Several days ago, I served as a committee member of the interviews of new graduate students. Although most students are motivated to study high energy physics, quite a lot are not familiar with what they will engaged in. Too many students expressed their wishes to do physical analysis, as if the analysis is more physical. Very few wish to work on hardware. Actually, physics is essentially an experimental science. Technology of detector is the foundation of physics research. It could be more important than the data analysis itself.
Telescope is a good example. 2009 is Internal Year of Astronomy by UNESCO, to memorize Galileo’s first observation of the sky with telescope 400 years ago. In 1608, a glasses producer in Holland invented telescope. The next year, Galileo made a telescope himself and used it to investigate stars. In the following 400 years, telescope changed entirely our view on the universe. To name a few, we observed the tiny advance of Mercury perihelion, which is the first evidence of Einstein’s General Relativity. We know the Universe was born 15 billion years ago with a “Big Bang”, keeping inflating, and full of black holes. We know the normal stars are only several percent of the total mass of the universe. Others are mysterious dark energy and dark matter. As we build larger and larger neutrino detectors deep underground, in the sea, or in the ice, they can serve as neutrino telescope to observe the universe, totally different from the telescope detecting electromagnetic waves including light.
In Chinese, 聪明means clever, wise, or bright. It is consisted of two characters. The first one, 聪, means good hearing. And the second, 明, means good sight. The left part of 聪 is an ear. The top right part is two eyes. The middle right is a mouth. And the bottom right is heart, which ancient Chinese believe to be in charge of thinking. Physical thoughts won’t be created without reason. It is inspired by the information we get from the ear, eye, and mouth, and finally analyzed by the heart. Telescope greatly enlarged our view, thus human become cleverer. In high energy physics, detectors are our eyes.
有了望远镜，人变聪明了
前几天参加了高能所的研究生面试。尽管有志于从事高能物理研究工作，但相当多的学生对将来要从事的工作性质并不是特别了解。过于多的学生希望做物理分析工作，似乎这样更像物理研究，很少提出做硬件。实际上，物理本质上是一门实验科学，探测技术的发展是物理研究的基础，往往比数据分析具有更重要的意义。
望远镜是一个很好的例子。2009年是联合国定的国际天文年，以纪念伽利略首次用望远镜观测天体400年。1608年，一个荷兰眼镜商发明了第一架小望远镜。次年，伽利略用自制的望远镜第一次观测星球。400年来，望远镜技术的发展彻底改写了人们的宇宙观。例如，我们知道了微小的火星进动，必须由广义相对论来解释；我们知道了宇宙诞生在150亿年前，在不断膨胀，知道了宇宙中遍布着黑洞，知道了常规的星体只占宇宙质量的百分之几，其余则是神秘暗能量和暗物质。随着中微子探测技术的发展，人们在地下、海底、南极冰层中建立了巨大的中微子望远镜。
在汉语中，“聪明”一词大约来源于“耳聪目明”。耳朵尖，眼睛亮，就是聪明。特别是“聪”字，左边一个耳，上面两只眼，中间是口，然后由心做分析。物理思想不会凭空产生，往往由耳朵听到的，眼睛看到的，嘴巴交谈的，然后在心里激发出新的想法。望远镜拓展了人的视野，人也因此变成更加“聪明”。对高能物理来说，探测器就是我们的眼睛。
