Author: Sean Carroll

  • Rose Center Contest Videos

    The Rose Center for Earth and Space at the American Museum of Natural History has sponsored a video contest, asking participants to express in two minutes or less how science has moved them or impacted their lives. These contests are great ways to let an “audience” become real participants in a process, and have some fun along the way.

    Sadly the deadline is passed, so we can’t encourage you to contribute, but you can check out the entries. Here’s a video about the LHC, by Luke Cahill. (I’m using YouTube’s new “iframe” embedding scheme; let me know if it doesn’t work.)

  • Edge-Serpentine Map Marathon

    Edge is collaborating with the Serpentine Gallery in London on projects at the art/science interface. Last year they looked at equations; this year they’re looking at maps. It’s a playful and broad conception of what constitutes a “map”; you will see a few astrophysical examples in there.

    Here’s an excerpt from a map of the emotions by Emanuel Derman, based on Spinoza’s Ethics. I zoomed in on the cluster centered around pain, because that’s what people will be drawn to first anyway.

    Map of Emotions, according to Spinoza

  • Insane Clown Posse Channels Walt Whitman

    Every astronomer knows this poem, not with any special fondness:

    WHEN I heard the learn’d astronomer;
    When the proofs, the figures, were ranged in columns before me;
    When I was shown the charts and the diagrams, to add, divide, and measure them;
    When I, sitting, heard the astronomer, where he lectured with much applause in the lecture-room,
    How soon, unaccountable, I became tired and sick;
    Till rising and gliding out, I wander’d off by myself,
    In the mystical moist night-air, and from time to time,
    Look’d up in perfect silence at the stars.

    Now, I really like Walt Whitman, but this was not his finest moment. These days, the don’t-bother-me-with-explanations torch is carried by the Insane Clown Posse — two middle-aged white guys, Violent J and Shaggy 2 Dope, who put on makeup and rap approvingly about violence and misogyny. (Sorry for the comparison, Walt, but you brought it on yourself.) They received a lot of scorn from scientists for their recent song Miracles, which featured the immortal lines

    Fuckin’ magnets, how do they work?
    And I don’t wanna talk to a scientist
    Y’all motherfuckers lying and
    getting me pissed.

    Now there is a scary and illuminating interview with the duo by Jon Ronson in the Guardian, where they double down on their dislike of explanation and understanding. (Via Ezra Klein.) It’s all good, but here’s an especially clarifying moment:

    “I did think,” I admit, “that fog constitutes quite a low threshold for miracles.”

    “Fog?” Violent J says, surprised.

    “Well,” I clarify, “I’ve lived around fog my whole life, so maybe I’m blasé.”

    “Fog, to me, is awesome,” he replies. “Do you know why? Because I look at my five-year-old son and I’m explaining to him what fog is and he thinks it’s incredible.”

    “Ah!” I gesticulate. “If you’re explaining to your five-year-old son what fog is, then why do you not want to meet scientists? Because they’re just like you, explaining things to people…”

    “Well,” Violent J says, “science is… we don’t really… that’s like…” He pauses. Then he waves his hands as if to say, “OK, an analogy”: “If you’re trying to fuck a girl, but her mom’s home, fuck her mom! You understand? You want to fuck the girl, but her mom’s home? Fuck the mom. See?”

    If you’re confused, Violent J doesn’t actually want to have sex with his paramour’s mother. He is simply advocating not changing your behavior just because a parent is in the house. One word serving many purposes.

    Oh yes, and they are evangelical Christians. There are many different senses in which science and religion might come into conflict — personally I care about “religion makes claims about how the world works that aren’t true,” but there are certainly others. Here is one of them. As Shaggy puts it: “But since then, scientists go, ‘I’ve got an explanation for that.’ It’s like, fuck you! I like to believe it was something out of this world.”

    I don’t think religion is causing these lovable mop-tops to rebel against the power of scientific explanation; that’s too cheap an explanation. Rather, there is an underlying attitude that both pushes them away from science, and toward religion: a strong preference in favor of believing a certain set of things about the world, well before any evidence is in. First we decide that rainbows and magnets and Stonehenge are miraculous and mysterious things that cannot be accounted for by ordinary, understandable processes; then we reject science and turn to religious beliefs because that’s what flatters our preconceptions. It’s hard to know how to reach people like that. I’m thinking Phil Plait and Brian Cox should put on clown makeup and start rapping about Maxwell’s equations.

