文化融合的必然過程

過去六個月，香港經歷了前所未有的社會動盪，由最初的「反修例」示威，到目前以「守護香港」為目標的大規模反建制運動。市民所提出的五大訴求，以至在區議會選舉所反映的民意取向，歸根究底是對「一國兩制」投下的不信任票和對抗拒文化入侵所作出的自然反應。太陽底下無新事，從歷史的角度來看，大家所看到的將會是一個「融合」的過程而已。

100年前的香港人主要是新界原居民和漁民（水上人），英國人侵佔了香港後，香港人也曾經激烈的反抗過，最終也「融合」了英國人的統治和生活模式。從文化融合的角度來看，1950–1960年代從大陸湧入了大批有學識、有資金、有技術和來自不同背景的移民，同樣對當時的香港人也帶來巨大的文化衝擊。回想起來，過程也是典型的「衝擊、排斥和融合」的三部曲，當年的新界原居民當然認為他們才是真正的香港人，突然變成少數，感到「被侵略」是可以理解的，他們也曾經激烈地保衛他們相信的傳統權益，政府亦在所謂「丁屋」政策上給予讓步 。香港社會在1970-1980年代也經過多方面的融合，最終產生了香港的一派本土文化和接受了西方的一套價值觀。回歸後的10年，中港文化融合的速度相對較慢，文化衝擊和排斥也相對輕微。到了第二個10年，中央的政策明顯有所改變，加強推動中港融合，可惜操之過急，拿捏欠穩。中央的重點是「一國」，香港人卻把「兩制」視為命根，由於中央和香港人對「高度自治」的理解存在巨大分歧，造成香港人對管治的不信任和對現行制度的否定， 特區政府夾在香港人與中央之間，無法化解矛盾。

從歷史的角度來看，文化融合是不停循環的演化過程，只有動態，沒有穩態。過去五千年來，中國經歷過無數次文化融合，每次都出現不同程度的動盪，過程也必定包括衝擊和排斥的階段，才可達到融合的目標 。香港人正在重新走過一個文化融合的循環週期，而且還處於週期的初段。這六個月的動盪，也許是為新一波的文化融合揭開序幕。再過多20年，香港的政治體制、官場文化、經商模式、教育方針、行政制度、法治制度、辦事手法、媒體報導方式，以至娛樂形式、生活習慣等等，統統跟內地真正的融合起來，新一代香港人取代原有的香港人，矛盾自然消失，天下自然太平！

但變幻原是永恆，真實的世界又豈有永久的太平！衝擊、排斥和融合將會循環不息，而我們今天就站在其中一個循環週期的前段，見證了必然的動盪過程。

2019年12月10日

終結的開始

沒有大台，各自爬山 → 誰不聽誰，勇者越勇，無商討餘地 → 「和理非」行動停頓，剩下口號式的不割蓆，抗爭方式全面以暴力取代 → 錯判香港人的平常心*，觸動香港人的惻隱之心，支持者意見分歧！

從11月10日的中大衝突和「三罷」引發的民怨，我看到的是這場運動的終結的開始。

起初，抗爭者和支持他們的市民以為，只要大家齊心，無論政府（警察）擁有的武力有多龐大，在當前的香港社會是用不著的，這一點本應是政府的要害！當抗爭者訴諸武力，在不傷人的情況下，市民還可勉強接受；可惜，一旦暴力升級，政府順理成章使用更大武力；最終，勇武示威者在沒有大台、無商討餘地、以「莫問前程兇吉，但求落幕無悔」的作戰心態，看不到大局，迷失了方向，同時做出了置人命於不顧的行為，支持者意見開始分歧，政府亦將乘機文武夾攻，可能以成立某種獨立調查委員會暫熄民憤。

「三罷」的第一天，我心中強烈感到他們已經走錯方向，香港人有惻隱之心的怎會接受這種形式的抗爭？我看到有人在理工的新行人天橋上投擲雜物下去漆咸道北，幾乎擊中下面經過的一輛電單車，險些兒可以攞命！有市民清除路障，被弓箭伺候。有七旬老翁被磚塊擊中不治。繼而出現的是對大學無意義的刻意破壞，縱火焚燒隧道收費亭，向鐵路路軌投擲雜物的可致命破壞。然後，一眾「和理非」繼續口號式的說「核爆都唔割」，無聲支持勇武抗爭者的做法，加上文宣對抗爭者的美化、浪漫化和英雄化，間接把他們推到死亡的邊緣！

若暴力抗爭持續，最終必會被中央強行收拾。當香港的原有制度在中央眼中不能保持穩定，中央絕對可以插手改變香港的制度和遊戲規則，甚至製造法律，置你們於死地！別再天真！你們根本不是對手！

2019年11月17日

________________

參考：*「失人心者失天下」— 劉山青 （立場新聞11月17日）

What's Behind the Mask?

