Archive for August, 2008


By Sean Carroll | August 29, 2008 12:12 pm

So John McCain picks Alaska Governor Sarah Palin as his Vice-Presidential nominee. I know nothing about her, so will suspend judgment. But she is a woman, which is fantastic. The U.S. will either have an African-American President or a female Vice-President, which is the kind of history that should have been made long ago; so kudos to McCain for his courage in making that choice.

Beyond that, there are just a few tidbits that seem to be trotted out in all the stories about Palin. She is very firmly pro-life. Unless you are a polar bear. She is in favor of domestic partnerships, although against gay marriage (which puts her in the official Democratic position). She’s been embroiled in some sort of scandal, although it’s always hard to tell at first glance how serious those things should be taken. Perhaps her signature issue, as far as national politics is concerned, is drilling for oil all over the place — she’s in favor.

One might wonder whether McCain undermines his message of the importance of experience by picking a 44-year old governor with no national experience at all. But one might wonder whether Obama undermined his message of bringing change to Washington by choosing a white male Washington lifer from the Northeast; so clearly the McCain camp thought this was worth the risk. We might learn terrible or wonderful things about her in the next few months, but for the moment this seems superficially like a more palatable pick than any of the bigger Republican names that had been floating around — clearly it was in McCain’s eyes. (Brad DeLong wonders whether a similar line of reasoning didn’t leave us with Dan Quayle twenty years ago.)

Update: I originally included a link to this YouTube video of Palin making Craig Ferguson an honorary citizen of Alaska, which I think speaks to her sense of humor. But it also involves Ferguson making jokes about her giving off a sexy librarian vibe, which is fine in the context of a late-night comedy show, but isn’t a fair first impression for a female candidate for a major national office. All sorts of jokes will doubtless be on their way, we might as well make some meager effort to start things off with more substantive considerations.

Update again: Because I don’t know anything about Palin, I’ve tried to be open-minded about the pick. But 24 hours later, the obvious first conclusion to which one is tempted to jump appears increasingly correct: this is a person who has no business being anywhere near a national ticket. Sufficient evidence for this conclusion comes from the words of her supporters, along the lines of: Sure, she’s woefully underqualified, but in all probability John McCain will live for at least another four years! And if he doesn’t, we’re sure she will have the good sense to resign.

I wonder how many times she has visited Iraq to get the facts on the ground?


The Thousand Best Popular-Science Books

By Sean Carroll | August 29, 2008 11:17 am

Over at Cocktail Party Physics, Jennifer has cast a baleful eye on the various lists of the world’s greatest books, and decided that we really need is a list of the world’s greatest popular-science books. I think the goal is to find the top 100, but many nominations are pouring in from around the internets, and I suspect that a cool thousand will be rounded up without much problem.

We played this game once ourselves, but like basketball, this is a game that can be enjoyed over and over. So pop over and leave your own suggestions, or just leave them here. To prime the pump, off the top of my head here is a list of books I would nominate. A variety of criteria come into play; originality, readability, clarity, and influence — but just because a work appears here doesn’t mean that it scores highly on all four counts.

  • Guns, Germs, and Steel, Jared Diamond
  • Godel, Escher, Bach, Douglas Hoftstadter
  • Cosmos, Carl Sagan
  • Einstein’s Clocks and Poincare’s Maps, Peter Galison
  • How the Universe Got Its Spots, Janna Levin
  • Chronos, Etienne Klein
  • The Language Instinct, Steven Pinker
  • Surely You’re Joking, Mr. Feynman, Richard Feynman
  • The Mismeasure of Man, Stephen J. Gould
  • Lonely Hearts of the Cosmos, Dennis Overbye
  • The Inflationary Universe, Alan Guth
  • The Elegant Universe, Brian Greene
  • Warped Passages, Lisa Randall
  • The Astonishing Hypothesis, Francis Crick
  • The Double Helix, James Watson
  • Prisoner’s Dilemma, William Poundstone
  • The Blind Watchmaker, Richard Dawkins
  • One, Two, Three… Infinity, George Gamow
  • Warmth Disperses and Time Passes, Hans Christian Von Baeyer
  • Time’s Arrow and Archimedes’ Point, Huw Price
  • A Brief History of Time, Stephen Hawking
  • At Home in the Universe, Stuart Kauffman
  • Einstein’s Dreams, Alan Lightman
  • Black Holes and Time Warps, Kip Thorne
  • The First Three Minutes, Steven Weinberg
  • The Mathematical Experience, Davies and Hersh
  • The Periodic Table, Primo Levi
  • Beamtimes and Lifetimes, Sharon Traweek
  • The Diversity of Life, E.O. Wilson
  • The Emperor’s New Mind, Roger Penrose
  • Longitude, Dava Sobel
  • The Structure of Scientific Revolutions, Thomas Kuhn
  • Flatland, Edwin Abbott
  • The Fabric of Reality, David Deutsch
  • Nobel Dreams, Gary Taubes

I didn’t peek at anyone else’s lists, but I admit that I did peek at my own bookshelves.

