Physicists have certainly been ahead of the information-technological curve at times. The web was invented at CERN, and of course we mastered open publishing simply by doing it, while other disciplines have struggled to come up with workable models. But senior physicists — not youngsters, who are always eager to try new things, but more established types — have generally looked askance at blogging, for hard-to-discern reasons. In math we have Fields Medalists blogging up a storm, in economics there are multiple blogs by Nobel Laureates, but physicists on the far side of the “young and striving”/”senior and respected” divide have largely stayed away. (My colleagues here at CV are enormously respected, but in my mind they will always be youthful.)

So we’re extremely happy to note that Martin Perl (at an enthusiastic 84 years young!) has jumped into the blogosphere, with Reflections on Physics: From the Tau to Dark Energy. Perl shared the Nobel Prize in 1995 for the kind of result that every physicist dreams of achieving, but few actually do: the discovery of a new elementary particle. In particular, the tau lepton, the heaviest of the three charged leptons (along with the electron and muon). Not too shabby.

Martin’s first post is on Faster-Than-Light Neutrinos and the Dynamics of the Internet. He finds the OPERA results intriguing, but thinks that figuring them out is going to require new experiments, not clever outsiders trying to figure out where they went wrong. I would tend to trust his judgment here.

It’s fantastic to have another great physicist taking the time to reach out to a broader audience. Note that Martin is at SLAC, along with our own JoAnne and Risa. Something about the Palo Alto coffee that nudges one toward blogging?

To celebrate my birthday today, I’m heading back into Second Life to do a chat with Alan Boyle of MSNBC.com fame. Alan has previewed some of the topics we’ll be discussing in a post at Cosmic Log. It’s possible the Nobel Prize will be mentioned. (The physics one. Don’t expect any insight from me on quasicrystals, except that they’re awesome.)

We’ll be chatting at 9pm Eastern/6pm Pacific, at the Stella Nova Theater. If you’re not already on Second Life, it’s super easy (and free) to join. (Here’s some very useful information for beginners.) And you get to design an avatar that looks like you would want to look, rather than your inevitably-disappointing real self.

The chat is part of the Virtually Speaking series hosted by FireDogLake, in this case co-produced with the Meta Institute for Computational Astrophysics. Alan does a regular series of interviews on science, so you may get hooked. Our chat will be a multi-media extravaganza, so you can choose to listen in various ways:

• Directly in Second Life.
• Audio on BlogTalk Radio. This is an archived podcast, available on iTunes, so you can listen later if you like.
• There is also live chat on IRC. Enter #vspeak into the channel field.

Yes I know, very complicated. If simplicity is more your bag, here’s a guest video on dark energy that I did for the wonderful Minute Physics series.

Risa already blogged about James’ Op-Ed piece in the LA Times. We should also mention another excellent Op-Ed piece by an astronomer in the past week: Priya Natarajan discussing math education in the Huffington Post. She starts:

This has been the summer of our numerical discontent.
As a nation, we’ve been riveted by the debates over the debt-ceiling crisis, the credit downgrade, the dizzying ascents and descents of the stock market. But how many people actually understand the numbers they’re watching?

Priya decries the general innumeracy we see everyday, writ large and small. She argues persuasively for an increased focus on math education, especially in light of the current fiscal troubles.

It is critical that the science community reach out to the general public, and opinion pieces in newspapers are an incredibly effective way to do this (blogs aren’t too shabby, either). Op-Eds allow individuals from all walks of life to communicate directly with the public, without being mediated by reporters, radio hosts, or TV producers. And they reach literally millions of people. These two terrific examples from Priya and James will hopefully help encourage other scientists to get involved, and make their opinions known.

Kris Stanek alerted me to this fun idea from the astronomers at Ohio State: when they submit a paper to arxiv, they accompany it by a simple YouTube video that explains the basic idea. Called “Coffee Briefs,” there is only one such video so far, for a paper by Jennifer van Saders and Mark Pinsonneault. But they hope to make it regular series.

