Kristian Olaf Bernhard Birkeland (born 13 December 1867 – 15 June 1917) was a Norwegian space physicist, inventor, and professor of physics at the Royal Fredriks University in Oslo.

The discovery of X-rays inspired Birkeland to develop vacuum chambers to study the influence of magnets on cathode rays.

Recognizing that technological invention could bring wealth, he developed an electromagnetic cannon and, with some investors, formed a firearms company.

At a dinner party only one week later, Eyde told Birkeland that there was an industrial need for the biggest flash of lightning that can be brought down to Earth in order to make artificial fertilizer.

There were no more attempts to sell the firearms company, and he worked with Eyde only long enough to build a plasma arc device for the nitrogen fixation process.

The resulting company, Norsk Hydro, hugely enriched Norway, and Birkeland then enjoyed adequate funding for research, his only real interest.

He wrote: "It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds.

It does not seem unreasonable therefore to think that the greater part of the material masses in the universe is found, not in the solar systems or nebulae, but in 'empty' space.

Potemra[15][16][17] As a scholar with wide interests, Birkeland joined the control commission of NSFPS (Norwegian Society For Psychic Research).

The 299 members of the society included, by 1922, people like prime minister Gunnar Knudsen, as well as a wide range of doctors, professors and shipowners.

Professor Birkeland exclaimed on that occasion, "I'm supposedly against all witch burnings, but a teeny weeny one in honour of Mrs Wriedt would not have been in the way.

An example of one of his experiments is depicted on the left front of a previous version (issued in 1994) of the Norwegian 200 kroner note;[20] it shows a magnetized terrella, simulating the Earth, suspended in an evacuated chamber.

The ring encircling the magnetic pole depicted on the back of the bank note is similar to the patterns predicted by Birkeland and shown more recently by satellites.