Is a cut-out of a multi-object spectrum obtained with LUCIFER showing the tell-tale signs of gas heated by young stars at unimaginable distances of billions of light-years. Such a spectrum is the decomposition of light into its different wavelengths (colors). At certain wavelengths, emission lines can be found depending on the chemical composition and physical conditions of an object. They are fingerprints for the investigation of what goes on in stars and galaxies. For distant galaxies, the most interesting lines are found in the near-infrared, where observations were less efficient until now. With LUCIFER and the LBT, large samples of galaxies can now be studied using its multi-object capability.