Blogs / Cosmic Variance

Chad Orzel is wondering about the origin of some irritating habits in science writing. His first point puts the finger right on the issue:

Myth 1: First-person pronouns are forbidden in scientific writing. I have no idea where students get the idea that all scientific writing needs to be in the passive voice, but probably three quarters of the papers I get contain sentences in which the syntax has been horribly mangled in order to avoid writing in the first person.

It’s not exactly right to call this a “myth”; as Andre from Biocurious points out in comments, the injuction to use the passive voice is often stated quite explicitly. There’s even an endlessly amusing step-by-step instruction guide for converting your text from active to passive voice. What would Strunk and White say?

The same goes for using “we” rather than “I,” even if you’re the only person writing. There are also guides that make this rule perfectly explicit. The refrain in this one is:

Write in the third person (”The aquifer covers 1000 square kilometers”) or the first person plural (”We see from this equation that acceleration is proportional to force”). Avoid using “I” statements.

Interestingly, these habits did not just emerge organically as scientific communication evolved — they were, if you like, designed. I learned this from a talk given by Evelyn Fox Keller some years ago, which unfortunately I’ve never been able to find in print. It goes back to the earliest days of the scientific revolution, when Francis Bacon and others were musing on how this new kind of approach to learning about the world should be carried out. Bacon decided that it was crucially important to emphasize the objectivity of the scientific process; as much as possible, the individual idiosyncratic humanity of the scientists was to be purged from scientific discourse, making the results seem as inevitable as possible.

To this end, Bacon was quite programmatic, suggesting a list of ways to remove the taint of individuality from the scientific literature. Passive voice was encouraged, and it was (apparently, if Keller was right and I’m remembering correctly) Bacon who first insisted that we write “we will show” in the abstracts of our single-author papers.

It always seemed a little unnatural to me, and when it came time to write a single-author paper (which I tend not to do, since collaborating is much more fun) I went with the first-person singular. I decided that if it was good enough for Sidney Coleman, it should be good enough for me.

Keller has a more well-known discussion of the rhetoric of Francis Bacon, reprinted in Reflections on Gender and Science. Here she examines Bacon’s personification of the figure of Nature, specifically with regard to gender roles. Bacon was one of the first to introduce the metaphor of Nature as a woman to be seduced/conquered. Sometimes the imagery is gentle, sometimes less so; here are some representative quotes from Bacon to give the gist.

“Let us establish a chaste and lawful marriage between Mind and Nature.”

“My dear, dear boy, what I plan for you is to unite you with things themselves in a chaste, holy, and legal wedlock. And from this association you will insure an increase beyond all the hopes and prayers of ordinary marriages, to wit, a blessed race of Heroes and Supermen.”

“I am come in very truth leading you to Nature with all her children to bind her to your service and make her your slave.”

“I invite all such to join themselves, as true sons of knowledge, with me, that passing by the outer courts of nature, which numbers have trodden, we may find a way at length into her inner chambers.”

“For you have but to follow and as it were hound nature in her wanderings, and you will be able, when you like, to lead and drive her afterwards to the same place again.”

[Science and technology do not] “merely exert a gentle guidance over nature’s course; they have the power to conquer and subdue her, to shake her to her foundations.”

But, while Nature is a shy female waiting to be seduced and conquered, we also recognize that Nature is a powerful, almost God-like force. Tellingly, when Bacon talks about this aspect, the metaphorical gender switches, and now Nature is all too male:

“as if the divine nature enjoyed the kindly innocence in such hide-and-seek, hiding only in order to be found, and with characteristic indulgence desired the human mind to join Him in this sport.”

So much meaning lurking in a few innocent pronouns! We like to pretend that the way we do science, and the way we conceptualize our activity, is more or less inevitable; but there are a lot of explicit choices along the way.

