Blogs / Cosmic Variance

Salon’s K-Chronicles provide something to think about whenever you listen to the simplistic world-view of our President

Doesn’t Keith Knight know it’s unAmerican to try to understand how other people might view this country’s actions? You’re either with us or against us man; no questions asked!

Hey, Lufthansa has wireless in the sky — how cool is that! So here I am at roughly 38,000 ft, somewhere over Canada, 6.5 hours into the flight with 4.5 hours left to go…. I’m on my way home from the International Center for Theoretical Physics (ICTP) in Trieste, Italy, where one of the last summer schools of the season just finished. The topic was Expecting LHC, which was the hot topic for summer schools this year. In fact, everybody who is anybody had one. The LHC is turning on next year and everyone wants the new crop of graduate students to be prepared!

The school was great and I enjoyed the whole experience. (But, then again, I adore Italy!) My lectures were on Non-Supersymmetric Physics Beyond the Standard Model and Extra Dimensions. That’s both a fairly broad and specific topic! I first reviewed the symmetries of the Standard Model, which any model of new physics must clearly satisfy, and briefly covered something called Little Higgs models as they contain new quarks, new gauge bosons, and new Higgs bosons, all at once! However, I spent most of my lectures on Extra Dimensions, covering the motivation, basic theory, and collider signatures for the main models. Other lecturers covered the Standard Model (QCD and Electroweak and Heavy Flavors), Higgs, Supersymmetry, and the LHC accelerator and detectors.

The students were great! It is always a joy to lecture to a room full of enthusiastic students. They were chock full of good questions and were not shy about asking them, so the lectures (and the coffee breaks, and the meals) were very interactive. There were about 100 students registered from various places ranging from Pakistan to Palestine. This set of kids shows that the world is full of eager, bright and budding physicists!

The main program of the ICTP is to foster the development of theoretical physicists from developing countries. The Center was founded in 1964 by Abdus Salam, a theorist from Pakistan who was a co-creator of the Standard Model, and it serves its purpose very well. There are many shining examples of successful theorists who have worked there, including Gia Dvali who co-invented the model of Large Extra Dimensions (a main feature of my lectures) while he was there.

Us lecturers were very well looked after, pretty much as described by Sean when he lectured at their Cosmology school earlier this year. Since he already posted a picture of the guesthouse, I will share a picture of the jellyfish with you instead. (Be thankful you are spared my numerous sunset shots.) The small bay of the Adriatic Sea where the ICTP and its Guesthouse sits was filled with the things, about 1-2 ft long. Superb!

It’s tough being a scholar sometimes. Just ask Pope Benedict. In the course of a long speech, he took the time to tell a little story about a 600-year-old meeting between two educated thinkers, one Christian and one Muslim. And now he has the whole Islamic world angry at him. His story went something like this:

The Pope’s speech quoted from a book recounting a conversation between 14th century Byzantine Christian Emperor Manuel Paleologos II and an educated Persian on the truths of Christianity and Islam.

“The emperor comes to speak about the issue of jihad, holy war,” the Pope said.

“He said, I quote, ‘Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached’.”

Benedict described the phrases on Islam as “brusque”, while neither explicitly agreeing with nor repudiating them.

Hey, this is a popular blogging technique! Just link to a story somewhere else, without giving any explicit endorsement. I wonder if Benedict has been reading Instapundit, or Little Green Footballs?

So now apparently Muslims are upset, as they don’t appreciate the linkage between Islam and violence. Personally, I find it unpersuasive to claim that the two are unconnected when so many people persist in connecting them. Also, if your goal is to insist that your religion is one of peace and tolerance? Probably burning the Pope in effigy is not the best way to get that message across.

The real problem with the Pope’s speech was his claim that violence had no place in true religion (you know, like Christianity).

“Violence is incompatible with the nature of God and the nature of the soul,” the Pope said.

We all know that most big-time religions have many examples of terrible violence in their past, and Christianity is certainly no exception. Even putting aside the many recent incidents, it’s interesting to consider the record that is part of official Church doctrine, as recorded in Scripture. Steve Wells has done the hard work of going through the Old Testament and counting up the death toll for both God and Satan, taking care not to exaggerate by only including those examples for which specific figures are given. (Via Cynical-C.) The final tally:

• God: 2,270,365.
• Satan: 10.

This doesn’t include stuff like the Flood, for which reliable figures are unavailable. If violence is incompatible with the nature of God, He sure has a funny way of showing it.