CATEGORIZED UNDER: Science and Society, Words

We Shall Always March Ahead

By Sean Carroll | August 28, 2008 10:44 pm

You may have heard that history was made tonight. After an up-and-down convention, Obama hit his speech out of the park. And it was an awfully big park.

It was a tightly constructed, pitch-perfect speech. Obama came out feisty, challenging McCain directly and by name. Then he shifted briefly into wonk mode, laying out some of his policies for those who are too busy to check his web page. (My words, not his.) And he concluded by bringing out some of the soaring rhetoric that he does best. Here’s the text. And a tiny excerpt:

America, our work will not be easy. The challenges we face require tough choices, and Democrats as well as Republicans will need to cast off the worn-out ideas and politics of the past. For part of what has been lost these past eight years can’t just be measured by lost wages or bigger trade deficits. What has also been lost is our sense of common purpose – our sense of higher purpose. And that’s what we have to restore.

We may not agree on abortion, but surely we can agree on reducing the number of unwanted pregnancies in this country. The reality of gun ownership may be different for hunters in rural Ohio than for those plagued by gang-violence in Cleveland, but don’t tell me we can’t uphold the Second Amendment while keeping AK-47s out of the hands of criminals. I know there are differences on same-sex marriage, but surely we can agree that our gay and lesbian brothers and sisters deserve to visit the person they love in the hospital and to live lives free of discrimination. Passions fly on immigration, but I don’t know anyone who benefits when a mother is separated from her infant child or an employer undercuts American wages by hiring illegal workers. This too is part of America’s promise – the promise of a democracy where we can find the strength and grace to bridge divides and unite in common effort.

Tomorrow we can be all analytic and careful. Tonight, I’m just enjoying this.


Seeing the Sky with Different Eyes

By Sean Carroll | August 28, 2008 4:42 pm

I just got back from the Cosmo-08 conference in Madison, which was great fun (and I’m sorry I had to miss the last couple of days). But just because I’m traveling, doesn’t mean that science stops happening. It just means I might be late in blogging about it, if I were moved to do so, which in this case I am.

The big news is that the Gamma-Ray Large Area Space Telescope, a satellite observatory launched back in June, reached two milestones: (1) it got a name change, from GLAST to the Fermi Gamma-Ray Space Telescope (on the theory that not enough things are named after Fermi), and (2) they released the first new picture of the gamma-ray sky! And here it is; click for higher resolution.

You can clearly see the Galactic plane, of course, as well as a few objects that shine brightly in gamma-rays — a handful of pulsars, and one distant blazar. GLAST Fermi will be cranking out the science over the next several years, from down-and-dirty astrophysics to searches for annihilating dark matter. See Andrew Jaffe, Phil Plait, and symmetry breaking.

Meanwhile, some of the folks who brought you the Bullet Cluster have now come up with MACSJ0025.4-1222 (or MAC-Daddy-J, as pundits have suggested).

It’s a similar story — two giant clusters of galaxies smacked into each other, allowing their dark matter to separate from the hot ordinary matter in between. Gravitational lensing lets you figure out where the dark matter is, while X-ray observations reveal the ordinary matter. The Bullet Cluster was pretty darn convincing, but it’s a scientific truism that nothing ever happens just once, so it’s nice to see that magic repeated.

Finally, I wanted to mention something that is somewhat old news, but that somehow had escaped my attention until Dan Hooper‘s nice talk at Cosmo-08. That is the WMAP Haze, a phenomenon originally noticed by Douglas Finkbeiner. The WMAP satellite, trying to observe primordial temperature perturbations in the cosmic microwave background, measures several different frequencies, to help correct for foregrounds. The CMB isn’t the only thing that emits microwaves, but nearby dusty astrophysical sources generally depend on frequency in different ways, so one can try to remove their effects by seeing how the maps at different frequencies compare with each other. Some people, apparently, are actually interested in those dusty foregrounds, so they try not only to remove them, but to understand them. And Finkbeiner claims that when we remove all of the foregrounds that we know how to explain, and mask out the parts of the galaxy that are simply too bright to deal with, we are left with this:

There is some mysterious emission near the center of the galaxy, dubbed the “WMAP haze.” There is an explanation on the market, which is what Hooper’s talk was about — the haze could come indirectly from dark matter! Dark matter particles annihilate, so this story goes, giving off a bunch of lighter particles, including electrons and positrons. These electrons and positrons swirl around in the galactic magnetic field, giving off synchrotron radiation, which is what we see as the haze.

