Sean Carroll on “a universe from nothing”

April 29, 2012 • 3:46 am

Physics has gotten so arcane that I must struggle to make sense of even popular expositions of its advances, and my understanding always breaks down when someone claims that the notion of time doesn’t mean what I think it does, or could even be illusory. In modern physics, trying to understand things using common-sense notions just doesn’t work. I’m not comfortable in such a realm, which is why I’m happy to have people like Sean Carroll try to explain it to the rest of us.

The latest brouhaha in popular physics is, of course, the question of why there is something rather than nothing—a question that has pushed to the fore with Larry Krauss’s new book, A Universe from Nothing. If you haven’t been in Ulan Bator, you’ll know that that book was handled roughly by David Albert in his New York Times review. Since then, the principals have been sniping at each other, leaving folks like me a bit confused.

Enter physicist Sean Carroll, who gamely tries (and, I think, succeeds) in unravelling the controversy in a post at his website Cosmic Variance: “A universe from nothing?” He thinks that Albert and Krauss are talking at cross purposes: that there are really two sets of questions that are fundamentally different, and each physicist faults the other for not considering his pet question. I’ll post a few excerpts from Sean’s piece, which is not easy reading but will well repay your attention. These are not substitutes for reading his whole post, but will at least outline the debate, and why it’s gone nowhere:

Very roughly, there are two different kinds of questions lurking around the issue of “Why is there something rather than nothing?” One question is, within some framework of physical laws that is flexible enough to allow for the possible existence of either “stuff” or “no stuff” (where “stuff” might include space and time itself), why does the actual manifestation of reality seem to feature all this stuff? The other is, why do we have this particular framework of physical law, or even something called “physical law” at all? Lawrence (again, roughly) addresses the first question, and David cares about the second, and both sides expend a lot of energy insisting that their question is the “right” one rather than just admitting they are different questions. Nothing about modern physics explains why we have these laws rather than some totally different laws, although physicists sometimes talk that way — a mistake they might be able to avoid if they took philosophers more seriously. Then the discussion quickly degrades into name-calling and point-missing, which is unfortunate because these are smart people who agree about 95% of the interesting issues, and the chance for productive engagement diminishes considerably with each installment. . . .

Carroll then explains the two ways Krauss considers how one gets something from nothing: one way sees time as a fundamental property of the universe, the other as an emergent property—indeed, even an illusory one. (Don’t ask an aging biologist to explain how time can be illusory; that’s above my pay grade.)

So modern physics has given us these two ideas, both of which are interesting, and both of which resonate with our informal notion of “coming into existence out of nothing” — one of which is time evolution from empty space (or not-even-space) into a universe bursting with stuff, and the other of which posits time as an approximate notion that comes to an end at some boundary in an abstract space of possibilities.

What, then, do we have to complain about? Well, a bit of contemplation should reveal that this kind of reasoning might, if we grant you a certain definition of “nothing,” explain how the universe could arise from nothing. But it doesn’t, and doesn’t even really try to, explain why there is something rather than nothing — why this particular evolution of the wave function, or why even the apparatus of “wave functions” and “Hamiltonians” is the right way to think about the universe at all. And maybe you don’t care about those questions, and nobody would question your right not to care; but if the subtitle of your book is “Why There Is Something Rather Than Nothing,” you pretty much forfeit the right to claim you don’t care.

And that’s apparently Albert’s criticism: Krauss doesn’t explain why we have laws of physics that permit the creation of something from nothing.  According to Sean, we have no idea why the laws of physics are what they are instead of something else.

And sometimes, on the other hand, modern cosmologists talk about different laws of physics in the context of a multiverse, and suggest that we see one set of laws rather than some other set for fundamentally anthropic reasons. But again, that’s just being sloppy.. . . We are still left with the question of there are those deep-down laws that create a multiverse in the first place.

Now having read Carroll over the past few years, I think he’s previously answered that question with the simple end-of-regress statement, “That’s just the way it is.”  I may be wrong, but he now seems to consider that we can potentially investigate the question:

We should be good empiricists and be open to the possibility that what we think of as the universe really does exist within some larger context. But then we could presumably re-define that as the universe, and be stuck with the same questions. As long as you admit that there is more than one conceivable way for the universe to be (and I don’t see how one could not), there will always be some end of the line for explanations. I could be wrong about that, but an insistence that “the universe must explain itself” or some such thing seems like a completely unsupportable a priori assumption. (Not that anyone in this particular brouhaha seems to be taking such a stance.)

Sean’s conclusions are two:

1.  Krauss’s book is useful at dispelling the theological notion that God is required to create something from nothing:

Lawrence’s book makes a lot more sense when viewed as part of the ongoing atheism vs. theism popular debate, rather than as a careful philosophical investigation into a longstanding problem.

