Sean Carroll

Author: Sean Carroll

  • The Great Muffin Joke Debate

    Muffins Our current task, as Serious Bloggers, is to pass judgment upon whether the Muffin Joke is funny. Here is the joke itself:

    So there are these two muffins baking in an oven. One of them yells, “Wow, it’s hot in here!”

    And the other muffin replies: “Holy cow! A talking muffin!”

    John Tierney (New York Times) thinks the Muffin Joke is not funny. Brad DeLong (Berkeley) disagrees, claiming that the Muffin Joke is, in fact, funny, although he offers no argument to support his conclusion. Jack Balkin (Yale) also finds the Muffin Joke funny, and does offer a rationale:

    The muffin joke is funny because it is self-undermining. The punch line undermines the suspension of disbelief that the joke’s narrative presumes. It is kind of like breaching the fourth wall in drama. It’s like the line in Dr.Strangelove “You can’t fight in here. This is the War Room!” or the Atheist Hymn we came up with in high school: “There is no God, there is no God, He told me so himself.”

    He admits, however, that by offering this explanation, he has thereby wrung all of the funniness out of the Muffin Joke. That’s as may be.

    I come down on the pro-Muffin-Joke side of the debate. To me, it’s quite funny. Is this some sort of Ivory-Tower Academics vs. Hard-Nosed Journalists thing?

  • Catholic Priest Proposes New Model for Creation

    Lemaitre and Einstein It was new at the time, anyway. The model being spoken of is the Big Bang, first suggested by Father Georges-Henri Lemaitre in 1927. (The expanding-universe solutions to general relativity had also been derived by Alexander Friedmann in 1922, but he hadn’t emphasized the nature of the intial singularity in such models.) Lemaitre, a Belgian priest who studied at Harvard and MIT, proposed what he called the “Primeval Atom” or “Cosmic Egg” model of the universe, and derived Hubble’s law, two years before Hubble and Humason actually discovered that the universe is expanding. Einstein wasn’t all that fond of Lemaitre’s idea — having been assured by his astronomer friends that the universe was static — but he encouraged Lemaitre in his investigations.

    All of which springs to mind because the Modern Mechanix blog has unearthed a Popular Science article from 1932 by Donald Menzel, an astronomer at Harvard, that explains Lemaitre’s ideas. (The time between Hubble and Humason’s discovery and Menzel’s article is somewhat less than the time between the 1998 discovery of dark energy and Richard Panek’s New York Times Magazine article from yesterday.) Menzel’s piece does a great job of explaining the basics of the Big Bang model, long before it was given that name by Fred Hoyle. Indeed, he touches on many of the questions that still arise in a good Cosmology FAQ! For example, he emphasizes that the redshift is due to the expansion of space, not to the Doppler effect.

    The case of the universe is analogous, except that the expansion, being of a three-dimensional volume, cannot be visualized. The phenomena are, however, comparable. The nebulae are not running away from us. Their recession is due to expansion of space. This may, perhaps, seem to be quibbling over terms, since it amounts to the same thing in the end. Nevertheless, the distinction is worth keeping. According to the relativity theory, there is a difference between the running away of the nebulae and expansion of the medium in which they are imbedded.

    Sadly, he also appeals to the much-hated balloon analogy for the expansion of the universe, although he uses the surface of the Earth rather than the surface of a balloon; in fact, it’s a better choice. And he’s not afraid of diving into the sticky questions, like “What happened before the Bang?”

    DR. LEMAITRE’S hypothesis does away with the old query as to the state of affairs before the beginning of things. Going back to the parent atom we may inquire about what happened before the cosmic explosion took place. The answer is: — Nothing. – Computation shows that space would have closed up around the massive atom and, certainly, nothing can happen where there is no room for it to happen. Time has no meaning in a perfectly static world. The age of the universe is to be reckoned from that prehistoric Fourth of July, when space came into existence. Since then, space has been continually expanding before the onrushing stars, sweeping the way for them, forming a sort of motorcycle squadron to make room for the star-procession to follow.

