Science Blogging Anthology

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Science Blogging AnthologyIn the shortest turnaround time for a book ever, Bora “coturnix” Zivkovic (of Blog Around the Clock fame) has put together The Open Laboratory, a collection of the greatest science blogging of all time. Which is a little bit less impressive than it sounds, since science blogging hasn’t been around for that many centuries. Still, it’s a fun concept, to take all of those words on the internet and bind them between covers. I’ll admit that I nominated my own quantum puppies post, in the tradition of all great media shamelessness.

For those of you not quite willing to pay for what you find for free by pointing and clicking, you can peruse all 50 of the selected posts, or the complete list of nominees, without ever leaving your computer. For those of you who are willing, here you go.

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The Best Things in Life Can Be Pricey

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For those of you who had better things to do than read blogs over the holidays, you missed out on the story everyone was linking to: this ten-part expose of the Noka chocolate company. It was a well-done piece, by someone who really knows his chocolate.

Apparently there is an important distinction between “chocolate makers” and “chocolatiers.” The former actually pick the cacao beans and turn them into chocolate, while the latter will buy basic chocolate (“couverture”) from someone else and turn it into truffles or into whatever other form you prefer your dark sinful goodness. A pretty good system, overall; no shame in representing either half of the pipeline, although many manufacturers do serve both functions. Noka is a chocolatier — one of the most expensive in the world. Hundreds of dollars per pound, minimum.

The problem is that Noka pretends to make their own chocolate from scratch, even though they don’t. They don’t quite come right out and lie, but they shamelessly weasel around the truth, trying to give the impression that they’re out there picking beans themselves. Unlike other chocolatiers, who are perfectly happy to reveal who is providing their raw chocolate, Noka keeps it a closely-guarded secret.

But there aren’t that many chocolate makers in the world, and Noka does make a long list of claims about its chocolate — enough, as it turns out, to uniquely pin down who their supplier is! It’s a tiny French company named Bonnat. Apparently, Noka doesn’t even do a very artful job at turning their couverture into delectable truffles; they just melt it down and squeeze it into different shapes. And then sell it at a markup of anywhere from 1,000% to more than 6,000%. But you do get a pretty sweet stainless-steel box, if you go for the more expensive stuff.

Noka and Bonnat chocolate

All in all, a nice bit of investigative reporting, and a pretty damning indictment of Noka’s spin machine. But I was frustrated by a couple of aspects of the expose. Most obviously, with all of the elaborate effort that the author (credited only as “Scott”) went to test and characterize Noka’s chocolate, at no time (apparently) did he directly address the most important question — how good does it taste? The impression is given that it can’t possibly taste any different from the basic chocolate one could purchase directly from Bonnat, and here and there a disparaging comment about Noka’s presentation is thrown in. But really, the entire point is how it tastes, no? I’m ready to buy the argument that it can’t possibly live up to the hype, but I’d like to see that hypothesis explictly tested, with a blind taste test or some such thing.

The other issue is more subtle, and almost certainly unintentional on the part of the author, who is clearly a chocophile. Unavoidably, by revealing the pretense behind a fancy-schmancy chocolate operation, the expose will confirm the suspicions of those who think that the whole concept of boutique chocolate is a scam, targeted at yuppies with more money than sense. Or any boutique food product, really. There are people out there — I won’t name names — who harbor a lingering suspicion that anything more upscale than a good Hershey’s chocolate bar is just an exercise in name recognition, totally divorced from considerations of quality. And that kind of talk makes my sensitive elitist-snob blood boil.