Each year, John Brockman’s Edge asks a collection of deep thinkers a profound question, and gives them a couple of hundred words to answer: The World Question Center. The question for 2005 was What Do You Believe Is True Even Though You Cannot Prove It? Plenty of entertaining answers, offered by people like Bruce Sterling, Ray Kurzweil, Lenny Susskind, Philip Anderson, Alison Gopnik, Paul Steinhardt, Maria Spiropulu, Simon Baron-Cohen, Alex Vilenkin, Martin Rees, Esther Dyson, Margaret Wertheim, Daniel Dennett, and a bunch more. They’ve even been collected into a book for your convenient perusal. Happily, these questions are more or less timeless, so nobody should be upset that I’m a couple of years late in offering my wisdom on this pressing issue.

Most of the participants were polite enough to play along and answer the question in the spirit in which it was asked, although their answers often came down to “I believe the thing I’m working on right now will turn out to be correct and interesting.” But to me, there was a perfectly obvious response that almost nobody gave, although Janna Levin and Seth Lloyd came pretty close. Namely: there isn’t anything that I believe that I can prove, aside from a limited set of ultimately sterile logical tautologies. Not that there’s anything wrong with tautologies; they include, for example, all of mathematics. But they describe necessary truths; given the axioms, the conclusions follow, and we can’t imagine it being any other way. The more interesting truths, it seems to me, are the contingent ones, the features of our world that didn’t have to be that way. And I can’t prove any of them.

The very phrasing of the question, and the way most of the participants answered it, irks me a bit, as it seems to buy into a very wrong way of thinking about science and understanding: the idea that true and reliable knowledge derives from rigorous proof, and anything less than that is dangerously uncertain. But the reality couldn’t be more different. I can’t prove that the Sun will rise tomorrow, that radioactive decays obey an exponential probability law, or that the Earth is more than 6,000 years old. But I’m as sure as I am about any empirical statement that these are true. And, most importantly, there’s nothing incomplete or unsatisfying about that. It’s the basic way in which we understand the world.

Here is a mathematical theorem: There is no largest prime number. And here is a proof:

Consider the list of all primes, p_i, starting with p₁ = 2. Suppose that there is a largest prime, p_*. Then there are only a finite number of primes. Now consider the number X that we obtain by multiplying together all of the primes p_i (exactly once each) from 2 to p_* and adding 1 to the result. Then X is clearly larger than any of the primes p_i. But it is not divisible by any of them, since dividing by any of them yields a remainder 1. Therefore X, since it has no prime factors, is prime. We have thus constructed a prime larger than p_*, which is a contradiction. Therefore there is no largest prime.

Here is a scientific belief: General relativity accurately describes gravity within the solar system. And here is the argument for it:

GR incorporates both the relativity of locally inertial frames and the principle of equivalence, both of which have been tested to many decimal places. Einstein’s equation is the simplest possible non-trivial dynamical equation for the curvature of spacetime. GR explained a pre-existing anomaly — the precession of Mercury — and made several new predictions, from the deflection of light to gravitational redshift and time delay, which have successfully been measured. Higher-precision tests from satellites continue to constrain any possible deviations from GR. Without taking GR effects into account, the Global Positioning System would rapidly go out of whack, and by including GR it works like a charm. All of the known alternatives are more complicated than GR, or introduce new free parameters that must be finely-tuned to agree with experiment. Furthermore, we can start from the idea of massless spin-two gravitons coupled to energy and momentum, and show that the nonlinear completion of such a theory leads to Einstein’s equation. Although the theory is not successfully incorporated into a quantum-mechanical framework, quantum effects are expected to be unobservably small in present-day experiments. In particular, higher-order corrections to Einstein’s equation should naturally be suppressed by powers of the Planck scale.

You see the difference, I hope. The mathematical proof is airtight; it’s just a matter of following the rules of logic. It is impossible for us to conceive of a world in which we grant the underlying assumptions, and yet the conclusion doesn’t hold.

