How far is Pluto from the Sun? The Solar System has a radius of two light years.
"At the heart of the great cluster,where the nebula was so thick as to be a nearly featureless glow, pearl-hued and shot with rainbows, the stars were themselves so close that thousands could be seen." (p. 772)
"'Everything astronomical in abundance, close together and interacting.'" (p. 773)
I have tried to quote and summarize to convey Poul Anderson's account of the Cloud Universe but there is no substitute for reading or rereading "Starfog." The Cloud Universe is both a cluster and a nebula.