Blogs / Cosmic Variance

Everyone’s talking about this Paul Krugman essay on where economics, as a discipline, went wrong. Partly, “going wrong” means the failure to appreciate the risks in our financial system, and the corresponding failure to predict the crash we’re currently trying to deal with. But from an insider’s perspective, something else has happened: an uneasy consensus between two different approaches to economics has been shattered. One, which Krugman labels the “saltwater” approach, is associated (in the U.S.) with some variety of post-Keynesian analysis, generally identified with some willingness to have the government intervene in the economy over and above the Fed’s control of the money supply. The other, the “freshwater” approach favored by the Chicago School and other inland economists, is more purely free-market and non-interventionist. (Truth in advertising: I am not an economist.) These camps could more or less get along when everything was going fine, but have dramatically different reactions to a crisis. To the extent that you find freshwater economists claiming that unemployment is currently high, not because there aren’t many jobs, but because there are too many incentives for people not to work.

One of the reasons it’s a great essay is that it’s a wonderful example of popularizing science. You can debate all you like about whether economics counts as a science, but there’s little doubt that Krugman does an amazing job at explaining esoteric ideas in non-technical language, and is so smooth about it that you hardly realize difficult ideas are even being discussed. I wish I could write like that.

One part of the essay worth commenting on, or at least musing about, is the punchline. Krugman thinks that a major factor leading to the failures of economics to understand the mess we’re currently in was the temptation to think that beautiful models must be right.

As I see it, the economics profession went astray because economists, as a group, mistook beauty, clad in impressive-looking mathematics, for truth. Until the Great Depression, most economists clung to a vision of capitalism as a perfect or nearly perfect system. That vision wasn’t sustainable in the face of mass unemployment, but as memories of the Depression faded, economists fell back in love with the old, idealized vision of an economy in which rational individuals interact in perfect markets, this time gussied up with fancy equations. The renewed romance with the idealized market was, to be sure, partly a response to shifting political winds, partly a response to financial incentives. But while sabbaticals at the Hoover Institution and job opportunities on Wall Street are nothing to sneeze at, the central cause of the profession’s failure was the desire for an all-encompassing, intellectually elegant approach that also gave economists a chance to show off their mathematical prowess.

Without knowing much of anything about the relevant issues, I nevertheless suspect that this moral might be a bit too pat. Sure, people can fall in love with beautiful theories, to the extent that they overestimate their relationship to reality. But it seems likely to me that the correct way of understanding all this, once it’s properly understood, will look pretty beautiful as well. General relativity is widely held up as an example of a beautiful theory — and it is, when understood in its own language. But if you put the prediction of GR in the Solar System into the language of pre-existing Newtonian physics (which you could certainly do), it would look ugly and ad hoc. Likewise, Newton’s theory itself is quite elegant, when phrased in the language of potentials on a fixed spacetime background; but if you express the theory in terms of differential geometry (which you could certainly do), it looks like a mess. Sometimes the beauty/ugly distinction between theoretical conceptions is more a matter of how well we understand them, and less about their intrinsic qualities.

So my counter-hypothesis would be that it wasn’t beauty that was the problem, it was complacency. If you have a model that is beautiful and works well enough, you’re tempted to take pride in it rather than pushing it to extremes and looking for problems. I suspect that there is a very beautiful theory of economics out there waiting to be developed, one that understands perfectly well that individuals aren’t rational and markets aren’t perfect. One that has even more impressive-looking equations than the current favored models! Beauty isn’t always a cop-out.

The mountains surrounding Los Angeles are on fire. One of the world’s largest metropolises has an uncontrolled wildfire at its very doorstep:

The Mount Wilson Observatory sits in the middle of the San Gabriel Mountains, and is visible on a clear day from many places in the Los Angeles basin. As you walk around Pasadena you can’t help but glance up at the dome, and imagine Hubble diligently performing his observations almost a century ago. By demonstrating that the nebulae aren’t in our galaxy, he ushered in one of the most humbling developments in the history of humanity. He showed that our galaxy is only one of many, and that the Universe stretches well beyond the limits of our familiar Milky Way. And, as if this weren’t insulting enough, he established that the rest of the Universe is running away from us at a tremendous clip.

The fire is now threatening this historic observatory. A live webcam (more commonly used to provide astronomers sky conditions [is it snowing?]) shows the view from the top (it occasionally goes down due to heavy traffic; if it doesn’t load for an extended period it may be a bad sign). Lots of smoke, but no flames at the moment. This is, of course, a chilling reminder of the 2003 fire at Mount Stromlo. You can follow the progress of the fire here. Perhaps our man on the ground will chime in with some live-blogging? Note: Phil is keeping us informed.

