https://bobostory.wordpress.com List

  • 13 Things I Found on the Internet Today (Vol. 687) - [image: 13 Things I Found on the Internet Today (Vol. 687)] 1. Truth Windows A traditional feature of strawbale houses is the truth window – a small secti...
    19 hours ago
  • 陳韻文的《滋事札》 - *陳韻文著︰《滋事札》* 陳韻文八十年代在《星島日報》的專欄,陳進權先生經年剪存,如今選輯修改,訂成一冊,最近終於面世,書友無不捧場。五十多篇文章,有些未必來自《星島》,大部分經過重寫,和專欄原貌大不相同,不少寫的更是這數年的人事,完全可當是新書看。〈引子〉寫「滋事札」名字之由來(原來轉自鵲鴝「豬屎渣」之名)...
    2 days ago
  • 蒟蒻 - 蒟蒻,就是魔竽,英文名稱為魔舌Devil’s Tongue,是一粒粒的球狀根物,外表漆黑,肉雪白。 主要成分是 […]
    3 days ago
  • belated February 2024 Patreon round-up: EXCLUSIVE - True Detective: Night Country + ADVANCE - TWIN PEAKS Character Series entry - Although I offered a couple standalone sci-fi episodes last fall, *True Detective: Night Country* is my first (but probably not my last) patron-exclusive...
    1 week ago
  • Politics (論政治) - 要做醫生,先要讀醫;要做司機,也要考牌。世上唯有從政,可以完全沒有受過訓練就上任。其實從政應該如何入手呢?回看上世紀的政治人物,不少都受過深厚的哲學訓練,那是因為哲學一般分為形而上學、自然哲學、倫理學以及政治哲學。其中政治哲學研究的,正是政府的形式、權力的分配、革命的基礎等。美國的開國領袖不少便是美國哲學學會的...
    4 weeks ago
  • Live Q & A with David Harvey & Miguel Robles-Durán - Join me and Miguel Robles-Durán for a live Q&A session tomorrow, Wednesday, January 10th at 2:00pm (EST). Support our Politics in Motion Patreon to submit ...
    2 months ago
  • 下坡的思維 - 當我們沿迎風坡而下時,風顯得大而勁了。我穿在許臂彎裡的手慣性的縮回而拉一下裙裾。陡然,我感到這種無意識動作的可 … 繼續閱讀 下坡的思維
    3 months ago
  • 鄭明仁:41年歷史《旅行家》成絕響 - 陳溢晃帶隊遊新界。 資深旅行家陳溢晃於1972年成立正剛旅行隊,半個世紀以來他每周都帶隊作本地遠足遊;1982年1月他創辦了《旅行家》雜誌,到今年已41年,是香港歷史最悠久的本土旅遊雜誌。遺憾的是,陳溢晃月前急病離世,正剛和《旅行家》恐怕要停辦了。 陳溢晃離世,是香港旅行界的損失。 *研究本地史的寶貴資料...
    4 months ago
  • 翻译:巴迪欧《真理的内在性》第二章四种有限类型的辩证法 - 第二节 辩证法 就某一类消极有限性而言,这绝不是一个将无限性与有限性相对立的问题。因为所有真正的力量最终都需要在有限记录(registre )中运算。问题在于,要假设出一种积极有限性,而这种有限性不会成为无限性的消极废值。 一、主要假设 既然如此,我提出以下假设:要想有真正的活动,要想让有限的东西...
    2 years ago
  • 溫度日記 APP:用柔美的手繪插圖來療癒你的心、豐富你的手帳日記!(Android、iOS) - 無意中看到「溫度日記 Hearty Journal」,赫然驚覺,原來我們每天的生活早已被社群網站、即時聊天軟體攻佔已久,忘了有多久沒有靜下心來寫一段文字或是陳述自己的心靈告白,或為自己那荒蕪的一方天地灌溉過一滴水分呢? 吉娜承認自己心癢了!因為溫度日記不僅僅是日記網站、線上日記或是日記App,他更像是一個文字...
    2 years ago
  • 溫度日記 APP:用柔美的手繪插圖來療癒你的心、豐富你的手帳日記!(Android、iOS) - 無意中看到「溫度日記 Hearty Journal」,赫然驚覺,原來我們每天的生活早已被社群網站、即時聊天軟體攻佔已久,忘了有多久沒有靜下心來寫一段文字或是陳述自己的心靈告白,或為自己那荒蕪的一方天地灌溉過一滴水分呢? 吉娜承認自己心癢了!因為溫度日記不僅僅是日記網站、線上日記或是日記App,他更像是一個文字...
    2 years ago
  • 【藝術源於生活,但高於生活】 - ​ 【藝術源於生活,但高於生活】 脫口秀大會第四季的slogan「還是生活最幽默」,周奇墨決賽的段子顯示他對生活的敏銳觀察,加上深厚的表演經驗,更有第三季跌跌撞撞的表現,殺君馬者道旁兒的網路磨難,讓他從線下小劇場到線上綜藝節目表演的交換舞台,更小心拿捏那條線。更難得的是笑果文化在打造激烈的脫口秀大會喜劇擂台同時...
