The universe appears to be uniform on large scales, meaning that it looks the same in all directions and at all locations in space. This uniformity is known as isotropy and homogeneity.
The most widely accepted explanation for this uniformity is the inflationary theory of the early universe. According to this theory, in the first fraction of a second after the Big Bang, the universe underwent an exponential expansion. This rapid expansion smoothed out any variations in density or temperature that existed before, making the universe appear uniform on large scales.
In addition, the cosmic Microwave Background Radiation (CMB) also supports the idea of a uniform universe. The CMB is the afterglow of the Big Bang and is nearly uniform in temperature across the entire sky. Any variations in temperature in the CMB are very small, and they provide evidence that the early universe was very smooth and uniform.
Status:: #wiki/notes/mature
Plantations:: Cosmology
References:: Parallel Worlds