The Theoretical Minimum

A number of years ago I became aware of the large number of physics enthusiasts out there who have no venue to learn modern physics and cosmology. Fat advanced textbooks are not suitable to people who have no teacher to ask questions of, and the popular literature does not go deeply enough to satisfy these curious people. So I started a series of courses on modern physics at Stanford University where I am a professor of physics. The courses are specifically aimed at people who know, or once knew, a bit of algebra and calculus, but are more or less beginners.

-- Leonard Susskind 



2013.05.20 Monday ACHK

未來人

.

What you are seeking is seeking you.

– Richard Nelson Bolles

.

.

.

2009.02.14 Saturday ACHK

多重網誌 1.2

這段改編自 2010 年 4 月 3 日的對話。


（安：但是，對一般人來說，你網誌給予他們的「第一印象」，就直接影響到他們決定，會不會繼續閱讀。

我會閱讀你的網誌，主要是因為我認識你本人，從而知道你網誌的部分文章，會十分有趣。但是，對於大部分原本不認識你真身的網民而言，他們不會知道。他們第一次路過你的網誌時，只會覺得它千奇百怪，不看也罷。

這就大大限制了你網誌的讀者人數；削弱了你網誌的發展潛力。）

實情是，我不會給一般人，我網誌的正式地址。他們並不會見到，那多重內容的網誌。

暫時，地球上，只有你、我 和 我弟弟 知道我網誌的真身：

http://rpflee.blogspot.hk/

其他生命體，我都只會給予他們，我的「地球博客」：

http://rpflee.blogspot.hk/search/label/Earth

；

和我的「學問部落格」：

http://rpflee.blogspot.hk/search/label/study


-- Me@2013.05.18



2013.05.20 Monday (c) All rights reserved by ACHK

Cumulative concept of time, 14

cause

~ necessary condition

~ part of


Event A is a cause of event B

= Event A is a necessary condition of event B

= Event A is part of event B


We can remember the past but not the future because the past is part of the future; the whole contains its parts, but not vice versa. 

-- Me@2011.08.21



2013.05.19 Sunday (c) All rights reserved by ACHK

Back to the Future, 3.2

人生是一個「來自未來」、「回到未來」的過程。

-- Me@2011.01.02



2013.05.19 Sunday (c) All rights reserved by ACHK

多重網誌 1.1

這段改編自 2010 年 4 月 3 日的對話。


（安：你可以考慮一下，開一個新的 blog（網誌），用來輯錄你一些很有意思的文章。）

那就即是我原本的那一個網誌。為什麼我要另外，開一個新的呢？

（安：你原本的網誌，夾雜了很多各種主題、不同類型的文章，閱讀起來十分不連貫。有時，我有無所適從的感覺。）

你沒有必要閱讀我「整個」網誌。其實，你只要點擊任何一個 label（標籤），你就會只看到，那一個主題的系列文章。例如，如果你在我的網誌上，點擊「Earth」標籤，你就會閱讀到我同你的對話紀錄，主要研究「地球事務」。又例如，如果你點擊「study」，你就會閱讀到我的教學過程，主要有關「讀書心得」。

-- Me@2013.05.18



2013.05.19 Sunday　(c) All rights reserved by ACHK

Identical particles 4

Indeed, if certain objects could move infinitely fast, we might expect to find the universe populated with large sets of indistinguishable particles, all of which are really instances of a small number of prototypes moving infinitely fast from place to place, so that they each occupy numerous locations at all times. This may sound implausible until we recall that the universe actually is populated by apparently indistinguishable electrons and protons, and in fact according to quantum mechanics the individual identities of those particles are ambiguous in many circumstances. John Wheeler once seriously toyed with the idea that there is only a single electron in the universe, weaving its way back and forth through time. Admittedly there are problems with such theories, but the point is that causality and the directionality of time are far from being straightforward principles.

-- 1.7  Staircase Wit

-- Reflections on Relativity

-- mathpages



2013.05.17 Friday ACHK

深淵

.

# 與魔鬼戰鬥的人，應當小心自己不要成為魔鬼。當你遠遠凝視深淵時，深淵也在凝視你。

– 尼采

.

.

.

2009.06.19 Friday ACHK

微積分 1.2

這段改編自 2010 年 6 月 29 日的對話。


「微積分」其實只是一個「高級一點的乘數表」。　

「微積分」沒有什麼好怕；只要你把「微積分公式表」當成「乘數表」般詳加背誦，在日常應用時，就不會有什麼大困難。

-- Me@2013.05.16



2013.05.16 Thursday (c) All rights reserved by ACHK

Research 4

It takes nine months full time to just understand a field of research...

-- Me@2011.08.19


... in order to start your research in that field. 

-- Me@2013.05.15



2013.05.15 Wednesday (c) All rights reserved by ACHK