The first things we noticed, as we climbed into the back seat of the taxi, were the books. A tiny six-volume library, tucked between the driver’s and passenger’s front seats — just a bit of reading material offered to customers who would rather read through a silent journey than chit-chat with the driver. Interesting books, too: I noticed Natalie Angier’s Woman: An Intimate Geography, as well as Ambrose Bierce’s The Devil’s Dictionary. None of the American taxis I had ever been in had sported anything more literary than glossy magazines packed with ads.

We had just landed in Ireland, and despite the literary offerings, the taxi driver had no intention of letting the ride pass in silence. He inquired what had brought us on the long trip from Los Angeles, and I explained that I was participating in a debate at the Literary and Historical Society of University College, Dublin. That was a mistake, as I should have seen the next question coming: What was the debate about? Well, it was going to be about the existence of God; the L&HS revisits the topic every year, and I was one of a handful of visitors they were bringing in this time to defend either side of the question. And which side was I on? Trapped, I confessed that I was on the “does not exist” side. It’s not a discussion I like to force on people, but he did ask.

Our taxi driver took a moment to reflect on this information. Then he came back with: Well, you know Ireland has traditionally been one of the most religious countries in Europe, with an extremely strong Catholic tradition — but in the last couple of decades it had become increasingly secular. I hadn’t actually been familiar with the situation; despite my name (which I was politely informed should really be spelled “Seán”), I don’t have much connection with Ireland.

But I did have a remarkable cab driver, who was willing to fill us in. His theory of Irish religious consciousness began with the very early Church, which had co-opted many of the existing pagan traditions. Druidical rites, women priests, celebrants running around naked, that kind of thing. The turning point, he explained, was the Synod of Whitby in 664. (Whitby Abbey is actually in Northumbria, northern England, but apparently the repercussions of this event spread through Celtic society.) The ostensible focus of the synod was fairly narrow: how do we calculate the date of Easter? The choices were between the algorithm favored by the indigenous church, and that advocated by the catholic hierarchy in Rome. So it wasn’t really a controversy over the Easter Bunny’s work schedule; it was a power struggle between the locals and the establishment. Needless to say, the establishment won; the synod agreed to calculate the date of Easter using Roman methods.

Thus began (our loquacious driver continued) centuries of Catholic dominance over Irish religious life. And he pinpointed the peak of that dominance quite precisely: the 1979 visit of Pope John Paul II to Ireland. The Pope was treated like a rock star, speaking to audiences of hundreds of thousands of cheering supporters. But it was the beginning of the decline. The years to come would witness a dramatic collapse of religious devotion in Ireland generally, and in the influence of the Catholic church in particular.

What happened? Our cabbie had a theory, and it had nothing to do with the implications of natural selection or the logical status of the ontological proof for the existence of God. It was simple: Loss of moral authority of the Church. (Back home and consulting the Google, I find that Kieran Healy agrees.) And the loss of moral authority could be traced to a constellation of issues centering on … sex. On the one hand, the Church in Ireland took its usual predilection for sexual repression to extremes — while Americans debated over the right to have an abortion, in Ireland it was illegal to use any form of contraception as late as 1978. On the other hand, it was increasingly clear that clergymen weren’t always the best examples of sexual morality. Cases of priests fathering babies with their housekeepers or abusing young children (and then being protected by the Church hierarchy) were rampant. And so, while most Irish continued to symbolically profess the Roman Catholic faith, the populace converted gradually from fervent believers to modern secularists.

It’s very chagrining for we believers in logic and rationality to be confronted with the real reasons why people often change their minds about things. Belief in God isn’t something about which most people start with a completely open mind, sit down and carefully weigh the options, and reach a conclusion based on reasoning and evidence. More often, they believe in God because it serves a purpose in their lives, offering purpose and meaning and structure and guidance that is otherwise hard to come by.