To be serious for a second: my thing about religion is generally not that it’s bad, but that it’s false. The history of religion is far too complex to be summed up as “good” or “bad,” and there are obviously components of both. The Salvation Army, odious discrimination policies notwithstanding, does a tremendous amount of good. Religious people are generally better at donating to charity than non-religious ones (last I heard; I don’t have specific figures, so this could be wrong). And I like a lot of the art and architecture.

The overall effect of religion may be good or bad, I don’t know how to judge. But if you’re going to talk about it (which the Pope is definitely going to do, given his job description), you should at least be honest, including all the ugly parts. Pretending that either Islam or Christianity is all about non-violence and peaceful dialogue is patently false. You can try to say that the episodes of violence are aberrations, not reflective of the “real” religion, but that’s just the No True Scotsman fallacy. What a religion is, for all important purposes, is revealed by what its adherents actually do, for better or for worse. If Pope Benedict had said “We are all fallible human beings, and people of our faiths do not always act wisely, but we should all strive to promote peace over violence within our churches,” perhaps there would have been fewer effigies.

A new physics-oriented blog carnival, Philosophia Naturalis, has just appeared at Science and Reason. Here’s some background explanation. Looks like a great selection of articles.

To celebrate the birth of this new project, I’ll mention this quote from Al Franken, who is contemplating a Senate run in 2008:

There’s all kinds of things that need to be done. Respecting science again. I would like to do a law where no political appointee can change the language of a scientific report without getting the scientists who made the report to sign off on the language change. That’s a law I’d propose on the first day, I think.

Franken brought this up unprompted during an interview with Lindsay Beyerstein. It shows an admirably pro-natural-philosophy viewpoint.

In contrast, we have George W. Bush, who sees his foreign policy as part of a new religious rebirth:

“A lot of people in America see this as a confrontation between good and evil, including me,” Bush said during a 1 1/2 -hour Oval Office conversation on cultural changes and a battle with terrorists that he sees lasting decades. “There was a stark change between the culture of the ’50s and the ’60s — boom — and I think there’s change happening here,” he added. “It seems to me that there’s a Third Awakening.”

The First Great Awakening refers to a wave of Christian fervor in the American colonies from about 1730 to 1760, while the Second Great Awakening is generally believed to have occurred from 1800 to 1830.

Sadly, the one who views his actions through the lens of a titanic supernatural struggle is the President of the United States, while the one who faces up to the real world is a comedian. Draw your own conclusions about the decline of Western civilization.

The New York Times has a brief but interesting article covering the results of two separate teams that are seeking to get a handle on the formation of the first galaxies in the universe. This is a particularly pressing question these days, after the WMAP satellite’s improved measurement of the reionization of the universe, thought to have been prompted by the death throes of the first or second generation of stars.

Teams using the Hubble Space Telescope and the Subaru Telescope on Mauna Kea carried out the relevant observations. They show a rapid increase in the number of galaxies within the first billion years after the big bang (13.7 billion years ago). The article states

How the dark ages ended is a matter of hot debate. From 300 million to 1 billion years after the Big Bang, figures from NASA’s Wilkinson Microwave Anisotropy Satellite show that the hydrogen in space was reionized and split back into electrons and protons by radiation from stars or, perhaps, black holes.

Calculations suggest that the first stars to form, out of hydrogen and helium produced in the Big Bang, would be 100 times as massive as the Sun and would rapidly explode, scattering heavier elements like oxygen, carbon, nitrogen and iron — the stuff of planets and life — into space to serve as material for a new generation of stars.

The stars forming in the newly discovered galaxies are probably of the second type, Dr. Illingworth said.

referring to Garth Illingworth, from the University of California, Santa Cruz, a member of the team using Hubble.

A particularly fun aspect of the article is the feeling of the rapid progress currently going on in cosmology.

Nor is the Japanese record likely to last long. Richard Ellis of the California Institute of Technology said in an e-mail message that he had used the Keck Telescope on Mauna Kea and a quirk of Einsteinian gravity to find protogalaxies even farther in the past, less than 500 million years after the Big Bang. These objects, too feeble and small for the Hubble to have seen them, have been amplified by the gravitational fields of intervening galaxies.

Oh well, gotta run - this is an incredibly busy week. On Monday I gave the Physics colloquium at Cornell, which was great fun - seeing collaborators and friends and meeting lots of new people, particularly students. And tomorrow I’m giving the same talk here at Syracuse. But tomorrow evening I should start to see my own first light at the end of the tunnel.

