Ji's profile足迹PhotosBlogLists Tools Help
by 
October 16

Hiking Tmr

秋天马上就要来到,似乎依然来到。非常想念密歇根的秋天,枫叶似火,层林尽染。最近发现一下这条trail南加州两个可以看到秋季色彩变化的地方之一。希望明天可以看到。

View Aspen Grove Trail in a larger map
September 23

A mini study of censorship

Definition of Censorship:
Example of Censorship:
Existing Tools to fight against Censorship:
Open Question:
What primary techniques are applied to carry out censorship?

++++++
September 22

Ph.D 必读的绝世好文

Zero Gravity: The Lighter Side of Science

Good Science
1.  Apple falls on Newton’s head.
2.  Newton discovers Law of Universal Gravitation.

Bad Science
1.  Apple falls on Newton’s head.
2.  Newton publishes the following paper:

On the Impact of a 0.12 kg Apple with the Head

Isaac Newton

Newton cartoon web

Fig. 1.  Experimental Setup

Abstract. We have carried out an experimental study to determine quantitatively the risks faced by people standing under an apple tree. The Collision Induced Pain (CIP) produced by a 0.12 kg apple on the head was measured.

Introduction. Since the early days of Creation, Man has been interested in apples [1]. Its nutritive properties [2] as well as its potential toxicity have been thoroughly discussed [3]. More recently, apples have found important technological applications [4]. However, little attention has been given to the critical issue of the risks faced by the eventual fruit picker who approaches the branches of an apple tree.

Experimental procedure and results. An experiment was carried out to determine the effect of an apple falling on the head. The experimental setup is sketched in Fig. 1. The experimenter sat under an apple tree for five consecutive days and different intervals of time ∆t (Table 1). On the fifth day an apple fell on the experimenter’s head from a distance d=1.8±0.1 metres. The mass of the apple was found to be M=0.12±0.01 kg. Immediately after the collision the experimenter reported a mild discomfort that decreased exponentially with time as he rubbed his hand against the Apple Impact Area (AIA).

 

ZG chart for web

Table 1. Recorded events

On a scale of 0 to 10, the Collision Induced Pain (CIP) was rated as 2.3±0.1 (Fig. 2) and it decreased down to negligible values after a time τ=14.6±0.5 seconds. Some authors suggest that a more vigorous rubbing on the AIA would reduce substantially the Pain Relaxation Time (PRT) [5], although this theory has been highly disputed. No structural damage was observed in the experimenter’s skull.

Conclusion. A quantitative determination of the effect of an apple falling on the head was carried out for the first time. A 0.12 kg apple falling on the experimenter’s head from a distance of 1.8 metres was found to produce a CIP of 2.3±0.1 arbitrary units. A future development of this work includes the measurement of the CIP induced by apples of different mass and investigating the collision with pears. These studies will be carried out as soon as the author finds a PhD student as he is not very keen on repeating the experience himself. 
Apple mass chart web

FIG 2. Plot of the CIP as a function of apple mass (solid square, d=1.8 metres).



Acknowledgments. The author thanks the University of Cambridge (UK) for providing the apple tree.
[1] Adam et al., Eden J. Nat. Hist. 1, 1 (8000 BC).
[2] Granny Smith, “1000 recipes with apples”, Orchard Publishers, Appleville, 1964.
[3] S. White and Seven Coauthors, J. Appl. Witchcraft A: Poisons 7, 2345 (1532).
[4] Macintosh et al., J. Hort. Comput. 52, 2167 (1973).
[5] Mrs. Newton, private communication.

Ed. Note: This Zero Gravity was contributed by Ricardo Torres of Imperial College. Since it is, essentially, a work of fiction, we hope our readers will indulge the author and forgive certain anachronisms and historical inaccuracies (e.g., the metric system had not been invented in Newton’s time, and the apple tree was in Newton’s home town of Woolsthorpe, not Cambridge).
September 18

damn vending machine....

