by Tim Sommers
I know you’ve heard this before. But it’s just too relevant to avoid, so, please, bear with me. It may, or may not, be a garbled version of something Bertrand Russell wrote in Why I am not a Christian, but it has become the equivalent of an urban legend in philosophy. It goes like this. Some famous philosopher or another, maybe Russell, maybe William James, is traveling in some non-Western country, probably India, because of the elephants, and they ask a local informant about their cosmology. The local says, “We believe that the world is a vast sphere resting on the back of four great elephants.”
The philosophy professor says, “But what are the elephants standing on?”
“The elephants are standing on the back of an enormous turtle.”
“What’s the turtle standing on?”
“An even larger turtle.
“But what is that turtle standing on?”
“You are very clever, sir, but I’m afraid it’s turtles all the way down.”
What is that so relevant to? Maybe, the cosmological argument for the existence of God, for one thing, but certainly this. Either the universe has existed in some form or another forever or the universe came into existence out of nothing at some point. That’s not physics or even cosmology. That’s logic. P or not P. Either some turtle is standing on nothing or it’s turtles all the way down.
How do we know what’s true here? Both possibilities seem preposterous, if not straight-up inconceivable. Some people disagree. They think one or another option seems inherently, if slightly, less ridiculous than the alternative. But, again, how can we know?
The best evidence we have, at least according to the physicists and cosmologists who have actually looked at the evidence and whose word I am really just taking on this, is that the universe began 13.7 billion years ago from some initial singularity via a big bang followed by rapid inflation which slowed down eventually to the expanding universe we see all around us today. If I am honest, I am not sure I even know the meaning of all the words in that sentence. But go back to the beginning. Was this initial singularity just sitting there forever waiting to give birth to the rest of the universe? Or was it, say, the product of a black hole in another universe or a previous expansion followed by a contraction back to just this? Or did it just, somehow, come into existence out of nothing? See what I mean. This is not science. It’s metaphysics. Kant would say, I think, we are asking the unanswerable, about the unconditioned, about that transcendences all possible experience. Anyway, I am not fan of metaphysics, but in it seems hard to not to at least ask the question, “Has the universe in some form or another existed forever or did it come into existence out of nothing?”
Not that long ago, 2012, physicist Lawrence Krauss caused quite a stir with a book called A Universe from Nothing – which seemed to throw the weight of contemporary cosmology behind the view that, in fact, the universe did, or could have, come into existence out of nothing. Briefly, it was all the rage, then things went sour fast. I think most people lost the track of the argument in all the controversy. So, let me start by just mentioning, but not getting into, all the different controversies that sprang up around the book.
First of all, it didn’t help that Richard Dawkins, who was already pretty controversial himself and about to become even more so, wrote an epilogue to the book claiming that its significance was on par with Darwin’s Origin of Species. If for no other reason, this claim is preposterous because Darwin’s book was a foundational contribution to the sciences of biology and zoology; whereas Krauss’ book was popularizing a few current trends in cosmology. But that’s not the only problem. Here’s what Dawkins actually wrote. “If On the Origin of Species was biology’s deadliest blow to supernaturalism, we may come to see A Universe from Nothing as the equivalent from cosmology.” That seems wrongheaded for a different reason. Krauss’ book is not at all about whether the universe was created, the vast majority of proponents on both sides – those that think the universe must have always existed in one form or another and those who think it might have come into existence out of nothing – would deny that. But if it were about that – whether or not the universe was created – it seems to me that the claim that it came into existence out of nothing is, if anything, more congenial to the idea that it was created. (Compare Catholic theologians’ enthusiastic embrace of the big bang theory.) But I promised to not get too far into this.
The next round of controversy had to do with Krauss’ proclivity for saying stupid things about philosophy, culminating in his paraphrase of Woody Allen that “Those who can’t do, teach, and those that can’t teach teach philosophy”. He was joined by Neil Tyson De Grasse and Bill Nye “the science (and apparently anti-philosophy) guy”. To differing degrees they have mostly repudiated some of their dumber remarks. But Krauss’ also took, it seems to me, to unhelpfully muddling his own argument in the process.
Finally, there is that, about which, I truly have nothing to say; see, The New York Times, October 22, 2018, for example.
Given all that a wiser person than I would probably just drop it. But this isn’t about Krauss or scientists who say dumb things about philosophy and it sure the heck isn’t about Dawkins. I just want to know if there really is an argument, based on contemporary cosmology, supporting the claim that the universe came into existence out of nothing.
And so we get to David Albert, a philosopher and a physicist, who wrote an extremely dismissive review of the book in The New York Times when it first came out. He went so far as to ask, “What, on Earth, could Krauss be thinking?”
As far as I can tell, which is not necessarily very far, pretty much the standard take has become Albert’s. That is, I think many people think that not only is Krauss wrong, but that he is very far wrong. But I don’t that’s true.
