End of Days

November 07, 2009

Are you ready for the End of the World? Master of the Apocalyptic Blockbuster Roland Emmerich unveils his latest doomsday disaster on Friday November 13: 2012, starring John Cusack as sci-fi writer Jackson Curtis, a divorced father who occasionally moonlights as a limousine driver. First come the mass suicides in Guatemala in anticipation of the end of the world. Then vast cracks are found in California fault lines; Curtis saves his ex-wife, child and her new boyfriend in the nick of time as Los Angeles crumbles into the sea. Rio, Washington DC, and the Vatican in Rome are all destroyed in short order. Oh, did I mention the sooper sekrit society that is constructing giant arks in the Himalayas to save a small fraction of humanity from impending doom? It's all delivered in Emmerich's trademark cataclysmic style (what io9 has dubbed "disaster porn"). Check it out:

The film's premise derives from a popular doomsday prediction centered on the Mayan calendar. It lasts 5126, at which point the calendar abruptly stops at December 21, 2012. For whatever reason, the Mayans didn't bother to count any further, leading certain highly imaginative, rather hysterical types to conclude this denotes the End of the World.

2012 conspiracy theorists have also bundled in the notion that this global destruction will occur when the legendary Planet X crashes into Earth. Astronomers were intrigued by the possibility in the mid-19th century, shortly after the discovery of Neptune -- they thought it might explain perceived discrepancies in the orbits of the great gas giants. Pluto, discovered in 1930, was initially heralded as Planet X, but it turned out to be too small to effect the orbits of the gas giants. Heck, it's not even technically a planet any more. (There is a dwarf planet called Eris just beyond Pluto, but it's in a stable orbit and isn't going to crash into Earth.)

And because you can never cram too many crazy ideas into a single Disaster Hoax, there are some people who believe Planet X is actually the mythical Nibiru, supposedly known to ancient Sumerians, which has a highly elliptical orbit and passes into our solar system every 3600 years. Earth itself, according to this crackpot theory, was created from a collision between Nibiru and some other object in the asteroid belt. Oh, Nibiru also doubles as a "spaceship" of sorts, in that an alien race supposedly traveled to Earth during one of its passes and founded the human race.

There isn't a shred of evidence for any of this, of course, and any number of articles and blog posts have been written debunking the nonsense -- along with Neil de Grasse Tyson, who does so with typical good humor in the clip below. That doesn't mean we won't thrill to the sight of a cinematic end of the world, because who doesn't love a good disaster flick now and then? But we should really focus our doomsday anxieties to more realistic scenarios.

WiFi in the Sky

November 03, 2009

Quick question: what do black holes and your laptop's WiFi connection have in common? A recently honored astronomer and engineer named John O'Sullivan has the answer. There are lots of astronomy related prizes out there, but the 2009 Australian Prime Minister's Prize for Science, awarded to O'Sullivan, is noteworthy because its impact has been felt far beyond the field of astronomy and astrophysics.

See, way back in 1977, O'Sullivan co-authored a technical paper about how a set of equations known as Fourier transforms could be used to improve the optical images from telescopes that had been distorted by the atmosphere. Fourier transforms are central to modern digital signal processing: they essentially take complex wave signals and break them down into their component parts. Once the "recipe" is known, it is possible to rebuild the signal, or build a signal that effectively cancels out the noise in collected data. Fourier transforms can be applied to any wave: sound waves, water waves, and light waves.

O'Sullivan developed his techniques because he was searching for radio waves emitted by exploding black holes -- a phenomenon predicted by Stephen Hawking in 1974. O'Sullivan didn't find those objects, despite his success cleaning up the distorted inter-galactic radio waves; the remnants of those radio emissions were simply too faint. But his techniques are now central to the wireless Internet revolution, making it possible for us to surf the Web without those pesky cable hookups -- and relatively free of distortion and interference from other radio sources.

So I congratulate O'Sullivan on being so honored, and thank him not just for my wireless connection, but also for improvements to radio astronomy that have yielded images like those below of the galaxy at the center of the Perseus cluster, courtesy of the Chandra Observatory. (The first is a composite image combining optical, x-ray and radio wave imaging; the second is the isolated radio wave image.)

