Kristian Birkeland (1867-1917), Norwegian physic- ist, with his apparatus for studying the cause of the aurora borealis, or Northern Lights. This comprised a metal sphere containing a magnet (simulating Earth) in a vacuum chamber (simulating space). He fired a stream of electrons at the sphere, which simulated the solar wind. The inter- actions of the electrons and the magnetic field produced lights analogous to the aurorae on Earth. Birkeland also invented a process for extracting nitrogen from air for fertiliser manufacture. He set up a hydroelectric power com- pany to fund his aurora research. He died of an overdose of sleeping pills in a Tokyo hotel room.

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