The State Key Laboratory of Dark Matter Physics and the Shanghai Key Laboratory for Particle Physics and Cosmology welcomed more than 300 visitors to the Tsung-Dao Lee Institute (TDLI) on May 30 for a public Open Day themed “From Particles to Galaxies: Exploring the Invisible Secrets of the Universe.”
Held as part of the 2026 Shanghai Science and Technology Festival, the event offered members of the public a unique opportunity to explore some of today's most ambitious scientific efforts—from the search for dark matter and neutrinos to astronomical observations of the distant Universe. Through lectures, laboratory tours, hands-on demonstrations, exhibitions, and observatory visits, participants experienced how fundamental research seeks to answer some of humanity’s most profound questions.
Exploring the Frontiers of Physics
The program began with a series of short public lectures delivered by the laboratory scientists.
Prof. Kun Liu introduced the world of elementary particles and modern collider experiments, while Prof. Huilin Qu explained how artificial intelligence is transforming the search for new physics. Prof. Yue Meng discussed the role of low-background technologies in dark matter experiments through the topic of everyday radiation, and Prof. Yumin Zhao explored the fascinating physics of atomic nuclei and their significance in the Universe.
The talks sparked lively discussions, with many young attendees eagerly engaging scientists during the question-and-answer sessions.
Visiting the Major Research Facilities
Visitors were invited to learn about several major research platforms hosted or supported by TDLI.
In the Dark Matter Detection Laboratory, Prof. Ning Zhou and Dr. Xiangyi Cui presented the development of the PandaX experiment, one of the world’s leading dark matter search programs. Participants learned how successive generations of liquid-xenon detectors, operating at the China Jinping Underground Laboratory nearly 2,400 meters beneath the Earth’s surface, have achieved increasingly sensitive measurements. Researchers also introduced plans for the next-generation PandaX-20T detector.
Through a virtual deep-sea journey, Ph.D. student Jingtao Huang guided visitors to a depth of 3,500 meters beneath the South Sea, where the TRIDENT Neutrino Telescope is being developed to detect elusive cosmic neutrinos.
At another exhibit, Associate Researcher Qinghui Sun used a model of the JUST Spectroscopic Telescope to explain how spectroscopic observations can help scientists investigate dark matter, dark energy, stellar explosions, compact-object mergers, and distant exoplanets.
Physics in Action
More than twenty interactive demonstrations transformed complex scientific concepts into tangible experiences.
Visitors observed muon detection systems, spark chambers, superconducting magnetic levitation, cryogenic phenomena involving liquid nitrogen, and optical polarization experiments. Researchers and student volunteers guided participants through the demonstrations, introducing experimental techniques widely used in modern physics laboratories.
A science-themed stamp collection activity added an element of exploration and discovery, particularly for younger visitors, encouraging them to engage with every exhibit throughout the day.
Science, History, and Inspiration
The exhibition area showcased both historical and contemporary milestones in scientific research.
Among the highlights were a replica of the Nobel Prize medal awarded to T. D. Lee in 1957 and a copy of his Nobel Prize certificate. Visitors also viewed research instruments including a PandaX-II detector component and an ATLAS Resistive Plate Chamber module, offering a close look at technologies used in cutting-edge particle physics experiments.
Inside Tianwen Hall, a panoramic timeline traced the 13.8-billion-year history of the Universe, illustrating humanity’s evolving understanding of cosmic origins and evolution.
The day concluded with guided tours of the Yuanqi Observatory. Although cloudy conditions prevented solar observations, visitors explored the observatory’s telescope facilities and learned about the scientific goals and observational techniques that underpin modern astronomy.
Inspiring the Next Generation
Modern scientific discoveries increasingly rely on facilities located deep underground, beneath the ocean, or atop remote mountains. Yet events such as this Open Day help bridge the gap between frontier research and the public.
Throughout the event, visitors of all ages demonstrated remarkable curiosity and enthusiasm. Children asked thoughtful questions, families explored scientific exhibits together, and students gained first-hand exposure to active research programs.
By opening laboratory doors and sharing the excitement of discovery, TDLI and its partner laboratories hope to inspire future generations of scientists and encourage a deeper appreciation of fundamental research.
As we continue exploring the mysteries of the Universe—from the smallest particles to the largest cosmic structures—we look forward to welcoming the public again next year.