As one might have expected there has been a good deal of hoopla over the recent discovery of the Higgs boson—or something much like it—but I was pleasantly surprised by the modest tone of the press coverage that I’ve come across. Famously dubbed the “the God Particle” some years ago, in previous coverage some journalists came close to suggesting that if it were discovered not only would the job of physicists be over, we’d have the answer to the ultimate questions of all: Why is the universe the way it is? Why does it exist at all? In fact, as many of the more recent press articles clearly explain, far from answering the ultimate questions, the discovery of the Higgs still leaves a great deal of work for physicists to do. An important prediction of the standard model of particle physics has now been confirmed, but we still don’t have a quantum theory of gravity, and in the last couple of decades we have discovered that ordinary matter—the properties of which are explained by the standard model—only make up a few per cent of the universe: the “dark” matter and energy which make up more than 90% of the cosmos remain mysterious. As it happens, the scientists at CERN are now looking for a few more billion Euros to upgrade their accelerator to take on these new challenges, so it isn’t perhaps surprising that we’ve been hearing more about all the work which remains to be done.
But then I came across Lawrence Krauss saying this in Newsweek magazine:
“Assuming the particle in question is indeed the Higgs, it validates an unprecedented revolution in our understanding of fundamental physics and brings science closer to dispensing with the need for any supernatural shenanigans all the way back to the beginning of the universe … a Higgs field validates the notion that seemingly empty space may contain the seeds of our existence. This idea is at the heart of one of the boldest predictions of cosmology, called inflation. This posits that a similar type of background field was established in the earliest moments of the big bang, causing a microscopic region to expand by more than 85 orders of magnitude in a fraction of a second, after which the energy contained in otherwise empty space was converted into all the matter and radiation we see today! Alan Guth, the originator of the theory, called it “the ultimate free lunch.” If these bold, some would say arrogant, notions derive support from the remarkable results at the Large Hadron Collider, they may reinforce two potentially uncomfortable possibilities: first, that many features of our universe, including our existence, may be accidental consequences of conditions associated with the universe’s birth; and second, that creating “stuff” from “no stuff” seems to be no problem at all—everything we see could have emerged as a purposeless quantum burp in space or perhaps a quantum burp of space itself. Humans, with their remarkable tools and their remarkable brains, may have just taken a giant step toward replacing metaphysical speculation with empirically verifiable knowledge. The Higgs particle is now arguably more relevant than God.” http://www.thedailybeast.com/newsweek/2012/07/08/how-the-higgs-boson-posits-a-new-story-of-our-creation.html
The inflationary cosmological theory that Krauss is talking about here is certainly a bold and important contribution to our understanding of our origins. It is amazing to learn that all the matter and energy in our vast universe could have sprung from a tiny random fluctuation in what looks like empty space. But when Krauss describes it is an “unprecedented revolution in our understanding of fundamental physics”, one which brings us “closer to dispensing with the need for any supernatural shenanigans all the way back to the beginning of the universe” he is seems to be suggesting that we now have a scientific explanation of everything, of why the universe takes the form that it does, why there is something rather than nothing. But this is simply (and seriously) wrong. What the inflationary theory allows us to do is understand how something with the size and complexity of our universe could come into existence given the laws of physics and physical fields which exist in our universe. Far from explaining why these laws exist, the inflationary theory—like any theory in physics—necessarily presupposes the existence of the laws. The ultimate questions are therefore left unanswered.
As it happens, last week I was reading Jim Holt’s excellent Why Does the World Exist? (Profile 2012), and this simple (but important) point is made, in a preliminary way, as early as p.6:
“What options do you have for resolving the mystery of existence if you let go of the God hypothesis? Well, you might expect that science will someday explain not only how the world is, but why is it. …. Hawking came up with a theoretical model in which the universe, though finite in time, is completely self-contained, without beginning or end. In this “no-boundary” model, he argued, there is no need for a creator, divine or otherwise. Yet even Hawking doubts that his set of equations can yield a complete resolution to the mystery of existence. “What is it that breathes fire into the equations?” he plaintively asks. “Why does the universe go through all the bother of existing?”
The problem with the science option would seem to be this. The universe comprises everything that physically exists. A scientific explanation must involve some sort of physical cause. But any physical cause is by definition part of the universe to be explained. Thus any purely scientific explanation of the existence of the universe is doomed to be circular. Even if it starts from something very minimal—a cosmic egg, a tiny bit of quantum vacuum, a singularity—it still starts with something, not nothing. Since may be able to trace how the current universe evolved from an earlier state of physical reality, even following the process back as far as the Big Bang. But ultimately science hits a wall. It can’t account for the origin of the primal physical state out of nothing.”
And since even the tiniest bit of quantum vacuum is—we now know—pervaded by a Higgs field, it is certainly not nothing in the strict sense of the term. For anyone looking for a readable and up to date introduction to the attempts of scientists and philosophers to answer the ultimate questions, I recommend Holt’s book.
Krauss himself has new book out On the Origin of Everything: A Universe from Nothing (Free Press, 2012). I haven’t yet read it, but if it is as good as some of his other popular science writing—which I have read—then it’s probably well worth reading. However, it’s also clear from David Albert’s review of it (March, New York Times) that Krauss is well aware of the line of criticism outlined above, but is curiously unmoved by them:
Relativistic-quantum-field-theoretical vacuum states—no less than giraffes or refrigerators or solar systems—are particular arrangements of elementary physical stuff …. the fact that particles can pop in and out of existence, over time, as those fields rearrange themselves, is not a whit more mysterious than the fact that fists can pop in and out of existence, over time, as my fingers rearrange themselves. And none of these poppings—if you look at them aright—amount to anything even remotely in the neighborhood of a creation from nothing.
Krauss, mind you, has heard this kind of talk before, and it makes him crazy. A century ago, it seems to him, nobody would have made so much as a peep about referring to a stretch of space without any material particles in it as “nothing.” And now that he and his colleagues think they have a way of showing how everything there is could imaginably have emerged from a stretch of space like that, the nut cases are moving the goal posts. He complains that “some philosophers and many theologians define and redefine ‘nothing’ as not being any of the versions of nothing that scientists currently describe,” and that “now, I am told by religious critics that I cannot refer to empty space as ‘nothing,’ but rather as a ‘quantum vacuum,’ to distinguish it from the philosopher’s or theologian’s idealized ‘nothing,’ ” and he does a good deal of railing about “the intellectual bankruptcy of much of theology and some of modern philosophy.” But all there is to say about this, as far as I can see, is that Krauss is dead wrong and his religious and philosophical critics are absolutely right. Who cares what we would or would not have made a peep about a hundred years ago? We were wrong a hundred years ago. We know more now. And if what we formerly took for nothing turns out, on closer examination, to have the makings of protons and neutrons and tables and chairs and planets and solar systems and galaxies and universes in it, then it wasn’t nothing, and it couldn’t have been nothing, in the first place. And the history of science—if we understand it correctly —gives us no hint of how it might be possible to imagine otherwise.
Albert’s review is (obviously) well worth a read, and is available here: