It is now accepted that the universe began with a Big Bang.  The Big Bang model, implicit in the Hubble expansion observed in the 1930s and firmly established with the discovery of the cosmic microwave background (CMB) in 1964, is now part of the classical canon.  Some astonishing  advances have been made in precision cosmology in recent years: age of the universe to (nearly) 4 significant figures; acceleration of cosmological expansion and gravitational repulsion at large distances; new forms of matter and energy, previously unknown, accounting for 96% of the universe; and firm knowledge of the history of the universe back to very early times.  One theme will be the displacement of speculation by accurate measurements and the emergence of cosmology as a precision observational science.

廣深港高鐵與港珠澳大橋是香港特區政府成立後兩項最大基建工程，亦是引起社會爭議最多的項目。究竟這些過千億元投資的工程為何而建？為誰而建？無論是有政治任務在身的官員、得益最大的發展商、被迫滅村的菜園村居民、受空氣污染加劇之苦的東涌社區、以至直接受惠的工程建築界，對項目的取態均截然不同。但最深遠的影響，莫如這些跨境項目所標示的中港融合，以至深港「同城化」的願景。正當本土意識在港日益高漲之際，重新檢視這兩個項目的深層意義，有助港人了解中港矛盾的來龍去脈，更可作為「香港往何處去」的參照座標。

文學中的真實，肉眼不能見，卻能穿透現實；它根本就是在再造現實，是一種將真實事物重新定義的能量。

新聞以發掘和報導真相為已任，為了求真，新聞工作者須付出多少努力和代價？在求真的路上，新聞工作者又遇到甚麼困難？過去兩年，香港出現頭條被改、主持被「炒」、採訪權被限制，以至編輯、記者、報館遇襲等事件，莫非求真即是惹火？與此同時，民間記者如雨後春筍；透過社交媒體，人人都可參與報導「真相」。一般普羅大眾，可如何閱讀這些新聞？

A description is offered in layman language on the basic scientific principles of global warming induced by human activities. The impacts of climate change on various components of the Earth System (atmosphere, ocean, land, cryosphere, etc.) are reviewed. The scientific research tools and methodology used to understand the current state of the climate system, and to project its evolution in the coming decades, are introduced. The role of the United Nations Intergovernmental Panel on Climate Change (IPCC) in coordinating and documenting the efforts of the scientific community is explained. The experience and observations of the speaker in contributing to the work of the IPCC during the past two decades are shared with the audience. An account is given of the social controversies surrounding the IPCC reports, with reflections of the personal hardships faced by several climate scientists in these debates.

1919年在北京爆發五四學生運動，隨後蔓延至上海及中國各大城市，演變為「罷課、罷市、罷工」風潮，綿延數月才告落幕。五四運動引起許多研究者的關注，然而歷史真相到底如何？過去周策縱教授、彭明教授各撰寫了一部專著，成為五四運動史的經典論述，但近年出版的公家檔案及私人紀錄告訴我們：有關五四運動的歷史細節，甚至包括一些關鍵性問題，都很有重新探討的必要。歷史工作者的求真之旅遇到甚麼挑戰？如何克服重重困難？本講細梳慢理政治詮釋和歷史詮釋層層交織的葛藤。