True? Plausible? Crazy? I don’t know. The good news is that the dark matter model required to make it work is not thrown together just to fit this result — it’s a fairly vanilla model of weakly-interacting massive particles. The bad news is that it’s hard to understand these dusty foregrounds, and difficult to be sure that you’ve accounted for all of the mundane ones.

The great news is that this is exactly the kind of thing that GLAST Fermi will test, by looking for the high-energy gamma rays that should also be emitted by annihilating dark matter. So stay tuned for some possibly exciting dark matter news, right around the corner.


The triumph of science over politics

By Daniel Holz | August 28, 2008 3:51 am

The democratic national convention has now officially nominated Obama as the democratic nominee for POTUS. Earlier in the week Willie Nelson performed. Tonight Vanity Fair and Google throw a shindig. As it happens, I could have finagled to hang out with Willie Nelson backstage. And it is not inconceivable that I could have swung an invite to the VF/Google party. (A long complicated story involving poker, kiteboarding, and an indolent brother). So, you may be asking yourself, am I now in Denver hanging out with all the politicos? Actually, no. I’m sitting in Waimea, Hawai’i. For years I have been wanting to go observing, but for some reason observers are hesitant to allow theorists to play with their $300M toys. But why should Julianne have all the fun?
The Keck telescopes. Obama/Biden.
Alison Coil and Ben Weiner have been kind enough to let me tag along on one of their observing runs. We’re looking at outflows from post-starburst galaxies at high redshift. We’d like to understand whether winds from starbursts or AGNs might have inhibited subsequent star formation. (More details in a future post.) We’ll be using the Keck observatory on Mauna Kea, arguably the world’s premier (Earthbound) telescopes. Our nights were allocated months ago. Apparently this is not the sort of thing you can switch at the last minute because you want to go to a party. Even a Google party.

So a difficult choice had to be made. After much soul-searching, science won out. Instead of socializing with movie stars and shaking Obama’s hand (again), I’ll be standing on a 4200 meter summit in the middle of the Pacific.

CATEGORIZED UNDER: Science and Politics

Non-Spherical Magnetic Cows!

By Mark Trodden | August 26, 2008 1:54 pm

Physicists often simplify or idealize phenomena to make them more amenable to an initial mathematical treatment. We jokingly refer to this as considering a “spherical cow”. Sometimes one can understand even very subtle phenomena using this technique. However, there are always important effects that one needs the full, non-symmetric nature of the situation to understand.

Here, from The Telegraph, is an example of experimental data illustrating just this point (emphasis mine)!

Dr Sabine Begall and colleagues from the University of Duisburg-Essen looked at thousands of images of cattle on Google Earth in Britain, Ireland, India and the USA. They also studied 3,000 deer in the Czech Republic. The deer tended to face north when resting or grazing.

Although, in many cases, the images were not clear enough to determine which way the cattle were facing they were aligned on a north/south axis.

The scientists concluded that they were behaving in the same way as the deer.

Huge variations in the wind direction and sunlight in the areas where the beasts were found meant that the scientists were able to rule out those factors as being responsible for the direction they were facing.

“We conclude that the magnetic field is the only common and most likely factor responsible for the observed alignment,” the scientists wrote in an article published in the Proceedings of the National Academy of Sciences journal.

All joking aside, I found this fascinating. It is hard to see why this feature would be useful to cows these days, but if you accept the evil theory of evolution, things become a lot clearer.

Their innate ability to find north is believed to be a relic from the days when their wild ancestors needed an accurate sense of direction to migrate across the plains of Africa, Asia and Europe.


Street Corner Science with Leon Lederman

By Sean Carroll | August 26, 2008 11:05 am

ScienCentral is an interesting organization. They are a production company that focuses, unsurprisingly, on science. The kind of thing they will do is to haunt the hallways of a big science conference, and snag interviews with scientists, and then turn them into short news stories that can play on local TV stations around the country (and be seen by millions of people in the process). And of course they do longer-form pieces as well.

