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The Planetary Society WeblogGuest Blogger: Andrew WestphalAugust 14-20, 2006
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Andrew Westphal is an Associate Director, Associate Research Physicist and Senior Fellow at the Space Sciences Laboratory at the University of California, Berkeley. His research interests include galactic cosmic rays, interstellar dust, and the fascinating relationship between them. He is a member of the Stardust science team and the Project Director of Stardust@home. He has flown instruments on high-altitude balloons in Antarctica and onboard the Russian space station Mir. The most challenging thing that he has ever done is learn to play the fiddle. He is married to Kim Taylor and has two young daughters, Theresa and Laura. |
Expect the Unexpected
Just a few days ago, on August 1, we launched Stardust@home -- a search, by thousands of volunteers, for the first contemporary interstellar dust particles ever returned to Earth for study. This "stardust" was captured in an aerogel collector that was carried by the Stardust spacecraft beyond the orbit of Mars and back to Earth, spending seven years in space and traveling over three billion miles. A re-entry capsule containing two aerogel collectors, one containing cometary dust and the other interstellar dust, parachuted down from space last January. At this very moment, hundreds of Stardust@home volunteers, our new colleagues, are searching digital micrographs of the Stardust collector for the tiny tracks of interstellar dust particles.
 A Particle Track in Aerogel This is what a single image from a Stardust@home movie looks like on the "virtual microscope." Since no interstellar dust particles have ever been captured, these samples were created in a high energy particle accellerator. Credit: Regents of the University of California, Stardust@home |
As we launched the project, our website said that everyone should expect both
major and minor glitches. We also gave everyone three reminders:
-- If you're not having fun, you're not doing it right
-- Expect the unexpected
-- This is research: the outcome of this project is highly uncertain
In this series of blogs for The Planetary Society, I will focus on each of these three reminders. First, reminder #2: Expect the Unexpected.
As anyone who has been participating in Stardust@home knows, our expectation
of major and minor glitches was borne out in spades. As we turned on
the project at 11 a.m. Pacific time on August 1, we were immediately
overwhelmed with traffic. We had done "load tests" of the Stardust@home website before, with the very kind help of members of The Planetary Society, so we thought that we were prepared to handle the traffic. How wrong we were! We spent the next few hours scrambling to add servers to handle the load, and we eventually did come back up, sluggishly, later in the day.
After this, things seemed to be running smoothly. But this was not to last. We were watching the Stardust@home forum and
noticed that our colleagues were reporting strange images -- wedding
photos, ballerinas, cars -- randomly inserted in our "focus movies".
These images were strange simply because they were so normal -- they
weren't risque and contained no hostile messages. Nevertheless, we
assumed that we'd been hacked. We spent a couple of hours trying to
figure out how this clever hacker had gotten into our system. Eventually,
thanks to the detailed information posted on the forum by our colleagues,
we realized that we hadn't been hacked after all, but that a subtle
bug had been introduced in the image distribution software. The result
was that rarely these random images were included in our focus movies.
We hadn't caught it because the insertions were so uncommon.
We quickly learned a lesson from this. Not only are our volunteer colleagues all over the world critical to the successful search for interstellar dust particles, they are critical to discovering, diagnosing and fixing problems with the website and Virtual Microscope. This is truly an amazing and fantastic scientific collaboration. Our new colleagues, working all over the world, are collegial, productive, and helpful. It is genuinely fun working with them. They are doing essentially all of the work. We have been humbled!
Although in a very general way we expected glitches, we had no idea what would come up. Who could have predicted ballerinas? But this is at the very nature of the scientific enterprise -- you never know what's going to happen next.
In fact, the possibility of finding something unexpected is what drives
every scientist I know. Here is an example. In 1936, Carl Anderson
at Caltech discovered a new subatomic particle that resembled the electron
but was about 200 times heavier. This particle is now called the "muon", and we now recognize it to be one of the handful of fundamental particles -- the electron is another -- in the so-called Standard Model of particle physics. (The Standard Model is our picture of the structure of matter at the very smallest scales that we can probe.) This discovery came completely out of left field. A prominent physicist of the day named I. I. Rabi, reportedly on the way to a Chinese restaurant, quipped "Who ordered that?" But
this unexpected discovery was not anomalous, but absolutely typical
of progress in the field. In a wonderful letter to Physics Today a few years ago (Physics Today,
July 2000, p. 15), Harry Lipkin pointed out that almost all discoveries
in particle physics (the strange and charm quarks, the tau lepton --
a cousin of the electron and the muon -- CP violation, and many more)
were completely unexpected -- that is, they were of the "who-ordered-that" variety.
Unfortunately, the way that most people think about science bears little
resemblance to the way it is actually done. We are often taught that
the Scientific Process consists of forming hypotheses and conducting
experiments to test them. To reinforce this picture, in science classes
we generally follow fixed recipes (misleadingly called "experiments"). We get an "A" if
we get the result expected by the teacher. What could be more boring?