Not that they’re always wrong. One area in which quality definitely matters, I think we can all agree, is fine single-malt Scotch whisky. My own introduction to the pleasures of good whisky came, at all places, at a cosmology conference. It was in Britain (of course), and as an evening’s entertainment the conference hosted a whisky tasting. It was presided over by a gentleman from J&B, who guided us through sips of several different single malts. Even to my untutored palate, the differences were unmistakable, and I was hooked. But the J&B guy, speaking in a charming Scottish accent, told a revealing anecdote: at one point they had a specific blend being sold only in Japan, which was suffering from disappointing sales. So they changed the name, slapped a different label on the same whisky, and tripled the price. Sales skyrocketed. Sometimes it really is about the cachet.

Other times, it’s not. Which I will proceed to rigorously prove by means of a counter-anecdote. I was having dinner with a friend at a fancy restaurant, the Ritz Carlton Dining Room in Chicago. She ordered the wine, keeping its identity a surprise by asking for it by the number on the wine list rather than by name. The bottle was brought to us by a different server, who offered it to me for tasting and inspection (being that I was the guy, naturally). This wine was — amazing. Words fail me. Robust and spicy and deep, with a profound elongated finish, but at the same time subtle and multi-layered, not merely an overly-alcoholic novelty trick. We both agreed it was the best wine we had ever tasted.

So we were enjoying the wine, when she proudly says “I knew you’d love this Barolo.” To which I replied, “What are you talking about? This is a California Cabernet.” Which claim was revealed, by inspection, to be true. And which, rather than causing some minor bemusement, filled us with fear. Obviously we had the wrong bottle, but had we made a mistake in ordering by number? This was a fancy place — she was trying to order a $100 bottle of wine, but there were plenty on the wine list that broke the $1000 barrier. And we didn’t really want to spend the rest of the evening washing dishes.

So, with some trepidation, we asked to peek at the wine list again. Turns out that the bottle we were drinking came in at $300 — not what we had meant to spend, but not completely obscene. And we hadn’t, in fact, ordered the wrong number; there was a mistake on the printed wine list, and two completely different bottles had the same number. Fortunately, this being a classy place, the wait staff was horrified that we hadn’t received what we had ordered, and offered to replace it (we declined), and wouldn’t think of charging us the more expensive price.

But the relevant point here is: paying a lot of money really does buy you quality, sometimes. This was a pretty good blind experiment, since we had no idea what we were drinking. I’ve had a few $100 bottles of wine in my day (not too many — I don’t move in those circles), and this was unmistakably better. Now, we can argue whether the increase of quality as a function of price is really linear, or something closer to logarithmic. But don’t you dare start arguing that there’s some non-outlandish threshold above which everything tastes just as good, no matter how much you pay. Sometimes, if you want the truly good stuff, you have to fork it over.

Now go out there and indulge in some good chocolate! What are you waiting for?

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Julianne

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Never let it be said that you can’t teach an old blog new tricks. In the interests of broadening our fan appeal and staying au courant, Cosmic Variance is bringing in a new contributor. Julianne Dalcanton has been a longtime commenter, and is also an astrophysicist at the University of Washington. We’ve set up her own author page and everything. Everyone welcome Julianne! In the immortal words of Pink, we better get this party started.

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Short Distances: Newton Still the Man

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Torsion Balance Via Chad Orzel, I see that the latest constraints on short-distance modifications of Newton’s inverse-square law from the Eot-Wash group at the University of Washington have now appeared in PRL. And the answer is: extra dimensions must be smaller than 0.045 millimeters (in any not-too-contrived model).

We used to think that extra dimensions must be enormously smaller than that, if they exist at all. If you have n extra compact dimensions of space, long-ranges forces like gravity and electromagnetism would go from falling off as an inverse-square law, 1/r 2, to something like 1/r 2+n. Gravity is weak and hard to test, but electromagnetism is easy to test, and it behaves quite conventionally down to scales probed by particle accelerators.