When Shadi Bartsch and I taught a course on the history of atheism at the University of Chicago, we certainly had no plans to proselytize, but we had some concerns that a vigorous to-and-fro concerning the existence of God might strike an emotional chord for some of the students. That was a naive worry; students could be intellectually engaged and rigorous when talking about philosophical arguments for or against atheism, no matter what their personal beliefs happened to be. But we covered one topic that some people weren’t comfortable hearing about: how the Bible was written. Sure, they may be willing to accept that the Pentateuch wasn’t really penned by Moses himself. But when you start digging into the details of the documentary hypothesis, demonstrating that the Bible is just like any other collection of essays, culled from disparate sources with incompatible agendas and stitched together by more or less conscientious editors — human, all too human, in other words — it really hits home. For most believers, their belief is not a logical conclusion, it’s a mode of living. And the erosion of that belief will typically not, for better or for worse, be accomplished by the presentation and examination of evidence; it will be through telling a better story than the one told by religion. One that helps make sense of the world, provides a template for a fulfilling life, explains the difference between right and wrong, and brings meaning to people’s experiences.

That was the most erudite and educational cab ride I’ve ever had. The next evening we had the actual debate, which was more amusing than enlightening; the visitors such as myself trotted out various shopworn arguments, while the student speakers showed flashes of genius, skewering our stolid positions with wit and verve and only marginal attention to which side they were supposed to be upholding. A vote was taken, and reliable eyewitnesses will uniformly testify that the “God does not exist” side came out handily ahead, although the result was recorded in the record of the Society as the other way. Divine intervention, I suppose.

And then we repaired to a pub across the street, to drink Guinness (a miracle forged of human hands) and tell jokes and swap stories and share small slices our varied experiences. Living life.

I am not sure if this is clean, or it’s green, but at least it doesn’t emit CO2.  The net is full of stories recently about new, miniature self-contain nuclear reactors which supply  25 megawatts of power, when and where you need it.  The technology was developed at Los Alamos National Lab, and is now apparently being commercialized via a company called Hyperion Power Generation, Inc. 

The miniature power plant  is truck-sized and buried underground for the five years it operates.  HPG says it has no internal moving parts, needs no maintenance, and emits no pollution (though I am guessing there amy be a few neutrons and gamma rays flying around, which is a good reason to bury it; HPG doesn’t talk about this).   After five years, you replace it, like a battery.   

It may be a while before one of these is literally in your back yard, since you probably don’t need 25 megawatts of power, and also because one of the units purportedly costs 25 million dollars.  But for, say, a university like mine which already has its own power substation, it might be quite feasible to install one of these babies underground, and enjoy much cheaper power, selling any excess back to the power company.

But all this kind of set off my inner skeptic…let’s do the math. Present commercial rates for power are about about 10 cents per kilowatt-hour. These mini-nukes last five years, putting out 25 MW. My trusty HP-15c tells me that this represents 219 million kilowatt-hours per year, or just over 2 cents per kilowatt hour!  That would be a nice savings. (Note – original post was in error here!)

Then, on the company’s own web site FAQ it ways that each module puts out 25 MW electric power, but 70 MW thermal!  Definitely don’t want that in my back yard – and so does one need a 70 MW cooling tower? Or use the waste heat somehow? This kind of ruins the nice picture of the thing sitting quietly underground while a couple strolls on the surface…70 megawatts is like 30 sticks of dynamite exploding per second.

In addition, of course, anti-nuclear activists will howl in protest: there are the obvious issues of nuclear waste storage (we won’t open Yucca Mountain until at least 2017), uranium mining, terrorism during transport, and more.  

But there may be plenty of applications where this would seem to be a great solution, like remote locations or already secure places with big power needs. In the long run we will need more nuclear power plants to offset carbon emissions.   Maybe this solution is better than giant multi-gigawatt installations?

Well, here goes with my first post after the big Discover move – welcome to any new Cosmic Variance readers!