Felicia Day, Cosmic Buzzkill

October 26, 2009

Via io9 and uber-fanboy Phil Plait, here's a genuine treat: actress and all-around Web goddess Felicia Day (Dr. Horrible's Sing-Along-Blog, The Guild) shows off her science chops in a new PSA from the Spitzer Science Center on behalf of the Spitzer Space Telescope. Apparently there was a bit of public consternation earlier this year when the folks at Spitzer announced the "imminent" collision of two distant galaxies.

Our intrepid heroine battles condescension and sarcasm from a highly misguided director -- not to mention awkward cameo voice-overs from Sean Astin -- to reveal the far less scary truth about what really happens when galaxies collide. "Once again, Felicia Day sucks all the fun out of our film," the director snipes; she clearly finds truth to be a buzzkill.

But wait! Maybe it's not entirely the director's fault! Consider the slightly sensational tenor of the opening paragraphs of the press release the Spitzer folks issued back in March:

A new image from NASA's Spitzer Space Telescope offers a rare view of an imminent collision between the cores of two merging galaxies, each powered by a black hole with millions of times the mass of the sun. The galactic cores are in a single, tangled galaxy called NGC 6240, located 400-million light years away in the constellation Ophiuchus. Millions of years ago, each core was the dense center of its own galaxy before the two galaxies collided and ripped each other apart. Now, these cores are approaching each other at tremendous speeds and preparing for the final cataclysmic collision. They will crash into each other in a few million years, a relatively short period on a galactic timescale. [emphasis mine]

No wonder the Spitzer Science Center found they needed a PSA to correct public misconceptions. The universe is an awe-inspiring place, and I'm all for punching up the prose stylings a bit when communicating science broadly. But if you describe colliding galaxies as "cataclysmic," don't be surprised if there are a few directors out there who get the wrong idea. As Felicia herself points out (in the name of Joss Whedon), real science is pretty darn cool all on its own. You don't need to punch up the verbiage quite that much.

Brueghel's Telescopes

October 13, 2009

History books generally identify the inventor of the telescope as one Hans Lippershey, an eyeglass maker in the Netherlands in the late 16th century. The story goes that Lippershey saw a couple of children playing with lenses in his shop, and overheard them exclaim that looking through the lenses made a nearby building seem larger.

Lippershey experimented a bit further, and built a device he called a "looker," using a convex objective lens and a concave eyepiece. Galileo snagged an early version of the telescope as it spread through Western Europe, and improved the design to make the first observations of the moons of Jupiter, among other momentous findings.

But Johannes Kepler suggested the instrument could be improved even more in 1611 by using a convex eyepiece, resulting in a wider field of view. Nor was it necessary any longer to plate the eyepiece so close to the eye of the observer. The only disadvantage: the resulting image is inverted. Astronomers adapted accordingly. The first Keplerian telescopes were believed to appear around 1631.

Of course, there is evidence that Lippershey may not have been the first to build a telescope after all. His 1608 patent application was denied because the knowledge that combinations of lenses could magnify objects was already well known by that time. And now Kepler's own contribution to the development of the telescope is coming into question, according to astrophysicists at the Instituto Nazionale di Astrofisica in Trieste. The evidence can be found in a painting by a Flemish artist named Jan Brueghel the Elder, which depicts a telescope of Keplerian design even though the canvas was painted a good 15 years before its supposed invention.

Paolo Molaro and Pierluigi Selvelli have studied five paintings by Brueghel depicting telescopes, and maintain the artist made the first such representation of the telescope in his work, "Extensive Landscape with View of the Castle of Mariemont." Brueghel was court painter to Archduke Albert VII of Habsburg, and it just so happens that Lippershey gave one of his earliest telescopes to Albert. Molaro and Selvelli believe the telescope in the painting is, in fact, that particular instrument.

Another painting, "The Allegory of Sight," depicts a telescope that seems very much to be of Keplerian design -- except the canvas dates from 1617, well before the first Keplerian telescopes supposedly were built. Molaro and Selvelli base their conclusion on the length of the painted instrument -- is is longer than the earlier Galilean designs, just like Kepler's telescopes -- and the size of the eyepiece, designed to limit how close the eye can be brought to the eyepiece lens.

It's always a bit risky to draw scientific conclusions from works of art: all artists take liberties with their subjects when creating a painting, after all. But sometimes historical paintings can offer tantalizing clues, particularly when so little is known about an era. I guess we'll have to wait and see if art (or science) historians manage to dig up some corroborating evidence to support Molaro and Selvelli's hypothesis. In the meantime, it certainly makes for an intriguing premise.