And now they have been upgrading their web presence, and the site has a lot of goodies (including a nascent blog). Here is a fun clip featuring Leon Lederman sitting on the sidewalk and answering science questions from passers-by. (This doesn’t usually happen.)

CATEGORIZED UNDER: Internet, Science and the Media

Beam Day at the LHC

By John Conway | August 25, 2008 1:40 pm

September 10 is looking more and more like Beam Day for the LHC at CERN. The entire ring is now at superconducting temperatures, which means all magnets can in principle be energized.

Today CERN announced that the final “synchronization test” was a success, injecting beam from the older Super Proton Synchrotron into the LHC, where it was guided a few kilometers through the LHC vacuum beam pipe. (I also heard a story at Fermilab last week that on at least one occasion, while performing controlled beam oscillation tests, they oscillated a bit too much, causing some beam to enter one of the magnets, causing it to quench, that is, go from the superconducting to normal conducting state. This causes a great mechanical stress on the magnet, for which it is designed, but which you’d like to minimize. It won’t be the last time…)

So then what is Beam Day? It is foreseen as the day on which they will attempt to run the entire LHC and injection complex, and get beam to circulate stably in the accelerator. My understanding is that they will attempt to circulate in both directions (the LHC is really two accelerators in one) at the energy with which the protons are injected, 450 GeV. If successful, there will ensue a several week period of studies, finding all the idiosyncrasies of the machine. The goal is to make sure that when, hopefully in October, they crank the energy up, the proton beam bunches will remain stably orbiting on their nominal axis. During this period there may be brief periods when the beam bunches collide. This will give a much needed first glimpse of actual collision data to the experiments (but not a glimpse of any kin of new physics) and help us start to shake down the detectors.

I believe that the plan is still to accelerate in October to 5 TeV and collide with a center-of-mass energy of 10 TeV, five times that of the Tevatron. If things go really well, and we get a reasonably significant amount of collision data at those energies, and the experiments work at a basic level, we’ll get a great start on getting the detector alignment and calibrations done.

Could we see new physics with 10 TeV data? A safe answer is “probably not” but, to me, that means there is at least a tiny chance that if nature has something really striking in store for us at high energies, we might see it. For example, even with poorly calibrated and poorly aligned detectors, if there is a new resonance at very high mass which decays to pairs of quarks, then we might see a “bump” (oh no, not bump hunting again!) in the mass spectrum.

In fact it’s not really even possible to say whether such a thing is “likely” or not (Sean’s earlier musings notwithstanding) since it will either be there or not.

If it’s there, though, we will see it, and we never would have before. With more energy and more data next year we can look for more and subtler effects, any of which could profoundly change our view of space and time, energy and matter. That’s what makes this such an exciting time, after two decades of planning and building and preparing we’re finally going to get to see what we never could before.

If we re going to mortgage our children’s future, let’s mortgage it on things like the LHC.



By Sean Carroll | August 25, 2008 1:30 pm

I probably just shouldn’t go here, but the truth is that as soon as I read this:

Senator Obama would go a long way towards healing these wounds if he were to specifically praise the accomplishments of the Clinton presidency in a line or two during his speech on Thursday. That should be painless — he isn’t running against the Clinton legacy anymore, and it would probably be a good idea to remind voters that the last time Democrats were in charge of the White House, we had peace and prosperity. Similarly, he could thank President Clinton for all of the work he did throughout his life to bridge the divides in our country. This is a cause near and dear to the president’s heart.

what I was immediately reminded of was this:

In his memoir of his year in Baghdad as head of the Coalition Provisional Authority, L. Paul Bremer recalled that President Bush once told him that the leader of a new Iraqi government had to be “someone who’s willing to stand up and thank the American people for their sacrifice in liberating Iraq.”

Bremer noted that Bush made this point three times in the course of a single conversation and further insisted that the president of Iraq’s first interim government should be Ghazi al-Yawar, an obscure Sunni Arab businessman, because Bush “had been favorably impressed with his open thanks to the Coalition.”

Then again, my Mom always gives me a hard time for not being very good about sending thank-you notes. So it’s possible that serving as President simply equips one with a finely honed sense of the importance of expressions of gratitude, which my so-far non-Presidential life has deprived me of.


Book Your Flight

By Julianne Dalcanton | August 25, 2008 12:23 pm

Lonely heterosexual male physicists may wish to try their luck in New York City (via the consistently funny and frequently off-color Overheard in New York).

CATEGORIZED UNDER: Humor, Science and Society

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