An interesting post by Chris Hayes on what goes through the minds of undecided voters. One telling excerpt:

Undecided voters aren’t as rational as you think. Members of the political class may disparage undecided voters, but we at least tend to impute to them a basic rationality. We’re giving them too much credit. I met voters who told me they were voting for Bush, but who named their most important issue as the environment. One man told me he voted for Bush in 2000 because he thought that with Cheney, an oilman, on the ticket, the administration would finally be able to make us independent from foreign oil. A colleague spoke to a voter who had been a big Howard Dean fan, but had switched to supporting Bush after Dean lost the nomination. After half an hour in the man’s house, she still couldn’t make sense of his decision. Then there was the woman who called our office a few weeks before the election to tell us that though she had signed up to volunteer for Kerry she had now decided to back Bush. Why? Because the president supported stem cell research. The office became quiet as we all stopped what we were doing to listen to one of our fellow organizers try, nobly, to disabuse her of this notion. Despite having the facts on her side, the organizer didn’t have much luck.

I remember back in the ’90’s talking to a woman who was between jobs at the time, and consequently without health insurance of any sort. She was worried about her situation, but took some solace in the fact that “at least Hillary’s plan never got passed.” Say what you will about the original Clinton health care proposal, I don’t think that “gives uninsured people even less insurance” would be a valid criticism.

The lesson I would draw from these stories is not to pat ourselves on the back for being well-informed while the unwashed masses are so clueless. It’s that we have built a system where people who don’t pay that much attention to politics are easy targets for disinformation. Why would anyone believe that Bush was the candidate to back if you support stem cell research? Well, because he and his supporters are happy to tell you that he supports stem cell research. It might not be “true” in any reasonable sense, but if you are generally predisposed to favor Republicans and you’re not following the details, it’s easy enough to believe. And there’s nothing especially partisan about the strategy; Democrats will obviously try to speak of themselves as being on the right side of every issue as well.

It’s an old story, but I blame the media. A few decades ago when a small number of TV/radio/newspaper outlets were the source of almost all information about politics and governance, one could make the argument that presenting some information and not passing judgment was the right thing to do. (One could also make the argument that such a strategy is simply impossible, but that’s not for right now.) In a world with thousands of such sources, the best thing that the largest news outlets could do is to not simply present all sides dispassionately, but make it clear who is right (factually speaking) and who is wrong. When someone claims that cutting taxes always increases revenue, let us know what the evidence is. In a world where information of some sort is everywhere, the important service is not to simply provide more, it’s to separate the wheat from the chaff.

Yesterday we went to see a chat with Alan Alda and KC Cole at USC’s Annenberg School for Communication, as advertised by Clifford here. Alda was apparently some kind of TV actor back in the day, but he is also quite the science aficionado — hosting Scientific American Frontiers on PBS, and originating the role of Richard Feynman in Peter Parnell’s play QED.

The most interesting story we heard was one that happened just the day before, when Alda and Cole visited with some students at USC’s engineering school. Apparently it was quite a day, beginning with short presentations by each of the students about the work they were doing. After the presentations, Alda led the students through a series of improvisation exercises from Viola Spolin’s classic workbook. After which, the students were asked to give their presentations again! Apparently (I have to take their word for it), the first time around the students were pretty darn good, but the second time they truly came to life.

Giving talks, or presenting ideas more generally, is one of the necessary skills of academic life that we usually presume one just picks up on street corners. The idea that, for example, college professors should learn how to teach classes would be an anathema to most actual college professors. But there is a lot of skill involved, and practice and learning can really make a difference. (The same would go for writing papers, or being an advisor, or a thousand other aspects of being a professor.)

My favorite part of the chat was Alda’s admonition to scientists to “Show the Love.” He was moved by the evident passion for their work exhibited by the students, but recognized that it didn’t always come through during scientific presentations. So here is some simple advice to young scientists giving talks: show the love! (Good advice to old scientists, too, but there’s no hope they would listen.) Let it be clear that you are absolutely fascinated by this work you are doing. You’re not in it for the money and fame, one presumes. Don’t look at a talk as a terrifying ordeal to be stoically survived; look at it as a chance to share some of your passion with other people who haven’t delved as deeply into the material as you have. I know we’re not supposed to use icky words like “love” in the rigorously austere corridors of professional physics, but this is a case where a little culture-changing wouldn’t hurt anybody.