On October 4, 2019, Hong Kong's Chief Executive Carrie Lam invoked the Emergency Regulations Ordinance for the first time since 1967 to pass a law that bans face masks to be worn during public assemblies. Carrie Lam officially said that the law would restore order and peace in the city, but at the same time, in self contradiction expected escalating violence in the coming weekend when the new anti-mask law came into effect! So, what is actually behind her anti-mask law?

Clearly Carrie Lam has made her cleverest move, rolling out the emergency anti-mask law at the best timing, even knowing its uselessness. Intentions are clear, however. First, the focus of the plot is now the November election of the District Boards involving decisions of huge community spendings, with considerable political and financial interests. Possibly 721 and 831 were not part of the plot, but 104 likely was, as the chronological orders did not explain the vandalisms in repeated police vacuum (as suggested by combinations of footages), and neither the Commissioner nor the Security Chief could offer a satisfactory explanation. However, 104 and the anti-mask law have successfully made the movement score negatively as life of locals is being affected beyond threshold, and this set desirable trends for pro-government camp to reclaim its lost terrain. Her advisors were doing their job now!

For protestors, it's time to stop while there is still a chance to make a change; otherwise the results of November election will repeat the past 20 years' fate if violence and casted violence continue! November election is indeed crucial! Can't we see why Hong Kong is in what it is in now?-- government's disrespect of people's views because of guaranteed number of votes in District Boards and LegCo, and hence the intensified bullying acts that denounced all peaceful protests in the past 10 years. The price to pay has proved too high! Now feedback control is inevitable to prevent overshooting!

Given the timing of invoking the emergency ordinance and the seemingly well anticipated vandalisms and escalating violence, Carrie Lam's strategy is too obvious to hide, which is to try to revert the election trend and protect the majority of pro-government seats so as to score back in at least one of her assigned duties.

Last but not least, to Hongkongers who have lived here for the past 52 years (since 1967), the emergency law is Carrie Lam's very clear warning that Hong Kong can now actually become lawless. In theory, the District Boards election can be cancelled or rescheduled by invoking emergency ordinance; LegCo and District Boards can even be dissolved under emergency ordinance; companies can be ordered to fire employers who make unwelcome remarks in social media under emergency ordinance; police officers can enter private properties without court warrants under emergency ordinance, etc., all in contrary to our conventional belief! The message sent to the public is more important than the anti-mask law itself.

October 8, 2019

再見！理大！

28年前的今日，我輕輕的來。

當年這裡還是一所理工學院，學系的簡碼是ENC，相信很少同事知道。理工學院於1995年正名為大學之後，學系的名稱也於1998年添了「資訊」兩個字，簡碼亦改為EIE，標誌著資訊年代的開始；自此，學系在科研和教學上不斷進步，在某些領域上已經攀上國際領導地位。我作為EIE的一份子，雖無貢獻可陳，「戥吓光榮」也感到驕傲！轉眼間過了28年，這裡畢竟是我人生中逗留過最長的地方，離別在即，希望自我檢討一番。在這悠長的歲月裡，除了履歷上的增長，我又能找到了什麼意義？很多人說，在辦公室難以建立長久的友誼，在理大渡過的28年裡，我卻感受到濃濃的人情味，幾位前輩好友陸續退休，但至今依然保持來往，彼此關懷。他們讓我學懂了真誠待人的好處，能放棄短暫的辦公室利益，賺來長久的友誼。

在擔任系主任的7年半間 (2005-2012)，有不少機會去探討和反思人際關係的各種問題，我體會到人與人之間的相處就好像一場化學實驗，而「信任」是所有良性化學作用的催化劑。不論是師生之間、同事之間、管理層與員工之間、校內校外人士之間，只要大家互相信任，沒有問題是解決不來的。十年前，我和系內的行政主任發起了為一位罹患重病的碩士生籌款，由於學校並沒有協助自支學生的官方機制，籌款是私人性質，而且需要低調進行，不少同事知悉這事之後，都義不容辭，慷慨解囊，其中一位系內的前輩跟我說了一句令我沒齒難忘的話，他讓我知道他是基於「信任」，才毫不猶豫的把鈔票交給我。

