The summer season is the slow news season so your local newspaper tries to earn its keep with enterprise stories, which are the kinds of stories that we come up with when we go, "Huh, what’s there interesting to write about?"
For the City Beat, it’s a good time to talk to the brains at UND. The non-brains here in the newsroom call it "nerding out." Well, I happen to enjoy reading and writing about science; I thought I’d become a biologist until I got to high school and realized that the kind of hot stuff discoveries you read about in magazines and newspapers take years and years and I don’t have that kind of patience.
On the other hand, I appreciate that not everyone really wants to learn chemistry in the newspaper, which is what makes these stories both enjoyable and painful to write. There are, I think, three levels of science writing and, in a newspaper, I’m trying to bridge the most obscure level with the most popular level.
The obscure level is the level of the scientific journals, the raw science that the layman would find almost impossible to fully comprehend. Sometimes when you talk to scientists, they talk at this level even though they might be trying their best to reach you.
Then there’s the science-for-nerds level, which is basically raw science rewritten for lay people who have a serious interest in science. This is maybe where Scientific American or maybe Discover is at. This is where I’m also at when I talk to scientists. It’s actually a fascinating place to be because scientists are fascinating people and, instead of listening to a lecture, I’m constantly asking questions. For the hour to hour and a half that I have for the interview, I’ve got myself a personal tutor.
And then there’s the science-for-dummies level, which is raw science rewritten for lay people who are interested in science, but don’t have a lot of time. Digesting that sort of knowledge takes time, like an hour to an hour and a half, that a lot of people don’t have. This is where Popular Science is at. It cuts to the chase and tells you why the science is awesome.
I think that’s the level newspaper science writing has to be. Now that I’m doing some of it myself, I have to applaud the people at Popular Science for making science so easy to grasp and entertaining.
Chemistry in theory
The first of the UND brains I called up was Dr. Mark Hoffmann, a theoretical chemist who studies the way molecules of volatile substances interact. He’s a Chester Fritz Distinguished Professor, which meant that he wasn’t just good at research, but also good at teaching. I’m not sure I would’ve called him if I didn’t think he could explain his work to someone who had never studied chemistry or physics (I took biology and advanced biology).
What I took away from our talk was that:
- Theoretical chemistry is cool because you can do chemistry where no experimentation is possible. The examples Dr. Hoffmann gave me were the atmosphere of Io, a moon of Jupiter, that we haven’t sent a probe to, and some very volatile chemicals that cause ozone pollution and destroys the ozone layer, but last for such a short time it’s difficult to study them.
Yeah, did you notice how smurfed up that is? Hydroperoxyl radicals, or HO2, create ozone and also destroy ozone. I spent a long time trying to explain that without going into all kinds of mind-numbing detail and just plain gave up. Now that I think about it, I probably could’ve just said in the heat of the furnace with the other chemicals present there, it makes ozone, and in the stratosphere with all that UV radiation it destroys ozone.
- Knowing how these volatile chemicals form and interact with other chemicals could help engineers find a way to prevent pollution. Let’s say you know how HO2 works and you find out that chemical X will bind with it before it creates ozone and, while ozone is harder to capture, chemical X is easy to capture, well, then you’ve figured out how to snuff ozone pollution.
Geology in theory
For some reason, this science-at-a-distance has been kind of a theme in my coverage.
I talked to astronomer Paul Hardersen months ago, February maybe, but we needed to get him out to the observatory for a photo and it was closed for the winter. Recently, I pulled out the audio recording of our conversation to start on the story again; we’re still waiting on a photo op so the story will have to wait.
What was interesting about our discussion was the fact that Dr. Hardersen’s main interest is the geology of asteroids.
One way of studying that would be to send probes out to the asteroids – many are beyond the orbit of Mars in the main belt, but there are some not far from Earth — gather samples and bring them back for study. Of course, it’s so blasted expensive that it’s a once in a blue moon occurrence.
The cheaper way is to study the way light bounces off the asteroids, particularly in the near infrared and infrared part of the spectrum, and compare that to the way light bounces off chunks of meteorite that have fallen to Earth. The problem with that, of course, is there maybe stuff that’s never fallen to Earth, so the catalog is incomplete.
(I wonder why infrared is so useful. I remember doing another nerd out on some engineering students using near infrared to study crops. Wikipedia says the frequency of infrared light is close to the vibrational frequency of most molecules, whatever that means.)
It’s interesting to note that, astronomers have long classified asteroids based mostly on how much light they reflect. Darker asteroids in the C class were thought to be made of some tar-like organic goop; lighter asteroids in the S class were thought to be stony and asteroids in the X class that, I’m guessing, reflect a little bit of this, a little of that were thought to be mostly metalic.