And if you’re not all that passionate about what you’re doing — switch to doing something you really do love.

Update: Jennifer adds more words, plus an amusing cartoon, and an annoying poem.

ESA has just done the first big press release for the Integral gamma-ray telescope, and the big woosh you’re hearing is the sound of numerous dark matter models flushing down the toilet.

For several years the community has been carefully eyeing an extended, apparently spherical excess of gamma-rays from the center of the galaxy. Theorists have been busy generating crafty models where the excess in gamma-rays comes from the direct annhilation of dark matter particles, or from a decay chain from the dark matter particles themselves. These models were attractive because the shape and extent of the gamma-ray detection was wrong for just about any Galactic source except for the dark matter halo itself. The dark matter halo would produce just the right sort of signal, since it’s presumably highly cuspy in the center, leading to high rates of the sorts of interactions which might lead to detectable photons, but only near the center of the galaxy. The halo is also expected to be mostly spherical, as was consistent with the previous observations.

Well, with the higher resolution of the new Integral telescope, the distribution of gamma-rays looks distinctly disklike and lopsided, which smells much more like a boring old astronomical explanation (where “boring” means something to do with neutron stars and black holes, but still — no one’s expecting the Nobel Prize for this one, yet).

I have no independent knowledge of the veracity of this report, but a local TV station in the Bay Area is reporting rumors that the SETI program running at the upgraded Arecibo radio telescope has detected an anomalous signal (or in the very high tech language of their reporting, a “mystery signal”). The report includes some quotes from Dan Wertheimer, the director of the program, so presumably the reporter talked to someone with verifiable science cred before writing the piece. The quotes from the project’s scientists are guarded enough that I’m guessing this is just a lousy job of science reporting in the local news.

The part that got my blood pressure going was the follow-up about what we should answer back. The idea that our backward, technologically impaired civilization should jump up and down and wave its arms around saying “LOOKY HERE!!!! LOOKY HERE!!!! PICK ME!!!!”, is,….what’s the word….oh….batshit crazy. History is not exactly awash in cases where the technologically less advanced civilization wound up the winner when two cultures collide. Usually, it gets rolled.

In spite of this, some crazy optimists in Russia are actually beaming signals out to nearby stars, right now. This “active SETI” program strikes me as completely foolish, and has already caused a rift within the SETI community (so apparently, I’m not alone in my abject fear of being spotted by a more advanced civilization). While this issue hopefully has less urgency than figuring out the political response to planetary climate change, we need to eventually get our collective goverments organized into a treaty about how to deal with this issue. Suppose someday we actually detect some alien space ship whizzing through our local neighborhood. Do we let the Raelians and Scientologists invite them down for a drink, even if the rest of us think it’s better to lay low?

In the meanwhile, Earth should just STFU.

(UPDATE: Link to timesonline changed to the original reporting that they swiped from a much better article by David Grinspoon at Seed.)

(AND ANOTHER UPDATE: Phil Plait did some actual reporting (you know, calling and actually asking), and yup, it’s just bad journalism, as expected.)

CV readers, ahead of the curve as usual, are well aware of the notion of Boltzmann’s Brains — see e.g. here, here, and even the original paper here. Now Dennis Overbye has brought the idea to the hoi polloi by way of the New York Times. It’s a good article, but I wanted to emphasize something Dennis says quite explicitly, but (from experience) I know that people tend to jump right past in their enthusiasm:

Nobody in the field believes that this is the way things really work, however.

The point about Boltzmann’s Brains is not that they are a fascinating prediction of an exciting new picture of the multiverse. On the contrary, the point is that they constitute a reductio ad absurdum that is meant to show the silliness of a certain kind of cosmology — one in which the low-entropy universe we see is a statistical fluctuation around an equilibrium state of maximal entropy. According to this argument, in such a universe you would see every kind of statistical fluctuation, and small fluctuations in entropy would be enormously more frequent than large fluctuations. Our universe is a very large fluctuation (see previous post!) but a single brain would only require a relatively small fluctuation. In the set of all such fluctuations, some brains would be embedded in universes like ours, but an enormously larger number would be all by themselves. This theory, therefore, predicts that a typical conscious observer is overwhelmingly likely to be such a brain. But we (or at least I, not sure about you) are not individual Boltzmann brains. So the prediction has been falsified, and that kind of theory is not true. (For arguments along these lines, see papers by Dyson, Kleban, and Susskind, or Albrecht and Sorbo.)

