从“向右转”到“向左转”——“左手材料(LHM)”

by nicco on 4月 14, 2007

文章的具体来源已经记不清了,不过第一次直面一种神奇的东东时,为其在电磁学领域的前景深深震惊!
不知道格致里面有没有这方面的高手……

左手材料——源于上世纪60年代科学家的假想

本世纪以来,一种被称为“左手材料”的人工复合材料在固体物理、材料科学、光学和应用电磁学领域内开始获得愈来愈广泛的青睐,对其的研究正呈现迅速发展之势,而它的出现却是源于上世纪60年代前苏联科学家的假想。

物理学中,介电常数ε和磁导率μ是描述均匀媒质中电磁场性质的最基本的两个物理量。在已知的物质世界中,对于电介质而言,介电常数ε和磁导率μ都为正值,电场、磁场和波矢三者构成右手关系,这样的物质被称为右手材料(right-handed materials,RHM)。这种右手规则一直以来被认为是物质世界的常规,但这一常规却在上世纪60年代开始遭遇颠覆性的挑战。1967年,前苏联物理学家Veselago在前苏联一个学术刊物上发表了一篇论文,首次报道了他在理论研究中对物质电磁学性质的新发现,即:当ε和μ都为负值时,电场、磁场和波矢之间构成左手关系。他称这种假想的物质为左手材料(left-handed materials,LHM),同时指出,电磁波在左手材料中的行为与在右手材料中相反,比如光的负折射、负的切连科夫效应、反多普勒效应等等。这篇论文引起了一位英国人的关注,1968年被译成英文重新发表在另一个前苏联物理类学术刊物上。但几乎无人意识到,材料世界从此翻开新的一页。

由于左手材料的显著特点是它的介电常数和磁导率都是负数,所以有人也称之为“双负介质(材料)”,通常也被称为“负折射系数材料”,或简称“负材料”。

Sandwich decoded!

by nicco on 4月 11, 2007

很多的孩子都喜欢到“麦哥”那儿,啃上一个Sandwich来填饱自己的肚子。4月10号的纽约时报登了一篇关于Sandwich的文章,想知道内容吗?
A:是关于垃圾食物的吗?
N:不是拉,是科学家居然开始用数学方程来解密Sandwich,信不信由你啊!

The Perfect Bacon Sandwich Decoded: Crisp and Crunchy

Should it be slithery or scrunchy, glutinous or grilled? The answer, British scientists say, may be divined by a formula:
N = C + {fb(cm) · fb(tc)} + fb(Ts) + fc · ta.—————这就是大名鼎鼎的sandwich方程!

好的三明治是需要用0.4牛顿的力产生0.5分贝的香脆声的!其中公式中的N就是吃三明治用的力啦!fb是关于火腿形状的函数,fc是关于调料或填充物的函数,ts是制作时的温度,tc是制作时用的时间,ta是添加调料的时间,cm表示制作的方法,c代表吃火腿的力。真的好麻烦啊!

That is the scientific answer to the question: what makes the perfect bacon sandwich?

And, no, it is not April 1.

Researchers at Leeds University(利兹大学,听说过英超的利兹联队吧,想了解这个学校可以看看这个网址吧http://www.leeds.ac.uk/) spent more than 1,000 hours testing 700 variants on the traditional bacon sandwich, which many Britons refer to as a bacon butty (不要奇怪英国人就是这么叫三明治的)(eschewing the term sandwich, said to have been coined to honor the fourth Earl of Sandwich’s habit of eating meat between slices of bread around 1762).

For Britons, butties come in a variety of guises — chip butties (French fries between slices of bread), crisp butties (ditto with potato chips) or even sugar butties, which are self-explanatory. None are viewed as especially healthful.

爱因斯坦眼中的科学与宗教

by nicco on 3月 28, 2007

Albert Einstein on: Religion and Science

说实在的,爱因斯坦对于科学与宗教有很多的阐述,其中也不乏名言,如:science without religion is lame, religion without science is blind.当然爱教授所指的宗教可不是我们想的那么简单啊!不信,就看看爱教授的观点吧!(下面有中文版)

This section is from Science, Philosophy and Religion, A Symposium, published by the Conference on Science, Philosophy and Religion in Their Relation to the Democratic Way of Life, Inc., New York, 1941.

下面是英文原版:
It would not be difficult to come to an agreement as to what we understand by science. Science is the century-old endeavor to bring together by means of systematic thought the perceptible phenomena of this world into as thoroughgoing an association as possible. To put it boldly, it is the attempt at the posterior reconstruction of existence by the process of conceptualization. But when asking myself what religion is I cannot think of the answer so easily. And even after finding an answer which may satisfy me at this particular moment, I still remain convinced that I can never under any circumstances bring together, even to a slight extent, the thoughts of all those who have given this question serious consideration.

一个有趣的英文心理测验

by nicco on 3月 25, 2007

鉴于里面的英文都很简单,就不再翻译了!
这个测试很准的,有几个朋友都试过了~请大家看完英文版的~

Hey it is quite accurate!!! Try and see!

Take a piece of paper and write down the answers.. The analysis is in the end….

Situation:
You are in a deep deep forest… as you walk on you saw an old hut standing there

(1) What is the status of the door? (Opened/closed)

(2) You enter the hut and see a table… What is the shape of the table?
(Round/Oval/Square/Rectangle/Triangle)

(3) On top of the table there is a vase… in the vase there is water. How much water is it filled up with?
(Full/Half/Empty)

(4) And what is the vase made of?
[(Glass/porcelain/clay)(metal/plastic/wood)]

(5) You walk out of the hut… as you carry on your walk in the forest… you see a waterfall from far…
there is water running down…What is the speed of the water?
(Choose a number ranging from 0 to 10)

(6) Some time after the waterfall… you step on something hard on the ground… as you look down… you see
glistening gold in colour. You bend down and pick it up… it is a keychain chained with keys…
How many key /keys you see hanging on the keychain? (Choose a number ranging from 1 to 10)

(7) You walk on and on… trying to find your way out…suddenly you see a castle.
What is the condition of the castle? (Old/new)

( You enter the castle and saw a pool of murky water with shining jewels floating on it…Will you pick up the jewel? (YES/NO)

(9) Next to the murky pool… there’s another pool… with clear water and money floating on it…
Will you pick the money? (YES/NO)
 
(10) Walking to the end of the castle there is an exit…you proceed to walk out of the castle. Outside the
exit, there is big garden, you see a box on the ground. What is the size of the box? (small/medium/big)