Archive for March, 2010

Sam Harris has recently given a talk at TED entitled “Science Can Answer Moral Questions“. This talk has garnered a lot of attention, and has been fairly controversial, as Sam Harris’s opinions tend to be in general. Sean Carroll has weighed in over at Cosmic Variance. I posted a lengthy comment there detailing my thoughts, which I repost below.

Hi Sean, interesting comments here, but I mostly disagree with you. By the way, Sam is soliciting criticism of his talk over at http://www.samharris.org/ted_talk, so I’d suggest you link him to this post.

Now, to the disagreement. It’s true that one will never be able to derive moral principles without making some assumptions, like axioms, at the base of everything. You are aware of this, stating “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?” Clearly if you begin with different goals you will reach different conclusions about what are the most moral actions. And of course those conclusions should be informed by the facts of the matter – for example, there may be ways to enhance “the autonomy of the individual”, and if you’re wrong about what those ways are, then you will fail in your goal.

But science is no different! Of course the Big Bang is based on facts, but it’s also an inductive generalization, and nothing in the facts tells us that any particular prediction of Big Bang theory is guaranteed to be right. At the base of science there are assumptions, for example, assumptions about how much confidence we should place in inductive generalisations. It’s mostly just an intuition, but that’s enough to get started, and we can make great progress once we stop worrying about the fact that our foundations are not absolutely set in stone. The foundations are solid enough to make progress, and we should not obsess too much over them. Your reaction to Sam’s talk seems to me to be equivalent to a radical sceptic thinking you’re wrong about the Big Bang because it’s impossible to have perfect knowledge.

In ethics, I think the situation is much the same. Once you decide on a goal (for example, wanting conscious beings to be in more pleasant brain-states), the methods you should use for deciding what actions are moral are basically the methods of science. I see this as Sam Harris’s main important point, but there is another. Now, of course you could choose a different goal and then you would get different conclusions about what constitutes acting ethically. Here, I think Sam makes a second major point (that I also agree with): that wanting conscious beings to be in more pleasant brain-states is implicitly the goal of the vast majority of moral systems. Even religious ones: for example, a fundamentalist Christian who believes in a literal hell may be justified in quite radical acts here on Earth – and this would be right if it was expected to prevent future eternal suffering of conscious beings. The error here is scientific: the evidence for a literal hell is so weak that there almost certainly isn’t one. Also, people who advocate individual freedom, or strong communities, do so because they think it produces the best lives for people – not because it’s an end in itself.

The foundations of ethics, and science, are not absolutely rock solid – but that’s okay. They’re solid enough to make progress. There is a place for intellectual hand-wringing about foundations, but that doesn’t mean that anything goes and that we may as well give up.


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Dinner, synopses

Finished the last of my 5 research synopses—outlines of projects I’d like to begin or make further progress with in the next two to three months—this afternoon; something for Alan & Fergus to work on when they come to visit next week! Also had dinner at PGFC with Daniela Huppenkothen, who is considering taking a PhD position at DARK, Lars Mattsson, who is visiting us from Uppsala this week to work with Anja on the physics of AGB stars, and two of our recently started PhD students. Good times.

But now I can’t sleep! I will watch the inevitable progress of Juggernaut Australia and our hapless trans-Tasman cricketing friends and hopefully be off to bed within the hour. After all, there’s a whole lot of cross-correlation paper writing to be done tomorrow!

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By now, ChatRoulette has reached even the most corneriest corners of the Internet, garnering mentions in academic blogs, friends’ Twitter feeds and blandly expository New York Times articles. I’m sure I’m not alone in being disappointed at the ease with which the open-ended potential of real-time video connections to random strangers has been channelled  into mundane middlebrow expression; also, gratuitous display of genitalia. (On the other hand, those folks are probably having a blast, and that’s not without merit.)

However, here is an inkling of a better world (some viewer discretion advised):

Update: Hello! Ben Folds follows up by Chat Rouletting Merton-style during a gig in Charlotte. The next time someone is all ‘Hmm… what is art  these days?’ in your vicinity, do the right thing and point them at this.

Amusingly, I think Merton’s lyrics are funnier, though having the crowd in the background really blows it away. I mean, imagine if this catches on. Imagine if every time you log in to Chat Roulette you have to prepare yourself for appearing in the middle of a concert.

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Yesterday I read a few of the recent papers of Francesco Sylos Labini, who has pursued a distinction between the common or garden type statistical homogeneity in the Universe that one reads about in textbooks, and a stronger form (‘super-homogeneity’) in which the mass fluctuations follow a behaviour that is sub-Poisson as a function of scale. This implies a sort of anti-correlation—a lattice of points is, for instance, sub-Poisson, as the points are deliberately avoiding one another—and has consequences for the form of the two-point correlation function:

\int \xi(r) d^3 r = 0

that look remarkably similar to those imposed by the integral constraint, but which are, in fact, quite different—the super-homogeneity condition affects the actual correlation function, while the correction usually referred to as the integral constraint affects estimators of the correlation function. I started writing a summary document on this topic for the reference of myself and others.

After DARK’s infamous \gamma\Lambda session, I hit a sweet spot in coding productivity and wrote a bunch of scripts to extract spatial features from galaxy images, along lines suggested to me a week or so ago by Andrew Zirm. These features are extracted from a matrix that encodes the frequency of adjacency between threshold intensity levels in the image. It’s the sort of thing best shown with pictures, which perhaps I can post once Andrew has decided which direction to pursue next.

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I’ve had cause to think just a little about entropy in the last week and though it’s not time to say more about that right now, it is worth linking to the recent adverti-view Stephen Colbert carried out with Sean Carroll for the latter’s new book. It’s something I will, perhaps, get around to reading someday soon, but there is no rush because Sean has been running a chapter-by-chapter book club on Cosmic Variance, which is a great resource to have on the digital shelf.