    2 years ago
  • John Cage: ASLSP(as slow as possible) - 在德国哈尔伯斯塔特的一座教堂里,一个不寻常的艺术事件正在进行,这个事件被称为「尽可能慢」。这并非一场普通的音乐会,而是由美国作曲家约翰·凯奇(John Cage)创作的一项持续时间长达数百年的音乐演出。 这个音乐演出的主角是一台巨大的管风琴(organ),位于哈尔伯斯塔特的圣母教堂内。这座管风琴被设计成每隔几...
    3 years ago
  • 林樹勛:馬吉〈臭屁〉的美感──兼讀其文集《時日悠悠》 - 馬吉文集《時日悠悠》,有一篇題為〈臭屁〉,全文如下: 兩口子睡在床上,意旺忽地在 … 繼續閱讀 →
    3 years ago
  • 蘇賡哲 : 他做不成杜月笙 - 杜月笙 舊書商回憶錄之四十 包括蔣介石在內,很多人喜歡和杜月笙稱兄道弟。因為任你有天大難題求助於他,他都若無其事,「閒話一句」就替你解决了。 當然,天下沒有白吃的午餐,但杜月笙的本事正在於,他要你還的人情債,即使是加倍奉還,必定是你還得起,樂於償還的。 奶路臣街有一位常作杜月笙狀的書商,他...
    3 years ago
  • 侶倫的《窮巷》 - 香港文苑書店1952年初版。書影來自香港中文大學圖書館。 香港文苑書店1952年初版。書影來自香港中文大學圖書館。 《窮巷》是侶倫第一部長篇小說,1948年動筆,隨寫隨刊於夏衍主編的《華商報》副刊《熱風》上,由1948年7月1日起,連載至8月22日止,共約3萬6千字。恰遇夏衍離開報館,新人上場,編輯方...
    3 years ago
  • 財富之城──威尼斯 - 剛讀完Roger Crowley(羅傑.克勞利)有關威尼斯共和國歷史的著作: City of Fortune: How Venice Won & Lost a Naval Empire (財富之城──威尼斯怎樣嬴取及失去其海上帝國)(台版:《財富之城──威尼斯共和國的海洋霸權》),作為我近年來閱讀地中海和威尼...
    5 years ago
  • 杭寧遊記 - 我的藏書裡有二部古籍和西湖相關,一是《御覽西湖志纂》,一是《西湖志》。
    5 years ago
  • 釐清香港議員取消資格案的法律概念:又名「跳出跳入打我呀笨蛋」然後被打 - 好多人真的不懂法律又要講法律。又有好多人以為只有香港才會有「人大釋法」。任何一個 … 繼續閱讀 →
    6 years ago
  • 照顧與創作 - 月前為谷淑美的攝影詩文集《流光.時黑》做了中文部分的編輯工作,實在因為是一種唇亡齒寒感。谷淑美的書,是關於她照顧年老患病的母親,過程中進而對母親生命、自己生命的發掘,轉化為攝影與文字創作。自己進入中年,身體開始變差,也進一步想到將來要照顧家人的責任,暗暗畏懼其龐大。於是,也就想通過進入谷淑美的歷程,讓自己學...
    6 years ago
  • - 暗夜小巴像搖骰,我們每個橫切面都刻了字,不知我們在終站會變成甚麼。或者是上帝,或者是狗。或者倒轉的日歷。紙張一天一天倒著依附,雨中有人望過來問:為甚麼不可以?聽到問題的人,心裡又虛又慌,因為撇除了時日的制裁,也沒有多麼費力。耗費也是不足夠的。如果真的有努力過的話,根本不會站在這裡。喂,他其實一早...
    6 years ago
  • 《別字》試刊號第二期出版﹗ - 立即下載:《別字》試刊號第二期 《字花》的網上純創作誌《別字》登場了! 「別字」一名,既有別冊之意,更寄望透過網上平台,另闢傳播門徑,開拓閱讀體驗。 暫定三個欄目,「透光」的作品從自由投稿中特別挑選,「有時」配合《字花》徵稿或另設新題,「極限」則專載萬字長篇。 試刊號第二期,以PDF形式呈現,供各位下載...
    6 years ago
  • 乌托邦遗迹 - [image: uploads/201510/18_114414_s1.1973peterderret.jpg] [水瓶节,宁宾,1973年。摄影:Peter Derret] 乌托邦遗迹 欧宁 宁宾(Nimbin)是澳大利亚新南威尔士东北部山区的一个小镇,因1973年举办水瓶节(Aquarius Fes...
    8 years ago
  • 「馬拉松 看世界」專頁 向世界馬拉松出發 - 如無意外,本周日我應該身在三藩巿,跑今年第五個外國比賽,也是人生第三十個馬拉松比賽(廿九個在香港以外)。雖然Blog有好一段日子沒有update,但跑步仍是繼續下去,這兩年尤其多,也去了俄羅斯、澳洲這些新國家、新大陸跑,是另一個飛躍期。 這些年的跑馬路上,有幸認識一些志同道合、見識廣博、洞察力強、對比賽有要...
    8 years ago
  • 自由路艱:再思肖友懷事件 - 文:野莩遣返或特赦肖友懷,無絕對之可不可行,但決定時當先考慮法理依據,而非道德情懷。我曾就此事詢問一位在入境處工作的朋友,她的答覆非常簡單:「1. 依法當遣返事主;2. 父母非港人,事主不能申請單程證;3. 除了酌情,事主無其他留港途徑。」那麼酌情先例會為制度開漏洞嗎?「Personally speaking...
    8 years ago
