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新的理论认为,类地行星很可能是生命的起源

New theory concludes that the origin of life on Earth-like planets is likely

A widely accepted argument from Australian-born astrophysicist Brandon Carter argues that the selection effect of our own existence puts constraints on our observation. Since we had to find ourselves on a planet where abiogenesis occurred, then nothing can be inferred about the probability of life elsewhere based on this knowledge alone.

澳大利亚出生的天体物理学家布兰登·卡特提出了一个被广泛接受的观点:我们自身存在的选择效应限制了我们的观测。既然我们必须在一个发生了非生物发生的星球上找到自己,那么仅凭这一知识就无法推断其他地方存在生命的可能性。

At best, he argued, the knowledge of life on Earth is of neutral value. Another way of looking at it is that Earth can’t be considered a typical Earth-like planet because it hasn’t been selected at random from the set of all Earth-like planets.

他认为,在最好的情况下,地球上的生命知识是中立的价值。另一种看待它的方式是,地球不能被认为是典型的类地行星,因为它不是从所有类地行星集合中随机选择的。

However, a new paper by Daniel Whitmire, a retired astrophysicist who currently teaches mathematics at the U of A, is arguing that Carter used faulty logic. Though Carter’s theory has become widely accepted, Whitmire argues that it suffers from what’s known as “the old evidence problem” in Bayesian confirmation theory, which is used to update a theory or hypothesis in light of new evidence.

然而,目前在亚利桑那大学教数学的退休天体物理学家丹尼尔·惠特迈尔(Daniel Whitmire)的一篇新论文认为,卡特使用了错误的逻辑。尽管卡特的理论已被广泛接受,但惠特迈尔认为,它受到贝叶斯确认理论中所谓的“旧证据问题”的困扰。贝叶斯确认理论是根据新的证据更新理论或假设。

After giving a few examples of how this formula is employed to calculate probabilities and what role old evidence plays, Whitmire turns to what he calls the conception analogy.

在举了几个例子说明这个公式是如何被用来计算概率的以及旧证据的作用之后,Whitmire转向了他所谓的概念类比

As he explains, “One could argue, like Carter, that I exist regardless of whether my conception was hard or easy, and so nothing can be inferred about whether my conception was hard or easy from my existence alone.”

正如他解释的那样,“有人会像卡特一样争辩说,无论我的受孕是难是容易,我都存在,所以不能仅从我的存在推断出我的受孕是难还是容易。”

In this analogy, “hard” means contraception was used. “Easy” means no contraception was used. In each case, Whitmire assigns values to these propositions.

在这个类比中,“硬”意味着使用了避孕措施。“简单”意味着没有使用避孕措施。在每一种情况下,惠特迈尔给这些命题赋值。

Whitmire continues, “However, my existence is old evidence and must be treated as such. When this is done the conclusion is that it is much more probable that my conception was easy. In the abiogenesis case of interest, it’s the same thing. The existence of life on Earth is old evidence and just like in the conception analogy the probability that abiogenesis is easy is much more probable.”

惠特迈尔继续说道:“然而,我的存在是古老的证据,必须被视为古老的证据。这样一来,结论就是,我的构想很可能是容易的。在我们感兴趣的非生物发生的例子中,也是一样的。地球上生命的存在是古老的证据,就像在概念类比中,非生物发生很容易的可能性更大。”

Read more at Phys.org

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