2.  Carroll sees Krauss as having screwed up badly when he dismissed philosophy in his post-book statements and interviews. I, too, find all the philosophy-bashing on my site and on Pharyngula (P.Z. also posted about Krauss’s philo-bashing and subsequent not-apology) regrettable and indefensible. Yes, I see some forms of philosophy as unproductive exercises in mental masturbation, but a good dollop of it is interesting and, yes, useful to scientists.  Here’s how Sean concludes his piece; I’ve put in bold the part I like, because, of course, I agree with it:

Second, after David’s review came out, Lawrence took the regrettable tack of lashing out at “moronic philosophers” and the discipline as a whole, rather than taking the high road and sticking to a substantive discussion of the issues. In the Atlantic interview especially, he takes numerous potshots that are just kind of silly. Like most scientists, Lawrence doesn’t get a lot out of the philosophy of science. That’s okay; the point of philosophy is not to be “useful” to science, any more than the point of mycology is to be “useful” to fungi. Philosophers of science aren’t trying to do science, they are trying to understand how science works, and how it should work, and to tease out the logic and standards underlying scientific argumentation, and to situate scientific knowledge within a broader epistemological context, and a bunch of other things that can be perfectly interesting without pretending to be science itself. And if you’re not interested, that’s fine. But trying to undermine the legitimacy of the field through a series of wisecracks is kind of lame, and ultimately anti-intellectual — it represents exactly the kind of unwillingness to engage respectfully with careful scholarship in another discipline that we so rightly deplore when people feel that way about science. It’s a shame when smart people who agree about most important things can’t disagree about some other things without throwing around insults. We should strive to be better than that.

At the end of all this, I regret that Carroll didn’t write that book instead of Krauss. Caroll’s own exposition in the piece I’ve highlighted above is, by his own admission, dense and a bit of a brain-stretcher.  But I have the feeling that, given the space of a book, Carroll could have explained the issue a lot more clearly than Krauss. Go read Carroll’s piece, and also his earlier essay, “Turtles much of the way down,” where he consider the question, “Why are the laws of physics like they are?”

Modern physics is an Alice-in-Wonderland world to many of us, and I worry that it will reach the point that, like modern mathematics, it’s become impenetrable to the layperson, for it invokes notions that run completely counter to our own experience.

The quote “If you think you understand quantum mechanics, you don’t understand quantum mechanics” is always attributed to Richard Feynman. It turns out that he probably didn’t say that, and it may be a paraphrase of a quote attributed to Niels Bohr: “Anyone who is not shocked by quantum theory has not understood it.” For me, the frustrating part is my inability to be shocked because of my inability to understand. (The two-slit experiment and experiments on Bell’s inequality, do, however, discombobulate me.)

I get groped again!

April 28, 2012 • 6:28 am

I have been groped again by the TSA.  In January of 2011, I was subjected to a humiliating groping at Logan Airport in Boston, where my rump was palpated by the assiduous minions of the TSA.  Well, now it’s happened again.  This time, before passing through the see-you-naked machine, I removed everything from my pockets except my boarding pass. That included my wallet.

After going through the machine, I was stopped by a uniformed officer, who promptly informed me that he was going to “pat down both legs from my knee to my upper thigh” (he meant “crotch,” of course).  And so he did. Then he asked me to turn around, informing me that he was going to “pat down my buttocks with the back of his hand” (does using the back of the hand make it not a grope?).  As I turned around, I could see my scan on the see-you-naked machine, which had a screen displayed to the officer. There were yellow rectangles on my legs and rump, obviously telling the guy where to pat me down.

Needless to say, they found nothing—I was as clean as my sister’s countertops.  But that wasn’t enough. They then had to swab my hands for explosives, making me wait until the swab was analyzed by the sniffer machine.

Well, there’s nothing I can do about this kind of humiliation. I understand why passengers have to be screened, but how could the see-you-naked machine detect things that aren’t there? They need to either set the tuning lower, or abandon this ridiculous security theater. (They won’t do that, of course.)  I am not reassured to see others having similar experiences; I’m just ticked off that they had to palpate my rump with the back of the hand.

Peregrinations

April 28, 2012 • 3:38 am

I’m taking off this morning for a week in Boston, or rather Cambridge.  The nominal excuse is that I’m giving a lecture in the public lecture series at Harvard’s Museum of Comparative Zoology (now called “The Museum of Natural History,” but I insist on using the name it had when I got my Ph.D. there).  If you’re in the area, you’re welcome to come. The topic: “Why evolution is true and why many people still don’t believe it.” The talk is free and at 6 p.m. Wednesday at the Museum. There will be a book signing afterwards.

As usual, posting will be less frequent during such a trip, but I’m hoping Matthew and Greg will have things to say.