The Sensitivity of Convection Zone Depth to Stellar Abundances: An Absolute Stellar Abundance Scale from Asteroseismology
Jennifer L. van Saders, Marc H. Pinsonneault

The base of the convection zone is a source of acoustic glitches in the asteroseismic frequency spectra of solar-like oscillators, allowing one to precisely measure the acoustic depth to the feature. We examine the sensitivity of the depth of the convection zone to mass, stellar abundances, and input physics, and in particular, the use of a measurement of the acoustic depth to the CZ as an atmosphere-independent, absolute measure of stellar metallicities. We find that for low mass stars on the main sequence with $0.4 M_{\odot} \le M \le 1.6 M_{\odot}$, the acoustic depth to the base of the convection zone, normalized by the acoustic depth to the center of the star, $\tau_{cz,n}$, is both a strong function of mass, and varies at the 0.5-1% per 0.1 dex level in [Z/X], and is therefore also a sensitive probe of the composition. We estimate the theoretical uncertainties in the stellar models, and show that combined with reasonable observational uncertainties, we can expect measure the the metallicity to within 0.15 – 0.3 dex for solar-like stars. We discuss the applications of this work to rotational mixing, particularly in the context of the observed mid F star Li dip, and to distguishing between different mixtures of heavy elements.

This example might not be immediately accessible to non-experts, but I think the idea is to pitch the video at the level of astronomy grad students. Certainly the participants deserve a lot of credit for trying out an innovative way to talk about their research.

The key to the ambition of making this a regular even is keeping it simple and easy. If it takes a couple of hours to put it together, no problem; if it takes a couple of days, enthusiasm will flag. I’m not sure what software was used to make the video and the simple graphics — iMovie, maybe? For the DNA computer video we showed some time back, it was quite an elaborate job, and you would worry that it would be onerous to do something like that for every paper one writes.

Last week I got to spend time in the NBC studio where they record Meet The Press — re-decorated for this occasion in a cosmic theme, with beautiful images of galaxies and large-scale-structure simulations in the background. The occasion was a special panel discussion to follow a Stephen Hawking special that will air on the Discovery Channel this Sunday, August 7. David Gregory, who usually hosts MTP, was the moderator. I played the role of the hard-boiled atheist; Paul Davies played the physicist who was willing to entertain the possibility of “God” if defined with sufficient abstraction, while John Haught played the Catholic theologian who is sympathetic to science.

The Hawking special is the kick-off episode to a major new Discovery program, called simply Curiosity. I predict it will make something of a splash. The reason is simple: although most of the episode is about science, Hawking clearly goes all-in with “God does not exist.” It’s not a message we often hear on American TV.

The atheistic conclusion is really surprisingly explicit. I had a chance to talk to someone at Discovery, who explained a little about how the program came about. The secret is that it was originally produced by the BBC — British audiences have a different set of expectations than American ones do. My completely fictional reconstruction of the conversation would go something like this. Discovery: Hey, blokes! Do you have any programs we could use to launch our major new series? BBC: Sure, we have a new special narrated by Stephen Hawking. Discovery: Perfect! That’s always box office. What’s it about? BBC: It’s about how there is no God. Discovery: Ah.

[Update: Alas, reality is intruding upon my meant-to-be-funny imaginary dialogue. The episode was actually originally commissioned by Discovery, not by the BBC, although it was produced in the UK. More power to Discovery!]

At first, I will confess to a smidgin of annoyance that an opportunity to talk about fascinating science was being sacrificed to yet another discussion about religion. But quickly, even before anyone else had the joy of pointing it out to me, I realized how spectacularly hypocritical that was. I talk about religion all the time — why shouldn’t Stephen Hawking get the same opportunity?

The more I thought about it, the more appropriate I thought the episode really was. I can’t speak for Hawking, but I presume his interest in the topic stems from similar sources as my own. It’s not just a coincidence that we are theoretical cosmologists who happen to go around arguing that God doesn’t exist. The question of God and the questions of cosmology arise from a common impulse — to understand how the world works at its most fundamental level. These issues naturally go hand-in-hand. Pretending otherwise, I believe, probably stems from a desire on the part of religious believers to insulate their worldview from scientific critique.

