Monday, March 31, 2008

A little bit of knowledge...or 21st century luddites

So, there is an article in the New York Times that discusses two men filing a lawsuit to stop CERN from operating the Large Hadron Collider:

Walter L. Wagner and Luis Sancho contend that scientists at the European Center for Nuclear Research, or CERN, have played down the chances that the collider could produce, among other horrors, a tiny black hole, which, they say, could eat the Earth. Or it could spit out something called a “strangelet” that would convert our planet to a shrunken dense dead lump of something called “strange matter.”

It actually worries me a little bit that this was such a popular article in the New York Times. Dennis Overbye is an excellent science writer, in my opinion, but I do worry a little bit that people who read the article won't understand the infinitesimal possibilities of what Wagner and Sancho are suggesting. Journalists in general tend to give equal weight to opposing viewpoints (and in general I suppose that is sound journalistic principle), but in science journalism, it is often disingenuous to give equal weight to say, the flat earth society against 100% of geologists who can show that the earth is spherical.

As one reads the article, however, it is very clear that Wagner and Sancho are woefully unable to make a cogent argument against the collider. Wagner "studied physics and did cosmic ray research at the University of California, Berkeley, and received a doctorate in law," while Sancho "describes himself as an author and researcher on time theory." I am not suggesting that I understand all the physics or possibilities of what could happen while operating the LHC, but I am comfortable suggesting that Wagner and Sancho certainly don't. They seem a bit like 21st century luddites, scared of the future.

My favorite line of the article is the concluding paragraph, which makes very clear what the reporter Mr. Overbye thinks of the lawsuit,
Dr. Arkani-Hamed said concerning worries about the death of the Earth or universe, “Neither has any merit.” He pointed out that because of the dice-throwing nature of quantum physics, there was some probability of almost anything happening. There is some minuscule probability, he said, “the Large Hadron Collider might make dragons that might eat us up.”

Saturday, March 22, 2008

Gamma ray burst observed from billion light years away

On 19 March the NASA Swift satellite observed a fifth magnitude gamma ray burst in the Bootes constellation. It was a remarkable discover, because the red shift of the observation suggests that the explosion originated seven billion light years away, sent at a time that the universe was only half its current age. Seven billion years ago, when this light was emitted, neither the Earth nor the Sun had been formed.

However, one of the overlooked aspects of this discovery is the swiftness (pun intended) with which the astronomical community responded to observing this gamma ray burst, which was visible with the naked eye for only about an hour before it faded. After Swift discovered the burst, it sent automated announcements to a network of world-wide telescopes, which in turn started to observe the burst. For short lived astronomical occurrences, such as gamma ray bursts or planetary microlensing, mobilizing a world wide network of telescopes means the difference between getting continuous observations versus getting eight hours broken with no observations for 16 hours.

This automated coordination gives astronomy a significant advantage in capture every possible interesting phenomenon.

Thursday, March 20, 2008

Arthur C. Clarke passes away

The long term health of scientific exploration rests squarely on inspiration. If young people are inspired by science enough to pursue a scientific career, then the brightest minds will be probing the deepest secrets of the universe, instead of chasing the biggest pile of money. The images of Hubble are definitely inspiring, but I'd say that for the last five decades the bigger contributor to scientific inspiration has been science fiction (and it isn't even funded by taxpayers!).

Arthur C. Clarke has been at the cutting edge of science fiction, blending a real understanding of science (he graduated with a physics degree from King's College London) with a fantastic creative imagination. He helped pull science fiction from the literary gutter into the main stream, inspiring both scientists and fellow science fiction writers along the way. The impact of the man on the advancement of space exploration cannot be overstated, as multiple generations grew up reading his novels.

On Tuesday, Mr. Clarke passed away in Sri Lanka, his home since 1956. He was knighted in 1998 by Queen Elizabeth II, and received too many awards to mention. His influence pushing space science forward will continue for the next century, or beyond.

Wednesday, March 19, 2008

Hubble finds methane on exoplanet; later, methane==life

Tomorrow Nature will publish an article where Mark R. Swain, Gautam Vasisht, and Giovanna Tinetti explain how they were able to tease out a discovery of methane in the atmosphere of HD 189733b using Hubble. In and of itself, the discovery is great, but what the discover portends is much more fantastic.

When I talk to people about my work in astronomy, often the subject of life on other planets comes up, and I am quick to tell them that evidence of life will be discovered on another planet in our lifetime, and probably in the next couple of decades. They are both intrigued and disappointed when I explain that we will find chemical signatures of life, and not intelligent aliens waving back at us (that, unfortunately, won't happen before my time is up on this pale blue dot.)

