style and substance

There was an interesting article in the New York Times over the weekend, a "Critic's Notebook" by one Edward Rothstein comparing the very different approaches to science education and outreach adopted by two leading science museums in California: the incomparable Exploratorium in San Francisco, and the slightly lesser known Tech Museum of Innovation in San Jose. Per the rather dualistic Rothstein's analysis: one focuses on experiment, the other on sensation; one pretty much ignores technology, the other unabashedly celebrates it; and one focuses primarily on substance, while the other shows a fondness for showy style. But both are facing unique challenges and major overhauls under the authority of new incoming directors.

It's no secret that we adore the Exploratorium here at Cocktail Party Physics, and we are not alone in our admiration: it is one of the most revered science museums in the country, and hugely popular with the public, enjoying half a milion visitors each year. Rothstein rightly praises the creativity of its exhibits, each of which conveys fundamental scientific concepts in clever, participatory ways. For instance, there's a water fountain with a copper-plated switch, so that when your lips touch the liquid, you complete an electrical circuit, causing music to be heard. How cool is that? Yet for all its creativity, he finds the Exploratorium somewhat dated in its subjects, musing that perhaps this is because things like nanotechnology and string theory are extremely difficult to demonstrate in a hands-on fashion.

The Tech Museum also employs hands-on exhibits and simulations, but Rothstein is less of a fan, criticizing its showier style and emphasis on the "Wow" factor of cutting-edge technology. These Times reporters can be such culture snobs; Jen-Luc Piquant considers them comrades-in-arms, paddling fiercely against the tide of crass consumerism and glitzy pop culture that Threatens The Very Foundations of Establishment High Culture. My tastes are much more plebeian.I have not visited the Tech Museum personally, but the chance to design my own roller coaster and then experience a simulation of that created motion seems like a pretty nifty idea. The building itself is certainly an impressive structure, featuring 132,000 square feet of exhibit space with its own IMAX theater. Alas, in the wake of the Silicon Valley crash, it has been attracting fewer visitors — and most of those come for IMAX films, not the hands-on exhibits.  And as the venture capitalist funds have dried up, some of the exhibits have apparently fallen into disrepair.

So the main criticisms of these two fine facilities is that one is hopelessly dated, and the other poorly maintained.  Rothstein's strict demarcation strikes us as a bit overly simplistic, but he offers what may be perfectly valid criticisms. Still, it all depends on one's perspective. We're frankly a bit spoiled here in the US; we take cutting-edge science museums for granted.

Regular readers may recall that last month we took a much-needed vacation to Buenos Aires. Among the local attractions we visited was the Planetario Galileo Galilei. It stands on the former 19th century cricket grounds where the city's first soccer team played, and its unique structure — our hosts described it as "a giant ice cream scoop" — was designed by famed Argentine architect Enrique Jan. It's basically a big dome resting atop three "legs," looking for all the world like it could spring into motion at any moment, laying waste to the city by shooting deadly laser beams from its dome. (Hey, it could happen! Just like the giant towers topped by flying saucers that turned out to be fully functional in the exciting climax of Men in Black!) The planetarium is also home to a surprisingly large number of stray cats, who  blithely scale its legs and railings and shamelessly beg  visitors awaiting admittance for scraps of food.

Compared to the Exploratorium and Tech Museum, it's not much to look at it. And the exhibits are practically carbon-dated: the highlights are a 3,390-pound chunk of meteorite and a replica of the first lunar module. There's a daily A/V show designed to illustrate the origin of planets and constellations, focusing on celestial things routinely visible in the southern hemisphere. But forget about IMAX: the antiquated projection equipment shows what appears to be recycled footage from old 1970s educational films. And you want to talk about disrepair? The restrooms are practically falling apart. We braved the ladies' room, having foolishly consumed a large bottle of "Coca-Lite" before the show, and one of the stall doors nearly fell off its hinges during our brief foray.

In short, the facility appears to be lacking in both style and substance. Yet for all its shortcomings by US standards, the planetarium is hugely popular with the local residents. We went to an evening showing on a Tuesday night, and barely got in: the place was packed, not just with schoolchildren, but families, teenagers on dates, even a few random solo adults — a fine random sampling of the city's inhabitants. Some people were turned away at the door, and seemed genuinely disappointed. It warmed our hearts to see so much local support and enthusiasm for the planetarium, and made us wish we were filthy rich so that we could make generous donations to allow the place to update its content, projection technology, and fix the decrepit bathrooms. Because the people of Buenos Aires deserve a better facility, gosh darn it, to foster their genuine interest in the night sky.

