Author Archives: rpflee

魚目混珠 4

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You have the illusion of security, which is far more dangerous than no security.

– Based on Jeff Atwood

The greatest enemy of knowledge is not ignorance, but the illusion of knowledge.

— Based on Daniel J. Boorstin

Partial knowledge is far more dangerous than no knowledge. 

For example, if you don’t know how to fix a television, you will not try. Instead, you will find a technician. There is no harm.

However, if you think you can fix a television when actually you cannot, you will try. That can lead to an explosion.

— Me@2011.10.23

2012.07.15 Sunday (c) All rights reserved by ACHK

Exponentiation by squaring

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Using the following observation, one can create a recursive algorithm that computes x^n for an integer n using squaring and multiplication:

[The second line is incorrect, for the power should be –n. — Me@2012-07-14] 

A brief analysis shows that such an algorithm uses log_2 (n) squarings and at most log_2 (n) multiplications. For n > about 4 this is computationally more efficient than naively multiplying the base with itself repeatedly.

— Wikipedia on Exponentiation by squaring

2012.07.14 Saturday ACHK

善利用愚蠢 1.2

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這段改編自 2010 年 3 月 20 日的對話。

Stupidity is like nuclear power; it can be used for good or evil.

– Dilbert

（安：那樣，即是愚蠢的人當中，有一部分你無論多麼用心教導，也不會變成賢智的人。那怎麼辦？）

愚蠢人士當中，有機會變成賢智人士的，我簡稱為「向智人士」；而沒有機會的，我則簡稱為「不智人士」。面對「不智人士」，很多時也沒有所謂「怎麼辦」。「面對」「不智人士」的最佳方法是，令到自己毋須面對他們。例如，如果你是一間公司的老闆或者高層管理人員，你的其中一個責任，就是避免聘請到「不智人士」。

（安：但是，有些情況下，無可避免要和「不智人士」相處。那又怎麼辦呢？）

你可以試試 copyleft 了「不智人士」的愚蠢。這裡「copyleft」的意思是，把原本有害的東西，透過新奇的用法，轉化成有益的東西。我會把「copyleft」翻譯成「反利用」，或者「幽默利用」。

例如，你有一個學生不智。他的不智之處，在於人云亦云，不肯有自己的思想，獨立思考。你多次告誡他，老師的話未必正確，所以只能作為參考，不能作為金科玉律。但是，他屢勸不改。那樣，你可以思考一下，怎樣可以善加利用，他這個「人云亦云」的缺點，令到他會長期做利人利己的事。

例如，你可以對他下達指令：對人要有禮貌。由於他「人云亦云」，他自然不會有任何哲學的考慮：「為什麼對人要有禮貌呢？」他只會盲從附和。那樣，他自此一生人，也會對人有禮貌。結果，「人云亦云」在這方面，反而對他有利。

— Me@2012.07.12 

2012.07.12 Thursday (c) All rights reserved by ACHK

Permutation City

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Permutation City is a 1994 science fiction novel by Greg Egan that explores many concepts, including quantum ontology, via various philosophical aspects of artificial life and simulated reality.

— Wikipedia on Permutation City

2012.07.10 Tuesday ACHK

Meaningful 5

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X is meaningful

= You can keep developing X

= X always has next steps

1. If you have a lot of good intellectual and social connections, you can keep having the next steps.

2. Action is a good way to create the next steps and decrease uncertainties. 

— Me@2012.05.14

2012.07.10 Tuesday (c) All rights reserved by ACHK

善利用愚蠢 1.1

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這段改編自 2010 年 3 月 20 日的對話。

（安：愚蠢的人，有沒有機會變成不愚蠢的人？）

這個問題很空泛，因為你沒有指明「哪」一個愚蠢人士。我只能說，有些愚蠢人士可以進化成聰明人士，有些不可以。

比喻說，如果你問，不漂亮的人，有沒有機會變成漂亮的人呢？我會答，有時可以，有時不可以。例如，如果一個人不漂亮的主因是髮型不好，他只要改善髮型，方可變成漂亮的人。又例如，如果一個人不漂亮的主因是心腸惡毒，導致面目可憎，他的樣子大概不可救藥。