The argument in favor of believing general relativity — a scientific one, not a mathematical one — is of an utterly different character. It’s all about hypothesis testing, and accumulating better and better pieces of evidence. We throw an hypothesis out there — gravity is the curvature of spacetime, governed by Einstein’s equation — and then we try to test it or shoot it down, while simultaneously searching for alternative hypotheses. If the tests get better and better, and the search for alternatives doesn’t turn up any reasonable competitors, we gradually come to the conclusion that the hypothesis is “right.” There is no sharp bright line that we cross, at which the idea goes from being “just a theory” to being “proven correct.” Rather, maintaining skepticism about the theory goes from being “prudent caution” to being “crackpottery.”

It is a intrinsic part of this process that the conclusion didn’t have to turn out that way, in any a priori sense. I could certainly imagine a world in which some more complicated theory like Brans-Dicke was the empirically correct theory of gravity, or perhaps even one in which Newtonian gravity was correct. Deciding between the alternatives is not a matter of proving or disproving; its a matter of accumulating evidence past the point where doubt is reasonable.

Furthermore, even when we do believe the conclusion beyond any reasonable doubt, we still understand that it’s an approximation, likely (or certain) to break down somewhere. There could very well be some very weakly-coupled field that we haven’t yet detected, that acts to slightly alter the true behavior of gravity from what Einstein predicted. And there is certainly something going on when we get down to quantum scales; nobody believes that GR is really the final word on gravity. But none of that changes the essential truth that GR is “right” in a certain well-defined regime. When we do hit upon an even better understanding, the current one will be understood as a limiting case of the more comprehensive picture.

“Proof” has an interesting and useful meaning, in the context of logical demonstration. But it only gives us access to an infinitesimal fraction of the things we can reasonably believe. Philosophers have gone over this ground pretty thoroughly, and arrived at a sensible solution. The young Wittgenstein would not admit to Bertrand Russell that there was not a rhinoceros in the room, because he couldn’t be absolutely sure (in the sense of logical proof) that his senses weren’t tricking him. But the later Wittgenstein understood that taking such a purist stance renders the notion of “to know” (or “to believe”) completely useless. If logical proof were required, we would only believe logical truths — and even then the proofs might contain errors. But in the real world it makes perfect sense to believe much more than that. So we take “I believe x” to mean, not “I can prove x is the case,” but “it would be unreasonable to doubt x.”

The search for certainty in empirical knowledge is a chimera. I could always be a brain in a vat, or teased by an evil demon, or simply an AI program running on somebody else’s computer — fed consistently misleading “sense data” that led me to incorrect conclusions about the true nature of reality. Or, to put a more modern spin on things, I could be a one of Boltzmann’s Brains — a thermal fluctuation, born spontaneously out of a thermal bath with convincing (but thoroughly incorrect) memories of the past. But — here is the punchline — it makes no sense to act as if any of those is the case. By “makes no sense” we don’t mean “can’t possibly be true,” because any one of those certainly could be true. Instead, we mean that it’s a cognitive dead end. Maybe you are a brain in a vat. What are you going to do about it? You could try to live your life in a state of rigorous epistemological skepticism, but I guarantee that you will fail. You have to believe something, and you have to act in some way, even if your belief is that we have no reliable empirical knowledge about the world and your action is to never climb out of bed. On the other hand, putting aside the various solipsistic scenarios and deciding to take the evidence of our senses (more or less) at face value does lead somewhere; we can make sense of the world, act within it and see it respond in accordance with our understanding. That’s both the best we can hope for, and what the world does as a matter of fact grant us; that’s why science works!

It can sound a little fuzzy, with this notion of “reasonable” having sneaked into our definition of belief, where we might prefer to stand on some rock-solid metaphysical foundations. But the world is a fuzzy place. Although I cannot prove that I am not a brain in a vat, it is unreasonable for me to take the possibility seriously — I don’t gain anything by it, and it doesn’t help me make sense of the world. Similarly, I can’t prove that the early universe was in a hot, dense state billions of years ago, nor that human beings evolved from precursor species under the pressures of natural selection. But it would be unreasonable for me to doubt it; those beliefs add significantly to my understanding of the universe, accord with massive piles of evidence, and contribute substantially to the coherence of my overall worldview.