我是理科出身，文化藝術是外行，謙談皮毛也嫌誇張。學校委以文化推廣之重任於我，是對我莫大的信任，我對此亦常懷感恩之心！過去十年來，看到文化推廣辦公室的同事們的積極態度和熱誠，令我深深領略到同事之間的「互信」所釋出的強大動力，而我身為在旁喝采的啦啦隊隊長，卻充分感受到「被信任」的「幸運兒」是何等幸福！這十年在文化推廣工作所經歷的每點每滴，也將成為我腦海中最珍貴的回憶！

過去幾個月，轉換工作環境的機會突然出現了，以往也有好幾次「跳槽」的機會，但今次的感覺卻不一樣！滿載誠意的未來老闆讓你看見一群滿懷信心的同事們將會與你同行，加上自己也意識到理大的變化，不如趁早轉到一個可能更需要你的地方去，心裡強烈感覺是離開理大的時候了！所以，沒有詳細考慮去留問題，憑直覺匆匆做了決定。我是天主教徒，相信一切都應該依賴天主，突如其來的機會必定是祂的旨意吧！

我將悄悄的走，正如我悄悄的來！回想過去在理大的日子，總算是歡笑多於唏噓！很感激多年來一起共事的伙伴、學生和同事們，沒有你們不吝的分享、幫助和包容，絕對不可能有今日的我。借此機會，向你們致以萬二分謝意！將來會怎樣？誰能知曉，亦無用計較，我相信「順其自然」永遠是最佳的選擇。

2019年9月17日

Faith in Mongolia

The idea of a pilgrimage to Mongolia, when first told by my friend Paul, sounded like an extended retreat in a country full of grass prairie and with sufficient fun! After all, apart from attending masses and perhaps helping out a bit in some local Catholic youth centers or schools, I could have plenty of time to see the beautiful Mongolian prairie and explore the proud history of this very special country which bred the world's greatest hero Chinggis Khan.

I had absolutely no idea how Christianity was being treated by the Mongolian authority, and thought it was like in Hong Kong where freedom of religion can be taken for granted. Before departure, the pilgrimage group met up for a briefing and everyone was given some "kids' stuff" (like stationeries, books, candies, toys, etc.) to be carried to Mongolia. This was the first official task each member was supposed to perform. Clearly, these things must be relatively scarce in Mongolia, and we were the couriers! I happily accepted the task knowing this was the first little good thing I could do for the needy!

Every day in Ulaanbaatar was a surprise! The fathers and sisters there were doing all they could to help the locals, like running special schools and youth centers, but without saying a single word of their religious belief. They were simply prohibited to preach, and could actually get into trouble if they were caught attempting to teach the Bible openly. Parish churches do exist, but they only conduct religious activities within the premises. Every day, we held our own mass within our own group at different churches, chapels and even on the Töv prairie (Gorkhi-Terelj National Park). Churches are simple, and could even be a Mongolian ger!

After a few days in Mongolia, I started to appreciate the power of demonstrating your belief rather than preaching directly. Longer I stayed and more I observed from the work of the Catholic priests and sisters here, more I got convinced that if you live your life as a Catholic, people look at you as a Catholic and judge what you do and how you treat people, and you don't need to hard sell the words of Bible, yet you can touch people's heart and make a difference to the beneficiaries. That's my biggest gain in this pilgrimage! I met a few missionaries who devoted their lives to serving the community here. Though they spoke nothing about Bible, they impressed the Mongolians they served positively by what they did. Their sacrifice, love, and hard work all spoke loud and clear about Catholic belief, and that was million times more effective than reading out the Bible texts to the people!

August 16, 2019

對香港年青人的誤解

2019年，香港政府提出「逃犯條例修訂草案」（簡稱"修例"），作了20天公眾資訊，匆匆提交立法會審議，並準備於7月立法會休會前通過。此項修訂引來社會各界的巨大回響，商界、法律界、學界及政治團體紛紛表態，反對修訂。6月9日，100萬市民上街示威，但政府依然堅持草案於立法會繼續審議，其後引發多次大規模示威及警民衝突，是香港自回歸以來，遇到最嚴峻的社會動盪和政治危機。

香港社會亦面對前所未有的撕裂，反對和支持政府的市民變成兩個敵對陣營。黃絲、藍絲之間的衝突，於傳統媒體、網上、街頭，全方位上演！表面看來，這場政治風波是由「修例」單一議題引起的，但事實上，香港過去20年積累的社會和民生問題，已經在社會各界別和階層製造了極深層次的矛盾。以下幾點因由可作參考：