  • 烏蘭巴托的夜 - 《烏蘭巴托的夜》是首蒙古歌曲。蒙古的作曲家寫的,賈樟柯重新填了詞,左小祖咒改編,電影《世界》插曲(湖南台的字幕打錯了)。左小原版的就好聽,他少有的比較「正經」地演唱。譚版也不錯,大氣,聲情並茂。 左小改編演唱的《烏蘭巴托的夜》 賈樟柯電影片斷(趙濤演唱) 蒙古族樂隊杭蓋的版本 烏蘭巴托的夜 作詞:賈樟...
    8 years ago
  • 莉娜骑士在盘子上 - 1874年12月25日,一个女孩诞生在罗马北部小城维泰博的贫民窟,迷信说,这一天诞生的人有特别的命运,父母为她取名“娜塔莉娜”(Natalina ),因为“natale”是意大利语里的“圣诞节”。12 岁开始,她当过卖花姑娘、包装女工,生活虽然贫寒,好在她天赋歌喉,每天从早唱到晚。邻居一个音乐教师给她上...
    9 years ago
  • 欲望的事故 - 欲望的事故 顾文豪 特里林在《知性乃道德职责》一书中引述亚里士多德关于悲剧的定义,认为悲剧的主人公具有某种程度的、可进行自由选择的可能性,他“必须通过自己的道德状况来为自己的命运进行辩解”,而其道德状况并非十全十... *博客大巴,你的个人传媒早班车*
    10 years ago
  • 給《明報》 - 一口答應寫一篇給《明報》,箇中心情,猶如「償還」。 明明我沒有欠這報甚麼,稿債沒有,瓜葛沒有。 都是人情吧。多老套。 這些年來,跟《明報》的這些年來,救命,怎麼細數。 第一次認真寫稿刊登,已是2003年的事了。正是馬家輝博士邀請,給世紀版寫一篇關於「網上飄流的香港家書」。(私人回憶:先生有份跟我寫的。)一年過...
    10 years ago
  • 召喚 新春秋 - 召喚 新春秋 諸劍仙現身, 草草一刀 頓首
    10 years ago
  • 偶然的發現 - 很久沒在facebook上看到湯正川的post,早上偶然看到他與另一DJ的對談,發現這首歌,先放上來,待電腦回復正常,再仔細欣賞。
    10 years ago
  • 阿城:你这个名字怎么念? - *你这个名字怎么念?阿城 * 堪萨斯州多好农地,广大,略有起伏,种着苞谷。苞谷快收了,一般高矮,一片灰黄。不过从车里望出去,灰黄得实在单调,车开得愈久,愈单调。 偶有棉田。两个人坐在路边白房子前,有车开过去,瞥也不瞥,呆看着棉花地。 从后视镜里望他们,愈来愈小了。发什么呆呢?棉花出了问题?第一次种棉...
    10 years ago
  • - *Chapeau...!*Cock your hat - angles are attitudes (Sinatra) By Heinz Decker Hats seem to stimulate the imagination; maybe because they are a prolongatio...
    11 years ago
  • 閱讀讓我質疑制度 - [本訪問稿乃〈不可能所有的真實都出現在你的攝影機前──賈樟柯、杜海濱訪談〉的第一部份。訪問稿全文網上版見以下網頁: http://leftfilm.wordpress.com/2012/07/17/jiaduinterview1/ http://leftfilm.wordpress.com/2012/07/17...
    11 years ago
  • 蜚聲卓越在書林──蘇州文育山房 - 蘇州的氣候溫潤,步調舒緩,水道與巷弄縱橫交錯,教人一來到此便安下心來。城裡的平江街區,從宋代便已經存在,以今日留存的巷弄來看,八百年來的格局規劃變化並不大,只是範圍縮小許多。而就在這僅存的街區裡,留下的不只是悠悠時光,亦有不少哲人賢士駐守的痕跡。書癡黃丕烈的百宋一廛、史學家顧頡剛的顧氏花園、清代狀元洪...
    12 years ago
  • 當世界留下二行詩 宣傳BV - 當世界留下二行詩瓦歷斯.諾幹Walis.Nokan本書以極簡的形式,現代詩行的排列,挑戰詩藝和語境的實驗風格觀察視角從台灣的土地與家園,擴及到族群、社會乃至世界的關懷。動情至深,引發共鳴,為作者近年來最新創意力作!短短的二行詩,宛如「芥子納須彌」激起無限想像空間,是一本趣意盎然、值得珍藏的現代詩集。向陽、李...
    12 years ago
  • V城系列明信片 - 圖:by 智海 and 楊智恆
    12 years ago
  • 【世界眼系列特别活动】迈克尔•桑德尔:公正,该如何做是好? - *迈克尔•桑德尔:公正,该如何做是好? Justice:What's the Right Thing to Do?* *开始时间:* 2011年5月21日 周六 13:45 *结束时间:* 2011年5月21日 周六 17:00 *地点:* 上海 长宁区上海市天山路356号长宁区图书馆10楼报告厅(地铁2...
    12 years ago
  • 诗歌是飞行术,散文是步兵 - *诗歌是飞行术,散文是步兵顾文豪* *刊于《南方都市报——阅读周刊》2009年10月11日* 在众多优秀诗人看来,散文不是适合他们展露才思表陈感情的文体,偶然为之,亦不过如布罗茨基所说的是一种“以其他方式延续的诗歌”。他还有另一个比喻———诗歌是飞行术,散文则是步兵。 是的,诗人兴许能在...
    14 years ago
  • 《般若波罗蜜多心经》印存 - 《般若波罗蜜多心经》印存 般若波罗蜜多心经 35*35*138mm 薄意山水巴林红丝冻石 观自在菩萨 26*35*80mm 貔貅钮巴林黄冻石 行深般若波罗蜜多时 30*38*90mm 貔貅钮巴林冻石 照见五蕴皆空 33*33*114mm 螭钮巴林黄彩石 度一切苦厄 25*2...
    15 years ago

