Lawrence M. Krauss (physicist) wrote a book entitled, "A Universe From Nothing". David Albert (philosopher) wrote a review of the book
for The New York Times in which he faulted Krauss for not answering the question he set out to answer. Said simply, Krauss doesn't actually explain how the Universe could come from "nothing". Instead, Krauss explained how particles are generated by quantum fields:
Where, for starters, are the laws of quantum mechanics themselves supposed to have come from? Krauss is more or less upfront, as it turns out, about not having a clue about that. He acknowledges (albeit in a parenthesis, and just a few pages before the end of the book) that everything he has been talking about simply takes the basic principles of quantum mechanics for granted. “I have no idea if this notion can be usefully dispensed with,” he writes, “or at least I don’t know of any productive work in this regard.” And what if he did know of some productive work in that regard? What if he were in a position to announce, for instance, that the truth of the quantum-mechanical laws can be traced back to the fact that the world has some other, deeper property X? Wouldn’t we still be in a position to ask why X rather than Y? And is there a last such question? Is there some point at which the possibility of asking any further such questions somehow definitively comes to an end? How would that work? What would that be like?
P1: Quantum fields are not "nothing".
P2: Krauss explained how particles could be generated by quantum fields.
Therefore, Krauss did not answer the question of how something comes from nothing.
Krauss became incredibly upset by this review. In an interview in The Atlantic
he responded to the review by saying some very mean-spirited things:
Philosophy is a field that, unfortunately, reminds me of that old Woody Allen joke, "those that can't do, teach, and those that can't teach, teach gym." And the worst part of philosophy is the philosophy of science; the only people, as far as I can tell, that read work by philosophers of science are other philosophers of science. It has no impact on physics what so ever, and I doubt that other philosophers read it because it's fairly technical. And so it's really hard to understand what justifies it. And so I'd say that this tension occurs because people in philosophy feel threatened, and they have every right to feel threatened, because science progresses and philosophy doesn't.
After numerous philosophers, and other professional academics, contacted Krauss and explained to him that he was acting like a gigantic dick, he issued a backhanded non-apology in Scientific American
So, to those philosophers I may have unjustly offended by seemingly blanket statements about the field, I apologize. I value your intelligent conversation and the insights of anyone who thinks carefully about our universe and who is willing to guide their thinking based on the evidence of reality. To those who wish to impose their definition of reality abstractly, independent of emerging empirical knowledge and the changing questions that go with it, and call that either philosophy or theology, I would say this: Please go on talking to each other, and let the rest of us get on with the goal of learning more about nature.
That's where the debate stands as of April 27, 2012.
I know that numerous people on these boards priviledge science over philosophy, since science makes inductions and abductions from color patches while philosophy generates the logical tools upon which scientists rely in order to construct arguments. I think this contemporary debate in academia might provide an interesting context within we we can play out our differences of opinion regarding the Science vs. Philosophy debate.
So, let's pick sides!
Team-Krauss: Boo Philosophy. Yey physics!
Team- Albert: Boo terrible definitions. Yey clarity of thought!
Seriously, though, what do you make of the relation between philosophy and physics, philosophy and the hard sciences? is there a virtue to philosophy's ability to construct logical tools and critique the language of science? Was A.J. Ayer right? Or can philosophy do more than say, "That's not what 'nothing' means?" On the pro-physics side, are philosophers laughable numbskulls who cannot reasonably critique physicists since they don't wear lab coats? Is science self-grounding, having left behind the philosophical context from which it historically emerged?
Debate and / or Discuss!
Edit: I forgot to include this article on NPR.org by Adam Frank
. It provides a wonderful summary of the debate and offers a pro-philosophy take on the argument between Krauss and Albert.
Edit: MrMister, who some wish had started this thread, made an incredibly informative post that fleshes out some of the backstory to this debate:
At the risk of sounding like a dick myself, I kind of wish MrMister had started this thread
I actually was planning on doing it later today! But I have been beaten to the punch. So instead of authoring a thread, without further comment I present some things that are interesting.