I think Albert makes two errors in his reading. First, he muddles together two separate lines of argument. I can’t blame him. In later statements, so does Krauss. The first line of argument is that when it comes to saying that the universe came into existence out of nothing, philosophers keep moving the goal post. Something like the relativistic-quantum-field- vacuum states that stuff comes out of all the time would have been considered “nothing” until very recently. So, if you mean to deny that the universe came into existence out of nothing by claiming merely that anything that the universe came out of can’t, by definition, be nothing…well, hmmm, it seems like you’re cheating. But I don’t want to defend that argument. I want to defend the argument that it gets muddled together with.
Let’s be very clear. I have no idea if Krauss is right about the absolutely key point here. He says that it is consistent with contemporary cosmology and physics that the universe could have come into existence out of nothing. Let’s assume that’s true. If not, all bets are off, of course.
If that’s true, it doesn’t prove that the universe did come out into existence out of nothing, just that it could have done so. If you are not impressed with the significance of that claim, consider general relativity. General relativity doesn’t prove that time is a fourth, space-like dimension, it is merely consistent with it. If you are as impressed with that as most people are, it seems to me, you should also be impressed with this other claim.
However, Albert thinks Krauss is just preposterously wrong here. Here’s the crux of it (I think). What is the universe made of?: energy and physical stuff. It seems likely that the overall energy of the universe is zero. So, what about the stuff? Krauss thinks that just as particular bits of physical stuff comes into existence out of relativistic-quantum-field-theoretical-vacuum states (whatever the hell those are) the universe as a whole might also just have popped into existence. Albert says:
“Relativistic-quantum-field-theoretical vacuum states — no less than giraffes or refrigerators or solar systems — are particular arrangements of elementary physical stuff. The true relativistic-quantum-field-theoretical equivalent to there not being any physical stuff at all isn’t this or that particular arrangement of the fields — what it is (obviously, and ineluctably, and on the contrary) is the simple absence of the fields! The fact that some arrangements of fields happen to correspond to the existence of particles and some don’t is not a whit more mysterious than the fact that some of the possible arrangements of my fingers happen to correspond to the existence of a fist and some don’t.”
Is that right? I think Albert is assuming the following sort of picture. Even if there is no physical stuff in the universe (as we ordinarily or used to think of stuff?), there is (or, I guess, would be) these vacuum states out of which stuff comes and/or that these count as stuff and they are just always there. But what are these states?
Here’s why I ask. Because there’s an older picture that is more congenial to Krauss’ argument. Some people used to think (maybe some still do) that even if there were nothing in the universe there would still have to be laws (or forms or something) waiting around for the universe to come into existence, else why would it come into existence obeying these laws? It’s more obvious what’s wrong with that picture. The laws are just abstract descriptions of how the universe does, in fact, behave derived from observing what it does. If you’re not a Platonist about physical laws, there’s just no temptation to think that they would have had to be around before the universe came into existence, rather than coming into existence along with the universe (and only “coming into existence”, at all, in the sense that they are, in fact, the laws that the universe does obey, not that they need to have some separable, Platonic existence).
How does that apply to Albert’s concern? On his model, if particle-stuff comes into existence out of relativistic-quantum-field-theoretical vacuum states, why can’t the universe as a whole? And why can’t the universe as a whole come into existence not out of a pre-existing rqftv-state, but together with the existence of such states going forward?
I realize I am on thin ice here. Albert would say, I think, that in the universe as it exists now rqftv-states are not nothing. But what are they? Are they more than complicated, well-behaved, law-like description of how the world behaves? Are they really “stuff”? They seem to count as stuff in the universe that already exists. As the universe comes into existence, then, they begin to exist relative to that universe. But before the other stuff that makes it a universe happen, were they there – anymore than, say, Newton’s laws, were there even before the universe began? I mean he says they are “fields” but aren’t they also “vacuum states”?
Physicist Sean Carroll says that, while we used to think that the universe was composed of, at bottom, some particles, we now think that it is, at bottom, composed of fields, in particular, these rqftv-states. If that’s true, then, I guess Albert is right that the issues stands were it always stood and the shift from particles to fields changes nothing. The question now becomes did these vacuum states always exist or did they come into existence out of nothing? And here’s where my amateur, arm-chair philosophy of physics comes to an end. Isn’t it, at least marginally, easier to believe that vacuum states, or even fields, came into existence out of nothing than, to use Albert’s own example, giraffes? If, at its most basic level, the universe is a zero-energy affair composed of vacuum fields that routinely bring material stuff into existence out of nothing, isn’t it at least a little bit easier than it used to be to believe that the universe as a whole, including these states, just came into existence, at some point in the distant past, out of nothing?
So, when Albert asks, “What, on Earth, could Krauss be thinking?”, I want to say, I guess, he’s thinking that on one interpretation of the basic physical facts as they are now thought to be by physicists and cosmologist, it seems slightly more possible than it used to that the universe came into existence out of nothing. Otherwise, after all, it’s just turtles all the way down.