No, it’s not. Don’t be alarmed: nobody is claiming that dark matter is supernatural. That’s just the provocative title of a blog post by Chris Schoen, asking whether science can address “supernatural” phenomena. I think it can, all terms properly defined.

This is an old question, which has come up again in a discussion that includes Russell Blackford, Jerry Coyne, John Pieret, and Massimo Pigliucci. (There is some actual discussion in between the name-calling.) Part of the impetus for the discussion is this new paper by Maarten Boudry, Stefaan Blancke, Johan Braeckman for Foundations of Science.

There are two issues standing in the way of a utopian ideal of universal agreement: what we mean by “supernatural,” and how science works. (Are you surprised?)

There is no one perfect definition of “supernatural,” but it’s at least worth trying to define it before passing judgment. Here’s Chris Schoen, commenting on Boudry et. al:

Nowhere do the authors of the paper define just what supernaturalism is supposed to mean. The word is commonly used to indicate that which is not subject to “natural” law, that which is intrinsically concealed from our view, which is not orderly and regular, or otherwise not amenable to observation and quantification.

Very sympathetic to the first sentence. But the second one makes matters worse rather than better. It’s a list of four things: a) not subject to natural law, b) intrinsically concealed from our view, c) not orderly and regular, and d) not amenable to observation and quantification. These are very different things, and it’s far from clear that the best starting point is to group them together. In particular, b) and d) point to the difficulty in observing the supernatural, while a) and c) point to its lawless character. These properties seem quite independent to me.

Rather that declare once and for all what the best definition of “supernatural” is, we can try to distinguish between at least three possibilities:

1. The silent: things that have absolutely no effect on anything that happens in the world.
2. The hidden: things that affect the world only indirectly, without being immediately observable themselves.
3. The lawless: things that affect the world in ways that are observable (directly or otherwise), but not subject to the regularities of natural law.

There may be some difficulty involved in figuring out which category something fits, but once we’ve done so it shouldn’t be so hard to agree on how to deal with it. If something is in the first category, having absolutely no effect on anything that happens in the world, I would suggest that the right strategy is simply to ignore it. Concepts like that are not scientifically meaningful. But they’re not really meaningful on any other level, either. To say that something has absolutely no effect on how the world works is an extremely strong characterization, one that removes the concept from the realm of interestingness. But there aren’t many such concepts. Say you believe in an omnipotent and perfect God, one whose perfection involves being timeless and not intervening in the world. Do you also think that there could be a universe exactly like ours, except that this God does not exist? If so, I can’t see any way in which the idea is meaningful. But if not, then your idea of God does affect the world — it allows it to exist. In that case, it’s really in the next category.

That would be things that affect the world, but only indirectly. This is where the dark matter comparison comes in, which I don’t think is especially helpful. Here’s Schoen again:

We presume that dark matter –if it exists–is lawful and not in the least bit capricious. In other words, it is–if it exists–a “natural” phenomena. But we can presently make absolutely no statements about it whatsoever, except through the effect it (putatively) has on ordinary matter. Whatever it is made of, and however it interacts with the rest of the material world is purely speculative, an untestable hypothesis (given our present knowledge). Our failure to confirm it with science is not unnerving.

I would have thought that this line of reasoning supports the contention that unobservable things do fall unproblematically within the purview of science, but Chris seems to be concluding the opposite, unless I’m misunderstanding. There’s no question that dark matter is part of science. It’s a hypothetical substance that obeys rules, from which we can make predictions that can be tested, and so on. Something doesn’t have to be directly observable to be part of science — it only has to have definite and testable implications for things that are observable. (Quarks are just the most obvious example.) Dark matter is unambiguously amenable to scientific investigation, and if some purportedly supernatural concept has similar implications for observations we do make, it would be subject to science just as well.

