Arno Penzias shared half the 1978 Nobel Prize in physics with Robert Wilson "for their discovery of cosmic microwave background radiation.” The remaining half was won by Pyotr Kapits “for his basic inventions and discoveries in the area of low-temperature physics." Arno Penzias built a MASER (microwave amplified by stimulated emission radiation) amplifier in a radio astronomy experiment for his PhD under Charles Townes. After his PhD he went to Bell Labs where he continued to work in radio astronomy. He and Robert Wilson measured the cosmic background winning the Nobel prize for their work. They made observations of galactic and intergalactic hydrogen by measuring the radiation they emitted. Later, their research involved millimeter electromagnetic waves, which led to the discovery of different molecules in space. Observations of interstellar substances could be traced back to nuclear processes. Their measurements provided evidence supporting the Big Bang theory.