Vid Iršič

Light from distant quasars, breaking through billions of years, leaves a pattern of dark absorption lines on the cosmic film — the spectroscopic Lyman-alpha forest. Each line is like a note in a grand score, written by the hydrogen of the intergalactic medium.

Light from quasar J0744+2052 traveled to us for almost 12 billion years. Along the way, it bumped into hydrogen clouds that snatched individual lines from the spectrum — like a comb sifting through delicate frequencies. Astronomers call this pattern the Lyman-alpha forest in spectroscopy.