5 December, 2012 6:23PM AEDT

Uncovering the mystery of the Northern Lights

Listen to the lesson: The Mystery of the Northern Lights - how one man's quest cost him his sanity and ultimately his life. Your teacher is Fred Watson, Astronomer-in-Charge of the Australian Astronomical Observatory in Coonabarabran.

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Aurora Borealis (the Northern Lights) are a natural phenomenon that can paint the night sky with unearthly, surreal colour. Similar to a sunset in the sky at night, it appears occasionally in arcs or spirals usually following the earth's magnetic field. They are most often light green in color but often have a hint of pink. Strong eruptions also have violet and white colours.

Since ancient times, spectacular displays of the aurora borealis have intrigued people in arctic regions.

The Sami people of northern Scandinavia, for example, regarded them with fearful awe, associating them with the dancing souls of the departed. In more modern times, Europeans were baffled by the lights; for example, a woodcut depicting a display seen in Augsburg on 12 Jan 1570 depicts them as a row of giant candles flickering above the clouds.

It was a Norwegian, Kristian Olaf Birkeland (1867-1917) who first suspected that subatomic particles from the Sun might be responsible.

Born in Kristiania (now Oslo) his father was a storekeeper and a ship-owner. He became interested in natural sciences at a very young age and it is claimed that the first thing he bought himself from his own money, was a magnet. Before he was 18 years old he wrote an important paper demonstrating his exceptional skills in mathematics.

When he published his theory on the Aurora Borealis, it was received with derision by British scientists, who thought they had discovered everything relating to the Sun, and his thinking of subatomic particles carrying electric currents from the Sun were a fairy-story.

Isolated from friends and colleagues, his depression caused him to use sleeping preparations which eventually reached dangerous levels . Already accustomed to drinking heavily and taking large doses of Veronal to cure his insomnia, his life spiralled out of control and led ultimately to his death.

In 1967 Birkeland's ideas were proved correct by direct measurements made in space by a US Navy satellite. As he had predicted, both electrons and protons from the Sun bombard the Earth.

Listen to the full lesson with Richard Glover.
