Sonifying the Cosmic Microwave Background

Abstract

We present a new technique to sonify the power spectrum of the map of temperature anisotropy in the Cosmic Microwave Background (CMB), the oldest observable light of the universe. According to the Standard Cosmological Model, the universe be- gan in a hot, dense state, and the first 380,000 years of its ex- istence were dominated by a tightly coupled plasma of baryons and photons, which was permeated by gravity-driven pressure os- cillations - sound waves. The imprint of these primordial sound waves remains as light echoes in the CMB, which we measure as small-amplitude red and blue shifts in the black body radiation of the universe, with a typical angular scale of one degree. With our software, users can observe how the temperature map and power spectrum of the CMB change in response to different compositions of baryonic matter, dark matter, and dark energy, and explore these different universes in ‘sound space.’ Our simulation is designed to enhance understanding of how we can infer properties of the uni- verse from the power spectrum of CMB temperature anisotropies. We discuss the theory, the software, and potential applications in education.