In 1998, Arkani-Hamed, Dimopoulos and Dvali realized we could hide extra dimensions that were much larger than that, by positing a three-dimensional brane on which all of the particles of the Standard Model were confined. Then it’s easy to see why electromagnetism wouldn’t notice the extra dimensions: photons couldn’t get there! But gravity can always get there. So it became a big new project to test Newton’s law of gravity at short distances. As a separate motivation for the large-extra-dimensions idea, you could explain why gravity is so weak by imagining that it’s really not so weak at a fundamental level, but gets diluted by the extra dimensions. It all works out perfectly nicely if you have two extra dimensions of about a millimeter in size, which was happily right where the experiments hadn’t quite probed. By now, as you can see, they have been pushed there and beyond.

Which by no means implies that the experiments aren’t worth doing any more — you never know what suprises you might find in regimes where you’ve never looked. The title of the new paper tries to score some motivational points by referring to the “Dark Energy Length Scale.” This notion is a bit less concrete than the size of an extra dimension, but okay. What cosmologists have measured in the case of dark energy is an energy density, about 10-8 ergs per cubic centimeter. But if we multiply by appropriate powers of Planck’s constant and the speed of light, we can convert this density into a length (to the -4th power), and that length turns out to be about 0.08 millimeters. Now, this little bit of dimensional analysis may or may not be connected to anything physical; they reference papers by Beane and by Dvali, Gabadadze, Kolanovic, and Nitti, speculating that this length scale actually corresponds to something important. These ideas are not completely baked, but they’re fascinating, and the important point is that we have a length scale at which stuff happens, and we don’t completely understand what’s going on, so let’s do all the experiments we can to try to dig up some clues.

The other important point about this work is that it puts to rest the vicious rumors we were hearing over a year ago, about which Eric Adelberger (leader of the Eot-Wash group) was nice enough to comment here. Namely, the rumor that they had actually found a weak repulsive force in their data. This is the kind of thing that happens all the time when you’re doing ultra-precise measurements at the very edge of what is possible; unforeseen effects creep in, and it takes time to stamp out everything that shouldn’t be there. These guys are careful, and would never jump up and down about a real effect unless they were truly convinced it was there. If I had been in charge (putting aside for the moment the fact that, if the experiment relied on my technical expertise, the lower limit on the size of extra dimensions would probably be measured in kilometers), I would probably have floated that rumor intentionally, just so people paid attention when the results did come out. Unlike me, Eric Adelberger has enormous integrity, so they just told the honest truth all along.

Chad keeps saying that these experiments don’t get enough credit, but I don’t know why he thinks that. (Chad, why do you think that?) Ever since the idea of large extra dimensions was floated in 1998, everyone working in string theory, particle physics, and cosmology has been very excited by the search for short-range forces, and most everyone knows that the Eot-Wash group is kicking butt within the field. Their 2000 paper, which pushed the limit on extra dimensions below a millimeter for the first time, has hundreds of citations, and Adelberger gets far more invitations to give colloquia and conference talks than he can possibly accept. Some influential theorists have even described the torsion-balance work as one of the most profound experiments in physics. This is not exactly a small, under-the-radar operation. We’re all looking forward to what they do next.

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Undergraduate Theory Institute

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Sadly, I’m not here to announce that applications are now being accepted for students who would like to participate in this year’s Undergraduate Theory Institute. That’s because there is no such thing as the Undergraduate Theory Institute, at least as far as I know. (Google doesn’t know of one either.) But I think it would be a great idea — maybe if I post it here on the blog someone will start it.

It’s increasingly common for physics students to particpate in some kind of research during their undergraduate years. The NSF has a very successful Research Experience for Undergraduates program, for example, that funds students to do summer research, typically at an institution other than their own. Getting involved in research as early as possible is a great idea for students, for a number of reasons. Most importantly, the flavor of doing real research, where the answers aren’t in the back of the book, is utterly different from almost any classroom experience or even self-study, where you are trying to learn material that someone else has already mastered. The move from following a course of study to striking out into the unknown is one of the hardest transitions to make during graduate school, and getting a head start is an enormous help. On a more prosaic level, it’s useful to work closely with an advisor who can end up writing letters of recommendation. And let’s not forget that it can be a lot of fun!

