Sunday, July 30, 2017

Come Up to the Lab


The laboratory is nestled in the side of the Mississippi river bank on a quasi-island, ensconced beyond the gray metal cages of a battery of Excel Energy transformers. The signs at the driveway leading down to it say Private Property, Keep Out. It's much easier to spot from the opposite side of the river--a boxy four-story building with banners hanging off it: Earth Water Life in a slightly rounded san serif font that's long been popular in the scientific community. Someone with good eyesight or binoculars might make out the sign adjacent: SAFL Outdoor Stream Lab.

I was delighted recently to receive an invitation from the U of M's alumni association to tour the lab.

I was one of perhaps fifty-thousand to whom the email was addressed, but I expressed an interest, and Hilary and I were given a slot on a one-hour afternoon tour. It turned out to be a two-hour tour...but I'm not complaining. There's a lot going on down there in the lab.


There may have been twelve of us in the group. Communications director Barbara Heitkamp started us off with a twenty-minute Powerpoint presentation. "I usually don't do this," she said, "but we're not going to be able to see the bottom floor of the lab, because we might disturb the fish in one of our experiments, so I thought I'd use the extra time to give you all an overview of what we're currently working on."

This turned out the be a blessing in disguise, because the visuals Barbara projected onto the screen gave a more vivid impression of some of the experiments than merely looking at wave machines and wind tunnels possibly could. For example, she showed us a video clip of snowflakes illuminated by floodlights as they whiz past a big wind turbine at night out in a field in Rosemount. You could see the eddies forming consistently in some places and the relative speed of the wind at various heights.

She also gave us a brief history of the building, which was built in the 1930s and has been used as a hydraulics lab ever since. 


Eventually we headed upstairs to take a look at the gigantic U-shaped wind tunnel, in which they were studying various aspects of wind power, including not only efficiency but issues related to noise pollution. They had discovered that the low rumble given off by the turbines—too low to be audible—makes some people seasick.

I was surprised to learn that in many experiments the substance they blow through the tunnel is a fine mist of olive oil. I suggested that if they grew enough lettuce on the grounds outside, they could put a big bowl of it at the end of the tunnel, catch the oil, and have salad for lunch every day.

I also had the temerity, when Barbara was done describing the tunnel and its uses, to ask where the wind actually came from. A big fan?

"Yes. It's right over there. We call it the 'BAF'—big-ass fan."  Yes, but probably not when giving presentations to the Board of Regents.


From there it was two flights down to the floors below the level of the Mississippi upstream from the nearby falls, with a brief stop first in some labs where blue-green algae growth under investigation.

Down below the upstream water table, access to water flow was as easy as opening a spigot or a gate. Yet several of the experiments were very small in scale, and I had my doubts about whether anything of substance was being "unearthed." On the one hand, a fancy laser had been installed that rode back and forth on a stainless steel track above the room. If I remember correctly, it was capable of registering 800,000 pieces of data in five seconds. Sounds like overkill to me. On the other hand, once a big delta had developed in a tank over the course of days or weeks or particle deposition, the common practice was to slice it in two, spray a long piece of white paper with adhesive, and press the paper against the now-exposed side of the deposits to capture the stratification. Rather crude.


At one of the water tanks we observed an enthusiastic undergrad from St. Thomas who was creating a delta with very fine sand, a big pile of which was lying on the floor beside his desk. The goal was to track the patterns of deposit, so that it would become easier to identify the layers of minute hydrocarbon particles might develop in "real life."

The entire enterprise reminded me of the summer I spent (1970) doing experiments at the bio-engineering lab on the main campus of the U. I was in charge of a machine designed to filter red blood cells from blood, allowing the plasma to flow in a continuous stream, thus obviating the need for cumbersome centrifugal separation. The machine didn't work; the blood cells popped open as they hit the filter, thus ruining the plasma. My job was to figure out the optimum pressure to avoid the hemolysis. 

I don't need to go into the details of my research here, or the chain of events that turned my attention away from science toward history and literature. But the atmosphere in the lab was the same: jerry-rigged one-of-a-kind machinery and bags of dog blood side by side with sophisticated viscometers and spectrophotometers. Graph paper, duct tape, and tin foil scattered here and there. (In those days there were no computer screens.) 

The operations at the lab also reminded me of my brother's sixth-grade science project—a plywood water tray the size of a small surfboard covered with metal filings, over which water flowed continuously. As you set obstacles of varying dimensions into the flow, the patterns in the filings would shift. It was fun to play with.

I was also reminded of how memorable those childhood days are when heavy rain send water gushing alongside curbs and through gullies. There were plenty of undeveloped areas in the neighborhood where I grew up, and as freshets developed in the woods and fields and roads it was mesmerizing to toss a twig of just the right size and weigh into the water and follow it as it floated downstream, bobbing past miniature rapids and plunging over waterfalls. If it was still raining lightly, all the better.


At our last stop we came upon three individuals—they might have been scientists or engineers but they looked like Mack and Meyer—fiddling with an antique motor rigged to a piston that was pushing a square piece of plywood back and forth in a Plexiglas trough filled with green water. This contraption was being designed to study the morphology of sediments deposited on a beach over time.

One of the men, whom Barbara introduced to us as Benjamin Erickson, turned out to be the building manager. Once again, he reminded me of people I used to work with at the bio-engineering lab--Gordie Voss, Dick Forstrum, Frank Dormand. I would characterize such people as brilliant children who had somehow worked their fascinating boyhood hobbies into lifelong careers, thus preserving their sense of wonder and of fun..  

The guy told Barbara that we were in luck. The fish had been removed from the experimental tubes through which they were trying to swim and the lower floor was now open. We headed down another flight of stairs, and at the bottom we came upon a variety of experiments, and also relics of other experiments. One dated back to the Cold War era, and involved a joint study by Honeywell and the U.S. Navy of the fluid dynamics involved in shooting a missile from a submarine. The gigantic tubes used in this study stood next to an exposed limestone wall that was actually part of the riverbank. Nearby were some very large tanks that had originally been used to store the water supply for the city of St. Anthony until a cholera outbreak in the 1860s (if I remember correctly) underscored the need for a better system.

We reemerged into daylight above an outdoor stream bed that was being used to study the factors that keep mussel environments healthy. Every mussel in the stream had been fitted with a sensor that registered whether it was open or closed, twenty-four hours a day. (You can see the stream bed winding through the prairie grasses in the photo below.)


If everything works out as planned, soon we'll all be eating fresh mussels daily, covered in a fine mist of olive oil and salt extracted from the soil under a wind turbine. We'll be reading Herodotus, and wondering why everyone was so anxious back in the twentieth century.

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