S. Juneau

The early universe was a hot soup of particles and light. In this soup, sound waves, fluctuations in density, spread outward from clumps of matter like ripples on a pond. When the universe cooled, these waves froze, leaving an imprint in the distribution of galaxies: they are slightly more abundant at a certain distance from each other.

In the early universe, when it was just a few hundred thousand years old, matter had not yet gathered into stars and galaxies; it was a hot soup of particles and light. Sound waves rippled through this soup — compressions and rarefactions, like ripples from a stone thrown into water.

Five thousand robotic fingers of the DESI spectroscopy reach toward the telescope's focus. In a single night, they record one hundred thousand light signatures. Hidden among these records are binary star systems with white dwarfs — cataclysmic variables.