This is a good place to mention the publication of O. J. E. Maroney’s 2007 paper ‘Does a Computer Have an Arrow of Time?’; apparently the lag time for publication is quite long in the philosophy of physics. The purpose of this article is to advance the idea that

… [A]ny computational process that can take place in an entropy increasing universe, can equally take place in an entropy decreasing universe.


This conclusion does not automatically imply a psychological arrow can run counter to the thermodynamic arrow.

I enjoyed skim reading the work.

Tangentially, see IOZ on airport ‘security’:

No. I will not settle for absolute security. I require, I demand the […] Government guarantee a negative probability of anything bad ever occurring to me. I demand that the chances of my not suffering from any external danger exceed unity. I order civilization to hack the seething quantum foundation of spacetime itself.

Maybe we should do a book club. Ignoring the fact that none of us (bloggers, readers, spambots) are really willing to commit time to it, what would be a good book for that sort of venture?

[The image at the top is from the concept art for Braid.]

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Blog innovation is good. Here is what David Hogg says:

  • I must post five days per week (I choose which five), except when traveling, no matter what I have done.
  • I must write only about research; no committees, no refereeing, no teaching, no excuses.

Well, the first rule sounds good, & I also undertake not to blog about committees, refereeing, teaching or excuses.

So, here is what happened today: I had a wisdom tooth taken out. It was impacted, which means that it was at an angle of somewhat less than the usual pi/2 radians relative to the gum-line and so obstructing access to its root, as though it knew it would one day be the target of this sort of operation. To get through the tooth itself, they used a technique that is new to me, called piezosurgery, which pulverises the tooth using ultrasonic rage rather than the traditional drill. The purpose of this is to reduce the physical trauma to the gum and thus reduce the swelling.

The whole thing took about 30 minutes from the application of local anaesthetic (which was, unsurprisingly, the most painful part) to me forking over what I feel is a reasonable remuneration in Danish crowns given the services rendered. And true to their word the swelling has been much less dramatic than is usually advertised in association with the removal of wisdom teeth. I will apply some more cold pressure to it, in the form of my tub of chocolate mousse from Irma*, and take non-prescription painkillers and see how things are in the morning.

As I am working from home today, to shield my coworkers from what I had presumed would be a visage worthy of Picasso, after cooking myself a simple lunch I updated to the latest release of Matlab (R2010a, 64-bit for Intel Mac), refreshed my default path locations, etc., and made some computations with some simple mock density fields corresponding to one of the fields of the WiggleZ survey, provided for me by Chris Blake. We are currently deciding between two methodological approaches and the computations I ran today are aimed at putting this decision on a quantitative footing. We call them ‘Method 1’ and ‘Method 2’ and, several times, I have forgotten which of these methods is which; I think this is a good way to do science. Once we have decided which label produces the better outcome, we can examine what method that label actually corresponds to.

* A Danish supermarket, not to be confused with a young woman, perhaps the eponymous Irma of the supermarket’s logo, who brought me mousse out of sympathy, or for some other reason.

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This post is part of a series on the fine-tuning of the universe. Here I will respond to the work of Dr. William Lane Craig. Craig is Research Professor of Philosophy at Talbot School of Theology. He is known for his defence of arguments for the existence of God, both in philosophical journals and public debates. Here, I will respond to a point that Craig has made in response to the multiverse (or many-worlds hypothesis; James Sinclair makes a similar point in his essay in “Contending with Christianity’s Critics”):

The error that that is made by the many worlds hypothesis is that it is basically an attempt to multiply your probabilistic resources without having any justification for doing so. It’s a way of saying that the improbable roll of the dice that we have come up with is rendered probable because there have been many throws. If you’re allowed to do that, then you could explain away anything. For example, imagine a couple of card players in a west Texas saloon. And every time one of them deals, he gets four aces, and wins the game. The other guy gets outraged and says, “Tex! You’re a dirty cheater!” And old Tex says, “Well, Slim, you shouldn’t really be surprised that every time I deals I gets four aces. After all, in this infinite universe of ours there’s an infinite number of poker games goin’ on somewhere. And so chances are in some of them I gets four aces every time I deals.” (more…)

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Last week I was in Zurich Monday to Friday, & though we haven’t the pictures to prove it, Luke and I caught up for several chats and a lovely dinner at Europe’s oldest vegetarian restaurant, organised by my host, Katarina Kovač.

The Institute for Astronomy at ETH is cosseted in a marvellous new building whose floors run from D, through E (Erdgeschoß, the ground floor) all the way to K, which is one floor above the Institute. While I was there, a Nespresso machine was installed in their kitchen area. Alexis Finoguenov, the inspiration for my going to Zurich, took the train down from Munich and set upon us with ideas about the bias and correlation between galaxies*.

Science happened. Whiteboards were filled and emptied. I extolled at length my concerns about non-Gaussianity. Reams of Matlab script, rather different to Owen’s, appeared on my Macbook. Chunks of the Universe were loaded, manipulated, cleared. And this is the beginning of the project!

There is much to do.

* Or, as I am apt to say, sets of points that represent galaxies.

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Copenhagen is just like this! Image links to comic at original size; more marks of wonder at Wondermark.

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Some of you may not have realised that the majority of Matt’s blogging for LtN actually takes place in the comment threads to Crikey articles, where his writing invariably attracts spirited criticism. As a service to our international readers, we collate, with the lightest of editing, a recent intervention into Live-blogging as PM Kevin Rudd speaks in Copenhagen; the progenitor article is less substantive and interesting than the following commentary, so don’t worry about clicking through.

Cue Bogdanovist:


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