Atmospheric nitrogen is transformed into reactive nitrogen through lightning. Thunderstorm rain contains saltpeter and nitrate that stimulate plant growth. As early as 1903, the Norwegians Kristian Birkeland and Sam Eyde tried to emulate lightning in order to bind nitrogen. With an electric arc they produced nitrogen oxides from nitrogen and oxygen. With nitrogen oxide as a base substance, fertilizers or explosives could be produced. Since the process consumed tremendous amounts of electrical energy it did not gain acceptance. The Birkeland-Eydeprocess can be emulated using a microwave to produce nitrogen oxide from nitrogen and oxygen.