1. 香港自回歸以來，脫離1970-1990年代的工業主導模式，經濟轉由服務性行業擔起（包括：金融服務、旅遊、貿易及物流、及專業服務及其他工商業支援服務1），無須實質創科技術支持，亦無須大型機械器材投資，幾乎純受制於地產霸權。2003年沙士後，中央大幅增加自由行城市的數目和放寬內地人來港限制，以致內地遊客激增（2018年達6千萬），同時也將地價（租價）推到全球頂峰。由於地產和零售業的利潤增長驚人，接近不勞而獲，政府無法再啟動任何工業發展，甚麼cyberport、中藥港、高科技產業，相對的風險比較高，投資者當然懂得選擇。

2. 香港的年青人基本上無法在這種經濟環境下生存，2000年後畢業的大學生的工資永遠追不上樓價的增幅。有人說，其他城市都是一樣啊！可以告訴你，是不一樣的！2019年，香港的"House Price to Income Ratio (HPIR)"高達50，即是說，打工仔平均要50年不喝不吃才有機會買到房子。哪個城市有這麼高的HPIR？（北美城市，10～15。）在香港，打工的基本上沒有機會，創業的也敵不過高昂的租金！除了世襲之外，年青人感到前路茫茫，找不到出路。香港中年人憑他們的經歷，告訴你在1970-1980年代，努力就自然有回報的哲學，今天已完全被否定！沒有家底的年青人與上了岸的中年人之間的矛盾，可想而知！

3. 心理因數也主導了社會的氣氛，老實說，香港在英國人統治時期，社會是比較公平，機會相對均等。有不少內地人問，為什麼97年前香港人不去找英國人爭取民主？現在要這麼激烈的爭取民主？很簡單，97年前，英國人懂得管理，看到老百姓「冇瓦遮頭」，政府建造大量公共房屋，低收入家庭平均1-3年可以分到房屋，夾心階層也可以勉強受惠於租務管制。現在呢？恐怕等10年也等不到公屋！軟實力就更不能比了！97年前香港人感覺受到尊重，英女皇說香港是她「皇冠上的寶石 (Jewel in the Crown)」！當時的行政局議員，還想為香港做點事，向英國國會遊說給予香港人「居英權」，穩定民心。現在，年青人聽到的是威脅言論，漠視民意的言論，他們要出來爭取民主，天真的希望能夠改變這個制度。

4. 近幾年，香港的管治方向更明顯改變了，打壓反對聲音，大白象工程接二連三，由於管理不善，浪費大量公帑。不考慮長遠成本較低的海水化淡方案，持續高價購買東江水，同時承擔高昂的運輸和過濾成本；現在再提出大規模填海，棄用現有土地！背後的目的？背後誰在操控？不言而喻！一國兩制的有效實行，也不言而喻！這一點也是香港問題的癥結所在，自2012年起，香港的自主權明顯逐漸被削弱，嚴格來說是對一國兩制的一種破壞。基本法定明，除國防和外交以外，內地部門不應干預香港事務；而事實上，中央官媒不停攻擊香港人在基本法下容許（但內地不容許）的言論和行為，並透過香港政府和親中商界加以封殺，違反當年設計一國兩制的原意。例如：香港在基本法保障下有言論自由，一位支持示威者的國泰員工並沒有違法，環球時報（官媒，非民辦媒體）是基於甚麼邏輯說他們對飛行安全構成威脅？中國民航局（官方、非民眾）為何要作出封殺國泰航空的言論？港鐵亦如是，起初關閉幾個車站，順應內地官媒的批評，結果遭市民報復，暴力升級至嚴重的刑事毀壞。內地官媒的言論對內地民眾來說，可能是正常不過，香港人卻視之為白色恐怖，破壞一國兩制之舉。問題並非誰對誰錯，乃制度和文化差異所致。國泰是香港上市公司，面對可能被中國封殺的危機，業績要緊，解僱支持示威的員工是理所當然。但是，香港的年青人眼中所見是破壞基本法之舉，他們就是基於恐懼將失去的自由而作出反抗！

5. 至於「逃犯條例修訂草案」本身的問題，就更清楚反映政府的愚昧。表面上看， 「逃犯條例」是關於移交逃犯的，若然不是逃犯，根本無須害怕，而且政府一直把修訂法例放在道德高地，說通過修訂可以防止香港變成逃犯天堂。聽起來很合理！而事實上，政府隱瞞了兩個重點！

   • 第一，所有未經審訊和定罪的所謂"逃犯"嚴格來說都只是"疑犯"，但由於目前中國法庭的獨立性和公平性仍然未能與國際接軌（2017年中國法庭的入罪率高達99.9%！2），移交"疑犯"到內地受審對"疑犯"極為不公道。