Sunday, March 23, 2014

邊度有書:澳門獨立書店風景


好吧,這次就別去金沙、也不要光留在威尼斯人酒店,去議事亭前地吧。不只行街購物,拾級而上,到訪這家澳門少見的獨立書店,你便體會到另一番光景。
書店名為「边度有書」,語帶相關,一是疑惑的詢問哪裏有書本?另一重意思則是以感嘆的語氣道出現代社會不堪的閱讀風氣-「(在社會上)哪裏有書啊!(眼睛只看到錢吧)」
當然這只是筆者個人的想像啦,別當真。然而書店門前的樓梯旁卻掛上一塊小字牌,寫著「只要閱讀,澳門邊度有‘輸’」。說的也是,這書店的出現,正好說明澳門不只賭場業務蓬勃。數百坪的二樓空間內,售賣不少中港台書籍,中、英文都有,而選書都是以人文氣息濃厚為主,說著社會上的故事,也說風土人情。譬如是講解活字印刷的書本、講述社會運動和抗爭的外國雜誌、紀錄緬甸旅遊趣事及生活紀錄的雜誌等等,你都會在「边度有書」找到。
店內窗戶旁有綠油油的植物,前面還有張三人座沙發及方形小桌子,上面擺放自家製橡皮圖章、音樂 CD 和耳筒,你可以買杯公平貿易咖啡,邊聽音樂邊為店家留言,隨興寫下想對他們或其他訪客說的話。正當很多野心勃勃的都市人只為生存打拼,忘記如何享受生活,便是時候走進這個不講輸贏的地方,翻開一兩本書或雜誌看看,將呼吸調慢下來吧。
很多遊客慕名前來看望書店內的小貓,看來獨立書店和貓咪的確是對好伴侶。另外,「边度有書」亦有自家出版,雖然為數較少,但亦是用心之作。而他們出品的帆布袋也是非常討喜,設計簡單樸素。
如果不太喜歡看書,可以再上一層到三樓,那裏有姊妹店「边度有音樂」,售賣黑膠唱片、店主精心挑選的各類唱片、原創手作雜貨,能看出經營者的用心。兩家店的牆上均貼滿文藝活動海報、明信片、即影即有相片等。如果喜歡貓貓,還可以留意上面有沒有與貓相關的活動。
「边度有書・边度有音樂」告訴人們的,除了推廣閱讀風氣這種老掉牙口號以外,正如書店的網誌所寫:「讓日本子再慢一點,再慢一點⋯⋯」