Ring Around the Planet

October 01, 2009

From the "In Case You Missed It" department, last week Dennis Overbye wrote a lovely profile of astrophysicist Carolyn Porco for The New York Times. The honor is justly deserved: Porco trailblazed a path for women in space science as part of the team that analyzed data from the Voyager spacecraft in the 1980s. She "demonstrated a knack for picking out important things," according to her thesis advisor, Peter Goldreich.

Mentored by Carl Sagan, among others, Porco now heads the camera team for the Cassini spacecraft, currently orbiting Saturn (as it has been for the last five years). She's also actively involved in science communication and outreach, both through the usual channels, and via Hollywood. She was a consultant on the film Contact, and more recently, for J.J. Abrams' summer blockbuster, Star Trek. Remember when the Starship Enterprise materialized inside clouds around Titan? That was Porco's contribution, and it made the cover of Cinefex, a publication devoted to special effects in the movies.

"To my mind, most people go through live recoiling from its best parts," Porco told The New York Times. "They miss the enrichment that just a basic knowledge of the physical world can bring to the most ordinary experiences. It's like there's a pulsating, hidden world, governed by ancient laws and principles, underlying everything around us -- from the movements of electrical charges to the motions of planets -- and most people are completely unaware of it. To me that's a shame." A shame, indeed.

As impressive as Porco is, Saturn and its amazing rings are even more impressive, even more so when one sees the latest mind-boggling imagery from Cassini. In the words of Bad Astronomer Phil Plait:

That, duh, is Saturn, taken by the ever-amazing Cassini spacecraft. It’s actually 75 different exposures stitched together, and was taken on August 12, just a little over a day after Saturnian equinox, when the Sun shines straight along the rings. The illumination from the Sun is about the same everywhere, but on the left the rings are illuminated by Saturn-shine glowing down on them, making them a bit brighter.

You can read more about this latest incredible image of the ringed planet over at Phil's place, which includes a link to the full, mega-pixel image. And you can hear about Cassini, Saturn and the glories of space exploration from Porco herself (via TED, currently the go-to site for all the best cutting-edge science communication):

Titan is a Gas

August 13, 2009

Titan has been making a bit of news over the last week. It is Saturn's largest moon, and the only moon in the solar system that boasts an atmosphere much like Earth's, along with an actual weather cycle: clouds and rain, just like Earth, except on Titan the clouds and rain are made of liquid methane. Weather is why it's in the news: a new paper in Nature describes the very first storm observed on Titan, courtesy of NASA's Infrared Telescope Facility and the Gemini North telescope in Hawaii.

The Dutch astronomer Christiaan Huygens discovered Titan in 1655, inspired by Galileo, who had used the then-newly-invented telescope 40 years earlier to discover four moons of Jupiter. But it wasn't until Voyager 1 and 2 that scientists began to suspect the moon had seas of liquid methane. Data from Hubble provided more evidence in 1995, and Cassini-Huygens spacecraft confirmed lakes of methane and ethane in 2007 and 2008, respectively.

But nobody is quite sure how the methane got there, since methane breaks down rapidly into other organic molecules when it's hit by sunlight. It would need to be replenished somehow.

There are two prevailing theories: chemical reactions from iron or magnesium beneath the Titan's surface, or occasional emissions from melting methane ice in the moon's interior -- geologic "belches," if you will. A new paper by planetary geologists suggests that recent measurements of the hydrogen/deuterium ratio in the methane is much better explained by the second hypothesis. And they think the same sort of primordial methane should also have formed on one of Saturn's other moons, Enceladus.

Regardless of where it came from, Titan's unique methane atmosphere and ethane oceans makes it among the leading candidates for some form of extraterrestrial life -- although that life form may be very different from ours. And that's the topic of the third Titan-related paper that's appeared recently. Jonathan Lunine of the University of Arizona argues that the conditions that exist on Titan might not be as unique as those on Earth. So he figures that if there's life on Titan, that same kind of life is far more likely to exist elsewhere.

It's certainly an intriguing premise. Lunine isn't the first to argue that "life" outside our pretty blue planet might look very different from what we find on Earth, and he probably won't be the last. Time will tell if Lunine's hypothesis can give alternate hypotheses like panspermia a run for their money.