First, David Albert, the philosopher who reviewed Kraus's book in the New York Times, also actually holds a Ph.D. in physics and has co-authored a number of seminal physics papers with Yakir Aharonov. This makes it all the more ridiculous that Kraus has repeatedly referred to him as a 'moron philosopher' who 'probably didn't even read the book.' Here is Albert's response to the charge that his review was inappropriate because it failed to engage with the larger portion of the contents of the book (spoiler alert, he also has a problem with the physics):
I did, for the record, read all of Professor Krauss’ book. And I would have very much liked to say more about the specifically scientific issues he discusses in my review. But the space allotted me by the Times was very limited – and I figured (given the title and sub-title of the book) that the issue that was first and foremost in Professor Kraus’ mind was the question of creation from nothing – and so I thought it best to use what space I had to write as clearly and simply and directly as I could about that.
But maybe it’s worth saying, now that the question has been raised, that the discussions of quantum mechanics in A Universe From Nothing are – from a purely scientific point of view – very badly confused. Let me mention just one example. Professor Kraus’ argument for the ‘reality’ of virtual particles, and for the instability of the quantum-mechanical vacuum, and for the larger and more imposing proposition that ‘nothing is something’, hinges on the claim that “the uncertainty in the measured energy of a system is inversely proportional to the length of time over which you observe it”. And it happens that we have known, for more than half a century now, from a beautiful and seminal and widely cited and justly famous paper by Yakir Aharonov and David Bohm, that this claim is false.
Of course, the physical literature is full of sloppy and misleading talk about the ‘energy-time uncertainty relation’, and about the effects of ‘virtual particles’, and so on – and none of that does much harm in the context of calculations of scattering cross-sections or atomic energy levels or radioactive decay rates. But the business of pontificating about why there is something rather than nothing without bothering to get crucial pieces of the physics right, or to think about them carefully, or to present them honestly, strikes me as something of a scandal.
Second, Kraus consistently conflates philosophers and theologians. He is one of those
physicists, like Hawking, who likes to speak disparagingly of the former by lumping them in with the latter. The irony here is that many philosophers--if not the majority--think that the question of why there is anything at all, and why it is this, is either: 1) unanswerable (and hence uninteresting), or 2) nonsense, because concepts of explanation and justification cannot sensibly be applied to the universe as a whole. They accept the answer: 'it just does, and it just is.' In pointing out that Kraus has failed to answer this question by reference to quantum fields, they are not trying to score points for theology, or to claim that the real answer has to do with God. Their view is that the question is either unanswerable or nonsense, so of course, they hold, Kraus has not answered it with physics. That just follows a fortiori
Imagine someone claimed that new advances in physics have answered the question: "is the sentence 'this sentence is false' true or false?' The philosopher objects not because they think it is a good question which goes unanswered by physics (which somehow proves that god exists?), but precisely because it is a bad one which cannot be answered at all. 'This sentence is false' is not well-formed. There is no answer to what it's truth value is, because it doesn't have one. Hence, it is certainly not the case that new advances in physics can tell us what its truth value is.
I find that this unreflective anti-philosophical sentiment is a common strain in the new atheist community. They lash out at philosophers because they associate them with mysticism. They forget that philosophers were the pioneer atheists, ever since Hume killed God in 1776.
Third and finally, Tim Maudlin, a prominent philosopher of physics, has some interesting things to say about the relationship between physics--especially fundamental physics--and philosophy. The upshot is that many of the questions philosophers are interested in now are, in a straightforward way, just about understanding the physics. But these questions nonetheless get shunned in physics departments for reasons of institutional culture. He hopes for a blending in the addressing of foundational topics--that practitioners are able to apply both the impressive formal mathematical competence of the physicist and the neatness and conceptual clarity of the philosopher.