It’s the final category, things that don’t obey natural laws, where we really have to think carefully about how science works. Let’s imagine that there really were some sort of miraculous component to existence, some influence that directly affected the world we observe without being subject to rigid laws of behavior. How would science deal with that? (more…)

Craig Callender is a philosopher of science at UC San Diego, who has written a lot about the nature of time, including a fun illustrated book. He’s more than a bit skeptical of the multiverse idea, and somewhat contrarian about the low-entropy nature of the early universe: he thinks it’s just a fact we should observe and accept (“nomological”), rather than a feature that cries out for a better explanation.

Here we’re having a chat on the recently launched Philosophy TV, sort of Bloggingheads for philosophers. Craig’s head obviously looms much larger than mine, so I had to use my wiles to bob and weave, intellectually speaking.

Callender and Carroll from Philosophy TV on Vimeo.

Stephen Hawking has a new book coming out (The Grand Design, with Leonard Mlodinow). Among other things, he points out that modern physics has progressed to the point where we don’t need to invoke God to explain the existence of the universe. This is not exactly a hot flash — I remember writing an essay making the same point for a philosophy class my sophomore year in college — but it makes news because it’s Hawking who says it. And that’s absolutely fine — Hawking has a track record of making substantial intellectual contributions, there’s every reason to listen to him more than random undergraduates waxing profound.

This issue is, of course, totally up my alley, and I should certainly blog about it. But I can’t, because I’m on hiatus! (Right?) So, as an experiment, I made a video of myself talking rather than simply typing my words into the computer. Radical! Not sure the amount of information conveyed is anywhere near as large in this format, and obviously I didn’t sweat the production values. I fear that some subtleties of the argument may be lost. But if we’re lucky, other people elsewhere on the internet will also talk about these questions, and we’ll get it all sorted out.

Let me know if the Grand Video Experiment is worth repeating and improving, or whether it’s just a waste of time.

Something that I should have said, but didn’t: there doesn’t need to be some sophisticated modern-physics answer to the question “Why is there something rather than nothing?” The universe can simply exist, end of story. But it’s still fun to think carefully about all the possibilities, existence and non-existence both included.

There’s a movement afoot to frame science/religion discussions in such a way that those of who believe that the two are incompatible are labeled as extremists who can be safely excluded from grownup discussions about the issue. It’s somewhat insulting — to be told that people like you are incapable of conducting thoughtful, productive conversations with others — and certainly blatantly false as an empirical matter — I’ve both participated in and witnessed numerous such conversations that were extremely substantive and well-received. It’s also a bit worrisome, since whether a certain view is “true” or “false” seems to take a back seat to whether it is “moderate” or “extreme.” But people are welcome to engage or not with whatever views they choose.

What troubles me is how much our cultural conversation is being impoverished by a reluctance to face up to reality. In many ways the situation is parallel to the discussion about global climate change. In the real world, our climate is being affected in dramatic ways by things that human beings are doing. We really need to be talking about serious approaches to this problem; there are many factors to be taken into consideration, and the right course of action is far from obvious. Instead, it’s impossible to broach the subject in a public forum without being forced to deal with people who simply refuse to accept the data, and cling desperately to the idea that the Earth’s atmosphere isn’t getting any warmer, or it’s just sunspots, or warmth is a good thing, or whatever. Of course, the real questions are being addressed by some people; but in the public domain the discussion is blatantly distorted by the necessity of dealing with the deniers. As a result, the interested but non-expert public receives a wildly inaccurate impression of what the real issues are.

Over the last four hundred or so years, human beings have achieved something truly amazing: we understand the basic rules governing the operation of the world around us. Everything we see in our everyday lives is simply a combination of three particles — protons, neutrons, and electrons — interacting through three forces — gravity, electromagnetism, and the strong nuclear force. That is it; there are no other forms of matter needed to describe what we see, and no other forces that affect how they interact in any noticeable way. And we know what those interactions are, and how they work. Of course there are plenty of things we don’t know — there are additional elementary particles, dark matter and dark energy, mysteries of quantum gravity, and so on. But none of those is relevant to our everyday lives (unless you happen to be a professional physicist). As far as our immediate world is concerned, we know what the rules are. A staggeringly impressive accomplishment, that somehow remains uncommunicated to the overwhelming majority of educated human beings.