  • DonorsChoose Challenge 2010

    u548696_sm Time once again (slightly late, actually) for our annual DonorsChoose fundraising challenge. It’s a great program. Public school teachers around the U.S. ask for small amounts of money for their classrooms, and the donor — that’s you — gets to pick exactly how much you give, and to what project. It will break your heart to hear about elementary-school kids in high-poverty areas who need a few bucks to buy whiteboards or calculators. But these basic tools can make a huge difference in inspiring someone to get excited about math and science. Check out some of these projects:

    Cosmic Variance Challenge 2010

    and see if you aren’t moved to throw a few bucks their way.

    As before, we are part of a larger Science Bloggers Challenge. A little friendly competition is good for the soul, and for the donating. Now, in the past, the readers here at Cosmic Variance have done incredibly well in donating — over $12,000 last year! Not sure how that happened, honestly. You guys are good. Can we possibly do even better?

    Donors Choose Science Blog Challenge

    One thing that will help is that your donations are leveraged. The folks at Hewlett Packard have agreed to match any donation up to $50,000. (Not that we would object if you chose to give more, but it’s not strictly necessary.) So every dollar you give is two dollars of impact.

    And who know? Maybe there will be gifts for people who are especially generous. We’re not above bribery. Any ideas for what would constitute a good bribe?

    Also! If any other bloggers want to put up a post encouraging their readers to donate at our page, we will be very happy to link back to them with assorted compliments. Heck, we’ll even link to tweeters.

  • John Huchra

    jph.2005John Huchra, a leading astronomer at the Harvard-Smithsonian Center for Astrophysics, passed away on Friday. I’m not sure of the cause, but he had been suffering from heart problems; he was 61 years old.

    John was most obviously known for his scientific accomplishments, especially as a guiding force behind the CfA Redshift Survey. For you youngsters out there, this project was the pioneering effort at mapping the large-scale structure of the universe. It revealed, to the surprise of many, that there was a lot of structure out there! The iconic image of cosmology in the 1980’s was the “CfA Stickman” reveal in the famous A Slice of the Universe paper by Valerie de Lapparent, Margaret Geller, and Huchra.

    CfA Redshift Survey

    The stickman was not the universe being playfully anthropomorphic, it was simply the Coma cluster as distorted in redshift space. (You measure positions on the sphere of the sky, but velocities along the line of sight; converting these velocities to distances is inevitably distorted because galaxies in a cluster have peculiar motions inside the cluster.) Before this map was released in 1986, many people assumed that the galaxy distribution would be basically uniform on these scales. They shouldn’t have thought that, in retrospect (you need to go to larger scales before the uniformity becomes apparent), but sometimes it takes real data to get a point across. The survey went on to discover the Great Wall of galaxies, arguably the largest known “object” in the universe.

    John had a number of other important contributions, including measurements of the Hubble constant and the discovery of Huchra’s Lens, one of the most dramatic early examples of gravitational lensing. He was also very active in the community, serving as president of the American Astronomical Society and numerous other roles.

    But many of us will remember him mostly for his spirit and good humor. When I was a graduate student at CfA, he was one of the most friendly and helpful senior faculty members around, someone you were always happy to bump into in the hallways. There is a guestbook here for people to leave their reminiscences about John; he will be greatly missed.

  • George Carlin on Science and the Meaning of Life

    George Carlin, asked about the meaning of life, proclaims his love for astrophysics and particle physics. And the cyclic universe scenario, in particular.

    The interviewer, sadly, is pretty clueless, and wears his cluelessness like a badge of honor. Carlin shows quite a bit of restraint.

  • The Arrow of Time and the Multiverse on Philosophy TV

    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.

  • Physicists Playing Poker

    Those of you who haven’t already seen it should check out the November issue of Discover, which features an article by a well-known science writer about physicists playing poker. This is not completely egregious, as big moneywinners like Michael Binger and Marcel Vonk are card-carrying (as it were) Ph.D. physicists. Vonk on the relative merits of hypothetically winning the Nobel Prize or the World Series of Poker: “I would choose to win the Nobel Prize. But, it’s close.”

    Of course there’s always much more to a good story than can be squeezed into a print magazine. So if you want the background scoop, see Cocktail Party Physics. Where, unfortunately, I’m (accurately) quoted as saying something in an old blog post that really isn’t true:

    “Texas Hold ‘Em is so popular because it manages to accurately hit the mark between ‘enough information to devise a consistently winning strategy’ and ‘not enough information to do much more than guess.’ The charm in such games is that there is no perfect strategy, in the sense that there is no algorithm guaranteed to win in the long run against any other algorithm. The best poker players are able to use different algorithms against different opponents as the situation warrants.”