On Sunday I returned from a wonderful week in Southern California, during which I worked hard, attended many talks, spent much time discussing science, and purely coincidentally got to enjoy exquisite weather and tremendous dining. On the previous Monday I had arrived in Claremont, home to the appropriately named Claremont Colleges, where on Tuesday I spent the day in the physics department at Pomona College, and ultimately delivered the departmental colloquium. I was speaking on “Is Cosmic Acceleration Telling Us Something New About Gravity?”, to a healthy-sized audience, given that the timing coincided with the polls closing in a number of states critical to the outcome of the presidential election (I was assured that the open laptops of some audience members were being used purely for taking notes.)

I finished on time and then marveled as the audience, determined to demonstrate their devotion to science over politics, asked question after question about how one constructs infrared modifications of gravity, how to evade solar system tests and the pitfalls of horrible instabilities, and then how we might use future cosmology missions to probe our understanding of gravity on the very largest scales. This was, of course, wonderful fun. But in due course our minds turned back to the potentially historic nature of the day (other than my colloquium, of course) and I left campus with my graduate school housemate Dwight, and our friend Patti, who came out from LA, and went in search of a large television and much wine with which to celebrate. We were, it is fair to say, deliriously happy about the Obama victory, but saddened that Californians seemed destined to write discrimination right into their constitution via Proposition 8, which appeared sure to pass.

On Wednesday, I awoke smiling at the prospect of a possible return to rationality in the white house, and drove in the beautiful sunshine down to Newport Beach, in anticipation of a fascinating three days to come. A couple of years ago, I took part in the Kavli Frontiers of Science Symposium. I was subsequently asked to join the organizing committee, and this year, my final one attending this meeting, I am chairing that committee. As I’ve mentioned before, this conference, supported by The Kavli Foundation, and run by the National Academy of Sciences, is one of my favorite, most intellectually satisfying events of the year. Unlike other meetings I go to, this one features invited speakers and attendees across most scientific fields, all under 45 years of age, for almost three days of talks, questions sessions, poster sessions, and intense interactions (in a great setting – the National Academies Beckman Center on the UC Irvine campus – with great food).

My session this year was on Quantum Gravity, and I was lucky enough to have recruited three talented and distinguished speakers. Leading off the session was my former colleague, gravitational physicist and oft-times string theorist, the irrepressible Don Marolf from the University of California, Santa Barbara. Don is one of the most enthusiastic speakers you’ll ever hear, and was the ideal person to bring the often highly-technical and abstract reasons why we need a theory of quantum gravity to our audience of smart-as-a-whip-but-mostly-non-physicist scientists. Don’s warm-up act then segued into a talk on the best known approach to these problems – string theory – by renowned Stanford theorist Eva Silverstein. Eva took the tack of spending part of her time describing string theory, but mostly focusing on the hope that cosmology might provide us with a fertile testing ground for this way of thinking about quantum gravity. She talked about some string theory models of the early universe (inflation, and string theory cosmic strings for you experts), and how these may leave their fingerprints on the cosmic microwave background radiation, and particularly on its gravitational wave components.

The final speaker was Laurent Freidel, from the Perimeter Institute. Laurent works on other approaches to the quantum gravity problem, and faced perhaps the largest hurdle with this audience, since although almost everyone has heard of string theory, approaches such as loop quantum gravity are far less a part of the common lexicon. Nevertheless, Laurent jumped in with both feet and did a tremendous job of getting across the basic ideas and challenges, and where he felt these differed from string theory. I felt that the session went very well, and questions filled the allotted 45 minute period after the presentations, and we continued to answer questions about quantum gravity, cosmology, and wider physics topics, for most of the rest of the week.

