Science. 1970 Dec 25;170(3965):1363-70. doi: 10.1126/science.170.3965.1363.
A brief review is given of what the study of galaxies has taught us about properties of the universe. It is assumed that the universe started from a general "explosion," and that the general expansion observed today, as well as the 3 degrees K blackbody radiation, are consequences of this explosion. The present average density in the universe is probably close to the critical value of 10(-29) g/cm(3). Only about 3 percent of this is contained in galaxies; the rest consists probably of intergalactic gas at a temperature between 10(5) and 10(6) degrees K. Observations in our own galaxy indicate that this intergalactic gas is still flowing into it.
简要回顾了星系研究告诉我们的关于宇宙性质的知识。宇宙被假设起源于一场普遍的“大爆炸”，而今天观测到的普遍膨胀以及 3K 黑体辐射都是这场爆炸的结果。目前宇宙的平均密度可能接近 10(-29)g/cm(3)的临界值。其中只有大约 3%包含在星系中；其余的可能由星系间气体组成，温度在 10(5)到 10(6)K 之间。对我们自己星系的观测表明，这种星系间气体仍在流入其中。