Unfortunately, the prospects are very different for students who want to do theory vs. experiment. It’s often true that, on an experimental project, a student with just a hand on the basics of introductory physics can come in and learn something about the particular experiment being undertaken, and after a brief learning period can soon be contributing seriously to the work. On the theoretical side, the learning curve is much less steep, and a lot more background knowledge is required before a student can do something interesting. In my field, until you’ve at least taken courses in quantum field theory and general relativity, it’s hard to do original work.

Nevertheless, like many other theoretical physicists, I get a lot of requests from undergrads who would like to do research. I very much enjoy doing research and having students, but to be honest it’s often very difficult to find things for them to do, since the background just isn’t there. I’ve done it, quite a few times — I’ve supervised four Bachelor’s theses, and three summer research students. Sometimes everything falls into place, and it ends up with an interesting publishable paper. More often it’s an excuse to let the students learn a bit GR or QFT, and maybe get started on the very basics of a problem, before they grow up and graduate.

There’s a perfectly good response to this situation, which is: even if you eventually want to become a theorist, it’s a great idea to do experimental research as an undergrad. Maybe you won’t be immersed in the kind of work you ultimately want to pursue, but (1) understanding something about how experiments work is an unambiguously good thing, and (2) the important lesson is not in the details of the particular field, but in what it’s like to do research, which is almost independent of the type of research you’re doing. That’s what I did, when at Villanova I did work on photometry of eclipsing variable stars; I got a nice paper out of that. (And my favorite star, Epsilon Aurigae, will be going into eclipse again in another couple of years, at which point I expect our model to be spectacularly confirmed, and fame and fortune to follow.)

And I tell this to people all the time, but still the students want to do theory! Impatient little buggers. But I can hardly blame them — we lure them into the field with elaborate tales of black holes and supersymmetry and dark energy, and it only eventually becomes clear that they won’t really learn about that stuff until they’re well into grad school, if then.

So I had the idea for an undergraduate theory institute. The amount of theoretical background you need to do useful work is quite substantial, much larger than one could squeeze into one summer, it’s true. On the other hand, six weeks of fairly intensive study between the junior and senior year could serve to introduce enthusiastic students to many of the basic ideas they will eventually be encountering as theorists. If nothing else, they could become familiar with a bunch of buzzwords they’ll be hearing for years. That sounds superficial, but could potentially be of great use — it means that they can immediately start going to seminars and chatting with professors when they get to grad school, and have a much better grasp on the kinds of ideas that are being thrown around.

So, a six-week summer course for undergrads. Much self-study, but regular lectures by faculty and perhaps postdocs. A couple of seminars on sexy stuff of current research interest, as a reward, but mostly focusing on the basic tools of theoretical research in field theory and gravitation. (Since that what I know about — other specialties are welcome to chime in!) Here’s what I imagine the syllabus to basically be like:

  1. Special relativity, index notation, vectors, tensors.
  2. Lagrangian and Hamiltonian mechanics.
  3. Classical scalar field theory.
  4. Gauge theories and electromagnetism.
  5. Basics of Lie groups, SU(n).
  6. Non-abelian symmetries.
  7. Spontaneous symmetry breakdown, the Higgs mechanism.
  8. Topological defects.
  9. Spacetime curvature and Einstein’s equation.
  10. Schwarzschild and Robertson-Walker spacetimes.
  11. Basics of field quantization and Feynman diagrams.

Something like that, anyway. It seems like a tremendous amount to cover, but it would all be fairly brisk, and there are benefits to be gained by seeing it all at once in the same place, surrounded by a group of other bright students studying the same material. Wouldn’t you have loved to have such an introduction as an undergrad? If we put together some nice lecture notes, I’m sure it wouldn’t be too hard to get them published as a cheap reference book.