As it happens, many communication towers are also found on Mount Wilson. Should the fire sweep across the peak, communications for much of the Los Angeles area may be compromised. No cellphones. No TV. No LAX. Back to the stone age.

Although this looks like a still from a Hollywood disaster movie, it is much scarier. This is really happening. It is a sobering reminder that, despite our best efforts, Nature still trumps Man.

I didn’t get a chance to hear last year’s Caltech commencement speech by Robert Krulwich, and apparently I missed something good. This I gather from Chad Orzel’s Worldcon speech, which includes a great comparison due to Krulwich. I can’t really do any better than blatantly stealing three slides from Chad’s talk (although the whole thing is worth checking out).

The point of the comparison is to contrast two competing modes of scientific communication, as embodied by our two heroes. Here would be Sir Isaac:

Previously, back in Italy, Galileo had tried a different tack:

With, of course, notably different results:

Admittedly, this stretches the historical narrative a bit in the service of making a point. The divergence between Newton’s and Galileo’s career’s can’t be credited solely to their differences in publication styles. Galileo was a troublemaker by nature, while Newton was a good company man. (Although perhaps there is some correlation there with writing styles?)

But the punchline remains valid: Newtonian publication remains better for your career. And, implicitly, this hierarchy creates problems for the public understanding/acceptance of science. I would add that there’s certainly nothing wrong, all by itself, with scientific publications that are highly technical and inaccessible to a wider audience; those are always going to be a big part of the way science gets done. It’s not a moral failing to write jargon-filled manuscripts that are aimed at other scientists rather than at the general reader; in many cases, that’s simply the appropriate style for the work at hand. The failing is when that is the only kind of writing that is respected and rewarded. Encouraging a diverse portfolio of scientists and scientific publication would both increase the vibrancy of the field and lower the barriers between science and the rest of society.

Also, I would like a pony.

I’ve posted before about Galaxy Zoo, and see also Phil Plait’s posts introducting the zoo, oncounterintuitive results and what do to if you find something weird.

They had a pretty cool collective result recently, discovering tiny galaxies that are rapidly forming stars, that they call “green pea galaxies” (which is apparently a different sort of beast from the non-galaxy I called a green crayon in my initial post) — see here for more or here for the paper itself.

Anyways, Galaxy Zoo has just announced a new project, the supernova zoo.

This time, not only are we classifying galaxies, but we’re hunting supernovae : exploding stars. Images of likely supernova candidates captured by a telescope in California are being fed to our website at http://supernovae.galaxyzoo.org”. Astronomers are standing by in the Canary Islands to follow up on the most exciting possibilities, but
first we need your help to decide where to point the telescope. Please take the time to go to the site, read the tutorial – and then start hunting.

I have to say I love the image of “astronomers standing by”. I tried it (classifying supernovae, not standing by) — it’s pretty cool, and actually a bit challenging. What you actually do is answer a series of questions about a supernova candidate, to determine whether it’s a good candidate or just a messed up image.

Here’s an obvious good one:

And one where the candidate (right image) is distorted so it doesn’t look like a star.

To my mind it’s not nearly as interesting as the galaxy zoo, because images of galaxies are just way cooler than low-resolution images of supernovae (supernovae remants are another story of course). But it’s a great use of human eyes, and a pretty good way to waste a few lazy August afternoons. It will definitely be interesting to see if the data is useful enough to help the supernovae followup substantially.

Have at it! Maybe they’ll name the next supernovae “SN2009cosmicvariancereaders”.

White Americans, anyway. That seems to be the result from this poll at Daily Kos (via Tom Levenson’s Twitter feed).

Research 2000 for Daily Kos. 7/27-30. Likely voters. MoE 2% (No trend lines)

Do you believe that America and Africa were once part of the same continent?

         Yes    No  Not Sure

All       42    26    32

Dem       51    16    33
Rep       24    47    29
Ind       44    23    33

Northeast 50    18    32
South     32    37    31
Midwest   46    22    32
West      43    24    33

White     35    30    35
Black     63    13    24
Latino    55    19    26
Other     56    19    25

Probably readers of this blog are not a representative sample of Americans, and most or you — even the white people! — know that Pangaea was the supercontinent that existed about 250 million years ago, before plate tectonics worked its magic and broke it apart.