William Lane Craig disses Stephen Law, cites irrefutable evidence for Jesus

April 28, 2012 • 3:37 am

A while back I wondered why atheists got so heated up about the historical existence of Jesus, even though none of us agree that the man was divine.  That was dumb of me; I should have realized that the existence of even a fully human Jesus would somehow buttress the Christian contention that he was the son of God, born of a virgin, resurrected, and so on. To that end, I suppose it’s meet that we apply the appropriate skepticism to whether there was a real Jesus around whom the miracle stories accreted.  That, of course, is what the argument between Bart Ehrman and Richard Carrier is about.

Reader Justicar called my attention to the fact that the faithful are already appropriating Ehrman’s conclusions in support of their theology. Ehrman, of course, believes that there was a historical Jesus, even though that rabbi was neither divine nor a wonder-worker.  But it doesn’t matter, as we can see in a piece by theologian/debater William Lane Craig, responding to Stephan Law’s piece, “Evidence, miracles, and the existence of Jesus,” which I discussed yesterday.

On Craig’s blog, Reasonable Faith (what an oxymoronic title!) he pats Ehrman on the back and then goes after Law’s call for caution in accepting even a historical Jesus in an essay called “Stephen Law on the non-existence of Jesus of Nazareth.”

When I first encountered [Law’s] article in my debate preparation, my first thought was that only a philosophy journal would publish such a piece! This article would never have made it past the peer-review process for a journal of New Testament or historical studies. Even a radical sceptic like Bart Ehrman savages the so-called “mythicists” who claim that we have no good evidence that Jesus of Nazareth was a real person:

Note that Craig calls Ehrman a “radical sceptic,” a label that Ehrman would deny but applies to mythicists like Carrier, who seem intransigent in their scepticism.  Craig then goes on to dissect and (to his mind) demolish Law’s argument (you can review Law’s six premises to be skeptical about Jesus here).  Recall Law’s premise 6:

6. There is no good independent evidence for even the mundane claims about Jesus (such as that he existed)

This is the one Craig singles out, but do look at the rest of his argument:

But premiss (6) is the most obviously false premiss in the argument. With respect to extra-biblical evidence Law is just misinformed. Jesus is mentioned in such ancient sources as Tacitus, Josephus, Mara bar Serapion, and Jewish rabbinic sources. If you’re interested in reading these, Robert Van Voorst has collected these sources in his book Jesus outside the New Testament. There is no reason to think that all of these sources are dependent exclusively on Christian tradition. For example, according to Van Voorst “the wording of almost every element” of Josephus’ original text “indicates that Josephus did not draw it, directly or indirectly, from first-century Christian writings.”

Worse, what Law doesn’t appreciate is that the sources in the NT itself are often independent of one another, so that we have independent evidence for many of the mundane, not to speak of the miraculous, events of Jesus’ life. It is precisely that multiple, early, independent attestation to many of the events of Jesus’ life that has persuaded historical scholars of the historicity of many of the events in the Gospel narratives. For example, we have references to Jesus’ burial in five independent sources and indications of the discovery of his empty tomb in no less than six independent sources, which is really quite extraordinary.

I’m no Biblical scholar, but I think every one of Craig’s claims here has been contested, particularly the “independence” of the sources of the New Testament! But Craig has further reasons for denying (6), and constructs his own three “principles”:

  • Principle of Sufficient Cause: Law says that Alexander the Great must have existed because of the military dynasties left in his wake. But in the same way, Jesus must have existed because of the first-century Christian movement left in his wake. Attempts to explain this movement away mythologically have failed.
I believe there is other independent evidence for Alexander the Great, not just the “military dynasties left in his wake”.  It’s my impression, in fact, that there’s far more evidence for Alexander’s existence than for that of Jesus.  And the “sufficient cause” principle is weak, and fails palpably with respect to other religions. Did Xenu exist because of the Scientology movement left in his wake, or the angel Moroni because his composition and delivery of the golden plates left Mormonism in his wake?
  • Embarrassment: Jewish Messianic expectations included no idea of a Davidic Messiah who, instead of throwing off Israel’s enemies and establishing David’s throne in Jerusalem, would be shamefully executed by them as a criminal. Jesus’ crucifixion was something the early church struggled to overcome, not something it invented. Jesus’ crucifixion is one datum upon which all historical scholars, even the most radical, agree.

I don’t think Carrier (or historical scholars, and Carrier is certainly one of these) fully agree on this, though I believe Ehrman does (I haven’t read his new book). At any rate, the fact that the crucifixion was embarrassing to early Jews doesn’t add one iota of support to its reality.  We need to look at the evidence for such an execution.