Ours was the first session. Over the next two days there were seven other sessions:

• Cryptography and Computer Security
• Ever closer to Pandora’s box: Zoonotic Transmission of Viruses to Humans
• Extrasolar Planets
• Food and Fuel
• Multiple Systems in Understanding Addiction
• Suspended Animation, Immortality, Regeneration
• The Expanding Frontier of Nucleic Acids Chemistry and Biology

There was plenty to enjoy here, but I’ll single out the beginning of the immortality session as particularly fascinating, as the speaker, Alejandro Sanchez, of the University of Utah described his work on the regenerative properties of planaria (flatworms). These creatures can regenerate no matter what you do to them, and their regenerative properties can be genetically modified so that, for example, they grow a head wherever they are cut. Lest you think this work is part of a master plan to give us all multiple heads, the real goal is to understand how such amazing regeneration works, so that perhaps humans can ultimately replace their own malfunctioning body parts.

If you are a scientist and you are ever lucky enough to be invited to one of these meetings you should just say “yes!”. Sure, it won’t directly further your immediate research, and there probably won’t be anyone there who can directly further your career. But these are good things, making for a remarkably refreshing, open and fun meeting, at which all there is to accomplish is learning. Revolutionary, no?

Well, it’s back to a busy week for me. I flew back on Sunday, drove to Philadelphia for meetings on Monday, back yesterday, give the Cornell Astronomy colloquium tomorrow and need to go back to Philly early on Friday. Plus, today I am in bed with a horrible cold that I just hope isn’t something worse that those terrifying “Zoonotic Transmission of Viruses to Humans” people were carrying around.

It’s fun to finally have made the transition to Discover. If you’re new here, I hope you enjoy Cosmic Variance. Bye for now.

On 10 a.m. Pacific time this Thursday, Los Angeles will be hit by a major earthquake. And how do we know this? Because it’s a pretend earthquake. I just received the following amusing/frightening email:

On Thursday, November 13, the Caltech community, along with millions of other Southern Californians in homes, schools, businesses, government offices, and public places, will participate in the Great Southern California ShakeOut Earthquake Drill. At 10 a.m., everyone is encouraged to drop, cover, and hold on for 120 seconds in simulation of a magnitude 7.8 earthquake on the southern San Andreas Fault. Throughout the day, Caltech will conduct emergency preparedness drills on campus. Audio and video earthquake recordings, which have been created for use in your drop cover and hold drill, can be downloaded at http://www.shakeout.org/drill/broadcast.html.

Yes, the The Great Southern California ShakeOut. Complete with sound effects, suitable for downloading. Kind of like a good old-fashioned nuclear bomb drill. Just part of the price we pay for being able to eat outside in January.

NASA’s Phoenix Mars Lander, which some time back scraped up direct evidence of water on Mars’s surface, is slipping gently into the night. Not a surprise; the mission was always scheduled to last just a few months, and at this time of Martian year there just isn’t enough sunshine to keep the batteries charged.

Mission engineers last received a signal from the lander on November 2, the space agency said.

Rumor has it that the signal read “Yes We Can!”

The future of NASA is going to be one out of approximately 50 million pressing challenges faced by the new President. Under the previous administration (what was that guy’s name again? I seem to have repressed it), the agency drifted, ranging from embarrassing ideological scandals to hopelessly inept planning to blatant censorship on climate change to a depressing de-emphasis of real science. Obama, and whoever he appoints as NASA administrator, will have a very difficult job balancing competing pressures: rebuilding a science program that has been devastated by funding cuts, while also restoring our capacity to send astronauts into space, and doing so in a time of tremendous budgetary pressures. Darksyde at Daily Kos has a good post about what some of these challenges are, and some of the struggles of current administrator Michael Griffin. It will be very interesting to see what direction the agency takes; in a multipolar world, the U.S. won’t be the only important player in space exploration and space science, but hopefully we won’t just sit on the sidelines, either.

(Did you notice the link to an article on Discover at the beginning of that paragraph? That’s because, when I cut open a vein to sign our new blogging agreement in blood [don't worry, it wasn't my vein], part of the contract was that we would link back to the site in every single blog post we do. I’m sure nobody will notice.)

