人類為什麼不能穿牆「普特聽力文摘」

看一些科幻片或者神話片的時候，我們有時候會想，為什麼自己不能穿牆。那麼，你知道為什麼人類不能穿牆嗎?下面這篇英語聽力文摘會給你答案。

　　聽力原文：

Shadowcat! She’s one of the X-Men, and she can walk through walls!

Unfortunately, however, Shadowcat can’t be real. This is because she violates a basic law of physics that says two things can’t share the same space.

But aren’t atoms mostly empty space? Couldn’t she just slip into that space? Unfortunately, no.

It’s true that atoms are mostly empty space. (If a helium atom were the size of the earth, the electrons would be out in earth’s atmosphere, and the protons and neutrons would be the size of a basketball at the core.) But atoms can’t overlap because only a limited amount of electrons can be in the same orbit.

The reason for this is what’s called the Pauli Exclusion Principle. Electrons have ‘spin’. Picture a screw. Its threads go in one direction, right? So imagine the screw turning in the direction of its threads, like how it screws into a board. Now picture placing two screws side by side, but pointing in opposite directions. Their spins are the reverse of the other, and you can get them close together.

But the Pauli Exclusion Principle only applies to particles like the ones in atoms. There are other types of particles, such as the ones that make up light, which can be in the same place at the same time.

　參考譯文：

幻影貓! 作為X-戰警中的一員，她可是擁有穿牆的本領呢!

然而，不幸的是，幻影貓無法出現在現實生活中。因為她違背了物理學的一條基本定律，那就是兩個物體不能同時存在相同的空間裏。

但是大多數原子內部不是空的嗎?難道她不能闖進那個空間裏嗎?可惜事實並非如此。

的確大多數原子內部是空的。(如果氦原子有地球那麼大的話，那麼電子就會位於地球大氣層當中，核心處的.質子和中子也只是一個籃球的大小)。但是原子之間無法重疊，因為只有有限數量的電子才可以處於相同的軌道上

產生這種現象的原因就在於泡利不相容原理。電子是旋轉的。想象一顆螺絲釘。螺紋的走勢是衝着一個方向，對吧?那你就想象一下螺絲釘是怎麼旋轉着擰進一個木板的。現在想象並排擺放兩個螺絲釘，把螺紋的指向擺成相反的，這樣它們旋轉起來就會越轉越近。

但是泡利不相容原理只適用於原子這樣的粒子，還有其他類型的粒子，比如光粒子，它們是可以同時存在於相同空間的。