All I need now is a substantial (and reliable) source of funding, someone to write the lectures and deliver them, a host institution, and an organizational wizard to take care of logistics. I will look over the whole operation as a benevolent, if somewhat disconnected, father figure, whose main role will be to shoot the breeze with the students at the late-night coffee and whisky hours. Any takers?

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(De)-Lurker Week

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Delurk button A little over a year ago we had great fun with Lurker Day, in which folks who read the blog but rarely comment were invited to bust out of their shell a little bit, say hi, and tell us why they think the blog is so wonderful. (At Cosmic Variance, we’re all about positive energy.) Now we are informed by Dr. Free-Ride that the second week in January has been declared De-Lurking Week. A whole week! Just to de-lurk. Seems a bit extravagant, but we must go along with what the blogosphere orders.

So leave a comment, especially if you usually don’t. This should fill some time while I am presently too busy to complete planned posts on gourmet chocolate, how to write a research paper, path-dependent utility, nationalism, understanding, moral humanism, and the beginning of the universe. There’s some incentive for you.

Note: Following Phil Plait’s suggestion, we’re experimenting with the wp-cache plugin. This speeds up performance by storing pages in a cache, rather than dynamically generating them each time they are accessed. The downside seems to be that comments don’t show up as long as the pages are cached. So we’ve set them to be cached for about three minutes, after which your comments should appear. There’s got to be a better way…

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Mystery Solved?

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Apparently New Zealanders are more naturally curious about things than Americans are — they also noticed the puzzling absence of God in The Queen on airline flights, and actually started asking around about it. (Thanks to Richard Easther for pointing this out.) And they found an answer!

The story is that the version that was shown on Air New Zealand, and presumably also on United, was actually meant for Middle Eastern airlines. Flight Productions, the company that distributed the bowlderized version, suggested that some airline had requested that “God” be bleeped out. This raises another question, of course: why? There isn’t any traditional prescription against saying “God” that anyone could think of.

Hassan Hosseini, an Iranian community spokesman in Auckland, said he could not see why it would have been a problem with Muslims, as Allah was God.

“We believe in God, we would not be offended. We use the word God.”

And then, of course, if you’re going to start bleeping out words, there are better choices.

The Anglican Dean of Auckland, Richard Randerson, said he had seen The Queen at the cinema and could not recall much use of the word God.

“There were plenty of other words. I think the Queen said ‘bugger’ when her four-wheel-drive vehicle got stuck in a Highland creek.”

This would be the appropriate thread in which to debate whether the Queen was referring to the commonplace, literal, interventionist “bugger,” or whether she had in mind a more sophisticated, ineffable notion of “bugger.”

Update: There’s now an alternative explanation (thanks to several people for pointing it out). CNN claims it’s just an overzealous editor. One way or another, it’s not standard operating procedure, apparently.

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COSMOS Reveals the Cosmos

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The internet works so that we don’t have to! This week is the big annual meeting of the American Astronomical Society in Seattle, so expect to see a series of astro-news stories pop up all through the week. The first one concerns a new result from the Cosmological Evolution Survey (COSMOS) — they’ve used weak lensing to reconstruct a three-dimensional image of where the dark matter is. Here is an image from the Nature paper by Richard Massey et al. (subscription required).

COSMOS dark matter map

It is, needless to say, really cool. The image itself is not where the real science lies, of course; it’s spatially distorted, and very hard to show error bars in a 3-d plot. But there is definitely important science lurking in the details; for example, they seem to find dark-matter concentrations with little or no ordinary matter in the same place. It’ll take some work to figure out whether this is easily compatible with the theoretical models (one could imagine dissipative effects clearing baryons out of a region, leaving dark matter behind, in a mini-version of the Bullet Cluster), or whether we’re going to be challenged. Fun either way!