Faithful readers, welcome to our new digs here at Discover. And stalwart fans of Discover, welcome to Cosmic Variance. We are thrilled to hear that our change in color scheme portends the Death of the Blogosphere. Who knew we had such power? Blogs are yesterday’s news, anyway, but we’ll putter gamely on for a while, just to keep up appearances.

To any new readers who might wander by, feel free to poke around a bit to get a feeling for the place; the archives are accessible from the sidebar, and we also have an About page. This is an extremely bloggy blog, in the sense that we are guided by whatever we want to talk about at the moment, rather than any externally-imposed idea of what should be talked about. Everyone should read one of the following two paragraphs, but not the other one:

One of the features of Cosmic Variance is that we are all working scientists, whose main activity involves doing research. We try to bring some of the excitement and inside scoop of the research process as it occurs. True, we change things up now and then with non-scientific posts, but that’s the price you must pay to attract the eyeballs of the common folk; the meaty posts about the glory of Science will always be a mainstay (and you can even use equations!).

One of the features of Cosmic Variance is that we are all working scientists, but we are also human beings. We try to highlight the human side of the scientific enterprise as we explore the wider world of ideas. True, there are occasional technical posts about some point of current scientific contention, but that’s the price you must pay to keep your academic credibility; the playful, discursive, interdisciplinary excursions will always be the fun part of the blog.

Hope that makes everything clear.

There may be some shaking-out process as we complete the transition over to the new site, so let us know if things work less effortlessly than usual. (Some of the last few comments might have been lost — sorry about that.) We’re happy to have found a new home.

Change we can believe in: starting Monday, Cosmic Variance will be bidding adieu to its life as a plucky independent blog, and huddle into the warm embrace of Discover Magazine. There will be a very brief transition period in which the blog disappears entirely, but hang in there — we’ll be back online before you know it.

Now, we know what you’re thinking: you knew us back when we were indie rock, keeping it real, and now we’re going all corporate? Yes, yes we are. If for no other reason than the thankless task of keeping the blog from crashing and handling the technical end of things will be put in someone else’s capable hands, not our clueless ones.

But there are other reasons. Hopefully the association with Discover will open up new opportunities, and bring new readers to our discussions. And we’re happy to be joining an elite community of blogs that are already up and running at Discover:

• Bad Astronomy: Everyone knows Phil Plait and his enthusiastic dissections of what’s right and wrong in astronomy and much more.
• The Loom: Carl Zimmer is another old friend, the go-to guywhen you have questions about E. coli (among other things).
• Reality Base: a great blog by Melissa Lafsky on science, politics, and the wider world.
• Science Not Fiction: Stephen Cass, Sam Lowry and Eric Wolff cover futuristic technologies in reality and in fiction.
• Better Planet: Benjamin Nugent specializes in portents of disaster environmental news.
• Discoblog: dispatches from the quirkier side of science.
• 80 Beats: Eliza Strickland scoops up the best science news of the day, and doles it out in bite-sized morsels.

So what does this mean for you, our cherished readers? Nothing, pretty much. You should still be able to get here by pointing your browser at “http://cosmicvariance.com/”; indeed, all of the archives should still be available under their old addresses. Likewise the RSS feeds should work as before; in particular, go here:

http://blogs.discovermagazine.com/cosmicvariance/feed

And of course our characteristic sprightly insouciance will continue undiminished. Admittedly, the glamorous blue theme we’ve sported since our humble beginnings will be traded in for an orange and white palate. But we’ve always been about the substance, not superficial appearances. Right?

Cosmologists find themselves in this interesting situation where they have a set of hypotheses — dark matter, dark energy, inflation — that serve to make impressively precise predictions that have been tested against a wide variety of data, but presently lack a firm grounding in established physics. We don’t know what exactly the dark matter is, what the dark energy is, or how inflation happened, if indeed it happened at all. So it behooves us to push at the boundaries a bit — start with the simple models and tweak them in some way, and then check whether the new version still fits the data. How confident are we that the dark sector has the properties we think it does, or that inflation happened in a straightforward way?