To be sure, sometimes science does consist of hypothesis testing, but
much of science does not proceed this way at all. In some fields, like
Astronomy, hypothesis-testing is practically unknown. To pick a trivial
(but typical) example: Galileo was not testing any hypotheses at all
when he looked at Jupiter for the first time with a telescope and discovered
four new worlds -- Io, Callisto, Ganymede, and Europa.
More recently, astronomers were not testing any hypotheses when they
discovered the mysterious "dark energy." They were simply exploring.
 Jupiter system montage Galileo Galilei first observed Jupiter's four planet-size moons -- Io (upper left), Europa (center), Ganymede (lower center), and Callisto (lower right) -- in 1610. These images of the Galilean satellites were photographed in early March 1979 by Voyager 1 and assembled into this collage. The moons and planet are not shown to scale. Credit: NASA / JPL |
But there are two other problems with presenting science in this recipe-like
fashion. First, the challenging -- and fun -- part of science is figuring out
how to make a good experiment or build a good instrument. If the experiment or
instrument is handed out on a silver platter, you've missed half the fun! Just
following a recipe that someone else wrote is like watching only the closing
credits of a two-hour action movie. If that were what science were about, honestly,
I'd be happier flipping burgers.
What about the other half of the fun? This is the possibility of new
discovery. If you only get an "A" when you get the expected result,
there is little room for new discovery. No wonder many people don't
enjoy science in school!
When a practicing scientist does a new experiment, the outcome is highly
uncertain. This is why it's called "research." This will be the subject
of my next blog.
This is Research: the Outcome is Highly Uncertain
In my first blog for The Planetary Society, I talked about how the possibility of unexpected discoveries drives scientists and (therefore) science. In this second piece, I want to throw a little cold water on the discussion, and talk about how hard and frustrating it can be to do science.
Einstein reportedly once said "If we knew what it was we were doing, it would not be called research, would it?" Almost all good research is done in unknown or at least poorly-explored territory. I've already talked about the irresistibly attractive aspect of this. But it can also be more than a little frustrating and discouraging. For every major discovery, there are many failures and disappointments. This is just the nature of the enterprise. Let me give some examples.
When I was just beginning graduate school here at Berkeley, a cautionary tale circulated among the first-year graduate students about the catastrophic experience of a certain advanced Ph.D. student. He had just spent years building an instrument to make a new measurement of the spectrum of the cosmic microwave background. The instrument was a one-shot deal -- literally. It was intended to fly on the top of a sub-orbital rocket, launched from Japan. The instrument was intended to spend a few minutes above Earth's atmosphere, making measurements, then would return to Earth and splash down in the Pacific Ocean and sink to the bottom and be lost. (The measurement data were of course returned by telemetry before splashdown.) At least in those days -- I don't know about now -- launching such a rocket was very expensive, because the Japanese Government had to pay a big fraction of the Japanese fishing fleet to stay out of the splash-down zone of the rocket, so on launch day you really had to be absolutely sure to be ready.
The day came, and the rocket with the instrument was launched successfully. The instrument performed flawlessly, but unfortunately the shroud (cover) didn't separate from the rocket. So the instrument very precisely measured the microwave spectrum of the inside of the rocket shroud -- not exactly the intended result! Despite this massive discouragement, the student was undaunted, and in less than a year built an entirely new instrument, flew it successfully, and got his Ph.D. His name is Andrew Lange, and he is now a distinguished full professor at Caltech and one of the foremost experts on experimental measurements of the cosmic microwave background.
Here is another tale --- also with a good ending. After the launch of Stardust, another Discovery mission was launched called Genesis. Genesis carried ultrapure collectors to capture a sample of the Sun from the extremely diffuse solar wind. Although Genesis was launched after Stardust, it had a shorter mission and returned before Stardust, in September 2004. In space, the mission performed flawlessly, but unfortunately on re-entry the electronics in the capsule failed to trigger the parachute release, and the capsule slammed into the ground at around 200 miles per hour. The ultrapure collectors were shattered and scattered into the Utah dirt.
 Thud! The damaged Genesis sample return capsule where it came to rest, half buried in the ground in the Utah desert, on September 8, 2004. Credit: NASA / JPL |
Fortunately, the leader of the Genesis mission is a remarkable man named
Don Burnett. Don is absolutely unflappable, and is, frankly, one of my heroes
in the scientific community. Don quickly realized that although the presence
of dirt added a lot of complication to the project, most of the science could
still be done, principally because the solar wind particles were embedded within
the collectors and could be distinguished -- with hard work -- from the terrestrial
contamination. This exciting work is going on right now, and results from Genesis
are continually coming in.