   • 第二，亦是最重要的一點，香港特區在回歸後的存在價值在於能否保存國際金融中心的地位。事實上，中國在2017年的實際利用的外資金額達1329億美元，當中有7成仍是來自或通過香港3，足以證明香港作為中國金融窗口的重要性仍然存在。而國際投資者對香港的信心是基於香港擁有一個獨立於中國的施法制度，逃犯條例修訂一旦通過的話，香港馬上失去一個被投資者信賴的施法制度，國際金融中心的地位將會蕩然無存，外資續漸撤離將在所難免。

6. 政府恃著立法會有超過半數（47名）建制派議員的支持，通過法例修訂的機會是100%，無須向任何反對人士妥協。從年初諮詢，到提交立法會審議，態度極為囂張，一直漠視民意，對學者、法律界人士和專業團體提出的憂慮全盤否定，視反對聲音為「全部廢話」(特首於立法會說 "these are all rubbish")。到6月，硬上立法會三讀，對100萬人和平示威視而不見！

年青人的憤怒，反映了他們對政府的種種不滿！他們本來希望以和平的方式表達訴求，但他們的聲音全被漠視，他們當中也有不少還抱著能改變制度的天真願望！對於少數激進示威者來說，2014年的「佔中」運動已經證明了和平表達是零效果的，再經過今年6月9日100萬人大遊行之後，政府依然無動於衷，又再證明所謂「和、理、非」只是空轉，他們最終選擇了使用違法的暴力手段，不惜破壞社會秩序，試圖逼使政府聆聽他們的訴求。對這些示威者的違法行為，我不能苟同，且感到非常心痛；但若然只聚焦他們在2019年某某日所犯的某種違法行為，而忽略了當權者過去數年來持續對他們的意見的漠視，也欠公道。令人最憤慨的，是政府選擇了利用前線警察作為對抗市民的工具，不惜破壞本來良好的警民關係來處理這場政治危機。

2019年7月21日（8月31日更新）

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1 https://www.censtatd.gov.hk/hkstat/sub/sp80_tc.jsp?productCode=FA1000992 Conviction rate: https://en.wikipedia.org/wiki/Conviction_rate3 https://news.ltn.com.tw/news/world/breakingnews/2825419

黃藍何以對立？— 相互否定論

假定：

• 一個城市的人口分為兩個敵對的群組：A群和B群。

• 每個群組的成員對於敵群成員都有先入為主的行為特徵偏見。

  • 即：A群組成員堅信B群組成員都具有「B行為特徵」；而B群組成員堅信A群組成員都具有「A行為特徵」。這裡的「A行為特徵」和「B行為特徵」都是負面特徵。

兩個群組交鋒的時候，互相指責敵群的那些行為特徵。當敵群成員聽到被貼上他並不認為代表自己的標籤時，便感到冒犯，覺得敵群無中生有，惡人先告狀。這樣，兩個群組互不信任、水火不容。

自2014年佔中以來，香港人就是活在這種對弈狀態，「藍絲陣營」認為「黃絲陣營」是暴徒，是被誤導的年青人，斷定有外國勢力支撐；而當黃營的一位普通成員（你或我）聽到自己被說成暴徒時，當然非常憤怒，也深信自己從來未被誤導，也沒有受到外國勢力影響，認為藍營的指控極為荒謬。反過來，黃營認為藍營的人是拿了共產黨的好處，盲目奉承，賣港求榮；而藍營的某普通成員（你或我）聽到指控亦非常憤怒，深信自己從來沒有收過半點利益。

假若你是某群組成員，你一定認為自己可以證實那些負面特徵在你身上從未存在過，所以斷定敵群生安白造、其心可議。這個困局是沒有基本解決的辦法，由於負面特徵的偏見是由某一邊對另一邊提出的單方面指控，而特徵的真正存在與否只可以由另一邊的人來驗證。若說你是一名黃絲，只有你才知道你為何支持黃營，他們說你是暴徒，你永遠含冤莫白！令情況進一步複雜化的是，A群也可以包括A1次群、A2次群、A3次群...，若然Ax次群成員確實表現某種負面特徵，而該種特徵被B群概括為所有A群成員的共同特徵，導致眾次群產生內控，變成深層次矛盾。

這個局面恐怕短期內不會改變，需要時間來修補社會的撕裂，沒有特效藥。政府應該盡力避免爭拗，絕不應再挑起事端，加深矛盾。

2019年6月14日

「一地兩檢、逃犯條例」— 你究竟害怕什麼？

去年的「一地兩檢」、今年的「逃犯條例修訂」弄得立法會一團糟！沒錯！香港人對大陸的執法方式和司法制度存有戒心，故對在香港境內設立內地執法區懷有恐懼之心，實在不難理解。同樣道理，移送疑犯返回大陸受審，港人聞風喪膽，實屬正常。