It's doubly ironic because Argentina just happens to be home to one of the most cutting-edge astrophysical observatories in the world:  the Pierre Auger Observatory, located hundreds of miles from Buenos Aires in the Mendoza Province — too far for us to visit during our brief stay, although we would have loved to do so. It's a $50 million facility spanning 1160 square miles of terrain on the Pampa Amarilla ("yellow prairie"), devoted to detecting and analyzing cosmic rays. The facility is named in honor of Pierre Auger, a University of Chicago physicist who memorably launched hot-air balloon experiments from the university's Stagg Field as part of his study of cosmic rays.

For the uninitiated, cosmic rays are charged particles that constantly rain down onto the earth from space. When they hit our atmosphere, they collide with other particles and shatter, dividing their energies between showers of secondary particles, which in turn decay into a third generation of particles, and so on. By the time we detect them, most of these have fairly low energies. But on October 15, 1991, scientists at the University of Utah's Flye Eye Cosmic Ray Detector observed a particle with energies on the order of 50 joules — more than a hundred million times more energy than the particles created in our largest particle accelerators, lie Fermilab's Tevatron. Extrapolate that to the macroscale, and it's equivalent to the kinetic energy of a baseball traveling about 60 MPH. That makes them the most energetic subatomic particles in the known universe.

Physicists were flabbergasted. It wasn't a fluke, either: some 15 similar events have been observed since then.  Astrophysicists call these high-energy cosmic rays "cosmic bullets," or (more cheekily) the "oh-my-god" particle. (It's a physics in-joke: the nickname of the hypothetical Higgs boson, believed to give matter mass, is the "god particle.") And they have no idea where they come from. Okay, they have some ideas about it, but there are competing theories, all of which have yet to be verified by convincing experimental evidence.

One idea is that they come from jets of matter spewed out by supermassive black holes, or are simply particles that have been accelerated to almost unimaginable velocities by the magnetic fields of spinning neutron stars. The more exotic theories hypothesize about effects stemming from extra dimensions of space, or so-called "topological defects" in the fabric of spacetime, akin to faulting and folding in the earth's crust. We haven't really been following the latest results on high-energy cosmic rays; in fact, the Auger Observatory has only just become fully operational this year, although it began taking data in 2004. But in January 2005, a physicist named Glennys Farrar reported on tracing five very similar high-energy cosmic rays (detected between 1993 and 2003) to a pair of colliding galaxy clusters 450 million light years from Earth, adding credence to the argument for acceleration by powerful magnetic fields.

It's going to take a lot more data before scientists can make any kind of scientifically compelling determination. The catch is that high-energy cosmic rays are  quite rare, and therefore difficult to detect. Statistically speaking, only about one of these lively little particles is likely to strike any given square kilometer (that's six-tenths of a mile, for those of us living in non-metric nations) every century. That's why the Auger Observatory spans such a broad area. It also combines two different detection techniques, in hopes of resolving conflicting findings from the two previous major experiments.

One technique is the deployment of fluorescence telescopes to detect the ultraviolet light such cosmic rays generate in the earth's atmosphere. The second involves scattering lots and lots of plastic water tanks that serve as ground detectors. Every now and ten, a cosmic ray will land in one of the detectors, and when it does so, its speed will change as it crosses from traveling through air to water. It will emit a telltale flash of light, which will be duly recorded and analyzed. (Those who long to know even more of the details can check out this excellent video interview with University of Chicago's Angela Olinto.)

You won't find an exhibit or A/V presentation on high-energy cosmic rays in the Planetario Galileo Galilei. But in fairness, you won't find them in the Exploratorium or Tech Museum either. The research is that cutting edge. Still, we would argue that this is precisely the sort of thing that should be included in science museums, especially those that purport to deal with celestial matters.  Teaching the basics is important, it's true, as is highlighting technological marvels. But it's possible to easily get both style and substance if the "Wow!" factor of a given exhibit comes from a genuine scientific mystery that researchers are in the process of investigating. At a time when the public's grasp of the scientific method is at an all-time low, this is a great opportunity to show them that very method in practice.

We hope the new directors of the Exploratorium and Tech Museum take such considerations into account as they're overhauling those facilities. And while we're waiting for some well-heeled benefactor to come to the aid of the Buenos Aires planetarium, Argentines can take pride in the presence of the sleek new Auger Observatory. Judging by how avidly they support their humble planetarium, they'd be visiting the small remote town of Malargue in droves, by the busloads, given half a chance.