Hiss And Mutter

Space is silent except when astronauts switch on their radios:

"Hitherto they had talked a little when working outside, not real conversation but a trivial remark now and then, a grunt for response...just enough to drown out the hissing of the stars."
-Poul Anderson, The Enemy Stars, 11, p. 83.

"Nakamura's voice crackled above the mutter of stars." (p. 85)

Descriptions of cosmic noise, as of the Milky Way, have become collectible items.

Meanwhile, I remain fascinated by the complexities of James Blish's overlapping After Such Knowledge Trilogy and Haertel Scholium. See Another Summary.