By John
Bennett
The Northern
Lights have always captured man’s imagination and as our last blog depicted,
there are many myths and legends surrending them.
As far as science was concerned though,
it took a very long time for man to uncover the scientific truth behind the
Northern Lights.
Galileo first used the term boreal
aurora (later changed to Aurora Borealis) after Aurora, the Roman goddess of
dawn. However it was a Norwegian
scientist named Kristian Birkeland who set out to achieve what many before had
tried and failed: to solve the mystery of the Northern Lights. To Birkeland, the Lights represented the
threshold between the visible and invisible worlds; the link between the planet
and the mysterious forces that shaped the universe. However in the late 19th Century the
prevailing belief was centred on Aristotle’s assertion that there could be no
interaction between the heavens and the Earth because the heavens were perfect
and unchanging. This resolute popular
conviction created a difficult climate for Birkeland’s propositions.
In the winter
of 1899 Birkeland spent five months isolated in a mountain-top observatory at
Kaafjord in the far north of Norway, a position known as having the most
sightings of the Lights. Eventually he
discovered that the force disturbing the magnetic field came directly from the
sun in narrow, high-velocity beams of negatively charged particles (electrons)
called cathode rays. Sometimes these
active particles hit the magnetic field of the Earth and followed the field
lines down towards the poles, where they struck atoms in the atmosphere. The energy created by the collisions was
emitted as light. The lights only
appeared during magnetic storms because the cathode rays from the sun were
moving beams of electrons, creating electric currents that, in turn, made their
own magnetic fields.
Birkeland’s
conclusions were published in 1901 and Norwegian newspaper headlines trumpeted,
“Riddle of the Aurora solved!” However the international scientific
community was not so impressed. Britain
was the global leader in science and would not shift from her resolute opinion
that space was an empty vacuum.
Birkeland’s findings were rejected.
He was bitterly disappointed but even more determined to prove his
theory The Norwegian government refused him any more funding, so he had to
raise the money himself. This he did
through the invention of a fertiliser (of which there was a chronic global
shortage at the time) using electromagnetic furnace technology. Birkeland continued his fanatical study of
the Lights over the following years and in 1908 published his monumental work,
“The Norwegian Aurora Polaris Expedition 1902-1903” describing his second,
bigger expedition to the far north. But again the scientific community was
disparaging of his ideas and he suffered another major blow.
Gradually
over the five years following this second disappointment, his life began to
crumble. His work was overshadowed by
other scientific developments at the time, such as Einstein’s theory of
relativity and Bohr’s model of the atom.
His obsessional relationship with his work drove his wife to leave
him. He was also growing increasingly
dependent on alcohol and the sedative veronal, and his health began to
deteriorate.
He spent his
final years in Egypt studying the Zodiacal Light. A combination of insomnia,
whisky and veronal fuelled chronic paranoia.
He became convinced that with the outbreak of war, one of his
inventions, the electromagnetic cannon, placed him in danger. He kept the copies of his patent in a
specially installed safe in his room, bought two guard dogs and three guns and
sacked his servants as he was convinced were plotting against him.
On the 16th
June 1919, aged just 49,Kristian Birkeland was found dead in a hotel room. The
post-mortem revealed him to have taken 10g of veronal the night of his death,
instead of the 0.5g recommended dose.
For 50 years
after his death, Birkeland’s reputation sank into oblivion. In 1970 space satellites found
incontrovertible evidence of a flow of electric particles from the sun. This proved that “empty space” was actually
not empty at all, but filled with electrified gas, which then forms “solar
wind”, which Birkeland had identified more than 60 years earlier. Today he is credited as the first scientist
to propose an essentially correct explanation of the Aurora Borealis.