At least, that’s what I believe, although I can’t prove it.

Want to enter a lottery where you are bound to win? Here is your chance (no pun intended): A physics student in the UK, Jaspal Kaur Jutla, for her third year project, has devised a quantum lottery in which you pick your numbers on line, and then on May 2, the winner will be determined based on the number of decay counts of cesium 137 in an apparatus she has put together.

Now, as Ms. Jutla points out, you are bound to win. Or at least one of your future world-paths will… In the many-worlds interpretation of quantum mechanics, all outcomes of any experiment are realized. Rather than the wave function, a superposition of all possible outcomes, “collapsing” to a single outcome, in the many-worlds interpretation the universe itself branches into all the possible outcomes. This interpretation was proposed in 1957 by Hugh Everett III at Princeton. The physics world thought this inerpretation came along with a bit too much metaphysical baggage to be taken completely seriously. Nevertheless the mathematics are certainly self-consistent, I think. His thesis has been on my shelf since I was a graduate student, and I have always been fascinated by these ideas. Could they not form the basis for a theory with another time dimension, one in which, if you travel, the things that happen (or have happened, or will happen) change? Hmm. Could be useful, no?

Personally I have little metaphysical difficulty with the idea of many worlds. We all live in many worlds, all the time, no? If I have no direct knowledge of what’s happening outside my direct experience, then I must regard that part of the universe as being in a superposition of many, many possible states. Another nice feature of the many-worlds viewpoint is that it removes the special status of the observer; in this view she or he is a quantum state like any other.

Anyway, interestingly, Everett went on to become a defense analyst, later founding a computer consulting firm. He died, far too young, at age 51. (At least, in my world he did.) If he was right, then perhaps he will experience quantum immortality. And so will you…

Quote of the Day: David Albert, philosopher of science at Columbia. He was interviewed for, and appeared in, What the Bleep Do We Know?, the movie that tried to convince people that quantum mechanics teaches us that we can change physical reality just by adjusting our mental state. After seeing the travesty that was the actual movie, he complained loudly and in public that his views had been grossly distorted; this quote is from one such interview.

It seems to me that what’s at issue (at the end of the day) between serious investigators of the foundations of quantum mechanics and the producers of the “what the bleep” movies is very much of a piece with what was at issue between Galileo and the Vatican, and very much of a piece with what was at issue between Darwin and the Victorians. There is a deep and perennial and profoundly human impulse to approach the world with a DEMAND, to approach the world with a PRECONDITION, that what has got to turn out to lie at THE CENTER OF THE UNIVERSE, that what has got to turn out to lie at THE FOUNDATION OF ALL BEING, is some powerful and reassuring and accessible image of OURSELVES. That’s the impulse that the What the Bleep films seem to me to flatter and to endorse and (finally) to exploit – and that, more than any of their particular factual inaccuracies – is what bothers me about them. It is precisely the business of resisting that demand, it is precisely the business of approaching the world with open and authentic wonder, and with a sharp, cold eye, and singularly intent upon the truth, that’s called science.

Read the whole thing. The use of emphases is characteristic of David’s writing style, which is also on display in his fantastic books on quantum mechanics and the arrow of time.

The only really misleading part of the above quote is choosing “the Victorians” as Darwin’s foil; things haven’t changed all that much, sadly.

One nice thing about being a scientist, or at least an academic one, is that occaisionally you get your mind blown without any drugs or anything. Someone comes along and just pulls the rug completely out from under you – a total Denial of Reality Attack – and then you are left on your own to pick up the pieces.

Today at UC Davis we had a seminar from Don Page of the University of Alberta. The title and abstract of this talk sounded like science fiction, so I reproduce it here:

Don Page, University of Alberta

Title: Is Our Universe Decaying at an Astronomical Rate?

