P12: News under the Sun (太陽底下有新事)

Every second, about a hundred trillion particles are released during nuclear fusion in the Sun and eventually reached Earth. Streaming through your body but you can hardly feel them, these particles are "neutrinos", carriers of the latest information from the Sun's core. When physicists first counted these "messengers" in the 1960s, two-thirds of the predicted amount were not detected. Was the experiment faulty? Was our understanding of the Sun wrong? Or was the neutrino hiding a secret? This thirty-year "detective story" ended with scientists rewriting the laws of particle physics, which earned them Nobel Prizes. Part of the mystery unfolded on Hong Kong's doorstep: world-leading and precise measurements were conducted next to the Daya Bay nuclear reactors, and the largest neutrino detector of its kind was switched on in the Greater Bay Area just last year.

每秒鐘都約有一萬億顆來自太陽進行核融合反應時釋放出的粒子抵達地球，悄無聲息地穿過你的身體，而你卻渾然不覺。這些粒子名為中微子，攜帶着來自太陽核心的訊息。然而當科學家在上世紀六十年代首次認真數算這些「信使」粒子時，竟發現有三分之二神秘失蹤。是實驗出了差錯？是我們對太陽的認知有誤？還是中微子本身藏有未解之謎？這場歷時三十年的科學「偵探故事」最終改寫了粒子物理學的基本定律，並為科學家贏得多個諾貝爾獎。這個謎團其中一部分就在香港的家門口揭開：科學家在大亞灣核反應堆旁錄得世界領先的精確測量；而全球規模最大的中微子探測器也於2025年在大灣區正式投入運作。

Speaker: Prof. Yiming ZHONG
Target Audience: Form 4 - 6
Duration: 45 minutes - 1 hour
Medium of Language: English or Mandarin

Registration: https://www.cityu.edu.hk/csci/local-school-outreach/popular-science-talks