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我们会见到外星生命吗?那些每天24小时用射电望远镜巡视宇宙,没日没夜地监听宇宙信号的科学家们随时准备接受这样的事实。我们也乐观地相信会有外星生命存在,并借此大胆地畅想一下外星生命会是个什么样子?想象另外一个没见过的东西,一个好的方法是先从与之有关的、你曾见过的东西开始。我们先来看看地球上的生命是个什么样子。从外观上看,地球上的各种生物之间尽管存在巨大的差异.但从遗传学的水平分析,地球上的所有生物都惊人地一致。地球上所有的生命都是以碳元素为基础的,并且均依靠DNA作为遗传物质来传递信息。你可能会很有见地地提出这样一个问题,“为什么生命都是以碳为基础的?为什么生命就不能以其他原子为基础进行构建?”的确,自然界总共有100多种不同的原子,其中很多都是普遍存在的,比如氢、氧、氮、铁等,碳是其中一员。在许多方面,碳原子有着跟其他原子一样的特性:性能很稳定,能与其他原子或其他碳原子产生键,从而形成小到仅有几个原子,大到含有百万个原子的分子。
Will we meet with extraterrestrial life? Scientists who visit the universe 24 hours a day using radio telescopes and listen to the signal of the universe day and night are ready to accept the fact. We also optimistically believe that there will be extraterrestrial life, and to take this bold imagination extraterrestrial life would look like? Imagine another never seen before, a good way is to start with the relevant, you have Things have started to see. Let’s take a look at what life is like on Earth. In spite of the vast differences between the various living things on the planet, all creatures on Earth are strikingly alike, based on the level of genetics. All life on earth is based on carbon and relies on DNA as a genetic material to convey information. You might very insightfully ask the question, “Why is life based on carbon? Why can not life be constructed on the basis of other atoms?” Indeed, there are more than 100 different kinds of atoms in nature, Many of them are ubiquitous, such as hydrogen, oxygen, nitrogen, iron, etc. Carbon is one of them. In many ways, carbon atoms have the same characteristics as other atoms: they are stable and can make bonds with other atoms or other carbon atoms, forming molecules as small as a few atoms and as large as one million atoms.