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Back to basics with Nobel Prize winner Masatoshi Koshiba

Masatoshi Koshiba, winner of the Nobel Prize in Physics in 2002 for his pioneering contributions to astrophysics, speaks at Tokyo University.
Masatoshi Koshiba

TOKYO (TR) – Following his graduation from the School of Science at the University of Tokyo in 1951, a young Masatoshi Koshiba departed on a two-week voyage by ship from Japan, still under Allied occupation following World War II, to the United States. He knew that with his father having served as an officer in Manchuria for the Imperial Army that there would be a psychological conflict. But after landing in Seattle, he was soon overwhelmed by something else altogether.

“The first impression I had of the U.S. was that it was such a big country,” says the soft-spoken Koshiba, 73, sporting a tweed jacket during an interview in April at Tokyo University, where he is professor emeritus. “People were eating a very big bowl of ice cream soda. And for me, during the war, that was something so high up in the sky. If these people are eating this everyday, I thought, it is no wonder that we lost the war.”

He graduated with a PhD in physics in 1955 from the University of Rochester, and through his future work he found more than sweet dreams high up in the heavens. In 2002, he was awarded the Nobel Prize in Physics for his observations of neutrino particles, which result from nuclear decay reactions, such as those taking place in stars like the sun.

Today he finds himself back to the classroom as chairman of the Heisei Foundation for Basic Science — a project that aims to get Japanese young people more acquainted with the fundamentals of science.

“Everyone has different appetites,” explains the native of Aichi Prefecture. “Some people feel music is most important. Some people think beautiful paintings are everything. Only part of the population has an intrinsic interest in science. If those people could not get interested in science because of education, that is very sad. What kind education would hinder those people to get acquainted with science?”

A study compiled by the International Association for the Evaluation of Educational Achievement indicates that average math and science scores for fourth- and eighth-grade students in Japan have mainly fallen between 1995 and 2007.

For its part, the Heisei Foundation collects lecture programs titled “Enjoy Science in the Classroom” onto DVDs and distributes them to middle schools, high schools, technical colleges and universities. Koshiba and other scientific luminaries provide instruction on everything from cell biology to evolution to, of course, physics. Questions are fielded from the assembled student audience and technical equipment pertinent to the subject is provided for better understanding.

“Between 10 and 15 years old, people either get interested in science or they do not,” he believes. “And for the teacher who teaches science to these young people, if they themselves did not enjoy science then the children will not get interested in science.”

Koshiba’s his entry into the scientific world was not direct. As a teenager, he was stricken with polio that resulted in weakness in his right arm, a condition that kept him out of the military and still lingers today. Then, following entry to the University of Tokyo, he found his greatest interest to be in German arts.

Studies in physics came about largely out of spite. “A professor denounced me as being no good at physics,” he remembers. “That made me furious. So I took the entrance exam for the physics department.”

Koshiba passed and later began experimenting with very sensitive photographic materials, called nuclear emulsion plates, that can track the path of fast-moving particles. “I knew then that I had found it — it was what I could do, and that was the beginning of my career in elementary particle experiments,” he says.

In 1963, Koshiba relocated to Japan permanently from the U.S. It was around this time that scientist Raymond Davis, Jr. began conducting solar neutrino detection experiments in mines in Ohio and South Dakota. Much like quarks, electrons and photons, neutrinos are one of the building blocks of the universe but very difficult to detect. Davis was the first to observe solar neutrinos and later concluded that the number reaching the earth from the sun was much less than predicted by theory, a discrepancy that was considered a puzzle by the scientific community.

Koshiba, who in 1970 became professor at the University of Tokyo, was inspired by the findings to do something himself. “I had to think about something that would impress young people and show that basic science is something really wonderful,” he explains.

In the 1980s, he constructed the Kamiokande detector in an abandoned zinc mine in Gifu Prefecture. The project wrapped highly sensitive detectors around the inside of a cylindrical tank containing thousands of tons of water.

Neutrinos arriving from a supernova explosion were observed in 1987, and, later, the project provided results that displayed that — as had been postulated — neutrinos can change characteristics in transit and thereby obscure detection results, a fact that explained the numerical discrepancy noticed by Davis.

To speak with Koshiba today is to discover a man of great modesty. Sometimes seen leaning on a cane, he is still motivated by his love of the sciences.

When he received the phone call in the fall of 2002 from Stockholm, Sweden announcing that he would be sharing the Nobel Prize with Davis and astrophysicist Riccardo Giacconi, who performed pioneering studies on cosmic rays, Koshiba could only think about the funding shortfall for establishing the Heisei Foundation for Basic Science.

“I was almost desperate. Then I received the telephone call from Stockholm,” he says very nonchalantly. “I was happy.”

The 35 million yen provided through the prize was still not enough. But Hamamatsu Photonics, which assisted in the development of the Kamiokande experiment, made up the difference. The foundation was founded the next year.

“If someone wants to do something seriously,” he says, “there is always a way to overcome the difficulty.”

Note: This article originally appeared in the June issue of iNTOUCH, the magazine of the Tokyo American Club.