    Two out of three sentences there are correct (which wouldn’t be such a bad average at a poker table, but is pretty lame in writing). The first sentence is right; what makes Hold ‘Em such a popular poker variant is that you know enough to do more than guess, but not enough to easily reduce the problem to a simple algorithm. But the second sentence is wrong, as written, at least under the perfectly reasonable reading that “win” includes “or tie.” One of John Nash’s major contributions to game theory was to prove, under reasonable assumptions, the existence of dominant strategies. Here, it’s not the opponents that are being dominated — it’s the other strategies a player might contemplate using. And “dominate” doesn’t mean “beat under any circumstances”; it just means “there is no alternative strategy that does better against every possible opponent strategy.” Since the rules of poker (integrated over all seats at the table etc.) are the same for every player, every player has the same dominant strategy — which means that there exists a strategy such that, if everyone used it, their expected returns would all be equal, and none of them could unilaterally change their strategy to improve on that expectation. Texas Hold ‘Em is sufficiently complex that the dominant strategy certainly isn’t known in closed form, but it does exist.

    What I was clumsily aiming for in that sentence was the correct sentiment expressed in the last sentence. While a dominant strategy is in some sense “least bad” against the complete set of possible opponent’s strategies, it’s certainly not guaranteed to be the best against every specific opponent. If you know that your opponent deviates from dominant strategy in some particular way (not folding enough to re-raises pre-flop, for example), you will make the most money by choosing to deviate from dominant strategy yourself, in such a way as to take advantage of your opponent’s weakness. That’s the idea behind exploitative strategies, as advocated by Chris Ferguson in Jennifer’s blog post. Good poker is all about being exploitative. Any surprise that it’s a popular game among politicians?

  • Time Explained

    Some of us write books, others express themselves through visual media. Here’s my new favorite theory of time, courtesy Saturday Morning Breakfast Cereal.

    Time explained

    (It continues; click.)

  • One Last Stab

    I’ve been too busy to contribute much to the laws of physics discussion, and now I’m about to hop on a plane to bluegrass country. But I am sincerely seeking the best way to make this point clear, so one more quick try. And I do appreciate the back-and-forth thus far; sometimes frustrating, but certainly very useful to me.

    If you were to ask a contemporary scientist why a table is solid, they would give you an explanation that comes down to the properties of the molecules of which it is made, which in turn reflect a combination of the size of the atoms as determined by quantum mechanics, and the electrostatic interaction between those atoms. If you were to ask why the Sun shines, you would get a story in terms of protons and neutrons fusing and releasing energy. If you were to ask what happens when a person flexes a muscle, you would hear about signals sent through nerves by the transmission of ions across electromagnetic potentials and various chemical interactions.

    And so on with innumerable other questions about how everyday phenomena work. In every single case, the basic underlying story (if that happens to be what you’re interested in, and again there are plenty of other interesting things out there) would involve the particles of the Standard Model, interacting through electromagnetism, gravity, and the nuclear forces, according to the principles of quantum mechanics and general relativity.

    One hundred years ago, you would not have heard that story, because it hadn’t yet been put together.

    But — here’s the important part — one thousand years from now, you will still hear precisely that same story.

    There might be new layers underneath, but it won’t be necessary to refer to them to give a sufficient answer to the original question. There will certainly be much greater understanding of the collective behavior of these underlying particles and forces, which is where most of the great work in modern science is being done. And hopefully there will be a deeper story about why we have the laws we do, how gravity and quantum mechanics play together, how best to interpret quantum mechanics, and so on.

    What there won’t be is some dramatic paradigm shift that says “Oops, sorry about those electrons and protons and neutrons, we found that they don’t really exist. Now it’s zylbots all the way down.” Nor will we have discovered new fundamental particles and forces that are crucial to telling the story of everyday phenomena. If those existed, we would have found them by now. The view of electrons and protons and neutrons interacting through the Standard Model and gravity will stay with us forever — added to and better understood, but never replaced or drastically modified.

    I’m not actually trying to say something controversial. I think it is pretty unambiguously correct, once I actually say it clearly. But it’s something I think is not as widely appreciated as it really should be.