Using eclipse to reconfirm relativity

Vancouver physics professor uses solar eclipse to have students verify Einstein’s general theory

By Tom Vogt, Columbian Science, Military & History Reporter

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As millions of people marveled at one of nature’s grandest spectacles last week, some of Toby Dittrich’s students were backstopping Einstein.

The Vancouver resident, a physics instructor at Portland Community College, used the Aug. 21 total eclipse as a chance for his students to verify Albert Einstein’s 1915 general theory of relativity.

Dittrich’s students recreated a 1919 experiment conducted by British astronomer Arthur Eddington, whose observations showed that the sun’s massive gravitational field could bend the light from nearby stars.

It’s an effect that can only be observed during a total solar eclipse.

“It’s not new science, but it is a chance for students to be involved in a world-class experiment,” Dittrich said Monday, a week after the Great American Eclipse.

And the photographs they took during the eclipse should be able to move the needle a bit, as far as science goes.

“We’re hoping to achieve accuracy better than what anyone has done using visible light and a telescope,” Dittrich said.

In 1995, scientists started using radio telescopes for similar research.

Fellow Vancouver resident Rod Lee is a physics and astronomy instructor at Portland Community College.

He took a team, including students Steve Pinkston and Andrew Jozwiak and aerospace engineer John Cooper, to an eclipse-watching event east of Prineville, Ore. College astronomy instructor Bob Ewing also participated

On eclipse day, Lee said, “We were monitoring the stars in Leo,” a constellation near the sun.

Another team, including students Jacob Sharkansky and Abraham Salazar, set up its telescope and camera in Lyons, Ore., east of Salem. The site is an alpaca farm owned by Richard Berry, an amateur astronomer, author and former astronomy magazine editor.

Dittrich was scheduled to be at a third site, on the Oregon Coast, but clouds were coming in. After what Dittrich described as an unbearable 90 minutes, he called the airport in Corvallis and was told the skies were clear, so he drove there to watch the eclipse.

Dittrich said that it will take three or four months to verify their findings. But with multiple camera downloads taken in two locations with clear skies, the 70-year-old physics instructor is confident in their data.

“Eddington had data points from seven stars, and that was enough to prove the theory of relativity,” Dittrich said. “To determine the deflection of a star, it’s on the order of one pixel in the camera.”

Lee credited the students with doing a lot of hard work.

“They spent several months learning to handle the equipment,” Lee said. “They did the hard labor and we were there supporting them.

“It was really amazing,” Lee said of the project, which was done with relatively low-cost equipment. “I’m blessed to be able to have done this at a community college.”

The Portland Community College project was one of about half-dozen attempts on Aug. 21 to duplicate Eddington’s experiment, Dittrich said. He wants to make it a possibility for other teachers during future total solar eclipses.

“I want to create a lab manual for this,” he said.

Dittrich pointed out that Argentina is scheduled for a total solar eclipse on July 2, 2019, and noted that “this would be a great opportunity for a cultural exchange.”