I tend to find this kind of argument fairly persuasive. But the bit about “a typical observer” does raise red flags. In fact, folks like Hartle and Srednicki have explicitly argued that the assumption of our own “typicality” is completely unwarranted. Imagine, they say, two theories of life in the universe, which are basically indistinguishable, except that in one theory there is no life on Jupiter and in the other theory the Jovian atmosphere is inhabited by six trillion intelligent floating Saganite organisms.

Continue reading ‘Boltzmann’s Universe’

Part of my recent blogging poopy-headedness has been dealing with a minor medical drama with my youngest kid. Over the past 3 or 4 months, we’d noticed that her speech was lagging behind her peers. At her age, lots of kids start to self-correct any unusual speech patterns (lisps, etc), but she just wasn’t doing it. She’d always been a bit delayed verbally compared to her older sister, but that just meant she was in the middle of the bell curve rather than a freak of nature, so we’d never been too concerned. However, in the midst of starting to look into speech therapy, I had an incident where it became completely clear that she just couldn’t hear me. Previously, we’d interpreted similar episodes as her just being very absorbed in what she was doing — if you’ve ever dealt with a three-year old, you know that they’re excellent at ignoring you when they choose. This incident was different, though, and pointed strongly at her being hearing impaired. A follow-up at the doctor’s confirmed our suspicion, when she could only hear the very loudest tone at any frequency. A bit after Christmas we got in to see the audiologists, who found that she had about 40 decibels of hearing loss. For comparison, dense foam earplugs are rated at a bit less than 30 decibels.

The uncertainty before we got into the audiologists was kindof awful (though we of course were very chin up about it). We didn’t know if her hearing loss was degenerative, if it was correctable, and if, to what level. Mostly, however, I just felt terrible for her, because she’d been struggling for years just to understand anything that was going on around her. At the same time, I was tremendously proud of how well she coped, because damn, she was good at figuring out what you meant from not a whole lot of aural cues. Most people were shocked to find out that she was hearing impaired, because she can hold a conversation with you. However, once you know, you notice that during every few conversational back-and-forths, her ability to extrapolate your meaning would break down, and she’d get screwed up. So, all this time she’s been devoting a huge fraction of her tiny little CPU to a highly-advanced voice-recognition system.

In spite of the fact that she’s been good at passing, there are a number of traits that made a lot of sense once we knew about the hearing loss. For example, she has always been very self-contained and independent, but I suspect that’s largely because she only can process what she’s directly paying attention to. She never overhears conversations or background sounds, and so is frequently oblivious of what’s going on (again, it’s easy to miss this being a medical symptom, rather than a bad case of being three). She has great difficulty finding you in the house, since she doesn’t hear footsteps, doors closing, or water running.

The good news is that I now have no need to take advantage of my new knowledge of where to learn ASL in the Seattle area. The audiologists found that the problem was that her middle ear was filled up with the ear’s equivalent of snot, which is easily correctable with tubes. She had the surgery today, and it is like she’s a different kid. The change was dramatic, and essentially immediate. Suddenly, she’s chatty. She no longer pauses before answering you — I’d never noticed that she’d had this processing latency until it went away. She heard my husband from across the room. She swiveled instantly at hearing the ding of the elevator down the hallway. She is about a factor of ten times more engaged with everything around her, and it is so completely gratifying to witness.

And the answer is: about 10¹⁰², mostly in the form of supermassive black holes. That’s the entropy of the observable part of the universe, at any rate. Or so you will read in this paper by Paul Frampton, Stephen D.H. Hsu, Thomas W. Kephart, and David Reeb, arxiv:0801.1847:

Standard calculations suggest that the entropy of the universe is dominated by black holes, although they comprise only a tiny fraction of its total energy. We give a physical interpretation of this result. Statistical entropy is the logarithm of the number of microstates consistent with the observed macroscopic properties of a system, hence a measure of uncertainty about its precise state. The largest uncertainty in the present and future state of the universe is due to the (unknown) internal microstates of its black holes. We also discuss the qualitative gap between the entropies of black holes and ordinary matter.

It’s easy enough to plug in the Hawking formula for black-hole entropy and add up all the black holes; but there are interesting questions concerning the connection between the entropy of matter configurations and black-hole configurations. They are explored in an earlier paper by Hsu and Reeb, “Black hole entropy, curved space and monsters,” which Steve blogged about here.