The next Categorically Not! is Sunday 24th September. You may recall my post on the Categorically Not! series of events held at the Santa Monica Art Studios. They’re fantastic, and I strongly encourage you to come to them. Have a look at the last two descriptions here and here, and the description of the recent special one on Uncertainty that was held at the USC campus is here.

Here is K.C. Cole’s teaser:

(more…)

The Bad Plus have a blog! How cool is that? (Via Marginal Revolution.) The BP are a jazz trio consisting of pianist Ethan Iverson, bassist Reid Anderson, and drummer Dave King, known for an energetic and imaginative style that ranges from free jazz to playful pop. Their version of Nirvana’s Smells Like Teen Spirit became quite a hit as these things go, and rightfully so. The blog is called Do The Math, so perhaps they are trying to compete in the nerd-off. It’s fantastic that a working jazz combo (or musicians more generally) have their own blog; anyone know of any other examples?

I haven’t had a chance to explore the blog very closely, but I noticed that they link to a recent NYT article by Ben Ratliff on Jazz at Lincoln Center’s upcoming Coltrane series, in honor of what would have been his 80th birthday. One of the pieces being performed is Giant Steps, an especially interesting tune. Coltrane knew his music theory backwards and forwards, and he put a tremendous amount of thought into composing Giant Steps; rumor has it that it was meant as an exercise for students, but has since grown into a popular standard, in much the same way as Bach’s Goldberg Variations. (Apparently Trane himself decided that it was too mechanical, and didn’t play it very much after the record had appeared.) The solo is based on an extremely rapid series of a particular type of chord changes, now known as Coltrane changes. In the tune, Coltrane plays four notes in each chord (the root, second, third, and fifth) as a series of eighth notes, changing chords every two beats. For those of you keeping score at home, that means each note is played precisely once before moving on the the next chord, not leaving much time for ornamentation. You can buy a whole book of transcriptions of Trane’s different takes of the chorus.

I know you want me to link to an audio file of Giant Steps, don’t you? But I have something even better. Via Wikipedia, here is an animation of Giant Steps by Michal Levy. It’s extremely well done, and the visual representation tracks the music faithfully while adding its own imaginative dimension.

For your obligatory science content, MR also points to a very clever animation of different dimensions, all the way up to ten! (Okay, the mixing of quantum mechanics and the higher dimensions is a little bizzare; but the pictures are nice.) Those MR guys are pretty good linkers, for libertarians.

Dr. Free-Ride is trying to goad us into proclaiming our nerdliness. Various science bloggers are having a friendly competition to see who is the nerdliest of them all, and she wants to know why CV isn’t represented.

Regrettably, I’m going to pass on this one. (Not that I couldn’t put up a respectable showing, since past indiscretions are apparently fair game; I loved my old RPN Hewlett-Packard calculator, and I’ll put the glasses I wore in high school up against anyone’s.) It’s just that I’m not entirely on board with the program of reclaiming “nerdliness” as a badge of honor, as gays have managed to reclaim queer and so forth.

Words like “nerd” or “geek” have two very different sets of connotations, and it’s hard to evoke one without the other. One has to do with technical mastery and know-how, or even a more broadly-based appreciation for things academic and intellectual. The other has to do with social awkwardness, the inability to comfortably converse with strangers at cocktail parties, and a tendency to dress in the least attractive way possible.

Roughly speaking, the first of these connotations is “good,” and the second is “bad.” But they’re both problematic. Nobody would be happier than me if we could somehow increase society’s appreciation for people with technical skills, and eliminate the defensive dismissal that so many people fall back on when confronted with math or science or computers. (There are only so many times you can tell people what you do for a living, only to hear “That was my worst subject in high school.”) So in that very particular sense, I’m all in favor of celebrating nerdliness. But for me it’s very much a part of what should be a general appreciation for intellectual endeavor, whether technically oriented or not. And as a matter of personal experience, I’ve found science and engineering types to be at least as anti-intellectual as the average person on the street, when it comes to non-technical kinds of scholarship. Naturally, there are plenty of pro-intellectual types, among people with and without technical backgrounds. That geek cred, however, lends a special kind of bite to know-nothingness when it rears its ugly head; someone with a Ph.D. in physics can not only dismiss philosophy or art or literature as airy nonsense, they can compare it directly and unfavorably to their own sphere of competence. And they do.

But it’s the social-backwardness aspect of being a nerd that is the biggest problem. You can protest all you want that you’re really talking about technical competence, not lack of social fluency, but the latter comes immediately to mind whenever anyone hears talk about nerds and geeks. Wikipedia spells it out:

Nerd, as a stereotypical or archetypal designation, refers to somebody who pursues academic and intellectual interests at the expense of social skills such as: interpersonal communication, fashion, and physical fitness.

