NTU HIGHLIGHTS October 2017  
  Special Report  

Alumnus Pursues Primordial Gravitational Waves in Antarctica and Tibet

Chao-Lin Kuo, a Stanford professor of physics and an alumnus of the NTU Department of Physics, is leading some of the world's most renowned astrophysicists to the extreme corners of the Earth in order to detect primordial gravitational waves.

At the South Pole, Kuo heads the United States-based BICEP3 team, which includes members from Harvard University, the California Institute of Technology, and the University of Minnesota. BICEP (Background Imaging of Cosmic Extragalactic Polarization) is a series of cosmic microwave background experiments that has deployed radio telescopes in Antarctica to detect primordial gravitational waves. The NTU graduate has worked on BICEP for well over a decade.

Although the BICEP team's claim of discovering gravitational waves at the South Pole in 2014 was later withdrawn, the team's detection and measurement resolution is still recognized as the most precise in the world.

Meanwhile, breathing the thin air atop the Tibetan Plateau, Kuo is collaborating with other researchers who intend to build the world's highest astronomical observation station at 6,000 meters above sea level.

On this project, Kuo leads a Stanford team that is working with a research team directed by Prof. Xinmin Zhang of the Chinese Academy of Sciences' Institute of High Energy Physics. Their objective is to find an extremely dry place suitable for observation with access to logistics in the Ali area on the Tibetan Plateau. Besides collecting data on the Northern Sky, the project team hopes to detect and confirm the primordial gravitational waves that Kuo's team has been seeking at the South Pole.

On July 16 this year, at the end of an epic journey, Kuo and his team members finally arrived at the No.1 Observation Station in Ali at the elevation of 5,250 meters where devices for detecting gravitational waves are under construction for the Phase 1 investigation. Moreover, the team members have started to venture up to the altitude of 5,950 meters in search of a better spot to set up high-frequency devices for the next phase of investigation.

In Taiwan, Prof. Kuo has invited three professors from the NTU Department of Physics to participate in the project. They are: Prof. Wei-Hsin Sun, who is also Director-General of the National Museum of Natural Sciences; Prof. Pisin Chen, who is Director of the NTU Leung Center for Cosmology and Particle Astrophysics; and Prof. Jiun-Huei Proty Wu.

Prof. Sun has worked on the Tibetan Plateau for nearly 10 years, building an optical telescope observatory and promoting astronomy education.

Primordial gravitational waves are the strong gravitational waves that appeared along with the Big Bang and expanded in the universe. The gravitational waves of black holes were detected last year, but the Holy Grail of cosmology—primordial gravitational waves—has yet to be detected and confirmed.