The Largest Structures
The downward path begins with an image representing 1 000 000 000 (109) light years of space -- a photon of electromagnetic radiation would take 109 years to travel from one edge of the picture to the other. Based on the latest evidence, the universe is some 10 to 15 x 109 years old. If we take one more step outward to show the next image of the series, we might be required to show the border or curvature of our universe -- the source of considerable debate and research. So we will begin our downward journey of 42 powers of ten here at 1025 meters. The dots of light represent only the largest and brightest galaxies. These galaxies are grouped into clusters of hundreds or thousands of galaxies, and the clusters are grouped into superclusters -- stretching at least ten times the size of this image in three dimensions.
Recent studies have determined that there are large volumes of space which contain few or no galaxies. These relatively empty volumes are surrounded by shells of clusters of galaxies. The overall picture is of huge bubbles in space, with the surface of the bubbles consisting of clusters and super clusters of galaxies with the interior of the bubbles relatively free of galaxies. My image represents this three dimensional bubble-like structure.
I have used the International System of Units (SI) throughout these pages. For more information about SI, see Some Words about Units.
Copyright © 2016 by Bruce Bryson