Wednesday, March 12, 2014

The 17 Equations That Changed The Course Of History


Mathematics is all around us, and it has shaped our understanding of the world in countless ways.
In 2013, mathematician and science author Ian Stewart published a book on 17 Equations That Changed The World. We recently came across this convenient table on Dr. Paul Coxon's twitter account by mathematics tutor and blogger Larry Phillips that summarizes the equations. (Our explanation of each is below):
Here is a little bit more about these wonderful equations that have shaped mathematics and human history:
pythagorean theorem chalkboard
Shutterstock/ igor.stevanovic
1) The Pythagorean Theorem: This theorem is foundational to our understanding of geometry. It describes the relationship between the sides of a right triangle on a flat plane: square the lengths of the short sides, a and b, add those together, and you get the square of the length of the long side, c.
This relationship, in some ways, actually distinguishes our normal, flat, Euclidean geometry from curved, non-Euclidean geometry. For example, a right triangle drawn on the surface of a sphere need not follow the Pythagorean theorem.
2) Logarithms: Logarithms are the inverses, or opposites, of exponential functions. A logarithm for a particular base tells you what power you need to raise that base to to get a number. For example, the base 10 logarithm of 1 is log(1) = 0, since 1 = 100; log(10) = 1, since 10 = 101; and log(100) = 2, since 100 = 102.
The equation in the graphic, log(ab) = log(a) + log(b), shows one of the most useful applications of logarithms: they turn multiplication into addition.
Until the development of the digital computer, this was the most common way to quickly multiply together large numbers, greatly speeding up calculations in physics, astronomy, and engineering. 
3) Calculus: The formula given here is the definition of the derivative in calculus. The derivative measures the rate at which a quantity is changing. For example, we can think of velocity, or speed, as being the derivative of position — if you are walking at 3 miles per hour, then every hour, you have changed your position by 3 miles.
Naturally, much of science is interested in understanding how things change, and the derivative and the integral — the other foundation of calculus — sit at the heart of how mathematicians and scientists understand change.
Isaac Newton
Isaac Newton
4) Law of Gravity: Newton's law of gravitation describes the force of gravity between two objects, F, in terms of a universal constant, G, the masses of the two objects, m1 and m2, and the distance between the objects, r. Newton's law is a remarkable piece of scientific history — it explains, almost perfectly, why the planets move in the way they do. Also remarkable is its universal nature — this is not just how gravity works on Earth, or in our solar system, but anywhere in the universe.
Newton's gravity held up very well for two hundred years, and it was not until Einstein's theory of general relativity that it would be replaced.
5) The square root of -1: Mathematicians have always been expanding the idea of what numbers actually are, going from natural numbers, to negative numbers, to fractions, to the real numbers. The square root of -1, usually written i, completes this process, giving rise to the complex numbers.
Mathematically, the complex numbers are supremely elegant. Algebra works perfectly the way we want it to — any equation has a complex number solution, a situation that is not true for the real numbers : x2 + 4 = 0 has no real number solution, but it does have a complex solution: the square root of -4, or 2i. Calculus can be extended to the complex numbers, and by doing so, we find some amazing symmetries and properties of these numbers. Those properties make the complex numbers essential in electronics and signal processing.
6) Euler's Polyhedra Formula: Polyhedra are the three-dimensional versions of polygons, like the cube to the right. The corners of a polyhedron are called its vertices, the lines connecting the vertices are its edges, and the polygons covering it are its faces.
A cube has 8 vertices, 12 edges, and 6 faces. If I add the vertices and faces together, and subtract the edges, I get 8 + 6 - 12 = 2.
Euler's formula states that, as long as your polyhedron is somewhat well behaved, if you add the vertices and faces together, and subtract the edges, you will always get 2. This will be true whether your polyhedron has 4, 8, 12, 20, or any number of faces.
Euler's observation was one of the first examples of what is now called a topological invariant — some number or property shared by a class of shapes that are similar to each other. The entire class of "well-behaved" polyhedra will have V + F - E = 2. This observation, along with with Euler's solution to the Bridges of Konigsburg problem, paved the way to the development of topology, a branch of math essential to modern physics.
bell curve
The normal distribution.
7) Normal distribution: The normal probability distribution, which has the familiar bell curve graph to the left, is ubiquitous in statistics.
The normal curve is used in physics, biology, and the social sciences to model various properties. One of the reasons the normal curve shows up so often is that it describes the behavior of large groups of independent processes.
8) Wave Equation: This is a differential equation, or an equation that describes how a property is changing through time in terms of that property's derivative, as above. The wave equation describes the behavior of waves — a vibrating guitar string, ripples in a pond after a stone is thrown, or light coming out of an incandescent bulb. The wave equation was an early differential equation, and the techniques developed to solve the equation opened the door to understanding other differential equations as well.