 下午快下班的时候,是能量供给的低潮,偶有些昏昏欲睡,就揣了一个dollar去自动售货机,打算买包零食。找零两毛五,只见那包薯片眼看掉下来了,却在最后时分卡在弹簧中。。。

俺就是个粗人,第一反应是,把它摇下来,撸起袖子,正准备发力,发现身后人来人往,只好打住。看来只能智取,于是打算再买一包,把前面那包也顶出来。可仔细一看,我那是最后一包。这次彻底歇菜了。。。
September 15

浪潮观后感

昨天看了Die Welle( 浪潮) 2008年德国电影。讲述了一个高中教师,用特殊的方式告诉他的学生什么是独裁。

教师文格尔的任务是在活动周内讲述“独裁政府”,学生们散漫,自由,觉得经历了二战的德国不可能出现独裁,因为没有民众基础。文格尔提出做一个小小的实验,选自己作为班里的领袖,既然是领袖,就得像模像样,应该得到起码的尊重,比如:上课不要喧哗,发言必须起立。学生们觉得好奇有趣,就暂时照做,也有人觉得变态而拒绝照做,于是被领袖赶出课堂。在一些细节上做到整齐划一后,集体的氛围让那些“刺头”觉得难受,于是就妥协了。

第二天,作为集体,文格尔先生觉得作为一个集体,是有一些标志的,最明显的比如麦当劳的员工,打扮一致,那么他提议,作为一个团体,应该有自己的特点,因为白衬衫牛仔裤人人都有,就以这种打扮作为他们的制服。这时候学生们的心理已经发生了微妙的变化,除了最初的好玩和好奇,这些散漫惯了的孩子觉得集体带给自己一种目标,一样的打扮弥合了家庭背景,贫富,种族,宗教的多样性---也就是,从细微处逐渐抹杀了个性。家庭不幸的孩子觉得集体是个家,移民的孩子觉得不再受到排挤。

第三天和第四天,学生们创造力迸发,觉得作为一个团体,应该有名字,自己的徽章,网站,主页,甚至是问候的手势。为了民主,大家投票选名字,最终敲定为“浪潮”, 徽章则是一个黑色的海浪,他们在MySpace上有了自己的主页,手臂波浪般的摆动一下就是他们之间问候的手势。他们走在一起,小混混被他们清一色的白衬衫吓住了,以为他们成立的自己的帮派。人人都觉得找到了奋斗的方向,觉得兴奋。越来越多的人加入到这个团体中来。大家都觉得很酷。

最后一天,他们集体出席校际水球比赛,在现场形成了令人震撼的氛围。文格尔先生在最后一堂课上要求每个人把这个周的感受和体会写下来,作为最后的作业。星期五的晚上,所有浪潮成员受到“领袖”的短信:明天再学校礼堂开会,决定浪潮的未来。

星期六,依然是清一色的白衬衫,整齐端坐在台下。文格尔先生开始读一些摘选的感想。“我感受到了团体的力量。。”,“差别没有了,让我觉得很安全”,等等,有很多积极的意义和收获。文格尔先生继续:“德国在全球化的过程中丧失了自我,政治沦为经济的傀儡,贫富分化更加严重。。。。。。。希望就从这里开始!! 我们的组织会像浪潮一样--席卷德国!!!” 他的慷慨激昂,得到了台下热烈的回应,大家觉得更有目标感了。可是有一位同学,他觉得这样不对,站起来反对,文格尔先生:“把叛徒押上来!! 我们应该怎么处置他?? 杀死他,对吗?? 你们都意识到你们刚才干了些什么吗??? 谁还敢说独裁在现在没有民众基础??? 这就是独裁!”

所有的人都懵了,一个学生难以忍受这样的刺激,拔枪打伤了自己的同学,在绝望中饮弹身亡了。。。

当一个团体开始排斥所有意见相左的人的时候,当一群人开始整齐划一的时候,当一个领袖、核心出现的时候,独裁开始滋生。看这部电影的时候,我想到了去年的王千源,那个站在藏独人群中的中国女孩。我也想到了事情发生之后她所遭受的待遇。无论她居心何在,我们作为一个群体,是否应该那样对她? 我想不能
 

Ji Ma

Occupation
Location
Interests
Photo 1 of 7
朋友介绍

足迹

为理想努力的日子
Stuff that I am working on