It would be easy, but wrong, to criticize the Genesis mission managers for not catching the problem with the parachute release electronics. One thing that is very important to understand about space missions of any kind is that they are inherently risky. The reason is fundamentally simple -- space missions are one-shot deals. Let's compare building and launching a spacecraft with, say, building and launching a new car model. When a car company invests in building a car, they know that they are going to build a million of them, so they can spread out the huge initial costs (design, factory tooling, etc.) over the millions of cars that they are going to build. With a spacecraft, you generally build only one. With a car, you get to tweak, modify, redesign, debug to your heart's content, even after the first thousand cars are out on the road. With a spacecraft, you have to over-engineer everything because (generally) you don't get a chance to fix any problems after launch. With a car, you get to test and test and test under realistic conditions right here on the ground. With a spacecraft, you test as much as you can in simulated space environments, but these are not perfect, and they are quite expensive. If you tested everything, you'd drive the cost of the mission through the roof, so you have to make judicious choices. It turns out that the parachute release system was almost (but unfortunately not exactly) identical to that of the Stardust mission. The spacecraft managers made the sensible decision not to test this system, since a nearly identical system -- on Stardust -- had been tested extensively. Maybe those who know more about this would disagree with me, but even in retrospect, it's not clear to me that this was the wrong decision. After all, those managers made hundreds of other similar choices that turned out fine. The spacecraft business -- as every astronaut knows and happily accepts -- is just inherently risky. You just do the very best you can.
In this blog I focused on astrophysics space missions, but any scientific research program has unforeseen twists, turns, glitches, catastrophes, triumphs. Just like life, I guess.
The same is true for the Stardust@home project. Many things could have gone wrong with this project already, and haven't. Much of this was due to good planning and good engineering -- not by me! -- but if we are honest we have to admit that much of it is also just good luck. The collector arm might have gotten stuck in the opened position after five years in space. The re-entry capsule heat shield was of a completely new design, and it might have failed -- if this had happened the collector would have been quickly destroyed. The re-entry capsule might have landed in a bomb crater full of water at the Dugway Proving Ground -- also essentially complete destruction. And on and on. Even now, we don't know what we will find in the Stardust Interstellar Collector. We might spend years searching and find nothing. We might find thousands of tiny interstellar dust grains. If we do find some, we have no idea what state they will be in -- they might be practically pristine, if we are lucky, or they might have been completely vaporized during capture.
 Aerogel sample collector on Stardust Credit: NASA / JPL |
In the face of all these problems, why don't all scientists just quit and go work on Wall Street? Because despite the problems, this business is just irresistibly fun. I'll talk about that in the next blog.
If You're Not Having Fun, You're Not Doing it Right!
In my last blog, I talked about how frustrating it can be to do science, and posed the natural question -- if it's so miserable, why don't all scientists just quit and go work on Wall Street?
The first answer is that many scientists do quit to go work on Wall Street. I knew several who did that after graduate school. But in almost every case, despite astronomical salaries, they came back to science. Wall Street, evidently, was just not challenging or stimulating enough.
The second answer is that almost all scientists do what they do because it's absolutely irresistibly fun.
I think that I was very lucky to learn early in life, from both of my parents, that having fun is important. My Mom, Jean, generally refuses to do anything unless she's having fun doing it. My Dad, Jim, started his career as a "doodlebugger" -- an oil prospector who searches for oil by using seismic waves. But he was also an amateur astronomer in Oklahoma and 6-meter ham operator. He was one of the first to hear the radio transmissions of Sputnik in October 1957. Through a combination of talent and luck -- he would say mostly luck -- he eventually became a professor of Planetary Science at Caltech. He was a talented experimentalist and was never afraid to try anything -- even if, or maybe especially if, it went against the conventional wisdom. He was one of the first to introduce digital imaging to astronomy and was the leader of the team that built the first main camera for the Hubble Space Telescope. He and his colleague Sue Kieffer dropped a homemade camera into Old Faithful in Yellowstone -- to understand how it worked -- and almost plugged it up! He said what he thought, which occasionally got him into deep trouble.
One of my Dad's favorite phrases was "If you're not having fun, you're not doing it right." He didn't mean this specifically about doing science -- he meant it as a general approach to living, no matter what you do. Although this philosophy might seem childish and naive, particularly in the rarified atmosphere of high-powered academia, it served him very well. He was particularly proud of the fact that he was the only professor at Caltech who did not have a Ph.D. He was always amazed that he got paid to do what he would be doing anyway, even if he were independently wealthy. He had a skeptical view of advanced degrees and thought that getting your hands dirty actually building things was almost always a better education than can be gotten through classroom lectures.
(As an aside, I am extremely grateful to my parents for recognizing this same attitude in Maria Montessori's philosophy of early childhood education, and sending me to Montessori schools as a child. My wife Kim and I now send our daughters Theresa and Laura to Montessori school, too, and I know that my Dad would have been delighted seeing them continually "getting their hands dirty" making things.)
My Dad died almost two years ago. I cannot picture him without a big child-like smile on his face, as if thinking to himself -- even if he wasn't saying it out loud --
"That's infinitely NEAT!"
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