Glossary term: 可观测宇宙
Description: 可观测宇宙指的是我们能看到的宇宙区域，它是一个以我们为中心的球体。可观测宇宙的半径取决于自宇宙诞生以来，光能向我们传播的距离。位于可观测宇宙边界的区域距离我们非常遥远，以至于在过去的 140 亿年里，它们的光线才刚刚有足够的时间到达我们这里；换句话说，就也是宇宙的年龄。
我们现在所能看到的最遥远的宇宙区域距离我们超过 400 亿光年。这是因为从这些区域发出的光到达我们这里之后，宇宙已经膨胀了很多。来自可观测宇宙之外的天体的光还没有足够的时间到达我们这里。
我们等待的时间越长，光线向我们传播的时间就越长，可观测宇宙也就越大。宇宙中的其他观测者也有自己的可观测宇宙：一个以他们为中心的球体，其半径是其他区域的光线能够到达他们的最远距离。
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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
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