Blast from science’s past

Story by Jim Bishop

It looks like something out of a Jules Verne novel.

John L. Horst, professor emeritus of physics at Eastern Mennonite University, recently salvaged from storage a large chart depicting “principles of electromagnetic radiations,” dated 1938. Horst taught at EMU from 1967 until retiring in 2004.

According to Horst, the 3 1/2-foot by 5-foot “elegantly complex” poster originally hung on the wall behind the lecture deck of the late M.T. Brackbill’s “creative, quirky” physics classroom in the basement of the old administration building. Brackbill taught science and many other courses at EMU from 1919 to 1956. He died in 1963.

The chart was edited by Arthur H. Compton, who shared the Nobel prize in physics in 1927 for the Compton Effect, a scattering experiment that demonstrated that x-rays are photons that have quantum particle properties. He later showed that cosmic rays are photons from deep outer space.

A sidenote: Compton’s mother was a Mennonite from Ohio. He attended Bluffton (Ohio) College (now University) for a year in the early part of the 20th century.

The chart moves the observer from top to bottom with “a flurry of ideas, depicting how various parts of the spectrum are generated,” Horst noted. “Many applications – from astronomy, chemistry, engineering, medicine and physics – are part of the spectrum, with everything related to existing technologies of 1938,” he said.

Physicist James Maxwell first described the wave theory of electromagnetic spectrum in the late 19th century. The particle theory of the spectrum emerged with the development of quantum mechanics in the early 20th century.

“The color scheme is striking and excellent for its day,” Horst said. The graphic arrangement is amazing considering the creators had no computer assistance back then.”

Horst noted that the chart “wasn’t carefully stored, and the bottom portion had some broken or missing pieces.” He credited local craftsman Raymond Shank for his “excellent restoration and framing work.” The chart is now displayed on the wall adjacent to the current physics laboratory in EMU’s Suter Science Center.

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