雙語暢銷書《艾倫圖靈傳》第3章:思考什麼是思考(21)

In practice, predictions could not be performed except in the most simple of cases, but in principle there was no dividing line between these and systems of any complexity.

但在實踐中，除了一些極簡單的系統之外，這種預測是無法實現的。而且在理論上，這些簡單系統，和複雜系統之間，也並沒有什麼本質上的區別。

It was also true that some sciences, thermodynamics and chemistry for instance, considered only averaged-out quantities, and in those theories information could appear and disappear.

還有一個事實是，在某些學科中，比如熱力學和化學，通常只考慮總體平均情形，在這些理論中，信息可以出現，也可以消失。

When the sugar has dissolved in the tea, there remains no evidence, on the level of averages, that it was ever in the form of a cube.

當一塊糖在茶中融化了，總體平均來看它還是一塊糖，但它本來攜帶的信息就消失了。

But in principle, at a sufficiently detailed level of description, the evidence would remain in the motion of the atoms.

但是，假如能夠充分描述其細節，那麼那些丟失的信息，仍然保留在原子的運動中。

That was the view as summed up by Laplace13 in 1795:

這就是拉普拉斯在1795年總結的觀點：

Given for one instant an intelligence which could comprehend all the forces by which nature is animated and the respective situations of the beings who compose it – an intelligence sufficiently vast to submit these data to analysis – it would embrace in the same formula the movements of the greatest bodies and those of the lightest atom;

假如有一位強大的智者，他能綜合所有驅動自然的力，以及施力物體的所有情況，並且能夠分析所有這些數據，那麼對他來說，就沒有什麼是不確定的。

for it, nothing would be uncertain and the future, as the past, would be present to its eyes.

未來就會如同歷史一樣，展現在他的眼前。

From this point of view, whatever might be said about the world on other levels of description (whether of chemistry, or biology, or psychology, or anything else), nevertheless, there was one level of description, that of microscopic physical detail, in which every event was completely determined by the past.

這個觀點意味着，對於我們用其它方式（比如化學、生物學或其它方式）描述的任何事物，都還存在着一個包含所有物理細節的描述，在這種描述下，一個事情完全取決於過去。