Final answer:
Redshift surveys in the 1980s were critical for astronomy and physics, mapping large-scale structures like superclusters in the universe and significantly advancing our understanding of galaxy evolution and the distribution of dark matter.
Step-by-step explanation:
The discussion regarding redshift surveys in the 1980s pertains to the field of astronomy and physics, specifically exploring the concept of large-scale structures in the universe such as superclusters. During that time, redshift surveys were instrumental in creating comprehensive sky maps and in understanding the distribution and evolution of galaxies. The Sloan Digital Sky Survey, in particular, provided an extensive dataset by measuring positions and redshifts of thousands of galaxies, revealing that galaxies are distributed in large filamentary superclusters, which are not uniform but rather arranged in vast networks extending hundreds of millions of light-years.
A significant finding from these surveys was that superclusters can be extremely massive, even 10,000 times more massive than the Milky Way Galaxy, with masses reaching a few times 10ⁱ⁶ solar masses. Advanced technology allowed astronomers to study detailed structures of these clusters, such as the Abell 1689 galaxy cluster, by analyzing the rich collection of data from both ground-based telescopes and space observatories like Hubble and Chandra. This has advanced our understanding of galactic distances, redshifts, and the role of dark matter in the cosmos.