This discovery gets us that much closer to finding this chemical evidence of life. Methane specifically is interesting, because in an oxygen rich atmosphere, methane along with sunlight breaks down in millions of years. That might seem like a long time, but for the lifetime of planets, it is pretty small. So, when we find methane in an oxygen rich atmosphere, we know that it is being replenished at least every few million of years. One of the big, regular sources of methane on the Earth are animals and decomposing plant matter. This particular planet, HD 189733b, is a gas giant and much too hot for any type of familiar life, but if we can detect methane on this planet, we can eventually detect methane on smaller, more hospitable planets.

In an article in the New York Times on the discovery, Sara Seager, one of my Ph.D. supervisors, suggests that Hubble, though quite remarkable, wasn't built with exoplanets in mind, and that the next generation of space telescopes will add exponentially to our understanding of these extrasolar planets, and specifically Earth sized planets. She really hit the nail on the head. An entire generation of astronomers is currently searching for planets, mainly because of the possibility of finding an Earth analogue. Sure, many astronomers are searching for Hot Jupiters now, but I think all of them would admit that what really interests them is finding Earth-type planets, and specifically life on other planets. This discovery of methane brings us one step closer towards that ultimate goal of finding life.

Monday, March 17, 2008

Oh that Dextre!

I am a fan of manned space flight, I always have been, and I always will be. I am a fan not because of the science we can discover by sending people into space, but mostly because of the inspiration manned space flight (so much more than robotic missions) can provide for young and old people alike.

However, some people like to play the "it's good science" game with manned space flight. Good for them for fighting the good fight. Most of the time it comes down to biological experimentation, and I completely agree that the most beneficial science that can come from manned space flight is studying the human body and natural systems in microgravity or weightlessness.

This focus on biological systems in space is one of the reasons I thought it was pretty funny that astronauts today installed Dextre, a Canadian-built robot onto the international space station. This robot can complete some of the mundane tasks that heretofore astronauts had to complete with space walks, at great expense and danger to themselves. It is ironic, since the justification of the space station is that people are needed to do good science, that the astronauts have just replaced some of their usefulness with a Canadian robot.

Don't get me wrong, I think it was a great move, to automate everything on the space station that can be automated, so that only the most interesting questions can be addressed by the human astronauts. However, why not naturally move towards no astronauts at all, and fill the station with some Japanese built robots? Hopefully because a station full of robots won't inspire people like Kirk and Spock do.

Friday, March 14, 2008

Checking in on that Moon acreage you bought...

If you haven't seen the videos of the moon's surface coming back from the JAXA Selene / Kaguya spacecraft, check them out. We've all become slightly jaded about videos of space-scapes due to all the animations and high-quality sci-fi out there, so it's important to remember that... WE'RE FLYING OVER A REAL PLANET!!  The spacecraft is 100 km from the surface, equivalent to the highest flights by research aircraft here on Earth, and the HD videos have a resolution of 10 km.  The movies beautifully show the exquisite detail of the crater structures and the drastic changes in surface topography; I highly suggest one of the clips flying over the terminator (V-044-0067 for example) where the shadows give the most contrast.

As pointed out in a nice BBC article, one of the interesting astrobiological questions for lunar exploration concerns the possible presence of water in the shadowed regions of large craters. The water would be left over from giant comet impacts and conserved due to the consistently cold temperatures in the shadows (temps on the Moon are ~ 100 degrees C in the sun and -100 degrees C in the shade). While it wouldn't necessarily be worth much on Earth (how much would you pay to drink a glass of Moon water?), water would be an incredibly valuable resource for building a sustainable human presence. Additionally, analyzing the chemical properties (such as the amount of deuterium, a heavier isotope of standard H2O) of pristine water deposits could tell us a lot about where Earth's water came from - and whether Earth-like planets around other stars would have a similar amount of water as our home planet.

Thursday, March 13, 2008

Growing Planets

One of the big problems in planetary formation is getting rocks to stick together. The basic idea is that the swirling gases and particles going around a star eventually make their way to being planets. We basically understand how small particles start to stick together to make bigger particles, and we can certainly figure out how little planets coalesce in order to make big planets, but somewhere in between particles and small planets we get a little hazy.

Our understanding is not helped all that much by a dearth of observations for this "in-between" stage of rocks going around a star, because little rocks don't reflect too much of the stellar light. Additionally, this "in-between" stage is fairly short-lived, which already puts at a disadvantage to observing.

Fortunately, a group led by William Herbst just announced in Nature today evidence of a 3 million year old star with sand-sized grains around it. This helps push forward the understanding of planet formation, which should also give us information on the abundance of planets, and what stellar systems are the best candidates for looking for planets. A little bit more observational data never hurt planet formation theorists (well, it hurts, but only at first.)