On Sunday, February 22, 2026 Associate Professor Yuji Chinone of the International Center for Quantum-field Measurement Systems (WPI-QUP, KEK) delivered a public talk titled “Unveiling the Secrets of Quantum Physics and the Universe on Cat Day” at a science café held at Saza Coffee Tsukuba University Alliance Branch.

This science café event was organized to commemorate the launch of a six-pack set of drip coffee bags featuring the original blend “Cosmic Composition Blend.” Created in 2025 through a collaboration between the High Energy Accelerator Research Organization (KEK), Saza Coffee, headquartered in Hitachinaka City, Ibaraki Prefecture, and OTASAKU Shoji, a company producing a wide range of original goods mainly in Ibaraki, this special blend symbolizes the composition of the universe. For this event, a newly designed package was introduced, and the special-edition six-pack set went on sale on February 22, known in Japan as “Cat Day.”

Despite the early start time of 10:00 a.m. on a Sunday, the venue was filled with participants who had registered in advance. Following an introduction to KEK and an overview of the event by navigator Yosuke Yamazaki of the KEK Public Relations Office, Chinone began his lecture.

In honor of “Cat Day,” he first explained the famous thought experiment in quantum mechanics known as Schrödinger’s cat. He then introduced the mysterious properties of quantum mechanics, clearly illustrating the question of whether particles behave as “particles” or “waves” using the slit experiment as an example. Throughout the talk, the content remained approachable and engaging, characteristic of a science café, and many participants were seen nodding and taking notes attentively.

Drawing an analogy with the “composition of the universe,” Chinone also presented his own life story using a pie chart and shared humorous anecdotes reflecting his love of coffee. His lively and witty storytelling frequently elicited laughter from the audience.

To conclude, he introduced his current research, focusing on observations conducted at the Simons Observatory for cosmic microwave background radiation in the Atacama Desert of Chile. Reflecting the wide-ranging nature of the lecture, the audience actively posed questions, including “, “Does dark matter feel gravity?” and “Could there exist a universe composed entirely of dark matter?”

Related Links
KEK｜Event (Japanese)
https://www.kek.jp/ja/event/202602221000otasaku