That doesn’t mean that all the interesting questions have been answered; quite the opposite. Knowing the particles and forces that make up our world is completely useless when it comes to curing cancer, buying a new car, or writing a sonnet. (Unless your sonnet is about the laws of physics.) But there’s no question that this knowledge has crucial implications for how we think about our lives. Astrology does not work; there is no such thing as telekinesis; quantum mechanics does not tell you that you can change reality just by thinking about it. There is no life after death; there’s no spiritual essence that can preserve a human consciousness outside its physical body. Life is a chemical reaction; there is no moment at conception or otherwise when a soul is implanted in a body. We evolved as a result of natural processes over the history of the Earth; there is no supernatural intelligence that created us and maintains an interest in our behavior. There is no Natural Law that specifies how human beings should live, including who they should marry. There is no strong conception of free will, in the sense that we are laws unto ourselves over and above the laws of nature. The world follows rules, and we are part of the world.

How great would it be if we could actually have serious, productive public conversations about the implications of these discoveries? For all that we have learned, there’s a tremendous amount yet to be figured out. We know the rules by which the world works, but there’s a lot we have yet to know about how to live within it; it’s the difference between knowing the rules of chess and playing like a grandmaster. What is “life,” anyway? What is consciousness? How should we define who is a human being, and who isn’t? How should we live together in a just and well-ordered society? What are appropriate limits of medicine and biological manipulation? How can we create meaning and purpose in a world where they aren’t handed to us from on high? How should we think about love and friendship, right and wrong, life and death?

These are real questions, hard questions, and we have the tools in front of us to have meaningful discussions about them. And, as with climate change, some people are having such discussions; but the public discourse is so badly distorted that it has little relationship to the real issues. Instead of taking the natural world seriously, we have discussions about “Faith.” We pretend that questions of meaning and purpose and value must be the domain of religion. We are saddled with bizarre, antiquated attitudes toward sex and love, which have terrible consequences for real human beings.

I understand the reluctance to let go of religion as the lens through which we view questions of meaning and morality. For thousands of years it was the best we could do; it provided social structures and a framework for thinking about our place in the world. But that framework turns out not to be right, and it’s time to move on.

Rather than opening our eyes and having the courage and clarity to accept the world as it is, and to tackle some of the real challenges it presents, as a society we insist on clinging to ideas that were once perfectly reasonable, but have long since outlived their usefulness. Nature obeys laws, we are part of nature, and our job is to understand our lives in the context of reality as it really is. Once that attitude goes from being “extremist” to being mainstream, we might start seeing some real progress.

(Cross-posted at NPR’s 13.7: Cosmos and Culture.)

Remember when, inspired by Sam Harris’s TED talk, we debated whether you could derive “ought” (morality) from “is” (science)? That was fun. But both my original post and the followup were more or less dashed off, and I never did give a careful explanation of why I didn’t think it was possible. So once more into the breach, what do you say? (See also Harris’s response, and his FAQ. On the other side, see Fionn’s comment at Project Reason, Jim at Apple Eaters, and Joshua Rosenau.)

I’m going to give the basic argument first, then litter the bottom of the post with various disclaimers and elaborations. And I want to start with a hopefully non-controversial statement about what science is. Namely: science deals with empirical reality — with what happens in the world. (I.e. what “is.”) Two scientific theories may disagree in some way — “the observable universe began in a hot, dense state about 14 billion years ago” vs. “the universe has always existed at more or less the present temperature and density.” Whenever that happens, we can always imagine some sort of experiment or observation that would let us decide which one is right. The observation might be difficult or even impossible to carry out, but we can always imagine what it would entail. (Statements about the contents of the Great Library of Alexandria are perfectly empirical, even if we can’t actually go back in time to look at them.) If you have a dispute that cannot in principle be decided by recourse to observable facts about the world, your dispute is not one of science.