9) Fourier Transform: The Fourier transform is essential to understanding more complex wave structures, like human speech. Given a complicated, messy wave function like a recording of a person talking, the Fourier transform allows us to break the messy function into a combination of a number of simple waves, greatly simplifying analysis.
 The Fourier transform is at the heart of modern signal processing and analysis, and data compression. 
10) Navier-Stokes Equations: Like the wave equation, this is a differential equation. The Navier-Stokes equations describes the behavior of flowing fluids — water moving through a pipe, air flow over an airplane wing, or smoke rising from a cigarette. While we have approximate solutions of the Navier-Stokes equations that allow computers to simulate fluid motion fairly well, it is still an open question (with a million dollar prize) whether it is possible to construct mathematically exact solutions to the equations.
11) Maxwell's Equations: This set of four differential equations describes the behavior of and relationship between electricity (E) and magnetism (H).
Maxwell's equations are to classical electromagnetism as Newton's laws of motion and law of universal gravitation are to classical mechanics — they are the foundation of our explanation of how electromagnetism works on a day to day scale. As we will see, however, modern physics relies on a quantum mechanical explanation of electromagnetism, and it is now clear that these elegant equations are just an approximation that works well on human scales.
12) Second Law of Thermodynamics: This states that, in a closed system, entropy (S) is always steady or increasing. Thermodynamic entropy is, roughly speaking, a measure of how disordered a system is. A system that starts out in an ordered, uneven state — say, a hot region next to a cold region — will always tend to even out, with heat flowing from the hot area to the cold area until evenly distributed.
The second law of thermodynamics is one of the few cases in physics where time matters in this way. Most physical processes are reversible — we can run the equations backwards without messing things up. The second law, however, only runs in this direction. If we put an ice cube in a cup of hot coffee, we always see the ice cube melt, and never see the coffee freeze.
AP050124019477
Albert Einstein
13) Relativity: Einstein radically altered the course of physics with his theories of special and general relativity. The classic equation E = mc2 states that matter and energy are equivalent to each other. Special relativity brought in ideas like the speed of light being a universal speed limit and the passage of time being different for people moving at different speeds.
General relativity describes gravity as a curving and folding of space and time themselves, and was the first major change to our understanding of gravity since Newton's law. General relativity is essential to our understanding of the origins, structure, and ultimate fate of the universe.
14) Schrodinger's Equation: This is the main equation in quantum mechanics. As general relativity explains our universe at its largest scales, this equation governs the behavior of atoms and subatomic particles.
Modern quantum mechanics and general relativity are the two most successful scientific theories in history — all of the experimental observations we have made to date are entirely consistent with their predictions. Quantum mechanics is also necessary for most modern technology — nuclear power, semiconductor-based computers, and lasers are all built around quantum phenomena.
15) Information Theory: The equation given here is for Shannon information entropy. As with the thermodynamic entropy given above, this is a measure of disorder. In this case, it measures the information content of a message — a book, a JPEG picture sent on the internet, or anything that can be represented symbolically. The Shannon entropy of a message represents a lower bound on how much that message can be compressed without losing some of its content.
Shannon's entropy measure launched the mathematical study of information, and his results are central to how we communicate over networks today.
16) Chaos Theory: This equation is May's logistic map. It describes a process evolving through time — xt+1, the level of some quantity x in the next time period — is given by the formula on the right, and it depends on xt, the level of x right now. k is a chosen constant. For certain values of k, the map shows chaotic behavior: if we start at some particular initial value of x, the process will evolve one way, but if we start at another initial value, even one very very close to the first value, the process will evolve a completely different way.
We see chaotic behavior — behavior sensitive to initial conditions — like this in many areas. Weather is a classic example — a small change in atmospheric conditions on one day can lead to completely different weather systems a few days later, most commonly captured in the idea of a butterfly flapping its wings on one continent causing a hurricane on another continent
17) Black-Scholes Equation: Another differential equation, Black-Scholes describes how finance experts and traders find prices for derivatives. Derivatives — financial products based on some underlying asset, like a stock — are a major part of the modern financial system.
The Black-Scholes equation allows financial professionals to calculate the value of these financial products, based on the properties of the derivative and the underlying asset.
cboe stock options trader
REUTERS/Frank Polich
Here are some traders in the S&P 500 options pit at the Chicago Board Options Exchange. You won't find a single person here that hasn't heard about the Black-Scholes equation.