What is worse, there’s a certain point of view (I won’t name names … some of my best friends are nerds) that actually celebrates social awkwardness for its own sake. (Trust me about this, I’ve been employed by both MIT and Caltech.) And that’s just wrong. I’m not talking about principled eccentricity, letting your freak flag fly — nothing wrong with that, in fact it’s admirable in its own way. Nor am I saying that everyone should be scouring the latest issues of GQ and Vogue for fashion tips; superficiality is just as bad as nerdliness. And laughing at our high-school (and college) selves is always fun and healthy. All I’m saying is that there is much to be valued in an ability to relate to other kinds of people in a disparate set of circumstances, take care of your appearance, and function effectively in a wider social context. These are skills we should try to cultivate, not disparage.

The point is that these two aspects of nerdliness operate against each other. If we want the rest of the world to appreciate technical skills, then we should work to eradicate the notion that they are necessarily associated with a lack of social skills. And that’s the connotation of “nerd,” like it or not. Celebrating knowledge and competence and intellectual curiosity is good, but celebrating nerdliness sends the wrong message, I would argue. There’s no reason why someone who programs in assembly and is deft with a contour integral can’t also be a well-rounded and engaging conversationalist who is at all the gallery openings and whom everyone wants at their parties — that’s the message we want to send.

What a killjoy, huh? In my defense, if you’d been sleeping on a concrete floor for the last several days, waiting for your furniture to arrive, you’d be grumpy too.

I have just finished reading Alex Vilenkin’s book, Many Worlds in One: the Search for Other Universes.

The anthropic principle is a topic that so easily prompts hysteria and overreaction and, since we’re going to be mentioning it a few times, I might as well make it clear what I think. It is a perfectly logically possibility that some features of our universe are anthropically determined. If such a possibility is predicted by a theory that is viable in all other ways, then one should take it seriously as long as it can be tested. If one cannot test this particular prediction, then one might find it a compelling argument, but one will never know if it is correct.

Vilenkin is one of the world’s leading theoretical cosmologists. He has made seminal contributions to the theory of cosmological inflation, the idea that the universe may contain topological remnants from particle physics phase transitions, to quantum cosmology, and to many other central topics. Perhaps most importantly for the ideas in his book, he has been an architect of the idea of eternal inflation, and one of the primary researchers embracing its implications for the anthropic principle.

Two things struck me right away when I picked up the copy that Alex’s publisher sent to me. First, it is a small book by the standards of popular cosmology writing; just over 200 pages. Second, when you read the author blurb inside the back dust cover, you find it to be just a bare bones description of Alex’s track to his Professorship at Tufts University. The lack of author promotion material is another unusual feature, and, to the extent that I know Alex, is an accurate reflection of his modest character. One finds this tone continued through the entire book; it is refreshing and adds to the appeal of the subject matter.

Almost exactly half of the book, with the exception of a brief discussion of the future of life in the expanding universe, is devoted to a description of the standard model of cosmology and its inflationary extension. I find it extremely difficult to know whether a given pedagogical approach is useful for the general public, although I think this material is at no more complicated level than other books on related topics. However, I do think that Alex’s description is an exceptionally clear and uncluttered account of the material for anyone with an undergraduate physics education. All the more impressive is that this cosmic tour contains enough personal information and anecdotes to give the reader a real feeling for the excitement and camaraderie that is an essential part of being a scientist. Vilenkin’s enthusiasm for the subject matter, and his affection for his collaborators and his students is infectious and carries the reader along into the second half of the book.

This is where Vilenkin gets into the more speculative material. First comes a description of eternal inflation. In many inflationary models, there is an argument that, due to fluctuations of the inflaton, there will always be regions of the space-time that are undergoing inflation, even as there are other regions in which inflation ceases and, in a subset of these, universes with properties somewhat similar to ours begin.

Given our understanding of quantum field theory, and some assumptions allowing one to try to understand the effect that such fluctuations would have on the background space-time, eternal inflation seems like a reasonable aspect of many inflationary models. But it is important to emphasize that this is not yet completely firmly established, and there are subtleties that one might worry about in trying to infer a nonperturbative effect on space-time from a quantum effect. It would be wonderful to see this settled definitively in a quantum theory of gravity, such as string theory.