理性一點，在西九高鐵站內設立內地執法區，就只有乘坐高鐵前往內地的旅客才會受到影響。若然你不打算往大陸，哪來西九高鐵站幹什麼？事實上，如果你選擇乘高鐵往大陸，一地兩檢只會減省你在兩邊口岸區所需的檢查時間。若然你永不踏足大陸的話，那乜地乜檢又與你何干？

「逃犯條例修訂」亦如是，假若你從來沒有在大陸犯過案，遣返逃犯又與你何干？不過，反對的人總可以扯上某些政治議題，例如擔心「逃犯條例」會被利用作為迫害異見人士的工具；或者，多年前在內地行賄疏通，怕被秋後算賬；又或者，某年某月得罪某某國內權貴，怕被插贓嫁禍。問題都是源於對中共政權的恐懼，而實質上「逃犯條例」對於一般市民的生活而言，根本扯不上半點關係！

雖然「逃犯條例修訂」對一般市民的直接影響輕微，但由於修訂將會容許內地法律伸延至香港，繞過香港法庭和立法會，直接遞補和移交疑犯。香港將會失去作為一個中國城市的獨特性，外國投資者對香港法制的的信心下降，撤資的可能性極高。「逃犯條例修訂」一旦通過，除非中國在法治制度上有根本性的改變，香港的國際金融地位將會蕩然無存！

2019年5月21日

Counting number in protest march

Every time after a protest march was held, I am always curious about the huge discrepancy between the Police's and the organizer's estimates of the number of people who participated in the march. In yesterday's protest against the extradition law1, the Police reported "22K at peak time", while the organizer claims there were 130K! So, they surely had done the counting in very different ways!

The Police's "22K at peak time" clearly implies a snapshot approach which only makes sense when the area is fixed and well defined. In yesterday's protest, however, people actually moved from Causeway Bay to Central over a period of 2 hours. So, we shouldn't be counting number at a particular time! Rather, we should be counting how many people had moved along the path of the march over a period of time. In other words, it is a flow problem rather than a static counting problem. Imagine you turn on the water tap in your kitchen and let water flow out for two hours. How much water can you collect at the end? That's the question!

Clearly, "22K at peak time" ("最高峰時有2萬2千人") is literally absurd, as far as a flow problem is concerned. Does "peak time" refer to the time when the largest number of people were present in the whole scene (from Causeway Bay to Central)? Did the Police take a snapshot at a particular instant of time and recorded a maximum of 22K people? Why does this "22K at peak time" relevant to the actual number of people who participated in the march?

In fact, the number can be quite easily worked out if it is taken as a flow problem. Let’s put the road in the "horizontal" direction for ease of referencing. (See figure below.) Suppose in roughly every S sec, a group ("vertical" line) of N people have flown through an observation point on the road. The flow rate is N/S.

Suppose three car lanes accommodate about N people lining up orthogonal to the road. News reported that people began walking from 3:40 pm, and the last group departed around 5:45 pm, i.e., a duration of 125 minutes.

The flow rate is just the total number of people flowing through the path divided by the total time, i.e.,

Now the question is how many people have moved through the observation point from 3:40 pm to 5:45 pm? A rough but reasonable estimate can be made if we take:

• Total time = 125 x 60 sec

• N = 25 , S = 2 (i.e., 25 people flew through every 2 sec)

Thus, there were 125 x 60 x N / S = 93,750 people passing through the observation point!!

If more or less people (20 < N < 30) actually moved faster or slower (1.5 < S < 3), the answer would be different. But the magnitude is still pretty much within the range 50,000 to 150,000.

I would say 90K shouldn’t be too far, after discounting early leavers. But if you include everyone who showed up, over 100K is still very probable. For this kind of protest marches, it makes no sense to talk about number at particular time, and as I said, the Police's "22K at peak time" is literally absurd. In yesterday's case, the main factor was the rather long duration of flow, more than two hours through a point along the trajectory!

April 29, 2019

_______________________1 Estimated 130,000 protesters join march against proposed extradition law that will allow transfer of fugitives from Hong Kong to mainland China — South China Morning Post, April 28, 2019.