    Like many contemporary cosmologists, Menzel is a little more definitive about this than he really should be. When asked “What happened before the Bang?”, the correct answer is really “We don’t know. According to general relativity, space and time do not exist before the Bang, so there is no such thing as ‘before.’ However, we have no right to think that general relativity is correct in that regime, so… we don’t know.” Few people are sufficiently straightforwardly honest to give that answer.

    And what about the future?

    SO MUCH for the present. What of the future? Einstein and the noted Dutch astronomer, Willem de Sitter, have talked of some future contraction, which might sweep up the stars along with cosmic dust and eventually bring the world back to its original state. Dr. Lemaitre thinks that such a contraction cannot occur. He prefers to believe that the whole universe was born in the flash of a cosmic sky-rocket and that it will keep expanding until the showering sparks which form the stars have burned to cinders and ashes.

    We still don’t know the answer to this one, but the smart money is on Lemaitre (and against Einstein, who liked his dice unloaded and his universes compact). Now that we know the universe is not only expanding but accelerating, the simplest hypothesis is that it will keep doing so. To be honest, of course — we don’t know!

    Lemaitre passed away in 1966, a year after Penzias and Wilson detected the microwave radiation leftover from the Primeval Atom.

  • Happy Birthday, PZ!

    PZ Myers — looming, hulking titan of the science blogosphere — turns an even half-century old tomorrow. Bloggers of all stripes are coming out to celebrate, with links being collected by John McKay, GrrlScientist, and Coturnix. (I’m not sure what’s the big deal about 50. The number only looks special because it’s the number of fingers on one hand times the number of fingers on both hands. A less parochially antropocentric anniversary would be 64, which is the square of the number of arms on a cephalopod. But I’m not in charge.)

    I would like to give PZ a nice birthday present, as he played an important role in my life as a blogger: he gave me my first link ever. I could write him a poem, like Richard Dawkins did, but trust me you don’t want that.

    So I had the great idea of sharing my favorite cephalopod-related video — this clip of a guy eating live octopus tentacles.

    But then I thought about where I had actually seen this first — and, yes, it was on Pharyngula. Damn you, PZ! Still, if you’re in the LA area and are jonesing for some live tentacles, we’ll hook you up.

    So finally I decided to give PZ something he’d really appreciate — his astrological chart.

    PZ's Astrological Chart

    The “interpretation” goes on and on about the implications that Pluto is in 28 degrees Leo, etc. (I guess they still think it’s a planet.) But here’s the punchline:

    Rising Sign is in 03 Degrees Aries

    You are a free spirit and you must be first at everything you do. Very energetic, self-assertive and active, things must be done your way. Even though you may feel calm and serene on the inside, you certainly do not act that way. You want to do everything full-tilt, 100 miles per hour! A great competitor, but a poor cooperator — you must learn how to lose more gracefully. Very self-confident, ambitious and passionate, you radiate positive energy. You are blunt and direct, but at times unfeeling and tactless, especially if anyone offers you any resistance. You fight for your beliefs, but your tendency to act first and think later often causes you much grief.

    Man, I don’t know. Seems pretty darn accurate to me. I might become a believer, despite my principled misgivings.

    Happy Birthday, PZ!

  • Skeptical Pluggery

    Readers who hang out in the Southwestern quadrant of the U.S. should be aware of the lecture series at Caltech sponsored by the Skeptic’s Society. Past speakers include such luminaries as Richard Dawkins and Lisa Randall; future highlights include a debate between Frank Tipler and Lawrence Krauss on “Can Physics Prove God and Christianity?” That should be, how shall we say, somewhat surreal.

    This Sunday at 2:00 there is a lecture on The Physics of Pouty Teenagers Fighting Vampires, or something like that. Apparently there is even a book along those lines. I’m too high-minded to think about such things myself, but I’ll probably go to this lecture, because the speaker looks like a total babe.

  • I prefer to read. Leave me alone.

