Humanities and Arts

A new kind of camera, which allows you to take the photo now, and focus later at any point you like. There is demo in the web.

The principle is that, you record not the sum of all the light cones, but the individual light ray's vector direction. So that you can focus to any plane by ray tracing method.

昨天看了一套教人深思的電影 - 〈Three Idiots〉，故與大家分享一下。快樂、生活、學習，其實都可以是很簡單的。

http://www.tudou.com/programs/view/h5RvIAx0sTU/

This is what education truly mean, to have fun and excitement during the pursuit of excellence.

Unblock me is a puzzle game in iphone. It's originated from rush hour. I am interested in solving the board game using computer. I can enter the board configuration into the computer one by one, but I would like to do it automatically. With image processing capatibability in Mathematica, the process can be done rather easily by taking screenshot.

上期我跟大家談過「拉腰」治坐骨神經痛這個話題，後來有人問我物理治療中是否有一項叫「拉頸」的方法，用作治療頸椎神經線受壓呢？不錯，其實頸椎神經跟坐骨神經一樣，都會因受壓而出現肢體感覺上的錯亂，而他所說的「拉頸」，便是其中一種頗為常用的治療方式。

You may have heard a saying that any paper cannot be folded more than 7 times. This video shows that it is possible. In fact, you can fold 11 times! But the paper they are using is as large as a football field, while the original saying is that, you can't fold an A4 paper more than 7 times. It is still an interesting video to watch.

近日有讀者來信，說她患了腰痛多年，近日痛楚更延至右腿外側，有時甚至擴散至小腿部分，間中還會出現麻痺感。

醫生建議她接受物理治療的「拉腰」療法。到底，「拉腰」是怎樣的治療方式呢？

「嬰兒斜頸」所謂何事：頸脖老是向一方歪斜，這是由於頸部一側的肌肉出現了腫塊。

昨天跟一位教車師傅聊天，發現原來他跟許多職業司機一樣，由於長時間坐在又軟又低的司機位上而患上「椎間盤性」的腰痛。近日更因此而引起坐骨神經痛，使他一旦久坐後便會出現腿部痺痛，極為不適。

「骨刺」，常教人聽而生畏，但其實它並非大家想得那般可怕。「骨刺」是關節退化過程中的「副產品」，是正常的生理現象。它的出現本來是對身體有用處的，可是有時亦會帶來痛楚，可謂「好心做壞事」。

Folding a square sheet of paper into an arbitrary 3D shape is proved to be NP-hard problem. It is proved by transforming the problem into circle packing problem[1].

[1] arxiv.org/abs/1008.1224: Circle Packing for Origami Design Is Hard

  ...