The cosmic microwave background can help scientists piece together the history of the universe. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Christopher Pattison does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations ...

A glow undetectable to the human eye permeates the universe. This light is the remnant signature of the cosmic beginning — a dense, hot fireball that burst forth and created all mass, energy, and time ...