    A whole life of making minimal demands, of keeping to myself, of doing all my chores promptly and well, of getting superlative grades, of being a star in band, of being a dutiful student of the piano, of having good and well-behaved friends, of working ever since I was old enough to drive — that all meant nothing. Being good hadn’t preserved me from random interrogations, in fact made me more vulnerable — I bought into their standard of judgment and tried to defend myself according to it, once even breaking down in tears, a seventeen-year-old kid, breaking down into incoherence, collapsing into a fetal position, and she just walked away. Even now, if something ever comes up in conversation, she acts like she doesn’t remember, like it was someone else entirely — she apologizes on behalf of this other person, over-eagerly, like she’s apologizing for some weird misunderstanding that she can’t fully assimilate.

    Dave Brubeck and Heidegger. Adam Kotsko tells a short cliched-sounding tale — growing up with parents who don’t understand you — that he elevates into a moving memoir. I’m glad to have been quite a bit more fortunate.

  • arxiv Find: Analysis of the Apparent Lack of Power in the CMB Anisotropy at Large Angular Scales

    Here’s a paper that was mentioned in comments, about which I’m not qualified to say all that much: astro-ph/0702723, “Analysis of the apparent lack of power in the cosmic microwave background anisotropy at large angular scales,” by Amir Hajian.

    We study the apparent lack of power on large angular scales in the WMAP data. We confirm that although there is no apparent lack of power at large angular scales for the full-sky maps, the lowest multipoles of the WMAP data happen to have the magnitudes and orientations, with respect to the Galactic plane, that are needed to make the large scale power in cut-sky maps surprisingly small. Our analysis shows that most of the large scale power of the observed CMB anisotropy maps comes from two regions around the Galactic plane (~9% of the sky). One of them is a cold spot within ~40 degrees of the Galactic center and the other one is a hot spot in the vicinity of the Gum Nebula. If the current full-sky map is correct, there is no clear deficit of power at large angular scales and the alignment of the l=2 and l=3 multipoles remains the primary intriguing feature in the full-sky maps. If the full-sky map is incorrect and a cut is required, then the apparent lack of power remains mysterious. Future missions such as Planck, with a wider frequency range and greater sensitivity, will permit a better modeling of the Galaxy and will shed further light on this issue.

    There are two issues here, as I understand it. Here’s a map of the temperature fluctuations in the CMB, from WMAP:

    CMB map

    When you decompose this into contributions at different angular scales (spherical harmonics), you get this power spectrum:

    WMAP power spectrum
    The point on the far left, the quadrupole at l=2, seems to be low compared to the predictions of the standard cosmological concordance model. That’s one thing. The other thing is that, when you dig into the individual contributions that are grouped together to make this plot, the other low-l contributions seem to pick out a preferred direction on the sky, sometimes called the axis of evil.

    So that’s intriguing, but it’s not completely clear whether it’s really significant, or just an accident. For one thing, the preferred direction seems to match up pretty well with the ecliptic (the plane in which the planets orbit the Sun), possibly indicating some systematic error rather than a cosmological effect. We don’t get an unvarnished view of the primordial microwave background; it comes to us through the galaxy, and through the material in the Solar System itself.

    This paper seems to be claiming that the large-angle anomalies are, in fact, just a matter of foreground contamination. At least I think that’s what it’s saying; there are a lot of negatives (“although there is no apparent lack of power…”). Of course, the abstract concludes in the way that all good data-analysis abstracts should: we need more data! Happily it’s coming, in the form of the Planck satellite. One or more of our expert readers may chime in.

  • The Tremulous Punditosphere

    We have an interesting illustration of how the internet is changing the nature of political punditry, in the form of the ongoing spat between Joe Klein and the liberal blogosphere. Bloggy triumphalism can be tiresome, and the MainStream Media aren’t going to be replaced in the foreseeable future, if only because they actually put a great deal of effort and resources into real reportage. You know, calling people on the telephone, traveling to places where interesting things are happening, stuff like that. Annoying as they may be at times, the MSM are still the primary source for information about what is going on in the world.

    When it comes to opinionmongering, though, we are faced with a completely different kettle of fish — ones with sharp teeth and short tempers. Journalism requires work, but anyone can have an opinion, and most everyone does. Not everyone has opinions that are interesting, or the ability to defend them persuasively using information and rational argument. That, in principle, is why we have pundits in the first place; they are supposed to be better-informed than average, and generally capable of intelligently articulating the opinions they have. The best pundits, presumably, should be those that have the most interesting opinions, and are the best at explaining and arguing for them.