  • Archaeology: Law accepts the historicity of Alexander the Great partly because of the archaeological evidence for the dynasties he founded. But how about Jesus? The Church of the Holy Sepulchre in Jerusalem has a very strong historical claim to be built over the actual tomb of Jesus of Nazareth. In 326-28 the mother of the Emperor Constantine, Helena, undertook a trip to Palestine and enquired where the tomb of Jesus was located. The locals pointed to a spot where a Temple to Aphrodite had stood for over a century. We have here a very old tradition as to the location of Jesus’ tomb which is rendered probable by the facts that (i) the location identified was inside the extant walls of the city, even though the NT says it was outside the city walls. People didn’t realize that the spot was, in fact, outside the original walls because they did not know the original walls’ location. (ii) When Constantine ordered the temple to be razed and the site excavated, lo and behold, they dug down and found a tomb! But if this is the very tomb of Jesus, then we have archaeological evidence for his existence.

Oy vey!  “Local tradition”? And, of course, archaeologists have not given that tomb any credibility as the resting place of Jesus.

Krauss apologizes for dissing philosophy

April 27, 2012 • 5:11 pm

Over at Scientific American, Lawrence Krauss has written an apology for dismissing the importance of philosophy, as he seemed to do in his interview in The Atlantic.  Apparently set aright by Dan Dennett, and reminded of confrères like Anthony Grayling and Peter Singer, Krauss admits that philosophy has some value after all, though not so much when it comes to guiding the progress of physics.  He then clarifies what he meant by the “nothing” in “the universe from nothing”—a better explanation than, as I recall, he proffers in his book.

Krauss’s apology becomes a bit of a notapology in the last paragraph, though:

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.

I think the dismissive last two sentences refer in part to David Albert, who wrote a critical review of Krauss’s book in the New York Times.  I may be wrong, but I think Krauss was talking about Albert’s review when he wrote this in the Sci Am column:

Recently one review of my book by such a philosopher, which I think motivated the questions in the Atlantic interview, argued not only that one particular version of the nothing described by modern physics was not relevant.  Even more surprisingly, this author claimed with apparent authority (surprising because the author apparently has some background in physics) something that is simply wrong:  that the laws of physics can never dynamically determine which particles and fields exist and whether space itself exists, or more generally what the nature of existence might be.

This is in fact precisely what Albert said in his review. I’m not competent to judge that criticism, but if Krauss is referring to Albert, he shouldn’t have said that he’s a philosopher that “apparently has some background in physics.” Although Albert is a philosopher at Columbia University, he has a doctorate in theoretical physics, has published two books and a fair number of papers on quantum mechanics and other topics in physics.  “Apparently some background in physics” doesn’t quite cover that.

Oh, well. Krauss is right that philosophers of science must keep abreast of science, and when necessary inform their work with facts from the real world, but I still think that philosophy can guide the thinking of scientists in a productive manner, not just, as Krauss implies, the other way around.

One example (two, really) is Philip Kitcher’s work on evolutionary psychology and creationism.

Another is the work by Marc Hauser and colleagues on the fact that novel moral situations tend to provoke similar judgments from people of different cultures and different faith—or no faith.  (Yes, I know some of Hauser’s work has been retracted, but not the moral-survey work.) That’s basically applied philosophy—Gedankenexperiments submitted to subjects—and it may imply that some of our moral judgments are innate and therefore evolved.  It’s early days for this speculation, but it’s an intriguing clue about the possibility of an evolved moral sense.

“When you’re in love you want to tell the world”: the Dawkins episode of “Beautiful Minds”

April 27, 2012 • 6:40 am

The one-hour “Beautiful Minds” (BBC4) episode on Richard Dawkins has just appeared on YouTube, and I proffer it below for your delectation. I definitely think it worth watching, even if you’re well acquainted with Richard’s oeuvre.

It’s refreshing that the show is largely about his scientific work (especially the composition and reception of The Selfish Gene), and doesn’t deal with the atheism business until the last ten minutes.

There’s a good bit on Richard’s youth (including an interview with the public school teacher, stil alive, who influenced Richard’s love of science), and an analysis of the roots of The Selfish Gene, including his teaching Bill Hamilton’s work in 1966 and the influence of John Maynard Smith’s papers. Richard does admit that the title of the book, however, might have been a mistake.

Don’t miss the youthful Dawkins at 36:53.

Some of the talking heads include Helena Cronin, John Krebs, Armand Leroi, John Maynard Smith, Alan Grafen, Steven Rose (cast as the devil’s advocate, who asserts that the gene isn’t unit of selection). The annoying Madeleine Bunting appears at 53:30 as a believer in belief.

The show, and Richard’s career, is well summed up by a statement he makes near the end:

“The true scientific understanding of the nature of existence is so utterly fascinating; how could you not want people to share it? Carl Sagan, I think, said ‘when you’re in love, you want to tell the world.’ And who, on understanding a scientific view of reality, would not, as it were, fall in love and want to tell the world.”