Nearly 400 high school students from 86 countries converged on Lisbon, Portugal, last month for the 49th International Physics Olympiad. The weeklong event, held 21–29 July, included two days of exams interspersed with sightseeing and other activities.
The overall winner was China’s Yang Tianhua, who achieved the top scores on both the experimental and the theoretical parts of the competition. Every member of the teams from China and India took home a gold medal—it’s the first time the latter country achieved the feat. Medals were awarded on the basis of total individual scores.
With three gold and two silver medals, the five US competitors finished sixth overall in combined points—behind the two all-gold teams and Russia, Singapore, and South Korea. In total, 42 participants from 18 countries earned golds.
The US gold medalists were Gopal Goel of Portland, Oregon; YuQing Xie of Wilmington, Delaware; and—with the second-highest score on the theoretical exam—Daniel Zhu of Silver Spring, Maryland. Mich Song of Fremont, California, and Anthony Ou of Carmel, Indiana, won silvers. Paul Stanley of Beloit College in Wisconsin and JiaJia Dong of Bucknell University in Pennsylvania led the US team, which is sponsored jointly by the American Association of Physics Teachers and the American Institute of Physics, with additional support by AIP’s other member societies. (Physics Today is published by AIP.)
Before going to Portugal, the US team spent a week preparing in Riga, Latvia, with that country’s squad and the team from Australia.
For the first experimental problem, students had to characterize different types of transistors—including paper transistors, which were developed a decade ago by researchers in Portugal. In a second challenge, the competitors conducted various experiments with a viscoelastic thread to determine three characteristic relaxation times.
The theoretical part of the competition consisted of three problems. One involved using properties of the first directly detected gravitational-wave signal, found by the Laser Interferometer Gravitational-Wave Observatory, to estimate parameters of the source, a pair of orbiting black holes. The students then analyzed high-energy particle collision data from the Large Hadron Collider and calculated parameters including neutrino momentum and the mass and lifetime of the top quark. Competitors also tackled a problem about the physics of blood flow in vessels and tumor growth and treatment.
Taking a break from problem solving, students attended lectures on the physics of sports and on life inside the International Space Station. Other highlights included excursions to historic villages, the beach, and an adventure park.
The 50th International Physics Olympiad will be held 7–15 July 2019 in Tel Aviv, Israel.