Read more: http://www.businessinsider.com/17-equations-that-changed-the-world-2014-3#ixzz2voZ5Hq3k

Monday, March 3, 2014

實用書局

健威 <此時此刻>

說不完的香港故事。

有七十年歷史的實用書局因老闆龍良臣去世,將於六月結業了。讀了新聞,大為詫異:怎麼實用書局還在?

滄海桑田,我以為它一早就消失於時代的波濤中,想不到,它仍在。龍先生跟孫女說:「以前好威水㗎,成條街都是書局。」他說的是文化的集體盛況;那是他那帶鄉音的孫女、也是現在年輕一代沒法想像的——六七十年代,奶路臣街、西洋菜街一帶書店密布;除了書店,還有擺地攤的;而在西洋菜街的實用書局,就是其中頗體面的一間,實用主要賣的是文史哲書籍,店內書籍分類、陳列整齊,跟一般稍混亂的舊書店很不一樣;那時內地文化大革命,焚書坑儒,除了政治宣傳書籍,出版幾近停頓;卻幸而有香港的小型出版社延續一線文化香脈,不斷翻印一些在內地不可能出版的絕版書,這幾家出版社是龍門(司徒華是股東之一)、神州、滙文閣、波文……而實用又是其中之一,其翻印得最多的是,周作人的文集,幾乎沒錯失任何一本;我愛讀周作人,把實用翻版的七八本周作人全都買下了。

龍先生說自己是共產黨的地下黨,他的性格的確有點像,因為他內歛不多言,永遠跟人保持些距離,所以我沒認真跟他說過幾句話;但觀乎他晚年的窘境,又懷疑「地下黨」是不是一種過分的想像——正如七十年代西湖邊上,所有小販工人都有「國安」身份,那恐怕是外圍又外圍,但都可以「國安」稱之。

旺角的文史哲書店到了八十年代都灰飛煙滅,實用也消失了,我以為它早已化成記憶,沒想到,它搬到油麻地一幢亂七八糟、色情場所密布的大廈去,而且苟延了三十年。文化人的堅持真可歌可泣,可悲亦可嘆。說香港沒文化,對得起龍先生嗎?