Besides, people find it interesting, and rightfully so. Professional scientists are sometimes irritated by the tendency of the public to dwell on what scientists think are the “wrong” questions. Most people are fascinated by questions about God, life after death, life on other worlds, and other issues that touch on what it means to be human. These might not be fruitful research projects for most professional scientists, but part of our job should be to occasionally step back and look at the bigger picture. That’s exactly what Hawking is doing here, and more power to him. (In terms of his actual argument, I’m sympathetic to the general idea, but would take issue with some of the particulars.)

Nevertheless, Discovery was not going to feature an hour of rah-rah atheism without a spoonful of sugar to help the medicine go down. Thus, our panel discussion, which will air immediately after the debut of Curiosity (i.e., 9pm Eastern/Pacific). The four of us had fun, and I think the result will be an interesting program — and hopefully I did the side proud, as the only legit atheist participating. Gregory seemed to enjoy himself, and joked that he might have to give up politics to do a weekly show about cosmology. (A guy can dream…) But we all agreed that it was incredibly frustrating to have so little time to talk about such big issues. The show will run for half an hour; subtract commercials, and we’re left with about 21 minutes of substance. Then subtract introduction, questions, some background videos that were shown … we three panelists had about five minutes each of speaking time. Not really enough to spell out convincing answers to the major questions that have troubled thinkers for centuries. Hopefully some of the basic points came across. Let us know what you think.

Last year, friend and fine Philly science writer Faye Flam wrote a guest post for us here at Cosmic Variance, in which she chronicled her experiences writing about climate science as part of her brief at the Philadelphia Inquirer. You may recall that her articles on this hot-button topic led to quite over-the-top responses, including a death threat. And our comment section after her post was certainly lively, although relatively well-behaved.

Well, now Faye is tackling a new controversial (although it shouldn’t be) topic. While continuing with her regular writing, she has, over the last few months, begun writing a blog for the Inquirer on the topic of evolution. Titled Planet of the Apes, the blog features Faye’s writing paired up with illustrations from the paper’s staff editorial cartoonist, Tony Auth.

It’s a fun read, and covers current news in evolution as well as taking on some of the questions that come up when discussing the topic with those who, for whatever reason, are resistant to this established branch of scientific knowledge. Take a look at the back catalog to see some of these.

I wish Faye the best of luck with this new endeavor, and hope that we’ll see another guest post here from her soon.

Through the Wormhole with Morgan Freeman, the hit (as these things go) show from the Science Channel, has commenced with its second season. It shows Wednesdays at 8 p.m. Eastern/Pacific time. If you watch tomorrow night’s episode, “Is Time an Illusion?”, there’s a good chance you will see me in a bar fight. Or at least in a bar, with fighting going on around me. And I’m pretty sure that if you wait until July 27th’s “Can We Travel Faster Than Light?”, you’ll see me throwing a Slurpee out of the window of a car to demonstrate addition of velocities. (What you won’t see is the long discussion we had about whether we should call it a “Slurpee” or a “Slushee.”)

I appeared on one episode of the show last year, and I’ve been on a few other science documentaries. But I don’t usually plug them ahead of time; not, as anyone who reads the blog will attest, out of any general reluctance to plug my stuff, but because you typically don’t get to see these shows before they air. And I’d just as soon not be associated with a complete piece of garbage.

But on the basis of what I’ve seen so far — last week’s episode, and several from last year — as well as talking to the show’s creators, I genuinely think that Through the Wormhole is well above the usual standard of quality one expects for these endeavors. Not that anything is perfect — there are one or two times when you’ll be thinking “how in the world did that person get interviewed here?” But there’s clearly been a lot of effort made to get the science largely right, and more importantly to take on big topics and tell something approaching a coherent story about them. Programming like this is growing thin, even on Discovery and the Science Channel, so when it appears and succeeds it should be applauded.