「利瑪竇」音樂劇

向來很少觀看宗教題材的話劇，怕困在劇院內被硬銷某教派所擁抱的真理。我不是反對人傳教，但比較接受在生活中體驗信仰的奧妙。年初聽到劉松仁先生傾力炮製「利瑪竇」音樂劇，非常好奇這位在娛樂圈打滾了數十年的資深演員和虔誠的教徒如何把利瑪竇的事蹟搬上舞台，如何平衡一般觀眾的期望和他製作此劇的初心，極盡視聽之娛，能否收傳道之效？

上星期六看過首演之後，大感佩服劉先生處理此劇的手法！縱然是一齣帶強烈宗教色彩的舞台劇，但並無絲毫刻意傳教的感覺，反而令我反思在中國實踐文化共融的巨大挑戰！利瑪竇500年前來華傳教，面對文化差異，波折重重。最欣賞的是鄭國江老師的詞，活化了本來極為沈重的宗教題材，借古諷今。一首又一首的歌詞對人性的刻畫，入木三分！尤其感動的是當利瑪竇唱出 「心灰意冷，天主已忘掉我 ... 」劇中講述朝廷的迫害和來自四方的壓力，至今可有絲毫減退，這詞正好獻給苦難中的中國教會，勉勵信徒仰仗天主的帶領，最終必能走過黑暗的幽谷！「... 別絕望，為有祂伴著你行... 有苦有甘，記取由人...」

2019年4月25日

What happened to the Boeing 737 Max 8 ?

Two Boeing 737 Max 8 jets crashed within 6 months.1 Several basic facts have recently emerged, which prompted authorities to ground this new variant of the popular Boeing 737 airliner. While more investigations would be needed to identify the detailed causes of the deadly crashes, the several basic facts collected so far already permit a crude mural to be drawn up for the likely events that might have taken place in the cockpits of the Boeing 737 Max 8 jets right before they went down.

In order to see how a control system typically fails, one needs to understand the way a closed-loop system works and the inevitable hazard of oscillation. In laymen terms, any closed-loop system is prone to instability when the control efforts and the feeding of sensing signals fail to work in harmony. For instance, when you're listening to music while adjusting the volume of the speakers or airpods, you're controlling a closed-loop system. If you feel the sound being too loud, you attempt to turn the volume down. This is a typical feedback action, creating a closed loop. But if you react too slow and too drastic, the volume goes too far down, and after some delay the sound becomes too soft to be heard. Then, you would turn the volume up again, and if you do it a little too drastic, the volume gets too far up after a typical delay. Attempting to turn the volume down again repeats the process, and creates an oscillation. The situation for the Boeing 737 Max 8 crashes could be made more complicated by an apparent but "unintended" two-loop control.

Facts

1. The satellite track data of the Boeing 737 Max 8 crash last October in Indonesia and the crash earlier this month in Ethiopia consistently show typical oscillatory transients leading to the crashes.
2. The pilots of both flights had struggled to save the aircrafts for a period of time before the aircrafts crashed.

Likely Events

First, the new automatic MCAS system (Maneuvering Characteristics Augmentation System) on the 737 Max 8 works on a typical feedback principle to prevent the jet from getting into a stall2. Basically, it senses the so-called angle-of-attack (AOA) and commands the aircraft's nose to dip down to prevent a potential stall. However, the operation of this new MCAS may not be clearly known or understood by the pilots who have flown the conventional Boeing 737 jet for many years and would do the nose control in the usual way.

The problem is that the 737 Max 8 allows the pilot to intervene while its MCAS works to fix the same problem, creating a double-loop control situation. The AOA signal causes both the pilot and the MCAS to react, but with different speed and effort (technically called closed-loop bandwidth and gain).

The nose control overshoots and AOA continues to feed signals back, and always with delays of different magnitudes (even different orders of magnitude as human and machine do react quite differently). This might create an oscillatory response, as revealed by the satellite track data, in which the aircraft repeatedly climbed and descended under the two separate (pilot's and MCAS's) control actions.

The Deadly Event

The two-loop continues to work and creates an oscillatory response. In theory, this is fine as long as every parameter remains constant, and the loop gains are controlled precisely to maintain sustained oscillation within a safe range! But multiple factors may cause something to happen in a fatal way.

1. The human pilot, who is the controller of one of the loops, cannot repeat his action precisely every cycle even though all other parameters are perfectly constant.
2. External factors like wind speed and direction may introduce disturbances to the system that cannot be reacted precisely by the human pilot, especially since sustained oscillation normally requires irregular control effort (technically called nonlinear gain control).
3. The human pilot loses control and fails to follow the oscillatory pattern. In order for the aircraft to diverge its altitude, the gain and bandwidth of either loops must have drifted to the unstable region causing the aircraft to lose stability and eventually go down under the force of gravity.