（安：那樣，即是愚蠢的人當中，有一部分你無論多麼用心教導，也不會變成賢智的人。那怎麼辦？）

愚蠢人士當中，有機會變成賢智人士的，我簡稱為「向智人士」；而沒有機會的，我則簡稱為「不智人士」。面對「不智人士」，很多時也沒有所謂「怎麼辦」。「面對」「不智人士」的最佳方法是，令到自己毋須面對他們。例如，如果你是一間公司的老闆或者高層管理人員，你的其中一個責任，就是避免聘請到「不智人士」。

— Me@2012.07.10 

2012.07.10 Tuesday (c) All rights reserved by ACHK

Number theory

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Lately James Dolan and I have been studying number theory. I used to hate this subject: it seemed like a massive waste of time. Newspapers, magazines and even lots of math books seem to celebrate the idea of people slaving away for centuries on puzzles whose only virtue is that they’re easy to state but hard to solve.

Sure, it’s noble to seek knowledge for its own sake. But working on a math problem just because it’s hard is like trying to drill a hole in a concrete wall with your nose, just to prove you can! If you succeed, I’ll be impressed – but I’ll still wonder why you didn’t put all that energy into something more interesting.

Now my attitude has changed, because I’m beginning to see that behind these silly hard problems there lurks an actual theory, full of deep ideas and interesting links to other branches of mathematics, including mathematical physics.

— January 10, 2004

— This Week’s Finds in Mathematical Physics (Week 201)

— John Baez

2012.07.08 Sunday ACHK

缺乏寫作靈感 4

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Writer’s block 4

這段改編自 2010 年 3 月 20 日的對話。

（安：寫作的好處是，讀者可以高速閱讀作品。對話的問題是，聽者不可以高速聆聽。但是，寫作的問題是，由於沒有聽者的即時反應，你很多時也不知道應該怎樣寫下去。）

我已經 transcend 了這個問題。我的兩個網誌，都毋須我的寫作靈感。

我不會在我的 WordPress 網誌編寫長文章，而只會引用他人或者自己精警的一兩句。那些都是靠平日的收集紀錄，尤其是在自己靈機一觸時。

至於我 Blogger 網誌上的長文章，則來自抄錄自己與朋友的對話錄音。間中，我會寫一些不是由錄音抄錄下來的長文章。但是，那些課題，往往都是我和很多不同學生討論過。所以，那些課題中的任何一個，我已經講過無數次。幾乎所有可能的對話劇情，我都經歷過。換句話說，我腦海中早已儲存了全面的完整錄音。

總括而言，「避免」缺乏寫作靈感的最好方法是，令到自己寫作毋須靈感。在沒有必要寫長文章時，一句起，兩句止。

— Me@2012.07.05 

2012.07.05 Thursday (c) All rights reserved by ACHK

Good Old Games

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GOG.com (formerly Good Old Games) is a computer game sale and distribution service operated by GOG Ltd, a wholly owned subsidiary of CD Projekt RED.

In order to ensure compatibility with newer versions of Microsoft Windows, some games are pre-patched or bundled with Open Source emulation and compatibility software, such as ScummVM and DOSBox. Unlike some other services, the games do not use digital rights management …

Along with purchasing the games, customers are also able to download numerous extra material relating to the game they purchased. Often these extras include the game’s soundtrack, wallpapers, avatars, and manuals.

— Wikipedia on GOG.com

2012.07.04 Wednesday ACHK

雞蛋

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雞蛋，從外打破是食物，從內打破是生命。人生亦是，從外打破是壓力，從內打破是成長。

如果你等待別人從外打破你，你註定成為別人的食物；如果能讓自己從內打破，你會發現自己的成長，相當於一種重生。

–「李嘉誠」

— edited

2012.07.04 Wednesday ACHK

讀書技巧

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這段改編自 2010 年 6 月 2 日的對話。

讀書技巧不應一次過學太多，因為學了一個讀書技巧以後，你要嘗試學以致用，從而把它修改到最適合自己的版本。

一次過學太多的話，你就會來不及測試運用。讀書技巧如果不能充分利用，學來也沒有意思。

— Me@2012.07.03

2012.07.03 Tuesday (c) All rights reserved by ACHK

Chrono Trigger 3

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Masato Kato confirmed that Cross featured a central theme of parallel worlds, as well as the fate of Schala, which he was previously unable to expound upon in Chrono Trigger. Concerning the ending sequences showing Kid searching for someone in a modern city, he hoped to make players realize that alternate futures and possibilities may exist in their own lives, and that this realization would “not … stop with the game”.

– Wikipedia on Chrono Cross

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2011.05.02 Monday ACHK