Also? Morgan Freeman read my book. So I at least owe him this much of a plug.

I’ve been on somewhat of an unintended hiatus for the past few months, as I try to wrap up some projects, and deal with a few other things in my life. However, I just read something that has given me a kick in the pants. And I don’t mean that in a good way. In late December there was an article by Jonah Lehrer in the New Yorker titled “The truth wears off”. Much more suggestive was the subtitle, “Is there something wrong with the scientific method?”. The story discusses the “decline effect”: an article is published with startling results, and then subsequent work finds increasingly diminished evidence for the initial unexpected result. It’s as if there’s “cosmic habituation”, with the Universe conspiring to make a surprising result go away with time. The last paragraph sums things up:

The decline effect is troubling because it reminds us how difficult it is to prove anything. We like to pretend that our experiments define the truth for us. But that’s often not the case. Just because an idea is true doesn’t mean it can be proved. And just because an idea can be proved doesn’t mean it’s true. When the experiments are done, we still have to choose what to believe.

I don’t particularly disagree with any of this. But it’s completely besides the point, and to untutored ears can be immensely misleading. The article is a perfect example of precisely the effect it seeks to describe (there must be a catchy word for this? Intellectual onomatopoeia?). The article gives a few examples of people finding interesting results, only to have them disappear on sustained scrutiny. It makes it sound like there is an epidemic of declining confidence:

One of the first demonstrations of this mysterious phenomenon came in the early nineteen-thirties. Joseph Banks Rhine, a psychologist at Duke, had developed an interest in the possibility of extrasensory perception, or E.S.P. Rhine devised an experiment featuring Zener cards, a special deck of twenty-five cards printed with one of five different symbols: a card was drawn from the deck and the subject was asked to guess the symbol. Most of Rhine’s subjects guessed about twenty per cent of the cards correctly, as you’d expect, but an undergraduate named Adam Linzmayer averaged nearly fifty per cent during his initial sessions, and pulled off several uncanny streaks, such as guessing nine cards in a row. The odds of this happening by chance are about one in two million. Linzmayer did it three times.

Rhine documented these stunning results in his notebook and prepared several papers for publication. But then, just as he began to believe in the possibility of extrasensory perception, the student lost his spooky talent. Between 1931 and 1933, Linzmayer guessed at the identity of another several thousand cards, but his success rate was now barely above chance. Rhine was forced to conclude that the student’s “extra-sensory perception ability has gone through a marked decline.”

This all sounds quite impressive. I don’t know the details of how many cards he was going through, but it sounds like it’s easily thousands. I calculate the odds of a 9 card streak as a tenth of a percent if you go through a couple of thousand cards. This is much more likely than 1 in 2 million (which is relevant only if you only look at 9 cards, one time). No doubt getting 9 in a row three times over a period of a few weeks (or even years) would be a large statistical anomaly. But it’s a long way from something I would issue a press release about. Carl Sagan summed it up best: “Extraordinary claims require extraordinary evidence”. If you’re going to claim some “extra-sensory perception” that would require a new physical force, and fundamentally alter all of modern physics, you might need more than a one-time statistical fluke. How about a whole series of controlled, double-blind experiments? Lo and behold, when this is done, the effects vanish. But by then the original results are published, and the damage is done. We’re still talking about this one “experiment” 80 years later. But if we integrate over all the equivalent subsequent experiments, there’s no doubt that the effect regressed to the mean, and can be ignored. So how is this even remotely interesting?

It takes Lehrer six pages to finally get around to the topic of publication bias. Suppose you do an experiment and find a sensational, Earth-shattering result. Human nature being what it is, you’re likely to try to publish it (and journals like Nature are likely to publicize it). Fads happen all the time in science. It’s a human activity after all. And then you (and the rest of the community) do a lot more work, and if it’s a statistical fluke, or poorly analyzed data, or a poorly conceived or biased experiment, the result will fade into oblivion. The “decline effect” that this article is making a fuss about is precisely the process by which the scientific method works. The truth will out.

