Science Focus ( Issue 21)

Dear Readers, At the HKUST, in-person teaching has been fully resumed since September. The excitement from students who come to lecture theaters and laboratories is overwhelming! We also look forward to spreading the joy of science with you in upcoming outreach activities on campus. In this issue, we continue to bring you stories on how scientific breakthroughs illuminate the past and prepare us for the future. During evolution, body functions can be gained or lost to ensure the survival of a species. Have you ever wondered why pre- historic penguins gave up on flying? Thanks to advanced DNA sequencing technologies, we have also learned a lot more about our extinct, distant relatives who once l ived side-by-side with our ancestors. Fast-forward to the early 1900s, we take a look at experiments that led to the formulation of the periodic table. We also consider the science behind the blue sky, the preparation of hot chocolate and the nuisance of acne. Finally, we delve into the mathematical basis of data encryption and the method that can be used to separate different cell types in laboratories and clinics. We have an exciting series of posts lined up for Instagram. Do join us there for “quick bites” of scientific intrigues of everyday life! Please leave comments and we will try our best to address your questions. Yours faithfully, Prof. Ho Yi Mak Editor-in-Chief 親愛的讀者： 科大從九月起已經全面恢復面授課程，學生們都帶著興奮的心 情回到講堂和實驗室上課！我們亦希望把這份對科學的喜悅透過即 將在科大校園內舉行的外展活動分享給您。 今期我們會繼續向您介紹一些照亮昨天和締造未來的科學突 破。在進化過程中，物種可以透過獲得或失去身體功能使其得以延 續，您有想過史前企鵝為什麼放棄飛行嗎？多虧 DNA 定序技術， 我們現在也能認識更多關於我們的史前近親，這些已絕種的人類曾 經與我們祖先在同一段時間生活在同一天空下。然後讓我們把時間 快轉至 1900 年代，看看那些決定現代元素表排列方式的實驗。我 們亦會從科學角度探討藍天的原理、沖調熱巧克力的小現象和暗瘡 帶來的困擾。最後，我們更會討論數據加密的數學原理，以及在實 驗室和診所內把不同種類細胞分開的方法。 一系列精彩有趣的網上內容已經準備好，記緊留意我們的 Instagram 以獲取關於日常生活的科學小知識！歡迎大家留言，我 們會盡力解答您的問題。 主編 麥晧怡教授 敬上 Message from the Editor-in-Chief 主編的話 Copyright © 2021 HKUST E-mail: sciencefocus@ust.hk Homepage: http://sciencefocus.ust.hk Scientific Advisors 科學顧問 Prof. Jason Chan 陳鈞傑教授 Prof. Ivan Ip 葉智皓教授 Prof. Danny Leung 梁子宇教授 Prof. Pak Wo Leung 梁伯和教授 Prof. Julie Semmelhack Editor-in-Chief 主編輯 Prof. Ho Yi Mak 麥晧怡教授 Managing Editor 總編輯 Daniel Lau 劉劭行 Student Editorial Board 學生編委 Editors 編輯 Sonia Choy 蔡蒨珩 Peace Foo 胡適之 Kit Kan 簡迎曦 Henry Lau 劉以軒 Sirius Lee 李揚 Paolo Miguel Magallanes Mallorca Randy Stefan Tanuwijaya Graphic Designers 設計師 Tiffany Kwok 郭喬 Charley Lam 林曉薏 Cheuk Hei Tsang 曾卓希 Contents Science Focus Issue 021, 2021 What’s Happening in Hong Kong? 香港科技活動 Secrets of the Universe 3D 1 穹蒼解密 3D The Shaw Prize 2021 Exhibition 2021 邵逸夫獎展覽 Amusing World of Science 趣味科學 From the Sky to the Sea: The Evolution of Penguins 2 從翱翔天際到潛行深海：企鵝的進化 The Mystery of the Blue Sky 4 藍天之謎 Physics in Your Cup of Hot Chocolate 6 熱巧克力裡的物理 Genetic Inheritance From Our Long-Lost Relatives 8 從遠古近親而來的遺傳訊息 MythBusters: Acne 12 流言終結者：暗瘡篇 Science in History 昔日科學 The Periodic Table – Putting Each Element in the Right Spot 15 怎樣「證明」元素表的排列是對的？ Science Today 今日科學 Locking Up: Modern Day Encryption 18 重門深鎖：現代密碼學 Flow Cytometry: Sorting Cells by Their Appearance 22 流式細胞技術：如何識別您的細胞 Acknowledgements 特別致謝