They Might Be Scientists

July 22, 2009

Quirky pop band They Might Be Giants have come a long way from playing underground clubs on New York City's Lower East Side, having been featured on MTV and penning the title song for the TV sitcom Malcolm in the Middle. They've also delved into the world of children's music, releasing Here Come the ABCs in 2005 and Here Come the 123s in 2008 in DVD/CD sets. And how they're all set to release Here Comes Science, with catchy tunes about the periodic table, photosynthesis, the planets, the color spectrum and more.

It seems like a natural venue for TMBG's John Flansburgh and John Linnell, since one of their best-known tunes is "Why Does the Sun Shine?", containing the immortal lyrics, "Oh, the sun is a mass of incandescent gas/A giant nuclear furnace..."

Well, it turns out that science has come a long way since the tune was originally written (by Tom Glazer, not by TMBG, who covered it). So they've updated the tune for the new children's album, "Why Does the Sun _Really_ Shine?" The critical change in the lyrics: "Oh, the sun is a miasma of incandescent plasma..." Hmmm. I'm not convinced it scans quite as well. This might be an argument for taking the occasional liberty with the science for artistic purposes.

Still, since it is an educational album, it's probably a good thing the two Johns hired Eric Siegel of the New York Hall of Science -- a children's museum in Queens -- to vet the lyrics for the upcoming DVD/CD set. Per Flansburgh: "Frankly, I was a terrible science student in high school. My last memory of the periodic table was right before I lost consciousness."

The tantalizing song titles include "Meet the Elements," "Roy G. Biv," "Photo Synthesis," "Speed and Velocity," and my personal favorite, "The Ballad of Davy Crockett in Outer Space." That's already been making the rounds of YouTube, and the adventures of everyone's favorite buckskin astronaut is well worth including here:

Twinkle, Twinkle, Neutron Star

June 16, 2009

Neutron stars are mysterious beasts. Sure, astrophysicists know they're the result of a massive star compressing during a supernova and collapsing in on itself. And they know it retains most of its angular momentum in the process, and has an incredibly high surface gravity. But they don't know what exactly the surface of a neutron star is made of, although it's clear that iron plays a role -- our instruments have detected the telltale spectral signature of iron in emissions from these objects. Nor is it clear whether the iron is in gaseous form, thereby forming a sort of "atmosphere," or whether it forms an ultra-hard solid crust.

A couple of weeks ago, a paper appeared on the arXiv with an intriguing means of telling the difference. Two Spanish scientists at the Universidad Complutense in Madrid conclude that if the iron in a neutron star is solid, it will form a rare and unusual crystal that is perfectly smooth and would envelop the entire star. And they've devised a method to test this by studying the surface of neutron stars using x-ray crystallography.

The idea is to look for binary neutron star systems: one "dead," with an iron crust, the other an x-ray pulsar. X-ray emissions from the pulsar should hit the surface of its partner, and those rays should be diffracted and thus detectable by our terrestrial instruments. Assuming they can find these sorts of couplings -- roughly 5% of neutron stars belong to binary star systems -- scientists could learn a great deal more about the structure and behavior of neutron stars.

There could be yet another means of studying the structure of neutron stars: observing the frequency spectra of stellar oscillations, more commonly known as "starquakes." There is actually a subfield known as asteroseismology, although it specializes in ordinary stars. Neutron stars also have these sorts of seismic events, in which the stiff surface crust ruptures much like terrestrial (tectonic) earthquakes. It happens because as a neutron star ages, its rotation gradually slows down, and its shape becomes more spherical through a series of stellar quakes.

Stellar quakes also cause neutron stars to flare brightly temporarily with so-called x-ray oscillations. Astrophysicists think this is because after the quake, the equatorial radius is slightly smaller; neutron stars spin and thus have angular momentum, which must be conserved. So the extra energy is released as x-rays.

That's bad news for x-ray satellites, since they are momentarily blinded by the light. But it's good news for the x-ray photons themselves, which finally have sufficient energy to overcome the star's immense surface gravity (about 10<11> times that of Earth) and escape. Sometimes photons need their freedom, too -- it's a big, big universe out there.

Photo:  An artists's concept of the 2004 occurence in which a neutron star underwent a "star quake", causing it to flare brightly, temporarily blinding all x-ray satellites in orbit. Source: NASA. Public domain.