As it turns out, as sensors get better, it became evident that objects reflecting similar amounts of light weren’t necessarily made of similar substances. But, since scientists can’t agree to a new classification system and, as Dr. Hardersen implies, are still trying to figure out the differences among asteroids, they have to stick to the old system even though it probably makes as much sense as classifying a whale with an elephant because both are kind of gray.
What’s more interesting is how knowledge of asteroid geology can be applied.
- First, knowing what an asteroid is made of allows you to infer how it was formed billions of years ago. Knowing how it was formed gives us a glimpse into how a portion of the Solar System was formed. That’s kind of cool.
- Second, knowing what an asteroid is made of allows you to figure out how to make it not destroy the Earth, should it be on a collision course. I wrote about this last year when I interviewed Dr. Hardersen’s then-student, Vishnu Reddy. Interestingly, Dr. Hardersen was a student of another asteroid geologist, Mike Gaffey, following him to UND. So now we have this clan of asteroid geologists, a fairly small field, concentrated here in Grand Forks.
Rain formation in theory
You’d think that science would have fully understood by now something seemingly as simple as how raindrops form. And you’d think that would be the case for something that’s been done for decades, like cloud seeding.
But talking to atmospheric scientist David Delene, I realized there are some aspects of those two that still mystifies science. Dr. Delene is part of a multi-year study of a relatively new method of cloud seeding sponsored by the Atmospheric Resources Board, the state’s cloud seeding authority.
After getting a fairly theoretical explanation of how this cloud seeding method works, I asked one of those innocent questions that turned out to be thornier than I realized: Has cloud seeding been proven to work? The answer is "sort of."
Statistically, there’s evidence that it works, but scientists don’t know exactly how.
I suppose that shouldn’t be a surprise because they still don’t know how raindrops form. While doing research for the story, I ran across a story from 2006 about researchers looking into this problem and read this passage:
For decades, scientists have been debating over two main mixing mechanisms. One idea proposes that chaotic swirls of turbulent air work on tiny scales and mix up the droplets. The other describes a process called entrainment that happens when dry air mixes with moist air at the edges of clouds.
The big news from that story was a new sensor that uses lasers to measure the size of droplets that are a fraction of the width of human hair while said droplets are flying by at hundreds of miles an hour.
UND, as it happens, also has similar sensors on one of its research jets. The one I was impressed with was this one; it can detect droplets as small as 3 microns. That’s smaller than a red blood cell.
Basically, rain happens in at least two ways, scientists think.
First, the cold method: Droplets at the top of clouds freeze, forming ice crystals that get bigger and bigger until they’re too heavy to float in the air, and then they fall to the ground as snowflakes. When the weather’s warm down below, they melt and we get rain. When the weather’s cold, the snowflakes fall as snowflakes and we have to go shovel the driveway.
Second, the warm method: Droplets at the bottom of clouds absorb moisture from other droplets, then the bigger droplets bump into each other and merge, getting heavy enough to fall as rain.
Apparently the warm method is a little harder to pin down because it happens faster than scientists predicted using computer models; they think turbulence accelerates the merging action.
Anyway, the traditional cloud seeding method uses silver iodide to nudge cold droplets to freeze. But, in the summer when you want rain, getting the cold temperatures needed means the clouds have to be just high enough, the air being colder the higher you go. It’s not always easy finding the right cloud.
The relatively new method uses hygroscopic particles to attract warm droplets and get them to condense into bigger droplets. Hygroscopic means the particles, typically a salt, suck in water, like that stuff you find in the bags of beef jerky that you’re not supposed to eat. Here’s a picture of the stuff at work. I wonder why it has to be burned like that.
Normally, when scientists tests something really rigorously, they set up two or more identical samples. One is the control sample and you do nothing to it. The others are the experimental samples and you experiment with changes to them. Here, you’ve got miles-wide clouds that aren’t identical so that sort of thing is impossible.
Scientists could also gather lots and lots of samples to get a really good set of statistics, which is sort of what Dr. Delene and the Atmospheric Resources people are doing. But, like the challenge of getting samples from asteroids, it’s very expensive and the number of samples needed are huge. So the sampling that Atmospheric Resources is funding is just enough to satisfy the state that hygroscopic flares are about as useful as silver iodide, but really solid proof is still a ways off.
Dr. Delene was a little defensive when he explained why so much money has been poured into cloud seeding if it hasn’t been scientifically proven. It’s because making rain and, at the same time, suppressing hail are really really important to agriculture, he said.
Outside the realm of science, practicality rules. A half a chance is better than none at all and, if it seems to work, why it works is probably not that important.