope of the man’s knowledge was breathtaking. The nature of time, the ontological status of scientific laws, the extravagances of quantum cosmology: all yielded before his precise and rigorous understanding. And the sheer pleasure it all gave him (“I’m having a ball!”) was contagious.
I asked him whether it was possible that an entity in our universe’s distant future—an “omega point,” as some thinkers have called it—might have reached back in time and retroactively caused the very Big Bang that brought the whole show into being.
“Ah,” he said, “you’re talking about retrocausation. Is such a thing possible?” He then launched into a learned disquisition on cause and effect whose virtuosity reminded me of a great diva delivering an opera aria. I listened with more awe than understanding as he wrapped it up: “Well, they got it wrong because they misextrapolated from second-order equations in Newtonian mechanics, where forces are causes of accelerations, to a third-order differential equation, Dirac’s equation, in which forces are not causes of accelerations. So even though when you integrate over all future time you have force quantities in the integral—called ‘pre-accelerations’—that doesn’t mean that this instantiates retrocausation of acceleration by forces. Say, would you like a little gin? I think I’ve got some here.”
As he reached into a lower desk drawer for the salutary bottle and a couple of glasses, I gratefully accepted the offer.
HAD GRÜNBAUM SHAKEN my conviction that the mystery I was pursuing was a genuine one?
Well, the Great Rejectionist had certainly changed my mind about one thing. Contrary to what I had assumed—along with just about every scientist and philosopher who has ever pondered the matter—the Big Bang does not, in itself, make the mystery of existence more acute. It does not mean that the cosmos somehow “leapt into being” out of a preexisting state of nothingness.
To see why, let’s play the tape of the universe’s history backward. With the expansion reversed, we see the contents of the universe coming together, growing more and more compressed. Ultimately, at the very beginning of cosmic history—which, for convenience, we’ll label t = 0—everything is in a state of infinite compression, shrunk to a point: the “singularity.” Now, Einstein’s general theory of relativity tells us that shape of spacetime itself is determined by the way energy and matter are distributed. And when energy and matter are infinitely compressed, so too is spacetime. It simply disappears.
It is tempting to imagine the Big Bang to be like the beginning of a concert. You’re seated for a while fiddling with your program, and then suddenly at t = 0 the music starts. But the analogy is mistaken. Unlike the beginning of a concert, the singularity at the beginning of the universe is not an event in time. Rather, it is a temporal boundary or edge. There are no moments of time “before” t = 0. So there was never a time when Nothingness prevailed. And there was no “coming into being”—at least not a temporal one. As Grünbaum is fond of saying, even though the universe is finite in age, it has always existed, if by “always” you mean at all instants of time.
If there was never a transition from Nothing to Something, there is no need to look for a cause, divine or otherwise, that brought the universe into existence. Nor, as Grünbaum observes, is there any need to worry about where all the matter and energy in the universe came from. There was no “sudden and fantastic” violation of the law of conservation of mass-energy at the Big Bang, as his theistically minded opponents have claimed. According to the Big Bang cosmology, the universe has always had the same mass-energy content, from t = 0 right up to the present.
Still, why should all of this matter and energy exist in the first place? Why do we find ourselves in a spacetime manifold with a certain geometrical shape and finite age? Why is this spacetime saturated with all kinds of physical fields and particles an
d forces? And why should those fields and particles and forces be governed by a particular set of laws, and a rather messy set at that? Wouldn’t it be simpler if there were nothing at all?
Grünbaum had done his best to dispel the notion that there was anything metaphysically important about simplicity. He was willing to concede, for the sake of argument, that the Null World might well be the simplest form reality could take. Yet he could see no reason for this to stack the odds in favor of nothingness. “Why should we think that the simple is ontologically more likely to be true?” he kept asking rhetorically.