A couple of simple ways you can make the world a better place without leaving the comfort of your keyboard.

First, the American Physical Society has set up a convenient web page from which you can write to your representatives in Congress to voice your displeasure concerning the unexpected budget cuts that have decimated U.S. physics, particle physics and fusion research especially. As APS President Arthur Bienenstock writes:

Congress wrapped up the Fiscal Year 2008 (FY08) budget just before adjourning for the year. The budget, which wipes out $1 billion in increases approved last summer for the National Science Foundation (NSF), the Department of Energy’s Office of Science (DOE Science) and the NIST laboratories, does irreparable damage to science and abandons the Innovation/Competitiveness initiatives of Congress and the Administration.

While DOE Science programs received a 2.5 percent increase overall (exclusive of earmarks), they will decline by about one percent after inflation. High-energy physics and fusion will feel the greatest pain. High energy physics will likely have to eliminate hundreds of jobs, halt work on both the NOvA, the next step in neutrino physics at FermiLab and partially furlough many remaining employees. The Omnibus bill for FY08 also stopped R&D on the International Linear Collider project, an international high-precision step beyond the Large Hadron Collider, and zeroed out the U.S. contribution to the international ITER project, designed to demonstrate the scientific and technological feasibility of fusion energy. These actions are severely damaging to the U.S. standing in the international scientific community.

Second, Steinn has come up with the clever idea of making our own Presidential Science Debate (just in case the official one doesn’t come to pass, or at least while we’re waiting). There are a pair of upcoming primary debates January 30/31, one for each party, and the Politico is soliciting questions to be asked of the candidates. So let’s flood their inbox with sensible questions! Nothing about boxers v. briefs or whether they believe in the literal reality of transubstatiation — let’s ask about their commitment to basic research, their views on manned vs. robotic exploration of space, the promise of alternative energy sources, what have you.

Matthew Yglesias invokes interpretive charity to suggest that MIMS, in the nation’s number one single “This is Why I’m Hot,” is not guilty of affirming the consequent.

In a follow-up analysis, Rob Harvilla in the Village Voice analyzes the logical structure of the song’s argument.

Don’t pass up the chance to click through; there are Venn diagrams.

Via the Zeitgeister, a fun panel discussion at the Perimeter Institute between Seth Lloyd, Leonard Susskind, Christopher Fuchs and Sir Tony Leggett, moderated by Bob McDonald of CBC Radio’s Quirks & Quarks program. The topic is “The Physics of Information,” and as anyone familiar with the participants might guess, it’s a lively and provocative discussion.

A few of the panel members tried to pin down Seth Lloyd on one of his favorite catchphrases, “The universe is a computer.” I tackled this one myself at one point, at least half-seriously. If the universe is a computer, what is it computing? Its own evolution, apparently, according to the laws of physics. Tony Leggett got right to the heart of the matter, however, by asking “What kind of process would not count as a computer?” To which Lloyd merely answered, “Yeah, good question.” (But he did have a good line — “If the universe is a computer, why isn’t it running Windows?” Insert your own “blue screen of death” joke here.)

So I tried to look up the definition of a “computer.” You can open a standard text on quantum computation, but “computer” doesn’t appear in the index. The dictionary is either unhelpful — “a device that computes” — or too specific — “an electronic device designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations.” Wikipedia tells me that a computer is a machine that manipulates data according to a list of instructions. Again, too specific to include this universe, unless you interpret “machine” to mean “object.”

I think the most general definition of “computer” that would be useful is “a system that takes a set of input and deterministically produces a set of output.” The big assumption being that the same input always produces the same output, but I don’t think that’s overly restrictive for our present purposes. In that sense, the laws of physics act as a computer: given some data in the form of an initial configuration, the laws of physics will evolve the configuration into some output in the form of a final configuration. Setting aside the tricky business of wavefunction collapse, you have something like a computer. I suppose you could argue about whether the laws of physics are “the software” or the computer itself, but I think you are revealing the limitations of the metaphor rather than learning something interesting.

But if we take the metaphor at face value, it makes more sense to me to think of the universe as a calculation rather than as a computer. We have input data in the form of the conditions at early times, and the universe has calculated our current state. It could have been very different, with different input data.

And what precise good does it do to think in this way? Yeah, good question. (Which is not to imply that there isn’t an answer.)