On the other hand, suppose you do an experiment and find the result you (and everyone else) would expect. For example, you drop a ball and, indeed, it falls to the floor, exactly in accordance with our theory of gravity. You’re unlikely to write up the results. You’re even less likely to be able to get them published. And you’re certainly not going to spawn a whole bunch of follow-up experiments trying to duplicate your “null” results. So there’s no “incline effect”. This is not a surprise. It’s not a sign that science is broken. It’s a sign that we try to be selective and efficient in our experiments.

None of this is to say that there aren’t legitimate concerns. It’s one thing for publication bias and poor data to lead to a (temporarily) incorrect measure of the Hubble constant, and hence the age of the Universe. It’s an entirely different matter when a statistical fluke (encouraged by huge sums of money) engenders useless (or worse) medical treatment for millions of people. The only way to address this is by ever more careful and thorough application of the scientific method. (Obama’s Comparative Effectiveness Council, one of the many positive aspects of his new healthcare bill, is a good example of this.)

Lehrer’s article is a dramatic example of the problem he decries. The title and subtitle, and the first few pages, make it sound like there’s something profoundly and mysteriously wrong with the scientific method. Far into the article the obvious and rational explanations appear. Really, the article should be titled “Science works”, with a subtitle “The scientific method conquers all (eventually).” But that would be a lot less sexy, and my guess is that the New Yorker wouldn’t have published it. So there’ll be a bunch of people out there who misread or cherry-pick the article (Deepak Chopra: “Watch out, the truth is slipping away”), and end up convinced that the scientific method is broken. And they won’t vaccinate their children, and they’ll make important life decisions based on their horoscopes, and they’ll continue to believe that the world is magic. The scientific method is healthy and well. The problem is a society that, to a surprising degree, doesn’t pay much attention to it. And this article is a brilliant example of how things go wrong.

Astrophysical ambulance-chasers everywhere got a bit excited this week, and why wouldn’t they? Here are some of the headlines we read:

• Findings Raise New Questions About Dark Matter (redOrbit)
• Dark matter theory challenged by gassy galaxies result (BBC)
• More Evidence Against Dark Matter? (Science NOW)

Wow. More evidence against dark matter? I didn’t know about the original evidence.

Sadly (and I mean that — see below) there is no evidence against dark matter here. These items were sparked by a paper and a press release from Maryland astronomer Stacy McGaugh, with the rather more modest titles “A Novel Test of the Modified Newtonian Dynamics with Gas Rich Galaxies” and “Gas rich galaxies confirm prediction of modified gravity theory,” respectively.

I’m the first person to defend journalists against unfair attacks, and we all know that headlines are usually not written by the people who write the actual articles. But we can legitimately point fingers at a flawed system at work here: these articles are a tiny but very clear example of what is wrong wrong wrong about our current model for informing the public about science.

McGaugh’s new paper doesn’t give any evidence at all against dark matter. What it does is to claim that an alternative theory — MOND, which replaces dark matter with a modification of Newtonian dynamics — provides a good fit to a certain class of gas-rich galaxies. That’s an interesting result! Just not the result the headlines would have you believe.

It’s obvious what happens here. Nobody would read an article entitled “Gas rich galaxies confirm prediction of modified gravity theory” — or at least, most editors doubtless feel, fewer people would be interested in that than in evidence that went directly against dark matter. So let’s just spice up the story a bit by highlighting the most dramatic possible conclusion we can imagine drawing, and burying the caveats until the end. Net result: a few more people read the articles than otherwise would have, while many more people just read the headlines and are left with less understanding of modern cosmology than they started with. Scientists and journalists together have a responsibility to do a better job than this at making things clear, not just making things sound exciting.

But let me take this opportunity to lay out the problems with MOND. (more…)

A couple of years or so ago, Jonathan Feng at UC Irvine, George Musser from Scientific American and I began discussions about an article for the magazine. This week, that article finally hit the newsstands in the November Issue.

