When a sodium metal leak caused a small fire in the Energy Research Facility three years ago, physics professor Dan Lathrop’s research team received its first bit of media attention.
“There were no injuries and almost no damage, but we got a big response out of the local fire teams,” said Lathrop from his office on campus Monday.
Today, Lathrop, along with a technician and two doctoral candidates, is hoping to receive notoriety not from bringing rows of fire trucks to the campus but for constructing an artificial model of the earth’s core and spinning it to generate a magnetic field to be used as a predictive measure of the Earth’s magnetic field.
The 14-year experiment, which began with a smaller model and became “aggressively larger,” according to Lathrop, cost an estimated $1.6 million, most of which was devoted to the 26-ton, 10-foot-tall stainless steel sphere currently erected in an Energy Research Facility lab.
Lathrop said there is currently no predictive science for the Earth’s constantly fluctuating magnetic field, and if his project achieves its ultimate goal of predicting the magnetic field, it would enable scientists to prevent damage to electronics that orbit in space.
“By looking at the pattern of how these [magnetic field fluctuations] evolve in time you want to be able to say, ‘I’ve looked at what’s happened in the past 10 minutes; I want to be able to say what will happen in the next two minutes,'” Lathrop said.
The Earth’s iron core, also called a dynamo, powers the magnetic field as the Earth spins.
Currently Lathrop’s sphere is filled with water, not iron, but once the extensive safety measures are dealt with, his research team will replace the water with sodium, which melts more easily than iron.
Once the sodium is installed, the sphere will spin and Lathrop and his team will measure the results.
“Either it will generate a magnetic field or not,” Lathrop said simply. “It often takes weeks or months to actually understand what is going on in a new experiment.”
Though the experiment could take a while, physics professor Jordan Goodman, who was chair of the department until two years ago, said the experiment will provide great insight into this particular phenomenon.
“The idea of doing this experiment will let us potentially understand what is in store for the earth,” Goodman said. “It’s really very fundamental, interesting science.”
Excitement about the experiment has permeated the entire physics department, Goodman added.
“Everybody’s been waiting for it to happen,” he said. “Most of us are really glad the sphere’s not in our building. … Maybe he’ll generate a huge amount of magnetic field, which I would prefer to not have near my computer.”
Lathrop estimated the real experimentation will begin within the next year.
Lathrop modestly insisted he is mostly responsible for planning and fund-raising the project, but he also gave credit to his technician, Don Martin, and his student assistants, doctoral candidates Dan Zimmerman and Doug Kelley.
During a tour of the lab, Zimmerman, Kelley and Martin were spotted hard at work aside the massive silver ball, which is surrounded by an outer cube made of metal and a ladder required to reach the top.
“The inner and outer spheres are driven by two 350-horsepower electric motors,” explained Zimmerman. “We’ve designed the outer sphere so that we can rotate it at four times a second” – or, as Kelley interjects, about 90 mph.
Safety concerns prevented the men from taking the sphere for a spin, but Lathrop described the process as resulting in a quiet, humming sound, and Zimmerman said one can feel “a noticeable wind” when standing near the rotating model.
Zimmerman took a step back from the project and described his emotional investment in the sphere.
“It’s certainly been an interesting Ph.D. experience,” he said. “We still have some sodium preparations to make. The mechanical stuff seems to be working quite well – I’m proud of it.”
But the safety measures required before the highly flammable sodium can be installed will not be an easy task. Martin said practically every possible scenario has been discussed with safety officials.
Zimmerman still remained confident the experiment will be executed to plan, saying he has bigger priorities than safety.
“If you follow all procedures, you’ll be safe. If you don’t, you’ll be seriously injured,” Zimmerman said. “I’m worried more about getting my Ph.D. than I am about getting injured.”
Lathrop then reminded his laborers it was time to resume their work, but only after taking a moment to reflect on the imminent culmination of more than a decade’s worth of research.
“I think it is important to always run an experiment and let it speak for itself,” Lathrop said. “If a scientist puts too much emotional involvement in getting one result, then that’s not good for science.”
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