微波背景辐射的偶极---我们在宇宙中的速度

CMBR Dipole: Speeding Through the Universe
Credit: DMR, COBE, NASA, Four-Year Sky Map

Explanation: Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies. But these speeds are less than the speed that all of these objects together move relative to the cosmic microwave background radiation (CMBR). In the above all-sky map from the COBE satellite, radiation in the Earth's direction of motion appears blueshifted and hence hotter, while radiation on the opposite side of the sky is redshifted and colder. The map indicates that the Local Group moves at about 600 kilometers per second relative to this primordial radiation. This high speed was initially unexpected and its magnitude is still unexplained. Why are we moving so fast? What is out there?

翻译:
我们的地球并非静止不动。地球围绕太阳运转，而太阳则围绕银河系中心运动。银河系自己在本星系群中作轨道运动。本星系群则落向室女星系团。然而所有这些速度都比这些天体系统整体向宇宙微波背景辐射运动的速度慢。在COBE卫星的全天微波背景辐射图上，向地球发来的背景辐射表现出蓝移，而背向地球而去的背景辐射表现为红移。这张图告诉我们本星系群和宇宙这一原初背景辐射有600公里每秒的相对速度。这样的高速运动是我们没有预料到的，也很难以解释。我们不禁要问，为什么我们移动的如此之快。有什么在那里（造成本群如此大的相对速度）？