The above description is a very general control scenario, often described in elementary control engineering texts. To know the exact causes, we need to fill in a lot more technical details, likely different sets of details in the two crashes, which can only be unfolded through examining the detailed flight data.

March 16, 2019

_____________________

1 Ethiopian Airlines, Lion Air crash linked by new evidence — New York Times (March 15, 2019)2 Stall — An aircraft normally flies horizontally, and may climb up or descend at an angle within a certain limit. When the aircraft goes too steep up, its wings no longer provide the needed upthrust and the aircraft continues to move up almost vertically and surely loses speed under gravity. It soon stops as it reaches a peak altitude, which is called a "stall", and then drops rapidly under gravity. After the stall, the engines are not powerful enough to restore normal flying given the heavy weight of the aircraft, and disaster is inevitable. Modern jets usually have sophisticated control systems to prevent a potential stall.

My Dad

Since my dad passed away in January, I have kept retrieving from the back of my mind how he influenced the way I have lived in the past many years. He seldom talked to me anything formal about study, work or life, presumably not to my brother and sister either. In fact, I can't recall a single instance where he sat us down for a heartfelt conversation about any substantial life topics. But as I thought about what he did and made us do, I can almost conclude without a single doubt that I have all along been copying him. I can easily come up with a long list of things I have learned to do from watching him do, like peeling apples, frying eggs with a Chinese wok, stir-frying choy sum with beef, fixing a carton box, writing cheques with Chinese numeric characters, riding a push bike, calligraphy, .... and many useful skills! However, I probably never realized when I was young that he had imperceptibly bequeathed to me and my two siblings the way he treated people and his faith in God.

After he left, I found myself reflecting on the profound wisdom he had imparted to us. First, he was nice to people and his mantra was "When helping others, do not calculate!" I had witnessed how seriously he involved himself in voluntary works in Cheung Chau Life Saving Club, Auxiliary Medical Service, Chung Shak Hei Elderly Home, The Lady of Fatima Church, and Cheung Chau Rural Committee. However, it was during his funeral service that I learned of countless other acts of selflessness he had performed. While I have certainly not achieved the same magnitude of impact as he did, I have always strived to empathize with others and extend a helping hand whenever possible.

My father had an enormous amount of faith in God. I can never forget the way he reacted when I asked whether he was anxious about a pending open-heart surgery back in 1993, hoping to make him feel easier before the operation. I was speechless when I heard him say in less than a blink of an eye, "No! Nothing to be scared of? God is with me! (驚咩？有乜好驚？天主會同我一齊！)" He was actually very calm, quite unconcerned about any possible complication of the operation, and without a tiny bit of fear, and that moment I learnt the importance of having faith, and how faith helped overcome fear! Leave it all to God, and nothing needs to be worried about!

Now he has gone, but certainly not forgotten, especially his double package of life: be nice to people and have faith in God!

March 4, 2019

「風雨之後，也無風雨」

今日，到灣仔天地圖書參加洪朝豐先生的新書發佈會，聽這位曾患鬱躁症、飽受癌魔折磨的人分享他「風雨之後，也無風雨」的體會。半個小時訴說患病的故事，天不絕人，人間亦有情，令人感動！明白到原來自己有多強並不重要，能“放下“才是最重要！經歷過人生無常，領悟活著最大的“秘密”竟是簡單的“順其自然”！

洪先生，加油！

2019年1月12日

香港的「私處 Centre」

正所謂「唔怕生壞命，最怕改壞名！」剛落成的香港戲曲中心，英文翻譯為「Xiqu Centre」，外國人毫無頭緒，而大部份香港人不懂普通話拼音，也看得一頭霧水！

如果翻譯英文名稱的目標是為了給外國人（或不懂華文的遊客）知道這座別出心裁的建築物為何物的話，Chinese Opera 理應是最貼切了！但官方卻認為中國戲曲不應該譯作 Chinese Opera，憂慮會誤導公眾，以為中國戲曲乃係承傳自西方歌劇，最終敲定為「Xiqu Centre」。

換過角度看，縱使"opera"作爲中國戲曲的英文翻譯有不足之處，而成立香港戲曲中心的主要目的是為粵劇表演團體提供表演場地，觀眾也大多來自粵語區。那麼，"Hei Kuk Centre"是否更有意義？

若按此等邏輯來做翻譯，恐怕 Hotel 應該改為 kezhan (中國自古已有"客棧")，Breakfast 在餐廳的菜單上應叫 Zaofan (中國人自古都吃"早飯") ，「白粥油炸鬼」肯定要譯作 Baizhouyoujiagui。即是全部不用翻譯，以免令人誤會承自西方！

2019年1月3日