By Abigail Klein Leichman Nov 7, 2010
Two Israeli‑American citizens will be among the 10 recipients of the US National Medal of Science, to be presented by President Barack Obama on November 17. Both men maintain ties with Tel Aviv University (TAU) while holding academic positions at universities in California.
TAU Prof. Emeritus Yakir Aharonov, 78, boasts a lifetime of contributions to quantum physics. The first was the Aharonov‑Bohm Effect developed in 1959 to describe the action of atomic particles around a magnetic field, and the most recent is the theory of weak measurement ‑ a novel approach to measuring dynamic systems. He is now in his third year of research at California's Chapman University, and it was the chancellor there who nominated him for the medal.
Prof. Amnon Yariv of the California Institute of Technology will be honored for his advances in photonics and quantum electronics that revolutionized modern communications. Throughout his 36 years at CalTech and in the business world, the 80‑year‑old Yariv has maintained a permanent fellowship at TAU's Sackler Institute of Advanced Studies.
Aharonov: "It's only the beginning"
Aharonov was a graduate student at Bristol University in England when he and his thesis supervisor David Bohm came out with the Aharonov‑Bohm Effect that bears their names. Until then, quantum physicists assumed that if the speed of a particle was to be changed, the forces effecting that change must exist at the same place as the particle. Aharonov proved this assumption false by showing how a particle moving in a vacuum outside a magnetic field will still be affected by that field.
The Haifa‑born Aharonov, who frequently travels home to Tel Aviv, now works in the little‑understood field of quantum mechanics, which studies matter at the atomic level.
"Any form of energy ‑ for example, light ‑ is made up of lumps of energy you cannot divide further; that's what 'quantum' means," he explains for ISRAEL21c. Scientists couldn't predict precisely how these minute 'lumps' might behave in different circumstances since it was not possible to measure a system without disturbing it.
Over the past 20 years, the revolutionary 'weak measurement' theory developed by Aharonov and two colleagues has enabled the discovery of new properties of energy systems because it does not disturb them. Even as he continues to research and teach weak measurement at Chapman, physicists all over the world are using this method to examine microscopic events ‑ such as what happens when a laser beam gravitates from air to water ‑ that could never before be analyzed accurately.
"It's only the beginning," predicts Aharonov, a past Nobel Prize nominee who plans to attend the White House ceremony along with his wife, son and daughter. Previously, he has received the Wolf Prize (regarded as Israel's equivalent to the Nobel), the Weizmann Prize in Physics, the Rothschild Prize in Physics and the Israel Prize in Exact Science.
Yariv: Communication revolution
"Light is a fantastic medium," Amnon Yariv asserts to ISRAEL21c. "You can't really keep up with all of it, so you wind up following some segment of the field in which you already have a facility to understand it."
Still teaching CalTech graduate courses in applied optics and the physics of lasers, the professor early on chose to focus on tiny semiconductor lasers, used in delicate optical applications.
He began researching them in the early 1960s at the Bell Telephone Laboratories in New Jersey. By the time he joined CalTech in 1964, "I had reached the conclusion that semiconductor lasers would take over one day, so I bet the family jewels on them."
The wager paid off handsomely. "In the 1980s, the semiconductor laser became the mainstay of optical communication, which is the backbone of the whole Internet."
Yariv co‑founded and chaired Ortel, a corporation acquired by Lucent Technologies (now Alcatel‑Lucent) in 1998, as well as other start‑ups aimed at bringing the innovations of CalTech students to the marketplace.
Ortel's technology for transmitting cable TV signals through fiber optic (light) instead of coaxial (copper) cables vastly improved the quality and ease of transmission. The company was co‑founded by CalTech graduate students Israel Ury and Nadav Bar‑Chaim. Though Ury is the only one of the three now living in Israel full time, Yariv often visits the city of his birth to teach, "speak Hebrew full‑time, see relatives, and eat falafel," he says with a smile.
A past recipient of many prizes, Yariv says his most memorable award to date was the 1992 Harvey Prize from Israel's Technion Institute, which he shared with former Russian President Mikhail Gorbachev.
"We sat on the stage together and tried to talk, and eventually it turned out he knew some German and I knew some Yiddish," Yariv recalls. "He wanted to make sure I understood that none of the award money was going to him personally but to his foundation."
Yariv will travel to Washington to receive his medal from Obama together with his wife and three daughters.