With that in mind, let’s think about morality. What would it mean to have a science of morality? I think it would look have to look something like this:

Human beings seek to maximize something we choose to call “well-being” (although it might be called “utility” or “happiness” or “flourishing” or something else). The amount of well-being in a single person is a function of what is happening in that person’s brain, or at least in their body as a whole. That function can in principle be empirically measured. The total amount of well-being is a function of what happens in all of the human brains in the world, which again can in principle be measured. The job of morality is to specify what that function is, measure it, and derive conditions in the world under which it is maximized.

All this talk of maximizing functions isn’t meant to lampoon the project of grounding morality on science; it’s simply taking it seriously. Casting morality as a maximization problem might seem overly restrictive at first glance, but the procedure can potentially account for a wide variety of approaches. A libertarian might want to maximize a feeling of personal freedom, while a traditional utilitarian might want to maximize some version of happiness. The point is simply that the goal of morality should be to create certain conditions that are, in principle, directly measurable by empirical means. (If that’s not the point, it’s not science.)

Nevertheless, I want to argue that this program is simply not possible. I’m not saying it would be difficult — I’m saying it’s impossible in principle. Morality is not part of science, however much we would like it to be. There are a large number of arguments one could advance for in support of this claim, but I’ll stick to three.

(more…)

We’re very happy to have a guest post from Malcolm MacIver. See if you can keep this straight: Malcolm is a professor in the departments of Mechanical Engineering and Biomedical Engineering at Northwestern, with undergraduate degrees in philosophy and computer science, and a Ph.D. in neuroscience. He’s also one of the only people I know who has a doctorate but no high school diploma.

With this varied background, Malcolm studies connections between biomechanics and neuroscience — how do brains and bodies interact? This unique expertise helped land him a gig as the science advisor on Caprica, the SyFy Channel’s prequel show to Battlestar Galactica. He also blogs at Northwestern’s Science and Society blog. It’s a pleasure to welcome him to Cosmic Variance, where he’ll tell us about robots, artificial intelligence, and war.

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It’s a pleasure to guest blog for CV and Sean Carroll, a friend of some years now. In my last posting back at Northwestern University’s Science and Society Blog, I introduced some issues at the intersection of robotics, artificial intelligence (AI), and morality. While I’ve long been interested in this nexus, the most immediate impetus for the posting was meeting Peter Singer, author of the excellent book ‘Wired for War’ about the rise of unmanned warfare, while simultaneously working for the TV show Caprica and a U.S. military research agency that funds some of the work in my laboratory on bio-inspired robotics. Caprica, for those who don’t know it, is a show about a time when humans invent sentient robotic warriors. Caprica is a prequel to Battlestar Galactica, and as we know from that show, these warriors rise up against humans and nearly drive them to extinction.

Here, I’d like to push the idea that as interesting as the technical challenges in making sentient robots like those on Caprica are, an equally interesting area is the moral challenges of making such machines. But “interesting” is too dispassionate—I believe that we need to begin the conversation on these moral challenges. Roboticist Ron Arkin has been making this point for some time, and has written a book on how we may integrate ethical decision making into autonomous robots.

Given that we are hardly at the threshold of building sentient robots, it may seem overly dramatic to characterize this as an urgent concern, but new developments in the way we wage war should make you think otherwise. I heard a telling sign of how things are changing when I recently tuned in to the live feed of the most popular radio station in Washington DC, WTOP. The station had commercial after commercial from iRobot (of Roomba fame), a leading builder of unmanned military robots, clearly targeting military listeners. These commercials reflect how the use of unmanned robots in the military has gone from close to zero in 2001 to over ten thousand now, with the pace of acquisition still accelerating. For more details on this, see Peter Singer’s ‘Wired for War’, or the March 23 2010 congressional hearing on The Rise of the Drones here.

(more…)

Update and reboot: Sam Harris has responded to my blog post reacting to his TED talk. In the initial version of this response-to-the-response-to-the-response-to-the-talk, I let myself get carried away with irritation at this tweet, and thereby contributed to the distraction from substantive conversation. Bad blogger.

