“According to Hindu mythology, the Universe was created with a sound: “om.” It’s a syllable that contains within it everything that ever was and everything ever will be. When the Arecibo telescope is pointed at the space between the stars, it hears a faint hum. Astronomers call that the “cosmic microwave background.” It’s the residual radiation of the Big Bang, the explosion that created the universe 14 billion years ago.

But you can think of it as a barely audible reverberation of the original “Om.” That syllable was so resonant that the night sky will keep vibrating for as long as the universe exists. When Arecibo is not listening to anything else, it hears the voice of creation.”
– From The Great Silence, by Ted Chiang