This was the philosophy that led Lotty Ackerman, Mark Wise and I to ask what the universe would look like if rotational invariance were violated during inflation — if there were a preferred direction in space, which left some imprint on the cosmological perturbations that currently show up as large-scale structure and temperature fluctuations in the cosmic microwave background. I talked about how that paper came to be in a series of posts: one, two, three. And now there is even tantalizing evidence that our model fits the data! I don’t get too excited about it, but it’s something to keep an eye on as the data improve (e.g. when the Planck satellite gets results).

Ever since then, Mark and I have toyed with the idea that once you’ve broken rotational invariance, your next step is obvious: violate translational invariance! Instead of imagining a preferred direction in space, imagine there were a preferred place in the universe. Not because you have some good reason to think there is, but because you want to quantify the level of confidence we have in the assumption that there is not.

So we have now teamed up with Chien-Yao Tseng, another grad student here at Caltech, to do exactly that. The result is this paper:

Translational Invariance and the Anisotropy of the Cosmic Microwave Background
Sean M. Carroll, Chien-Yao Tseng and Mark B. Wise

Primordial quantum fluctuations produced by inflation are conventionally assumed to be statistically homogeneous, a consequence of translational invariance. In this paper we quantify the potentially observable effects of a small violation of translational invariance during inflation, as characterized by the presence of a preferred point, line, or plane. We explore the imprint such a violation would leave on the cosmic microwave background anisotropy, and provide explicit formulas for the expected amplitudes $\langle a_{lm}a_{l’m'}^*\rangle$ of the spherical-harmonic coefficients.

It took a while to put into equations what exactly was meant by “violating translational invariance” in an operational way. But once you figure it out, it’s obvious, and there are three ways to do it: imagining that there is a preferred point, line, or plane in the universe. Then you hypothesize that the density fluctuations are very slightly modulated in a way that depends on your distance from that preferred place. Once you have that, it’s just a matter of cranking out some monstrous equations. Thank goodness there are only three macroscopic dimensions of space, is all I can say.

So now we have some predictions to compare with data, so that we can understand exactly how well the cosmic microwave background really assures us that there is no special place in the universe. But aside from the general motivation of being careful to test all of our cherished assumptions, there is another reason for work like this: there are a handful of ways in which cosmological perturbations don’t look completely the same in every direction. As we say in the paper:

There is another important motivation for studying deviations from pure statistical isotropy of cosmological perturbations: a number of analyses have found evidence that such deviations might exist in the real world. These include the “axis of evil” alignment of low multipoles, the existence of an anomalous cold spot in the CMB, an anomalous dipole power asymmetry, a claimed “dark flow” of galaxy clusters measured by the Sunyaev-Zeldovich effect, as well as a possible detection of a quadrupole power asymmetry of the type predicted by ACW in the WMAP five-year data. In none of these cases is it beyond a reasonable doubt that the effect is more than a statistical fluctuation, or an unknown systematic effect; nevertheless, the combination of all of them is suggestive. It is possible that statistical isotropy/homogeneity is violated at very high significance in some specific fashion that does not correspond precisely to any of the particular observational effects that have been searched for, but that would stand out dramatically in a better-targeted analysis.

In other words, we have a handful of anomalies, each of which might easily go away, but perhaps when they are taken together they imply that something is going on. Maybe there is some incredibly strong signal out there, and we just haven’t been looking for it in the right way. We won’t know until we understand better how such anomalies would show up in the observations — and then go collect better data.

Now that the election is over and the LHC is delayed, for the next six months all of our posts will be about puppies. Let’s start with a live webcam.

(more…)

Here on the pulse of this new day
You may have the grace to look up and out
And into your sister’s eyes,
Into your brother’s face, your country
And say simply
Very simply
With hope
Good morning.

– Maya Angelou