Back in 2008, Jonathan and I had for quite a while been interested in the connections between particle physics and cosmology, and in particular how experiments at current, upcoming (the LHC at that point) and future colliders could inform and be informed by modern cosmology. In fact, I’d written about these connections a number of times here on the blog, discussing, for example, the nature of WIMP dark matter, and the origin of the matter-antimatter asymmetry of the universe. And these were the starting point for our interactions with George about a SciAm article.

The journey from these initial musings to a final article was a mostly enjoyable and interesting one, and for me it contrasted greatly with the vast majority of writing that I do, presenting my own current research for journals. In those efforts, the editorial input is generally small. One receives referee reports that are hopefully mostly positive, and can sometimes (although rarely, to be honest) contain excellent suggestions that improve the final version of the paper. The editorial role is mostly in the selection of referees by a scientist serving on the editorial board, and in general grammatical editing of the paper and verification of references as it nears the publication date.

But writing for a magazine is a different experience. From the beginning it was very much a collaborative effort, with Jonathan and I honing our ideas about what should appear in the article, and George pushing some ideas and downplaying others, to fit with his experience of the kind of article that most readers want. We were all searching for the right mix of background material, new directions in the field, and connections to work that Jonathan and I had been directly involved in, and so could comment on from direct experience. Although we didn’t always agree, it was definitely a constructive process, and the final content was a consensus in the best sense of the word, with what to emphasize and what couldn’t make it into the article for space reasons (which are very tight) the outcome of lengthy, but useful negotiations between us and George. That it took a couple of years from inception to publication is partly a reflection of the natural time it takes for a lot of back and forth between editor and authors who have busy day jobs, and partly because in the middle I moved institutions, putting me out of action for a while.

What we ended up focusing on is the intriguing possibility that the dark sector of cosmology might exhibit a considerably richer structure than our usual simple descriptions of a plain WIMP candidate for dark matter, and a cosmological constant, or sequestered dark energy component driving cosmic acceleration. Rather, it is possible that the dark sector contains it’s own set of new particles and forces, and that our detections, gravitationally based so far, have not yet been able to probe this underlying structure. We wrote about interesting possibilities for dark matter, some of which are related to work Jonathan has done, for much of the article, and at the end turned to the possibility of interactions with dark energy, which I’ve worked on and have occasionally written about here. As we concluded the article:

The only matter we know anything about, visible matter, comprises a rich spectrum of particles with multiple interactions determined by beautiful underlying symmetry principles. Nothing suggests that dark matter and dark energy should be any different. We may not encounter dark stars, planets and people, but just as we could hardly imagine the solar system without Neptune, Pluto and the swarm of objects that lie even farther out, one day we might not be able to conceive of a universe without an intricate and fascinating dark world.

The article isn’t perfect, of course. For example, there is a heading for one of the figures that reads “Experiments that claim to have detected dark matter”. We didn’t write that, but we should have caught it in proofs. It is wrong, of course, and should read something like “Experiments that are searching for dark matter”. Also, after being so close to the material for a while, there are some ambiguities that you don’t notice unless someone else reads them a different way and lets you know. But in all, I think Jonathan and I are pretty happy with the final article.

For me, it was an enjoyable experience, with several highlights. First and foremost, we had an engaged and sympathetic editor who understood both the science and the target audience. Thanks George! Second, it is wonderful fun to receive some actual draft page proofs, after months of exchanging a visually unappealing text file, and to see the art work that has been designed to accompany the article. We had some very rough ideas regarding one or two of the figures, but most of the visual parts of the article were created with no initial input from us. We helped tweak at the end, and certainly helped with text in the figures, but the gorgeous graphics were essentially all the magazine’s work. And finally, George never even hinted to us, but when we received copies of the actual magazine a few days before it appeared, we were shocked and delighted to see that our article was the cover article. I can’t tell you how thrilled my mother will be!

Just like the newsstand version, the online version of the article costs money of course. But if you do read it, I hope you enjoy it.