Abstract: Unless our universe is decaying at an astronomical rate (i.e., on the present cosmological timescale of Gigayears, rather than on the quantum recurrence timescale of googolplexes), it would apparently produce an infinite number of observers per comoving volume by thermal or vacuum fluctuations (Boltzmann brains). If the number of ordinary observers per comoving volume is finite, this scenario seems to imply zero likelihood for us to be ordinary observers and minuscule likelihoods for our actual observations. Hence, our observations suggest that this scenario is incorrect and that perhaps our universe is decaying at an astronomical rate.

Boltzmann brains? WTF? Intrigued, I went. This is a well-respected, highly-cited cosmologist after all. A former student of Stephen Hawking, no less. The jargon in the abstract, though bizarre, had a certain je ne sais quoi…

The idea Don put forward is this: there’s us, the ordinary observers (OO’s) in the world, who have achieved a certain stature after billions of years of evolution in the universe, and are now capable of making quite refined (or so we think) observations of the universe. Andre Linde called OO’s “just honest folk like us.” We’ve made it as a species, man- and womankind, and we’re figuring ou the really deep things that are going on like the Big Bang, genetics, and all the rest.

Then, though, there are the BB’s in the universe: Boltzmann Brains. Random fluctuations of the fabric of spacetime itself which, most of the time, are rather insignificant puffs which evaporate immediately. But sometimes they stick around. More rarely, they are complex. Sometimes (very very rarely) they are really quite as complex as us human types. (Actually, “very very rarely” does not quite convey just how rare we are talking now.) And sometimes these vacuum quantum fluctuations attain the status of actual observers in the world. But, the rarest of them all, the BB’s, are able to (however briefly) make actual observations in the universe which are, in fact, “not erroneous” as Don Page put it.

The man was a compelling speaker, and soon I realized there was an actual intellecutal debate underway in the high end of the cosmology/high energy community as to what the role of these BB’s might be in the universe, in the very far (or maybe not so far) future. We have a certain prejudice that, well, there just aren’t so many of them out there at this stage of the game, 14 billion years after the Big Bang. We’d like to think that we have the stage at the moment, we OO’s, um, assuming there are in fact more of us out there. (Any other non-human OO’s out there, could you let us know, please that you are listening? We have a few questions for you…)

The thing is, when you start talking about very very…very rare things like Boltzmann Brains, you are talking about REALLY long times. Much longer than we’ve had on earth (and I mean 4.5 billion years) by many orders of magnitude. Numbers like 10 to the 60th years were being batted around like it was next week in this talk. By those times, all the stars and all the galaxies have gone out, and gone cold, and space has continued to expand exponentially and things are long past looking pretty bleak for the OO’s still around, who (we presume) need heat and light and at least a little energy of some sort to survive, even if we are talking about very slow machine intelligence (even slower than humans for example).

So eventually, the mere fact that there is, at these long times, just oodles of space in the universe means that the BB’s become more and more common (even if they are rare) and eventually dominate the, uh, intellectual landscape of the universe. Of course this immediately raises all sorts of questions, such as mind/matter duality, the nature of reality and consciousness and multiple consciousnesses, perceived versus objective independent reality. Not to mention whether our “universe” is the only one. Okay, I’ll stop now…

Well, at this point in the talk, being new to this and my mind already quite blown, I had trouble keeping the thread. Somehow or other Don seemed to conclude that a BB-dominated universe was absurd (though are we sure we’re not in one already?) and then posited a radically different spacetime metric, an Anti-deSitter space, which he seemed to think might contain the problem. But then he hit another question which was the title of the talk: must the universe be decaying more rapidly than we expect? I am mangling this horribly, and of course before writing this I took just a glimpse at the already voluminous amount of literature on this topic, and realized that I have a lot of reading to do, both blog and academic. So it’s best I stop and let you all go look up Botzmann Brains, as I will, and do some more reading.

