大全-8-9（8/63杨继第8篇）中微子天文学，没找到讨论

huangyouhuifei

文章：
Passage 8 (8/63)
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.

题目：
According to the passage, one of the methods used to establish the properties of neutrinos was
(A) detection of photons
(B) observation of the interaction of neutrinos with gamma rays
(C) observation of neutrinos that were artificially created
(D) measurement of neutrinos that interacted with particles of seawater
(E) experiments with electromagnetic radiation

正确答案：
(C) observation of neutrinos that were artificially created

杨继书中解释：
C、观察人造中微子。正确。（见原文L29-L33）即用中微子显微镜观测中微子，可进行research工作，当然就可以确定其性质。
原文L29-L33：since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes.

疑问：
C怎么正确了？C说通过观察人造的中微子就能确定中微子的性质，为什么？原文L29-L33说：从那时起，关于中微子的所有研究都是针对人造中微子...这就能说明通过观察人造的中微子就能确定中微子的性质吗？

求解～～～～～

boozy

大哥，您的题目理解真的有问题，钻牛角尖了。题干里的establish只是表达了一种状态，所有的答案都指向用什么手段去研究中微子，没有一个说明到底确定了没有，题干也没有说下面哪种方式能够真正确定它的性质。换句话说，题目要找出的是去确定的方法，而不是能够得出其明确的性质的那种方法。

huangyouhuifei

大哥，您的题目理解真的有问题，钻牛角尖了。题干里的establish只是表达了一种状态，所有的答案都指向用什么手段去研究中微子，没有一个说明到底确定了没有，题干也没有说下面哪种方式能够真正确定它的性质。换句话说，题目要找出的是去确定的方法，而不是能够得出其明确的性质的那种方法。

-- by 会员 boozy (2011/1/26 11:32:24)

您这么一说，好像我是有点钻牛角尖。我最开始做此题的时候，没有定位，直接凭感觉选了D。现在基本想通了，您看我这样理解对不对：
第二段说：since then virtually all research with neutrinos has been with neutrinos created artificially。。。关于neutrinos的研究都是通过研究人造neutrino来完成的
第三段说： detecting cosmic neutrinos by harnessing the mass of the ocean。。。是说利用海水来探测neutrinos，而不是研究neutrinos
所以选C,不选D。
这样理解对吗？
boozy，太感谢了~~~

boozy

理解是对的。还有另一层区别：a group of astrophysicists has proposed a means of detecting cosmic neutrinos by harnessing the mass of the ocean. 说明海水探测法只是个proposal, 到底能不能实现只有天知道，靠谱不靠谱还有待检验，与真正操作过的人造中微子研究相比，恐怕还不够称之为method.

boozy

另外，文中只介绍了DUMAND的原理，怎么去发现中微子，解决干扰的问题，并没有说D选项中 measurement of neutrinos这样的细节内容。

huangyouhuifei

谢谢啦~~有了您的解答，我明白多了~~~

梦宝要米国

我想知道这篇文章的类型是什么呢？

向日葵的净土

全文明确说明是N的properties的定位其实没有，但是N不容易观测以及N携带环境信息都可以算作N的p,但是题目中强调的是method而且注意时态是was，文章第二段说detect N,那只要detect可以说总会发现一些N的特点，之所以这里不用专牛角尖，更应该是已经使用的方法上，那就只有第二段那种方法了。