关于月度狗里的dark的内容，中微子的部分（貌似是原文）

shiwen111

我考的时候，感觉很像，大家看下吧

Virtually everything astronomers known about objects outside the solar system is based on the detection of photons—quanta of electromagnetic radiation. Yet there is another form of radiation that permeates the universe: neutrinos. With (as its name implies) no electric charge, and negligible mass, the neutrino interacts with other particles so rarely that a neutrino can cross the entire universe, even traversing substantial aggregations of matter, without being absorbed or even deflected. Neutrinos can thus escape from regions of space where light and other kinds of electromagnetic radiation are blocked by matter. Furthermore, neutrinos carry with them information about the site and circumstances of their production: therefore, the detection of cosmic neutrinos could provide new information about a wide variety of cosmic phenomena and about the history of the universe.
But how can scientists detect a particle that interacts so infrequently with other matter? Twenty-five years passed between Pauli’s hypothesis that the neutrino existed and its actual detection: since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes. But a neutrino telescope, capable of detecting cosmic neutrinos, is difficult to construct. No apparatus can detect neutrinos unless it is extremely massive, because great mass is synonymous with huge numbers of nucleons (neutrons and protons), and the more massive the detector, the greater the probability of one of its nucleon’s reacting with a neutrino. In addition, the apparatus must be sufficiently shielded from the interfering effects of other particles.
Fortunately, a group of astrophysicists has proposed a means of detecting cosmic neutrinos by harnessing the mass of the ocean. Named DUMAND, for Deep Underwater Muon (muon: n. μ介子) and Neutrino Detector, the project calls for placing an array of light sensors at a depth of five kilometers under the ocean surface. The detecting medium is the seawater itself: when a neutrino interacts with a particle in an atom of seawater, the result is a cascade of electrically charged particles and a flash of light that can be detected by the sensors. The five kilometers of seawater above the sensors will shield them from the interfering effects of other high-energy particles raining down through the atmosphere.
The strongest motivation for the DUMAND project is that it will exploit an important source of information about the universe. The extension of astronomy from visible light to radio waves to x-rays and gamma rays never failed to lead to the discovery of unusual objects such as radio galaxies, quasars, and pulsars. Each of these discoveries came as a surprise. Neutrino astronomy will doubtless bring its own share of surprises.

shiwen111

还好还好啦，你不要不给自己信心，要对自己有信心

王百万

楼上的同学呐
我只是想采访一下 当你满眼都是这篇外星文时候 有没有一股我不入地狱谁入地狱的悲壮感！！或者我是地球人 外星关我毛事的感叹！！！
还是说 只有我这样？！！！咆哮！！！！
没法子 我是一个脆弱的胖子！！！

shiwen111

哈市作为背景知识看看吧

王百万

考试的那篇好长啊
我的眼睛都快爆炸了

shiwen111

题目不一样，但是文章应该是差不多的，考试里有问质量的题，文中也有提到

liyiran1209

这篇我考到了，确实和neutrino有关，但是和JJ差距很大，借鉴意义微乎甚微

birdmiao

支持

POOKYloveGMAT

up~

luoxlucy88

对呀对呀。顶起来。考过的童鞋快来看看呀。多谢多谢！！！！