Now, some of my best friends are white folks, so I don’t want to make any grand generalizations about their intelligence or education. But this is a good illustration of a point made by Jerry Coyne — the problem of scientific illiteracy is not a simple one, and in particular it’s not just a matter of better outreach and more Carl Sagans. Which is not to say that more and better outreach and science journalism isn’t important or useful — it clearly is, and I’m in favor of making structural changes to provide much better incentives for making sure that it happens. But there are also factors at work for which outreach isn’t the answer — political and social forces that push people away from science. Those have to be confronted if we want to really address the problem.

(I don’t know who was the mischievous person who thought of asking this poll question in the first place, but it was an inspired idea.)

Update: Aaron Golas in comments points to a post by Devilstower laying out that the question was worded in an intentionally provocative way, to illustrate how bad questions can fail to correctly gauge scientific understanding. Which is completely true, and a point worth making. But I argue that the poll does reveal something, namely the extent to which underlying cultural attitudes can influence one’s stance toward purportedly scientific questions. Thus, “White People Have Trouble Accepting Pangaea,” not “White People Don’t Know About Pangaea.” As a measure of what percentage of Americans truly understand continental drift, the poll is pretty useless; as an indication of how culture affects that understanding, it’s very illuminating.

The Romantic period (roughly 1770-1830) was better represented by poetry than by science. On the poetic side, you had Keats, Shelley, Byron, Coleridge, Blake, Wordsworth, Goethe, Schiller, Pushkin, and more. On the science side, you had Michael Faraday, William Herschel, Humphry Davy, Erasmus Darwin; no slouches, to be sure, but you wouldn’t pick out this period as one of the golden ages of science.

But the interesting thing about this era, according to Richard Holmes’s new book The Age of Wonder: How the Romantic Generation Discovered the Beauty and Terror of Science, is that the scientists and the poets were deeply interested in each others’ work. That’s what I gather, anyway — not having read the book yet myself — from Freeman Dyson’s review in the New York Review of Books. It’s a provocative look into the cultural mindset of another time, when the power of science to discover new things about the world wasn’t yet quite taken for granted. Dyson quotes a stanza from Byron’s Don Juan:

This is the patent age of new inventions
      For killing bodies, and for saving souls,
All propagated with the best intentions;
      Sir Humphry Davy’s lantern, by which coals
Are safely mined for in the mode he mentions,
      Tombuctoo travels, voyages to the Poles,
Are ways to benefit mankind, as true,
Perhaps, as shooting them at Waterloo.

Scientists and poets don’t talk to each other as much any more (although there are exceptions). I tend to lament the fact that science doesn’t mingle more comfortably with other kinds of cultural currents of our time. Maybe it’s just not possible — we’ve become too specialized, leaving no room for a writer like Coleridge to proclaim “I shall attack Chemistry like a Shark.” But the more we scientists take seriously to share our ideas with the wider world, the more those ideas will take root.

Not all scientists work at universities. (Maybe not even most? I honestly don’t know the breakdown.) But people who do work at colleges and universities sometimes talk as if that’s all there is, or that becoming a professor is the only logical goal for those pursuing a scientific degree — not necessarily from snootiness or elitism, but just because that’s what they know.

So it’s great that Chad Orzel has done a series of short interviews with scientists outside academia, and is gradually blogging the results. It’s a nice little bit of informal sociology of the field, and a useful resource for anyone who might be contemplating such a career path themselves.

Chad, as you probably know, has also written a book that will be coming out later this year. And he’s supposed to be doing scientific research, and keeps up an active blog! How is that possible?

Here at Cosmic Variance we love our teaching moments. Science is everywhere, and there’s no need to be stuffy about it. One of the best ways to communicate the excitement that we feel about science to a much wider audience is to connect it to popular culture in all sorts of ways — whether it’s Buffy the Vampire Slayer, NUMB3RS, or Angels & Demons.

So it’s great to see the producers of ABC’s hit TV show LOST jump on the bandwagon. This fall they will be releasing the DVD collection of the fifth season, and the Blu-ray edition is going to feature a special treat: mini-”lessons” on various academic subjects related to the show. (The final season of the show begins early in 2010.) One of those subjects is time travel, and you have a pretty esteemed group of professors guiding you through this fascinating subject: Nick Warner of USC (who taught me general relativity back in the day), our old friend Clifford Johnson, and myself. Suffice it to say, I’ve seen the rough cut, and they did a good job — and we had quite a bit of fun. I was only included because having all the professors speak with British accents would have seemed a bit posh.

