埃德温·哈勃发现宇宙
2020 April 26
Edwin Hubble Discovers the Universe
Image Credit & Copyright: Courtesy Carnegie Institution for Science
Explanation: How big is our universe? This very question, among others, was debated by two leading astronomers 100 years ago today in what has become known as astronomy’s Great Debate. Many astronomers then believed that our Milky Way Galaxy was the entire universe. Many others, though, believed that our galaxy was just one of many. In the Great Debate, each argument was detailed, but no consensus was reached. The answer came over three years later with the detected variation of single spot in the Andromeda Nebula, as shown on the original glass discovery plate digitally reproduced here. When Edwin Hubble compared images, he noticed that this spot varied, and so wrote “VAR!” on the plate. The best explanation, Hubble knew, was that this spot was the image of a variable star that was very far away. So M31 was really the Andromeda Galaxy — a galaxy possibly similar to our own. The featured image may not be pretty, but the variable spot on it opened a door through which humanity gazed knowingly, for the first time, into a surprisingly vast cosmos.
Centennial Celebration: Astronomy’s Great Debate was 100 Years Ago Today
Tomorrow’s picture: Another Great Debate?
埃德温·哈勃发现宇宙
影像来源及版权：感谢卡内基科学研究所供图
说明：我们的宇宙有多大？100年前的今天，两位著名的天文学家，就这个问题以及其他一些问题进行了辩论，这场辩论被称为天文学大辩论。许多天文学家相信我们的银河系是整个宇宙。不过，还有许多人认为我们的星系只是众多星系中的一个。在这场大辩论中，每一个论点都很详细，但没有达成共识。三年后，随着仙女座星云中单个点的变化被探测到，答案出现了，如图所示，这是数码复制的当年的原始玻璃底片。当埃德温·哈勃比较图像时，他注意到这个点发生了变化，于是他在底片上写下了“VAR！”。哈勃知道，最好的解释是，这个点是一个非常遥远的变星。所以M31实际上是仙女座星系——一个可能与我们相似的星系。这张特别的照片也许并不漂亮，但它上面那个变化的点打开了一扇大门，人类通过这扇大门，第一次有意识地凝视一个惊人广阔的宇宙。
明日一图预告：Another Great Debate?