Fortunately, I don’t have to go into details about the result, as others already have. Phil, Clifford, Rob, Angela, and Steinn have all blogged about the finding. (We’re all on a first-name basis around here.) Steinn’s post is, admittedly, pretty consise, but he wins points for breaking an even better story — Google is joining the Large Synoptic Survey Telescope consortium! Rob is even live-blogging the entire meeting, which is an heroic undertaking. (Yes, it’s true that he did bump into me up in Seattle, but I’m not there for the meeting! In fact I’m already back in LA. There are reasons to visit Seattle other than the AAS.)

Ah, I remember the good old days of ’04, when there wasn’t any competition out there in the cosmo-blogging world. Our internet is all grown up now. Sadly, Michael Bérubé is retiring from the game, which will leave the blogosphere a much poorer place. Read Sunday’s Credo for an example. Without his inspiration, I certainly wouldn’t be doing this myself.

Anyway — the COSMOS project is well worth being wowed by in its own right. It’s an ambitious undertaking; they take a two-square-degree field of the sky and beat on it with every telescope they can find — in optical, infrared, ultraviolet, X-rays, and radio waves. More than half a dozen ground-based telescopes, as well as five satellites (the Hubble Space Telescope, Spitzer infrared observatory, XMM and Chandra for X-rays, and GALEX for the ultraviolet), are joined in the effort. Here’s the abstract from one of their recent summary papers:

The Cosmic Evolution Survey (COSMOS) is designed to probe the correlated evolution of galaxies, star formation, active galactic nuclei (AGN) and dark matter (DM) with large-scale structure (LSS) over the redshift range z < 0.5 to 6. The survey includes multi-wavelength imaging and spectroscopy from X-ray to radio wavelengths covering a 2 square deg area, including HST imaging. Given the very high sensitivity and resolution of these datasets, COSMOS also provides unprecedented samples of objects at high redshift with greatly reduced cosmic variance, compared to earlier surveys. Here we provide a brief overview of the survey strategy, the characteristics of the major COSMOS datasets, and summarize the science goals.

This new dark matter map is just the beginning of fun stuff to emerge from this collaboration — stay tuned!

Update: There I go again.

“I like to think of visible matter as the olive in the martini of dark matter,” said Sean Carroll, a theoretical physicist at Caltech.

I love my job.

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Under the Hood

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When we started Cosmic Variance over a year and a half ago, we put quite a bit of effort into choosing a web host (Bluehost.com) and blogging software (WordPress) and a theme (K2, heavily modified) and spam-filtering software (SpamKarma) etc. Since then, however, for the most part things have just sailed along smoothly without much tinkering, which is exactly how we like it — none of us is the type who enjoys messing with the blog software just for the heck of it. But occasionally things do crop up that we might want to do something about.

  • We’re told that the blog doesn’t display correctly with the current version of Internet Explorer, IE7. Is this still true? This is the kind of problem you get when all the bloggers are sensible enough to use Firefox on Macs. Hopefully we will fix this problem, but I suspect it won’t be easy — to get a feeling for the kind of angst we went through to get the blog to look okay in the last version of Explorer, have a look at the box model problem. If my life had gone as I planned, I never would have had to know about the box model problem.
  • SpamKarma is great, and we certainly need it — we get hit with over 1000 spam comments in a typical day, and almost none of them get through. But occasionally it’s a wee bit over-enthusiastic, and respectable comments are filtered. (In particular, it’s been objecting to comments from people with “blogspot.com” URL’s.) If that happens to you, please do let us know, it’s easy to fix.
  • You may have noticed that occasionally you can’t see the blog because we’ve “exceeded our CPU allocation.” How is this possible for a humble little blog like ours? Something like that makes sense in the rare circumstances when we are linked from Slashdot or Fark, but it seems to happen almost every day. This is a problem with Bluehost that others have complained about, and about which the company seems rather unresponsive. If it gets really bad, we’ll contemplate switching to another host, as annoying as the prospect may be. Suggestions welcome.

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