And along with that, they’ve just launched an associated website: LOST University. You can see what the other courses in the curriculum are going to be, including Philosophy and Foreign Languages. At the moment the website is essentially promotion for the DVD’s themselves, but I’m hoping more content will appear over time. LOST has a tradition of enhancing the show with quite elaborate online activities, in the form of alternate reality games. So hopefully this new site won’t simply be an advertisement — one of the lessons of new media is that giving away cool stuff for free makes it more likely that people will pay money for the even cooler stuff.

To be clear: the science of time travel on LOST does not necessarily obey all the rules. None of us had anything to do with the show itself, and I have no idea what the writers did in terms of seeking science advice. But understanding how the rules are broken can serve as fodder for teaching moments just as easily as seeing them obeyed. That’s life here “on the cutting edge of tomorrow.”

The last couple of weeks have seen our Department teeming with the participants in the Penn Summer Science Academy. This wonderful program, now in its twelfth year, is run by Bill Berner, who can also pull together any demonstration you may wish for in your classes. Guided by Bill, a number of other staff members and a local high school physics teacher, the students (”academically qualified high school students currently enrolled in 10th, 11th, or 12th grade”) go through an intensive physics experience for four weeks, including mini-courses, demos, research lectures, lab work and field trips, finishing up with a panel discussion on careers in science, featuring professionals from research, education, and industry.

On Tuesday I got to play a small part in this by delivering a lecture on modern cosmology

I am repeatedly amazed whenever I do something like this by how eager people are to hear about cosmology, and by the great questions they come up with that get to the heart of what is known and what is at the edge of our understanding.

In Tuesday’s lecture I didn’t even get to any of the more esoteric topics, such as inflation, although we did talk about cosmic acceleration a little, and discussed dark matter quite a lot. Lots of times when one talks about dark matter, people are fascinated by the particle physics possibilities – sometimes they’ve heard of supersymmetry, for example, and want to understand what dark matter might have to do with it. But interestingly most of the questions I got yesterday were empirical in nature, concerning how we know what we know about dark matter, and why we think it behaves the way it does. This is, of course, as it should be. It might be a consequence of this being an experimentally focused program, but whatever it is, it is clear that Bill and everyone else is doing a great job.

It doesn’t take much time to take part in something like this – an hour of lecture and thirty to forty minutes of discussion afterwards. And it is immensely fun and rewarding. If the students enjoyed themselves half as much as I did then I’ll be delighted.

Forty years ago today Neil Armstrong did what no other member of our species had ever done before when he stepped from the ladder of the lunar lander onto the surface of the moon.

This was an outstanding achievement, by any measure, and one that has become emblematic of what we are capable of. I couldn’t possibly do justice to what it must have meant to people at the time – I was just a few months old when this took place – but there are wonderful accounts all over the web, and I’ve been enjoying reading almost all of them. I’m sure I would have had the same emotions on that day if I hadn’t been busy drooling, filling my diaper, and being forced to take a nap.

Along with these initial reactions to the event, I’ve also been reading other accounts of how the directions of people’s lives were driven by the moon landing. These are also fascinating, and I have been particularly interested by scientists who feel that it was this event that helped fuel their interest in science, because my own experience was somewhat different.

Although I had a healthy interest in science (as well as a lot of other subjects) from an early age, I have never felt that the space landings had an effect on it. I was certainly enthralled by the space program, read magazines about it, and the newspapers, and watched anything that was shown on television about it. I thought about being an astronaut, and fantasized about the excitement of traveling to other planets and beyond. Star Trek presumably had a hand in all this. But what grabbed me was the exploration, and the adventure. Not the science.

My current view is that while there may be a reasonable argument for the manned space program on the basis of exploration (and I find the idea exciting myself), it is hard to make a scientific argument for it. I often hear the argument that the space program is nevertheless useful to science because it inspires people to become scientists, or at least to be interested in science. This must be true at some level, but I’ve never found it a compelling argument. Nevertheless, this isn’t the point I’m trying to support with my comments above – clearly many scientists have felt inspired to be scientists by manned space travel. It just happens that I wasn’t one of them.

In any case, having been suitably serious, awed and humbled by the heroic endeavors of NASA, Armstrong, Aldrin, Collins and those who followed them, I thought I’d leave you with something a little lighter. Here’s British transvestite comedian Eddie Izzard’s (NSFW, due to some naughty language) take on how the astronauts could have made the moon landing even more entertaining.