Takaaki Kajita is one of the 2015 Nobel Prize winners in Physics.
He shared the prize with Canadian physicist Arthur B. McDonald. Although they were doing their research in different labs and on separate continents, they both did important and related work in neutrino research.
Takaaki Kajita has worked for many years on the Kamiokande and, later, the Super Kamiokande. These are important neutrino experiments conducted at the Kamioka Observatory at the Institute for Cosmic Ray Research. The name of the experiment is a kind of contraction of the name of the observatory, plus the name of the experiment. It started out as Kamioka Nucleon Decay Experiment. Then it was shortened to KamiokaNDE. Eventually, the last three letters stopped being capitalized.
The Kamioka Observatory is a neutrino and gravitational waves laboratory in Gifu Prefecture, Japan.
Although the word observatory makes most people think of telescopes aimed at the sky, this lab is actually located underground in an old mine of the Kamioka Mining and Smelting Co. The setting continues to be called the Mozumi Mine, though it has long since stopped being used as a mine. The lab in question is designed to make an entirely different class of observations than the ones made by telescopes turned skyward. Takaaki Kajita has used the special equipment located deep underground in order to study extremely tiny sub-atomic particles.
Takaaki Kajita is a Japanese national born March 9, 1959 in Higashimatsuyama, Saitama, Japan. He is married and his wife’s name is Michiko Kajita. He completed high school at Saitama Prefectural Kawagoe High School, and then he earned his bachelor’s degree from Saitama University in 1981. He also has a masters and a PhD from the University of Tokyo, Tokyo, Japan.
He is fortunate to have completed his doctorate in 1986 under Masatoshi Koshiba who served as his doctoral advisor. Koshiba is highly esteemed as one of the founders of Neutrino astronomy. He is, himself a Nobel Prize winner. He shared the 2002 Nobel Prize in Physics with Raymond Davis Jr. and Riccardo Giacconi, two American physicists. When Takaaki Kajita learned that he was to be jointly awarded the 2015 Nobel Prize, Koshiba was one of the first people he called to share the good news.
Over the years, Takaaki Kajita’s work has been recognized with numerous awards. Some of his most important awards include:
- 1988 — Awards Asahi Prize
- 1989 — Bruno Rossi Prize
- 1999 — Nishina Memorial Prize
- 2002 — Panofsky Prize
- 2012 — Japan Academy Prize
- 2015 — Nobel Prize in Physics
- 2015 — Fundamental Physics Prize
Since winning the Nobel Prize, he has also been honored by various universities around the world. Some of them have granted him honorary degrees on top of his existing degrees that were earned the usual way.
In his youth, Takaaki Kajita didn’t really like memorizing his school lessons. He took a different approach to his studies, one that apparently worked quite well. From an early age, he was interested in a variety of subjects, including world history, Japanese history and earth sciences. But his true love was physics and he went on to earn multiple degrees in physics, laying the foundation for his groundbreaking work and Nobel Prize in Physics.
His doctoral adviser Masatoshi Koshiba also ran the lab he later joined. Presumably, his advisor was familiar with not only the work itself, but also the quality of thought behind it in the man doing the work. Kajita has worked at this same lab since 1988. The lab is called the Institute for Cosmic Radiation Research and it is hosted by the University of Tokyo. Due to the association between the lab and the college, people who work for one basically work the other as well. Takaaki Kajita achieved the title of assistant professor at the University of Tokyo in 1992 and became a full fledged professor there in 1999.
The same year that he became a full professor, he took over as director of the Center for Cosmic Neutrinos at the Institute for Cosmic Ray Research (ICRR). Since 2017, he is also a Principal Investigator at the Institute for the Physics and Mathematics. This is also part of the University of Tokyo. On top of those esteemed roles, he is also the principal investigator of the KAGRA gravitational wave detector, another project being pursued at the Kamioka Observatory,.
But what exactly does Kajita do? Well, among other things, he investigates the properties of neutrinos.
No, neutrinos are not just made-up nonsense on Star Trek. They really exist.
Neutrinos are very tiny molecular particles, much, much smaller than electrons. Electrons are already tiny compared to protons and neutrons, so researching them is not easy.
Neutrinos get referenced in Science Fiction works for the same reason that Sci-Fi used radiation in stories decades ago to explain every weird thing it wanted to do, like bestow Spider-man with crazy powers: It is real science, but it is cutting edge enough that we don’t have all the answers. We don’t really know what neutrinos can and can’t do. This gives Sci-Fi writers wiggle room to imagine that neutrinos do anything they want done to fill in their plot holes in the story. But Sci-Fi writers may soon need to come up with some new cover story because Kajita is adding to our understanding of this very tiny particle. In 1998, his work established that neutrinos oscillate back and forth between two flavors when they first hit the Earth’s atmosphere. He also helped prove they have mass, though it is some mind-bogglingly tiny amount.
These two discoveries helped fill in some of the holes in the existing understanding of what neutrinos are, what properties they have, and what they might do. This was important enough information to garner him the Nobel Prize, which he shared with a Canadian physicist whose work corroborated his findings.