In any event, Sam elaborates his position in some detail, so I encourage you to have a look if you are interested, although it didn’t change my mind on any issue of consequence. There are a number of posts out there by people who know what they are talking about and surely articulate it better than I do, including Russell Blackford and Julian Sanchez (who, one must admit, has a flair for titles), and I should add Chris Schoen.

But I wanted to try to clarify my own view on two particular points, so I put them below the fold. I went on longer than I intended to (funny how that happens). The whole thing was written in a matter of minutes — have to get back to real work — so grains of salt are prescribed.

(more…)

(Update: further discussion here and here.)

Sam Harris gave a TED talk, in which he claims that science can tell us what to value, or how to be moral. Unfortunately I completely disagree with his major point. (Via Jerry Coyne and 3 Quarks Daily.)

He starts by admitting that most people are skeptical that science can lead us to certain values; science can tell us what is, but not what ought to be. There is a old saying, going back to David Hume, that you can’t derive ought from is. And Hume was right! You can’t derive ought from is. Yet people insist on trying.

Harris uses an ancient strategy to slip morality into what starts out as description. He says:

Values are a certain kind of fact. They are facts about the well-being of conscious creatures… If we’re more concerned about our fellow primates than we are about insects, as indeed we are, it’s because we think they are exposed to a greater range of potential happiness and suffering. The crucial thing to notice here is that this is a factual claim.

Let’s grant the factual nature of the claim that primates are exposed to a greater range of happiness and suffering than insects or rocks. So what? That doesn’t mean we should care about their suffering or happiness; it doesn’t imply anything at all about morality, how we ought to feel, or how to draw the line between right and wrong.

Morality and science operate in very different ways. In science, our judgments are ultimately grounded in data; when it comes to values we have no such recourse. If I believe in the Big Bang model and you believe in the Steady State cosmology, I can point to the successful predictions of the cosmic background radiation, light element nucleosynthesis, evolution of large-scale structure, and so on. Eventually you would either agree or be relegated to crackpot status. But what if I believe that the highest moral good is to be found in the autonomy of the individual, while you believe that the highest good is to maximize the utility of some societal group? What are the data we can point to in order to adjudicate this disagreement? We might use empirical means to measure whether one preference or the other leads to systems that give people more successful lives on some particular scale — but that’s presuming the answer, not deriving it. Who decides what is a successful life? It’s ultimately a personal choice, not an objective truth to be found simply by looking closely at the world. How are we to balance individual rights against the collective good? You can do all the experiments you like and never find an answer to that question.

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Update: Totally snookered. Via Kieran Healy, the disappointing news that the Habermas account is fake. Yet more evidence that the internet is less than an ideal speech situation.

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I’m not the only person to find it endlessly amusing that Jürgen Habermas, octogenarian theorist of communicative rationality, has taken to Twitter. (The account seems to be legit, but it’s hard to be sure.) This is so over-determined that just last year Lauren Fisher gave a presentation entitled “If Habermas could Twitter.” Well, now we know.

He’s still trying to master the 140-character limit, though. Here’s his latest set of tweets:

Well, yeah. The internet is (in some sense) an egalitarian public sphere, but it raises the danger of fragmentation into self-reinforcing interest groups. Remains to be seen how it will all ultimately play out.

Last week I Twittered/Facebooked some provocative results from a poll of philosophers. In particular, this little tidbit:

Teletransporter (new matter): survival or death?

Accept or lean toward: survival	337 / 931 (36.1%)
Other	304 / 931 (32.6%)
Accept or lean toward: death	290 / 931 (31.1%)

Yes, that’s all the detail presented in the question: “Teletransporter (new matter): survival or death?” As a professional philosopher, you’re supposed to be familiar with the issue, which I reconstruct as follows. Imagine that someone has invented a working teleportation device. You step in the box, lights flash and sparks fly, and “you” rematerialize in another box, exactly the same in every way, but constructed out of a completely new collection of atoms. The original version of you is destroyed. Did you die? (And then, what if a million years passed in between the two events?)