It is true that there are some particular questions that fall more into the domain of philosophy (e.g. accounts of the nature of scientific practice) and others that are firmly in the domain of physics (e.g. methods of calculating scattering cross-sections), but for the particular sorts of questions we are largely interested in here, I can see no way to assign the topic to “physics” or “philosophy”. Take the case of the “nature of the wavefunction”, for example. In one sense a “wavefunction” (as its name implies) is a mathematical object—e.g. a complex function on another mathematical object called “configuration space”—that is employed in physics as a representation of a physical system. That immediately raises many questions. One, which Einstein, Podolosky and Rosen famously raised, is whether that particular mathematical representation is complete. That is, does it explicitly or implicitly represent all of the physical features, the values of all of the physical degrees of freedom, of the system. Can two systems represented by the same wavefunction nonetheless be physically different in some respect? Can the same system be properly represented by two different wavefunctions? Are there mathematical degrees of freedom in the representation that do not correspond to physical degrees of freedom in the system itself? (As an example of the latter, should the physical state of the system correspond to vector or a ray in a Hilbert space? If a ray, then it is misleading to say that the physical state is represented by a vector in the space: the vector has mathematical properties that do not correspond to physical properties of the system.) If one asks whether this sort of question is one of philosophy or of physics, I (and Einstein) would say it is a matter of physics. Indeed, it seems to be an absolutely essential question if one is to understand the physical account of the world being provided by the mathematics. But it is a sociological fact that while it is perfectly acceptable and even expected to discuss questions like this in a philosophy department, or a philosophy course, it can be rare, or even frowned upon, to discuss them in a physics department or physics course. We all know the phrase “shut up and calculate”. This phrase was not invented by philosophers, and in my experience physics students immediately recognize what it describes in their physics courses. Steven Weinberg tells the cautionary tale of the promising physics student whose career was ruined because “He tried to understand quantum mechanics”.
The point of the story is that the physicist, as physicist, should not try to have a clear, exact understanding of the physical meaning of the mathematical formalism. But certainly this ought to be a question in the domain of physics! It is just a weird sociological fact that, since the advent of quantum theory and the objections to that theory brought most forcefully by Einstein, Schrödinger, and later Bell, a standard physics education does not address these fundamental questions and many physics students are actively dissuaded from asking them. But anyone with a philosophical temperament cannot resist asking them. So, for better or worse, discussing these questions is more universally recognized as an important and legitimate task in philosophy departments than in physics departments (even Bell characterized his seminal work in foundations as secondary to his “real” physics work at CERN). And the habits of mind—a certain sort of precision about concepts and arguments—that are needed to pursue these questions happen to be exactly those habits instilled by a good education in philosophy. So while Krauss and Hawking lament that many philosophers don’t know enough physics (which is true), it is equally the case that many physicists are sloppy thinkers when it comes to foundational matters. I’m not sure that collaboration is the proper model here—as the “example” of Einstein collaborating with himself suggests!—but rather an appreciation of both which details of the physics are important and where the physics is simply not clear and precise as physics. Learning sophisticated mathematics, which a a large part of a physics education, does nothing to instill appreciation of the sort of conceptual and argumentative clarity needed to tackle these foundational issues.
Let me give a quick example. Take the “vacuum state” in quantum field theory. (No, I’m not raising the question of whether it is “nothing”!) It is commonly said that the vacuum state is positively a buzzing hive of activity: pairs of “virtual particles” being created an annihilated all the time. But it is also commonly said that the quantum state of system is complete: to deny this is to posit “hidden variables”, and those are not regarded by most physicists with favor. But it is clear that these two claims contradict each other. Consider a system in the vacuum state over some period of time. Over that period of time, the quantum state is static: it is always the same. So if the quantum state is complete, nothing physical in the system can be changing. But the “buzzing hive” of virtual particles is presented as constantly changing: particle pairs are being created and destroyed all the time. So which is it? This strikes me as a straightforward question of physics. But it is more likely to be asked, I think, by a philosopher. And insofar as the observable predictions of the theory do not depend directly on the answer, it is even likely to be dismissed by the physicist as “merely philosophical”. But without an answer, we really have no understanding of the vacuum state, or the status of “virtual particles”.