    Problem is, these are subjective criteria. What typically happens in the MSM is that, by some quite mysterious process, an editor or publisher decides that some particular person with opinions would make a good pundit, whether its because of the sparkle of their prose or the cut of their jib. A column or regular TV appearances are granted. And then, amazingly, they’re in forever. Rarely are columnists fired for not making sense; once they claim that status, they tend to keep it, no matter how pointless or uninformed their work turns out to be. It’s as if the NBA drafted players straight out of high school, but then they never had to play a game; they all just received long-term contracts, with salaries based on how good they look during lay-up drills and dunk contests. Maureen Dowd will be taking up space on the New York Times Op-Ed pages for decades to come.

    Blogs work on a different model. Despite various well-documented biases and ossification of hierarchies, the blogosphere is still largely a meritocracy, in which success is driven by the free market of links. Say things that are interesting, well-informed, and thoughtfully presented, and someone will link to you. Word will spread, and you can be a success. Admittedly, you can also be a success by spouting complete nonsense, if you do it in a way that enough people approve of. The point is not that what rises to the top is exclusively meritorious; it’s that merit is one of the ways in which you really can rise to the top.

    Joe Klein, longtime columnist for Time magazine and anonymous author of Primary Colors, is doing his best to inadvertently prove the dramatic superiority of the blog model for developing pundits. Klein has never been a favorite among lefty bloggers; although purportedly liberal himself, he comes off more as a smug apologist for accepted Washington consensus than as a shrewd analyst. On the Iraq war in particular, he’s shown something other than courage; in fact, what ever the opposite of courage is, he’s pretty much shown that. Now that the war has turned out to be a disaster on all fronts, he insists that he was against it all along. Which is funny because, in all of those columns he regularly penned for our largest-circulation newsweekly during the time when the wisdom of going to war was actually being debated, he forgot to mention it. He was asked about the issue point-blank at the time, by Tim Russert on Meet the Press, and replied “This is a really tough decision. War may well be the right decision at this point. In fact, I think it–it’s–it–it probably is.” Somewhat short of a full-throated denunciation.

    But what’s a little weak-kneed simpering among friends? You don’t have to go on the Sunday talk shows every week, and in a few months whatever you said at the time will be forgotten anyway. But now Klein has embarked on a new adventure — he’s blogging, as part of Time’s group effort called Swampland. We begin to perceive the outlines of an actual conversation; there are comments on his posts, and other bloggers can link to him and offer critiques (with explicit citations) practically in real time. And they’ve been calling Joe Klein on his crap. (Or, I should say, “calling him on his shit,” since one of the standard fallacies wielded against bloggers is that they shouldn’t be taken seriously because they use curse words.) It’s like all those young draft picks had to suddenly start playing games, and not against the Washington Generals, either.

    The results haven’t been pretty. Atrios, in particular, has been tireless in combatting the idea that mainstream journalists are just liberal mouthpieces, and is quick to point out how often supposedly-liberal pundits like to carry water for Republicans. Most journalists probably do self-identify as liberals — but, much more relevantly, they are part of the professional political class. With a few notable exceptions, they tend to cozy up to power, and try their best to reflect the conventional wisdom of their friends in the same class. Smart political operatives have learned to play them like very loud fiddles, so that the desired message can be broadcast under the cover of neutral journalism.

    (more…)

  • I Fear for the Internets

    Thanks to Daniel’s post below, Cosmic Variance is presently the #1 Google hit for pretty pictures of love.

    Who says we don’t have a sensitive side?

  • Perspective is Bidirectional

    Today’s xkcd captures an important insight.

    Bidirectional Perspective
    Click for the whole thing. (Update: Darn it, Cosma Shalizi got there before me.)

  • Scientiae

    Dr. Free-Ride brings to our attention Scientiae, a new blog carnival devoted to posts about women in science, engineering, technology and mathematics. Apparently something that people still like to talk about! So if you’re a blogger with a good post along those lines, go ahead and submit it. And if you’re not, feel free to submit something else good that you’ve read.