可观测宇宙
(原标题: The Observable Universe)
2022-03-16
浏览次数: 13
你能看多远？你能看到的一切，以及你现在可能看到的一切，假设你的眼睛能探测到你周围所有类型的辐射——都是可观测的宇宙。在光中，我们能看到的最远的距离来自宇宙微波背景，这是138亿年前的一个时期，当时的宇宙像浓雾一样不透明。我们周围的一些中微子和引力波来自更远的地方，但人类还没有探测到它们的技术。这张特色图片展示了可观测的宇宙在一个越来越紧凑的尺度上，地球和太阳在中心，被我们的太阳系、附近的恒星、附近的星系、遥远的星系、早期物质的细丝和宇宙微波背景所包围。宇宙学家通常假设，我们可观测到的宇宙只是一个更大的实体“宇宙”的附近部分，在那里同样的物理原理适用。然而，有几条流行但推测性的推理断言，即使是我们的宇宙也是更大的多元宇宙的一部分，在那里要么存在不同的物理常数，不同的物理定律适用，更高的维度运作，要么存在我们标准宇宙的略有不同的偶然版本。可用：高分辨率图像版本与可读的注释|点击注释版本
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How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe. In light, the farthest we can see comes from the cosmic microwave background, a time 13.8 billion years ago when the universe was opaque like thick fog. Some neutrinos and gravitational waves that surround us come from even farther out, but humanity does not yet have the technology to detect them. The featured image illustrates the observable universe on an increasingly compact scale, with the Earth and Sun at the center surrounded by our Solar System, nearby stars, nearby galaxies, distant galaxies, filaments of early matter, and the cosmic microwave background. Cosmologists typically assume that our observable universe is just the nearby part of a greater entity known as "the universe" where the same physics applies. However, there are several lines of popular but speculative reasoning that assert that even our universe is part of a greater multiverse where either different physical constants occur, different physical laws apply, higher dimensions operate, or slightly different-by-chance versions of our standard universe exist. Available: High res image version with readable annotations | Clickable annotation version