He had a point. And for some philosophers, this is where the argument grinds to a halt. Why should considerations of mere simplicity make us think that, barring some preternatural force or cause, there should be Nothing rather than Something? What’s wrong, ontologically speaking, with complexity? Either you have a hunch that the sheer existence of the world needs an explanation, or you have a hunch that it doesn’t. Grünbaum stood firmly in the latter camp, and no intuitions about the alleged simplicity of nothingness were going to move him.
But maybe he was undervaluing the power of simplicity. For scientists, after all, simplicity is nothing less than a guide to truth. As the physicist Richard Feynman put it, “The truth always turns out to be simpler than you thought.” It is not that they want reality to be simple; rather, they want their theories of reality to be as simple as possible.
It’s surprisingly tricky to say what makes one theory simpler than another. Still, there are some agreed-upon criteria. Simple theories posit few entities, and few kinds of entity; they obey the principle of Occam’s razor: “do not multiply entities needlessly.” Simple theories also have the minimum number of laws, and those laws take the simplest mathematical form. (Straight-line equations, for example, are deemed to be simpler than complicated curves.) Simple theories are also parsimonious when it comes to arbitrary features—unexplained numbers like Planck’s constant and the speed of light.
Simple theories are obviously more convenient to use, more congenial to our intellects. They also appeal to our aesthetic sense. But why should they be more likely to be true than complex theories? This is a question that philosophers of science have never satisfactorily answered. “I suspect that it is not possible fully to justify the idea that simple theories are objectively more likely to be true than are complex ones,” Jack Smart has observed. Nevertheless, when scientists have in hand two rival theories that are equally consistent with past evidence, it is the simpler of the two that they invariably prefer, since it is seen as more likely to be confirmed by future data. And the conviction that simpler theories are more probable than complicated ones is not confined to scientists. Suppose you have two equally well-confirmed theories, A and B. Theory A predicts that all life in the Southern Hemisphere will be wiped out tomorrow. Theory B predicts that all life in the Northern Hemisphere will be wiped out tomorrow. And suppose that Theory A is very complicated and Theory B is very simple. Then which of us northerners would not be trying to get on a plane for the Southern Hemisphere tonight?
If simple theories are indeed more likely to be true than complicated ones, that must be because the world as a whole has a deep-seated bias toward simplicity. Such a bias seems to have been successfully exploited by physicists in their search for the ultimate laws of nature. The “symmetries” that physicists look for in those laws are, as the Nobel laureate Steven Weinberg has pointed out, really principles of simplicity—principles that say, for example, the future should resemble the past in its most basic respects.
But simplicity is, for scientists, more than a guide to truth. It is also, as Weinberg has observed, “part of what we mean by an explanation.” It is simplicity that distinguishes a “beautiful explanatory theory” in physics from a “mere list of data.” Richard Dawkins made a similar point. Complicated realities, Dawkins submits, are more improbable than simple ones, and therefore stand in greater need of explanation. Take the existence of biological life. To posit a God as its cause is a nonstarter, Dawkins argues, since “any God capable of designing a universe, carefully and foresightfully tuned to lead to our evolution, must be a supremely complex and improbable entity who needs an even bigger explanation than the one he is supposed to provide.” It is the simplicity of natural selection that makes it a satisfying explanation of life.
Now, the simplest theory of all is the one that says NOTHING EXISTS. This theory—the Theory of Nothingness—posits no laws and no entities; it has zero arbitrary features. If simplicity is indeed a mark of truth, then the Theory of Nothingness must enjoy the highest a priori probability. Absent any data about reality, the Null World is the one that should be expected to obtain. But it does not obtain! There is evidently a great abundance of Being. If we are scientifically minded, this should surprise us—shouldn’t it?
Yet it did not surprise Grünbaum. So what, he said, if the Null World has the greatest a priori probability? “Probabilities just do not legislate ontologically,” he kept insisting. Probability is not, in other words, a force driving the way reality should turn out, a force that had to be countered by another force, divine or otherwise, if there was to be Something rather than Nothing. That the universe seemed to confound the canons of science just didn’t strike him as an intellectual problem.