Dream a Little Dreaming

June 05, 2009

England has its Stonehenge, and Australia has Wurdi Youang, an egg-shaped ring of stones just outside of Geelong. It was built by the Wathaurung people -- long before the arrival of European settlers --and measures a good 50 meters across. And as with Stonehenge, no record exists of why the ring might have been built, or how it was used. But according to a new paper appearing this week on the arXiv, it might just be an example of Australia's earliest form of astronomy.

Aboriginal mythology is largely associated with the "Dreaming," an ancestral world of spirits who are still manifest in the night skies. Certain nomadic Aboriginal Australians apparently used the sky as a kind of calendar to determine when it was time to on to a new site, for example. And the various Aboriginal cultures across the huge continent share some common threads in their mythology. For instance, there is a female sun warming the land, and a male moon who starts out slim (the crescent moon) and grows fat as he ages (full moon), then dies to begin the lunar cycle again (new moon).

A cultural historian named John Morieson noticed a few years ago that, when viewed from three of the most prominent stones, the smaller outlying stones corresponded rather well with the position of the setting sun during equinoxes and solstices. Enter astrophysicist and astronomer Ray Norris, who confirmed those observations and co-authored the new paper with his colleague Duane Hamacher at MacQuarie University in Sydney.

Granted, the hypothesis has its skeptics, and even Norris insists that other similar sites with stone rings are needed before it becomes truly viable. For instance, the placement of the stones is accurate enough to within a few degrees, but the alignment could very well have occurred by chance. "The problem with all of this stuff is that you are never 100% certain -- are we constructing something with our 21st century minds that wasn't actually intended by the people who built it?" Norris admits, but believes there is sufficient evidence regarding Wurdi Youang indicating the tribe did know the astronomical significance of those directions.

Less convincing, according to Norris, is the arrangement of stones known as Ngaut Ngaut, located on the banks of the Murray river just north of Adelaide. It, too, has some hints of astronomical connections, most notably engraved images of the Sun and Moon, plus a series of mysterious dots and lines carved into the rock, believed to show the "cycles of the moon." The problem is that Norris and others haven't had much luck cracking this ancient symbolic "code." Until they do, the "evidence" is circumstantial at best.

Nonetheless, the entire question of Aboriginal astronomy is fascinating -- sufficiently so that Norris and a few colleagues from various disciplines have started the Aboriginal Astronomy Project to answer a few key questions:

(1) Are there cultures in which the astronomy is a central feature rather than lying on the periphery?

(2) Is there evidence that the complex motions of the sky have been recorded either verbally or in rock art or stone arrangements? and

(3) Is there evidence that transient phenomena such as supernovae, comets and meteors were recording?

The answers to those questions are still pending, but I like the idea of an investigation involving astronomers, archaeologists, anthropologists, and some of the indigenous peoples themselves (a few have appeared as co-authors on the group's journal publications). And the Melbourne Planetarium is apparently working with Norris on a new presentation about indigenous astronomy. If the group's working hypothesis is eventually borne out, that would make Aboriginal Australians -- already the world's oldest culture, dating back some 50,000 years -- the world's earliest astronomers.

Photos: (top) Arrangement of stones at Wurdi YouangT. (bottom) Engravings at Ngaut Ngaut. Source: Aboriginal Astronomy Project.

To the Moon

June 02, 2009

Regular readers know that my day job is director of the National Academy of Sciences' Science and Entertainment Exchange, boldly connecting scientists with writers, producers and directors in Hollywood in hopes of fostering ever-more-creative collaborations. And the Exchange now has its very own blog, The X-Change Files (natch!), with contributions from yours truly, as well as an impressive roster of leaders in both science and entertainment: husband/wife producer/director team Janet and Jerry Zucker (the Airplane movies, Ghost); Matt Partney, a writer for C.S.I.: Miami; Lawrence Krauss (author of The Physics of Star Trek); and Sidney Perkowitz (author of Hollywood Science).

We'll be covering all aspects of the intersection of science and entertainment -- aspects like a fantastic new film coming out June 12 called Moon. It's just the sort of quality filmmaking with a scientific bent that the Exchange hopes to promote even further. Written and directed by Duncan Jones (who also happens to be David Bowie's son), the film tells the story of Sam Bell (Sam Rockwell), a lonely lunar miner on the dark side of the moon, whose only companion is a robot named GERTY (sinisterly voiced by Kevin Spacey, with a nod to HAL). Sam is just finishing a three-year stint of unrelenting isolation -- and it all goes to hell in record time, as the clip below makes clear.

Would-be lunar colonizers, beware!