Sigh. The Ultimate Fate of the Universe is of course a nice escape from our quotidian grind. But, as Lenny Susskind wrote in his inscription to us in his book The Cosmic Landscape, at a signing last fall in Davis, “Hey, things could be worse!”

(And, Lo! They were worse…)

I love the internets, because they know more about the ancient Greeks than I do. Timaeus is one of Plato’s Socratic dialogues, the one that deals with the origin of the universe. (Long story short: the demiurge created our universe, but not out of nothing; rather, by organizing some of the pre-existing chaos.) It’s also where Plato talks about Atlantis, and has remained popular for that reason. I don’t know much about Plato, but I do know something about the creation of the universe, so I’ve been invited to a conference on Timaeus to be held in Urbana next year. Which means, I suppose, that I should actually read the thing.

But my ancient Greek is rusty, so I’ll be reading it in translation. Anyone who has made any non-trivial effort to read classics in translation knows that the particular translation makes all the difference in the world — two different translators can render the same text as stilted and incomprehensible or cogent and compelling. But how to choose? I’m not so dedicated to this project that I’m going to pick up six different translations and compare them side by side.

Fortunately — the intertubes have already done it for me! We’ve reached that lovely critical point at which, given any question you have, someone has answered it on a web page somewhere, and Google can lead you to it. A bit of poking around led me to this page by Joseph Wells. He seems more interested in arguing about the existence of Atlantis than in addressing the qualities of different translations, but whatever — I didn’t say your questions would be answered intentionally. The page lists side-by-side tiny excerpts from the Timaeus in six different translations, so you can compare for yourself. For example:

What more could you ask for? On this basis I’m going for the Zeyl translation, which seems to read the most like something that could have been written in English. I kind of like “navigable” rather than “passable,” but you can’t have everything.

Dr. Free-Ride reminds us of the celebrated free-verse philosophizing of Donald Rumsfeld, from a 2002 Department of Defense news briefing.

As we know,
There are known knowns.
There are things we know we know.

We also know
There are known unknowns.
That is to say
We know there are some things
We do not know.

But there are also unknown unknowns,
The ones we don’t know
We don’t know.

We tease our erstwhile Defense Secretary, but beneath the whimsical parallelisms, the quote actually makes perfect sense. In fact, I’ll be using it in my talk later today on the nature of science. One of the distinguishing features of science, I will argue, is that we pretty much know which knowns are known. That is to say, it’s obviously true that there are plenty of questions to which science does not know the answer, as well as some to which it does. But the nice thing is that we have a pretty good idea of where the boundary is. Where people often go wrong — and I’ll use examples of astrology, Intelligent Design, perpetual-motion machines, and What the Bleep Do We Know? — is in attempting to squeeze remarkable and wholly implausible wonders into the tightly-delimited regimes where science doesn’t yet have it all figured out, or hasn’t done some explicit experiment. (For example, it may be true that we haven’t taken apart and understood your specific perpetual-motion device, but it pretty obviously violates not only conservation of energy, but also Maxwell’s equations and Newton’s laws of motion. We don’t need to spend time worrying about your particular gizmo; we already know it can’t work.)

Rumsfeld’s comprehensive classification system did, admittedly, leave out the crucial category of unknown knowns — the things you think you know, that aren’t true. Those had something to do with his ultimate downfall.

I’ve been looking for this for years online — Monty Python’s classic International Philosophy football match, Greeks vs. the Germans.

“This is Nietzsche’s third booking in four games.”

Jacques is advertising the launch of a new physics group blog РThe n-Category Caf̩. Run by John Baez, David Corfield and Urs Schreiber ( of the String Coffee Table), with technical support from Jacques himself, their self-described brief is the interface between Physics, Mathematics and Philosophy.

They’re just getting going, but I expect we’ll see plenty of fascinating stuff from them, and I hope you drop by to welcome this new venture to the physics blogosphere.