Sometimes, of course, complicated theories do turn out to be true. As Grünbaum had pointed out, the modern theory of chemistry, which posits a whole periodic table full of elements, is a lot more complicated than the ancient chemical theory of Thales, based on water alone. But when scientists are faced with such complicated theories, they invariably look for simpler ones that underlie and explain them. A notable case is the contemporary quest for a unified theory of physics. Here the motive is to show that the four basic forces of physics—gravity, electromagnetism, the strong nuclear force, and the weak nuclear force—are all manifestations of a single underlying superforce. Such a unified theory—a “Theory of Everything,” as it is sometimes called—would be superior to the partial theories it supersedes because of its relative simplicity. Instead of positing four forces, each governed by a distinct law, it would posit a single force-cum-law. In doing so, it would offer a more comprehensive explanation of nature than the current theoretical patchwork. Indeed, such a unified theory might turn out to be the closest we can come to giving a complete physical explanation of why the world is the way it is. But the final theory of physics would still leave a residue of mystery—why this force, why this law? It would not contain within itself an answer to the question of why it was the final theory. So it would not live up to the principle that every fact must have an explanation—the Principle of Sufficient Reason.
On the face of it, the only theory that does obey this principle is the Theory of Nothingness. That is why it’s surprising that the Theory of Nothingness turns out to be false, that there is a world of Something. And any theory of this world of Something, however simple and ultimate, is doomed to fail the test of Sufficient Reason.
Or is it? Mightn’t there be, after all, a theory of this world that leaves no unexplained explainers, one that reduces the residue of mystery all the way to zero? Finding such a theory would be tantamount to answering the question Why is there something rather than nothing? Adolf Grünbaum and his ilk might think this theory is not worth searching for—especially if the search takes a supernatural turn. But their arguments, while admittedly formidable, did not leave me convinced that the quest should be abandoned. There is nothing I dislike more than premature intellectual closure.
THAT NIGHT I got a personal glimpse into the Abyss of Nonbeing.
The plan for the evening seemed a good one. Adolf, accompanied by his wife Thelma, would pick me up at my hotel. Then we would set off for dinner at a restaurant called Le Mont, perched high above Pittsburgh on Mount Washington. The view was reputedly spectacular.
Adolf was driving a late-model Mercedes-Benz. His wife, a charming and somewhat abstracted woman of the same age, sat next to
him. I sat, like their son, in the back seat.
It was when we got onto the freeway running along the Allegheny River that my pulse began to race. A diminutive man, shrunken by age, Adolf could barely see above the dashboard. It was like having, well, Mr. Magoo for a chauffeur. Oblivious to the heavy and fast-moving traffic around us, he maintained a constant monologue as he tried to work out the route. We were having one close call after another, but Adolf and his wife seemed blissfully unaware of the angry honks coming from the other cars. The longer we drove, the more Mount Washington seemed to recede from us. It was like a cruel real-life version of Zeno’s paradox.
Eventually we somehow found ourselves on the other side of the mountain—where, perversely, the speed and volume of the traffic only increased. The angry honking around us continued, and the probability of escaping a serious collision seemed headed toward zero. Would I walk away from the smoking wreckage? Possibly: we were, after all, in a late-model Mercedes. But I couldn’t help fearing that the precious flame of my consciousness was about to be extinguished eternally, that I was in danger of making the transition from Pittsburgh to Nothingness.
Finally Adolf responded to my frantic pleas to pull over with a breathtaking maneuver: he came to a dead stop in the middle lane. A passing state trooper took note of our predicament, and we were kindly set right and escorted to the mountaintop restaurant. On arriving, I found myself to be more than usually in need of a fortifying bumper of champagne.
“Go relax and enjoy yourself! Don’t worry about why there’s a world—it’s an ill-conceived question!” Grünbaum exclaimed to me nonchalantly, with a trace of paternal affection, once the three of us had been seated at our table. The view was indeed stunning. All of Pittsburgh lay spread out below us. I could see where the Allegheny and the Monongahela came together to form the Ohio River. Bridges, festooned with twinkling lights, spanned the waters every which way.