Why Does the World Exist?: An Existential Detective Story (10 page)

“That’s something I’ve suffered through and worried about,” he said, in his slow and deliberate diction. “People have made arguments against the coherence of the concept of nothingness, but many of those arguments seem fallacious to me. Take the claim that absolute nothingness is impossible because we can’t picture it. Well, you can’t picture hyper-dimensional physics either! But proving that the Null World is a genuine possibility is not my problem. It’s the problem of Leibniz and Heidegger and Christian philosophers and all the boys who want to make hay out of the question
Why is there a world rather than nothing at all?
If nothingness is impossible, then, as the medievals used to say,
cadit quaestio
—‘the question falls’—and I’ll just go have a beer!”

But, I asked, isn’t nothingness the simplest form reality could take? And wouldn’t that make it the most expected way for reality to have turned out—unless, that is, there were some sort of cause or principle to fill the void with a world full of existing things?

“Oh, I’ll grant that nothingness may be the simplest
conceptually
. But even if it is, why should this simplicity—this
presumed
simplicity—mandate the realization of the Null World in the absence of an overriding cause? What makes simplicity into an ontological imperative?”

It has become a “veritable mantra,” Grünbaum complained, that the simplicity of nothingness makes it objectively more probable.

“Certain scientists and philosophers gawk at the world and say, ‘We just know that simpler theories are more likely to be true.’ But that’s just their psychological baggage, their heuristic mode. It has nothing at all to do with the objective world. Look at chemistry. In ancient times, Thales held that all chemistry was based on a single element, water. When it comes to simplicity, Thales’s theory wins hand over fist against Mendeleyev’s nineteenth-century ‘polychemistry,’ which posits a whole periodic table of elements. But Mendeleyev’s theory is the one that matches reality.”

So I tried another tack. Simplicity apart, isn’t nothingness the most
natural
form reality could have taken?

Grünbaum scowled slightly. “We know what’s ‘natural’ only by looking at the empirical world,” he said. “It’s logically possible that a person might spontaneously metamorphose into an elephant, but we never observe such a thing. So we don’t feel the slightest temptation to ask why this logical possibility is not realized. The collapse of a skyscraper, on the other hand, is something that
is
observed to happen from time to time. And when it does, we want an explanation, because it takes place against an empirical record of skyscraper collapse
not
occurring. Indeed, these nonoccurrences are so common that we are warranted in taking them to be ‘natural.’ When it comes to the universe, however, we’ve never observed its nonexistence, let alone found evidence that its nonexistence would be ‘natural.’ So why should we be tempted to ask for an explanation of why it exists?”

Here I thought I had him.

“But we
have
observed its nonexistence,” I interjected. “The Big Bang theory tells us that the universe came into being only around 14 billion years ago. That’s a drop in the bucket when you consider eternity. What was the universe doing in that infinite stretch of time before the Big Bang singularity, if not failing to exist? And wouldn’t that make nonexistence its natural state?”

Grünbaum made short work of this objection.

“So what if the universe has a finite past?” he said. “Physics does not allow us to extrapolate back and say, ‘Before this singularity there was nothingness.’ That’s an elementary mistake so many of my opponents make. They mentally picture themselves at the initial singularity as observers endowed with memory, and this gives them the irresistible feeling that there must have been earlier moments of time. But the lesson of the Big Bang model is that before the initial state there
was
no time.”

Hmmm, I thought, Grünbaum seems to be a closet Leibnizian on the matter of time. In the late seventeenth century, Leibniz and Newton staked out competing positions on time’s true nature. Newton took the “absolutist” position, holding that time transcended the physical world and all that went on within it. “
Absolute, true
and mathematical time, of itself and from its own nature, flows equably without relation to anything external,” Newton declared. Leibniz took the opposite, “relationist” position. He argued, against Newton, that time was merely a relation among events. In a static world—a world without change, without “happenings”—time would simply not exist. Grünbaum, in contending that there was no time before the Big Bang, seemed to be echoing Leibniz. He was assuming that it would be meaningless to talk of time in a clockless and eventless state of Nothing.

But when I voiced this point, Grünbaum responded with a bit of jujitsu.

“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 and 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.