Since today, 6/6/06, is (granted some typographical latitude) International Number of the Beast Day, I should tell you about my visit on Sunday to the Augustana Lutheran Church near the University of Chicago. (Not to disparage my kind hosts, but I have to say that sacred architecture really took a turn for the worse after the Reformation; give me those Gothic cathedrals any day.) I was invited by Shane Caldwell, a student in my cosmology class, to speak to a group that meets to talk about science and religion. Of course, my take on the matter is that science and religion are in stark conflict. But they understood where I was coming from, and were interested in hearing my spiel on cosmology and atheism. (All practiced academics understand that it’s important to have a small number of spiels that can be adapted to multiple circumstances at the drop of a hat; mine was rather different in this case than Clifford’s.)

Hot dogs and hamburgers were served, and we had a fun time debating the meaning of “knowing” and the existence of God. Robert Smith, the pastor of the church who is also the campus minister of the UofC, was very welcoming, and excited to be starting this kind of dialogue between different parts of the community. Most of the small audience were actually students, some who had taken my classes and some undergrads who were members of the church. There were also a few representatives from the Zygon Center for Science and Society, an organization across the street that is dedicated to studying the relationship between science and religion.

I’ve given my “God does not exist” talk to a couple of religious audiences before, and they’re generally very interested in hearing a different perspective and thinking about the issues in an unfamiliar way. Granted, these audiences were highly selected and undoubtedly academic, not randomly chosen evangelical churches in the heartland. And you may suspect that nothing I might say would ever change anyone’s mind, but that’s not true; I had one professional theologian tell me that I did change his mind. Not about the existence of God, but about the efficacy of the argument from design. And there is a tight (inverse) correlation between age of the listener and willingness to engage with the ideas; the students were interested and ready to tackle my claims on their own terms, while some of the older folks wanted to argue that there were plenty of scientists more famous than me who were religious, so what right did I have?

There are a million things one could talk about concerning science and religion, and the discussions tend to become rapidly unfocused (or individually focused on the concerns of each person in the room, with everyone talking past everyone else). Not to mention that theology is a rich subject with a complex history about which I know only the basics. So I make a real effort to define all the my words very carefully, and limit myself to one extremely specific chain of reasoning: science and religion do overlap in their mutual interest in understanding the basic workings of reality, and therefore it is possible to judge at least some religious claims using the ordinary empirical criteria of science, and that when one does so, a materialistic conception of reality (in which there exist nothing but stuff following unbreakable rules) comes out very far ahead of a theistic one (in which there exists a separate supernatural/spiritual category not bound by the laws of physics). There might be other interesting things to talk about, and there are other things that religion is concerned with besides the workings of nature, and there could be other criteria besides the scientific method that one might want to use in deciding between different pictures of the world. But in the quite specific question I am choosing to address, I think there is a sensible answer.

At the same time, I want to argue that the answer is not inevitable, or it wouldn’t be worth going through the exercise. There are several ways that thinking like a scientist could have led us to believe in God (or the supernatural more generally). The most obvious would be if God just kept showing up in our world and performing miracles; a sensible scientific approach in that case would be to search for the “laws of nature” that were in effect when God wasn’t around, and treat his manifestations as outside that box. More subtly, we might look for evidence of design in nature, or we might look for impassable “gaps” in our understanding (like the beginning of the universe, or the origin of life and/or consciousness) that only God could bridge. I’m perfectly happy to contemplate that such things could be part of a logically possible world; I just strongly believe that, in the actual world in which we find ourselves, there are no such fingerprints of design or unbridgeable gaps, and hence no scientific reason to appeal to the supernatural. We don’t understand everything in nature, but there’s absolutely no reason to think that it’s not understandable (even the beginning of the universe etc.) in terms of purely mechanical laws. So God, as an hypothesis, is discarded along with geocentrism and phlogiston and the Steady State universe and whatnot. Sadly, it’s taking a little while for the discarding to actually sink in, but I suspect it’s just a matter of (perhaps a very long) time.