If eternal inflation does indeed take place, then Vilenkin argues for infinitely many realizations of non-inflating patches of the universe, with all possible values of constants of nature. This is then used to argue for an anthropic understanding of, for example, the cosmological constant.

Whether or not all this holds true, as I mentioned briefly above, depends on the correctness of inflation, the ultimate nature of the inflaton, and details of the ultimate theory of quantum gravity. To this end Alex devotes a chapter to string theory and, in particular, to the idea of the landscape as an example of how many different vacua, with different values of the cosmological constant might arise. This is, as many blogosphere readers will be aware, a controversial issue, and one that often gives rise to strong emotions. But Vilenkin confines his discussion of it to a chapter (and a few other comments here and there), and presents his central thesis without relying on the landscape. I found this very positive, not because I’m trying to make a deep point about the landscape, but because it makes Alex’s treatment more general, and hopefully will allow a wider interested readership access to the ideas without getting caught up in that particularly heated debate.

Many Worlds in One is a tour through one of the most exciting areas in modern physics, led by a modest guide, who most certainly has his own firm opinions, but who is much more interested in a serious discussion of the physics than in self-aggrandizement and evangelizing for a particular area. Vilenkin’s credentials in particle cosmology are unquestionable, and the book is fascinating as a selected review of his own contributions to the field.

Nevertheless, there are a number of comments in the book that I had problems with at one level or another. When Vilenkin first talks about the multiverse implications of eternal inflation he writes (on p.83)

The response I got from other colleagues was also less than enthusiastic. Physics is an observational science, they said, so we should refrain from making claims that cannot be observationally confirmed. We cannot observe other big bangs, nor can we observe distant inflating regions. They are all beyond our horizon, so how can we verify that they really exist? I was disheartened by such a cool reception…

I was a little surprised by this, since it seems to me to be merely a plain statement of what science really means. We get a better idea of what he means on p.91 when he writes

The main objection against it was that it was concerned with the universe beyond our horizon, which is not accessible to observation. But if the theory of inflation is supported by the data in the observable part of the universe, shouldn’t we also believe its conclusions about the parts that we cannot observe?

But again, I can’t really sign on to this way of looking at it, since I feel that one of the great strengths of science is the willingness to say “we don’t know” about things that are untestable, and to have to live with that.

Another criticism is that I would have liked to see a more detailed and complete discussion of the assumptions behind the conclusions Alex draws, and what needs to be done to put them on firmer ground or, in fact, refute them. What we have is a section, starting on p.116

SOME WAYS OUT: Many readers are, no doubt, wondering. … Is there any way to avoid these bizarre conclusions? … if you are willing to clutch at any straw at all to avoid it, let me offer you a couple of straws.

which is then followed by three short paragraphs - eight sentences - in which loopholes are briefly mentioned.

There are certainly other examples of individual comments with which I don’t agree, such as (p.151)

The observed value of the cosmological constant gives a strong indication that there is indeed a huge multiverse out there.

but these are small points.

I have gone into a little detail about some of the places where I take issue with Alex’s claims precisely because I want to be clear about my problems before stating that I actually liked this book very much and would most definitely recommend it to others. The writing is clear, the tone is appealing, and the science is discussed in an honest way, by a master who loves the subject. Vilenkin provides us not only with a fascinating account of the physics, but also with a fun and, in places, humorous picture of life as a scientist. (As a former MIT postdoc, the description of Alan Guth’s office had me smiling for a while)

In the end, I remain relatively unemotional about, but unconvinced by the arguments for an anthropic understanding of the cosmological constant. Of course, with significantly more theoretical progress that might change, as should always be the case. But whatever one thinks about this issue, Vilenkin’s book is a wonderful, likeable and refreshingly ego-free contribution to the popular discussion (there is plenty in there for experts to learn from as well). Even if you want nothing else but an excellent discussion of modern cosmology, it is well worth a read.

The past 2 weeks have flown by in what seems like a day. Does anyone else have this problem?

First, I went to visit my parents in their new digs. They were on the East Coast and I had been begging them for years to move to California. They finally capitulated - part way - and settled in Colorado….sigh….parents these days, what will they do next? After the visit, I was home for 10 hours (time enough to change the dirty clothes in my suitcase to clean ones) and went to Fermilab for a committee meeting. Upon my return home from that, I have been ear deep in writing sections for the committee report. That finally got finished today and now life can begin again. Whew! The report will be public in about a month and you will read all about it here. Meanwhile, I have 46 hours to prepare for my upcoming trip to Trieste, Italy….

In the meantime, I have missed too many blogging opportunities! I could have told you about: