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  • Physicists tell us that the universe is expanding, but does that mean we expand with it? I mean,

    物理學家告訴大家宇宙一直在擴張中,但是這樣代表我們是隨著宇宙擴張嗎?

  • if so, wouldn't no one notice because everything would scale up at the same relative size and

    如果如此的話,大家就都不會注意到了,因為萬物都成比例地變大,然後

  • it would seem like nothing had changed?

    就好像都沒有變大一樣?

  • Well, the truth is, the universe isn't expanding. Space is. Of course, everything else in the

    事實上,宇宙並沒有在擴張,但是太空有。當然,在宇宙裡的萬物

  • universe is "in" space, and ignoring the influence of any other forces, when the space between

    都在太空「裡面」,而且不受到其他力的影響,當物質之間的太空

  • things expands, those things will appear to be carried farther apart. But there are other

    擴張了,那些物質就會看起來像是被帶著分離得更遠了。但是在宇宙中

  • forces in the universe, and their strengths aren't directly affected when space expands.

    有其他的力,而且當太空擴張時,它們的強度並不會直接地被影響的

  • For example, gravity and electromagnetism are able to hold atoms and solar systems together

    舉例來說,重力和電磁力可以把原子和太陽系拉再一起

  • because these forces are too strong for the slow expansion of space to overcome.

    因為它們的重力超過了太空緩慢的擴張

  • Think of it like this - if you and your cat are standing on a piece of ground that starts

    想像一下像這樣,如果你和你的貓站在同一片地上,並開始

  • to stretch horizontally between you, the ground will pull you and your cat away from each

    在你們之間水平地擴張開來,那塊地就會把你和你的貓拉離彼此

  • other. But if the leash is strong enough - in particular, if it's stronger than the friction

    但是如果鍊子夠強壯,尤其如果鍊子的強度比你的腳和

  • force between your feet and the ground - it'll hold you and your cat together as space expands

    地板之間的磨擦力,這力量就會把你和你的貓拉在一起,就算太空同時在

  • beneath you.

    你腳下擴張

  • In the real universe, it's the strength of the electromagnetic force that determines

    在真實的宇宙之中,電磁力的強度會決定

  • the effective sizes of particles, atoms, and molecules so that even if the space they're

    粒子、原子和分子的實際尺寸,所以就算太空正在

  • in expands, the molecules don't. Electromagnetism is basically the leash that holds atoms and

    擴張中,分子也不會隨之擴張。電磁基本上就是那個鍊子,拉住原子和

  • molecules together - and gravity is the leash that holds solar systems and galaxies together.

    分子在一起,而且重力就是將太陽系和銀河系拉在一起的鍊子

  • Only over super super long distances is gravity's attraction weak enough and the cumulative

    只有當距離超級超級遠,重力的引力夠弱的時候,累積已久的

  • expansion of all that space big enough to cause galaxies and galactic clusters to actually

    太空擴張程度大到有辦法形成星系和星系團,以至於實際上

  • grow more distant from one another over time - we know this because the light from distant

    隨著時間在彼此間拉遠的距離,我們會知道的原因是因為從遙遠

  • galaxies gets red-shifted as it's stretched by the expansion of the space it's traveling

    星系的光線會紅移,就是因為光線在太空中傳播的時候被太空的擴張而拉長了

  • through. Gravity certainly still pulls distant objects towards each other, but space expands

    重力當然還是會將遙遠的物體拉近,但是太空擴張得

  • faster. Basically, the cat is off the leash.

    更快。基本上,那隻貓的鍊子已經掉了

Physicists tell us that the universe is expanding, but does that mean we expand with it? I mean,

物理學家告訴大家宇宙一直在擴張中,但是這樣代表我們是隨著宇宙擴張嗎?

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