Summary

Although galaxies attract the most popular attention as the contents of the cosmos, Tyson believes the “hard-to-detect things between the galaxies” may be “more interesting, or more important to the evolution of the universe, than the galaxies themselves” (62). Tyson begins this chapter with a laundry list of hard-to-detect things that make up the space between our known galaxies: “dwarf galaxies, runaway stars, runaway stars that explode, million-degree X-ray-emitting gas, dark matter, faint blue galaxies, ubiquitous gas clouds, super-duper high-energy charged particles, and the mysterious quantum vacuum energy” (64). Each of these things are equally difficult to detect, but advances in modern science, most specifically telescopes, allow scientists to begin to understand what makes up the perceived emptiness between galaxies.

Tyson begins his investigation with dwarf galaxies, which he claims, “outnumber large galaxies by more than ten to one” (64). Their smaller size compared to...