Last sound first
Here’s one version of the cosmic sound: in this case the first
million years, compressed to 5 seconds, shifted up by 50
octaves, and played at constant volume:
Click on the speaker icon to play.
These are .wav files
Note three stages: descending scream; deep roar; growing hiss.
What do these stages mean, and how can we possibly know this?
1. Observations of the Cosmic Microwave Background (CMB)
2. Detailed computer simulations of the early Universe
Let’s begin, then, with this Microwave Background……..