It would probably be annoying to real philosophers, but I personally put this question in the category of “Not that hard.” And I would phrase my answer as: “Who cares?” What we should care about is how well the teleporter actually works — is the reconstructed person really in exactly the same quantum state as the original one was in? Same memories, feelings, etc? That’s an interesting technology question.

But there’s no interesting question associated with “Did you really die when you were teleported?”, or “Are you really the same person after being teleported?” These are just bad questions. They assume a certain way of looking at the world that ceases to be useful once we’ve invented teleportation. Namely, they assume that there’s a certain “essence of you-ness” that is (somehow) associated with your physical body and continues through time. That’s a perfectly sensible way of talking in the real world, where we don’t have access to duplicator devices or transporter machines. But if we did, that conception would no longer be very useful. There is a person who stepped into the first box, and a person who stepped out of the second box, and obviously they have a lot in common. But to sit down and demand that we decide whether they are “really” the same person is just a waste of time — there is no such “really.”

Which isn’t to say there aren’t interesting questions along these lines, but they are operational questions — how should I actually act, or what should I actually expect to happen, in these situations? — rather than arid metaphysical ones. What if you murdered someone, and then teleported — would the reconstructed person still be guilty of murder? That’s not quite the right question, because it still relies on the slippery essence of continuous personhood, but there’s a closely related sensible question — should we treat the reconstructed person as if they had committed murder? And it seems to me that the answer is clearly “yes” — whatever good reasons we had for treating the pre-teleportation person in a certain way, those reasons should still apply to the post-teleportation person.

The issue of duplication seems much thornier to me than the issue of teleportation. If someone made an exact copy of a known murderer, should we treat both the original and the copy as murderers? (I vote “yes.”) Fine, but what about the view from the inside? Let’s say you have an offer to get paid $100 if you let yourself be copied, with the proviso that after being copied one of the two of you will randomly be chosen for immediate painless execution. Do you take that deal?

I think problems like that are legitimately interesting, although to a great extent their mystery relies on the inadequacy of our conceptions of death. Most of us don’t want to die, at least not right away. But if we did die, we’d be gone, and wouldn’t have any wants or desires any more — but it’s very hard to consistently reason that way. Note that if we replaced “immediate painless execution” with “prolonged torture,” it seems like a much more straightforward question.

This showed up in our long-ago discussion of the quantum suicide experiment. In the many-worlds interpretation of quantum mechanics, you can make measurements that split the wave function of the universe into distinct branches. In some sense, then, you really do have a duplicator machine — it’s just that the whole universe gets duplicated, not just you. Some folks have tried to argue against this idea by pushing adherents into a logical cul de sac. You shouldn’t (to make a long story short) be averse to bargains that leave you dead with large probability, as long as there exist branches of the wave function where you are alive and flourishing — after all, in the branches where you are dead you don’t care any more, right?

My point in that earlier post — a point I somehow managed to completely obscure — was that these are misleading thought experiments, because very few of us would take seriously the corresponding classical suicide experiment. “Here, I’ll flip a coin, and give you $100 if it’s heads and shoot you instantly dead if it’s tails. Deal?” Very little temptation to take that offer. But the logic is essentially the same — if you’re dead you don’t care, right? (For purposes of these thought experiments we always assume you have no friends or loved ones who would miss you; it’s just part of the philosophical game, not a comment on your actual social situation.)

At some point in thinking about the many-worlds interpretation, issues like this inevitably do come up. That’s what David Albert and I talked about a bit on Bloggingheads. There might be a certain measurement that yields result A 10% of the time, and result B 90% of the time. But in the MWI, the measurement splits the universe into two branches, and you end up either in the branch where you saw A or the branch where you saw B. What does it mean to say that you had a “10% chance of measuring A”? You either did or you didn’t — there is no ensemble of millions of you all doing the same experiment. People have made progress on these questions — here’s a talk by David Wallace on his work with David Deutsch in attacking this problem. (Don’t ask me why everyone who thinks about these issues is named “David.”) I haven’t ever looked at this work closely enough to have an informed opinion.

All I know is that being able to teleport around would be really cool.