So when I was invited to make a documentary about the sun, I accepted only because the brief was to find ‘human stories’ to illuminate the science. My research, strangely, led not to sun-drenched landscapes but to Arctic winters illuminated only by the Northern Lights, and to the man who first posited a correct theory to explain the eerie phenomenon of the Aurora.
His name was Kristian Birkeland. Born in 1867, he was seven times nominated for the Nobel Prize before dying of an overdose weeks before his best chance of winning it. What I learned of his brilliance, his calamities and his expeditions into the Arctic night to study the mystical Aurora, gripped me completely. Making the film was not enough. Within a few months I quit the BBC and set out for the Arctic Circle to learn more about Birkeland and to start a new chapter of my own life. It was a rescue job. My desire to save this obsessive, unlucky genius from undeserved obscurity gave me the courage to do what I had lacked the confidence to do, to write.
Birkeland was thirty years old and already his country’s foremost scientist, when he began badgering the impoverished Norwegian government, at that time only a satellite of its colonial master, Sweden, to fund his dream of building the world’s first, permanent, auroral observatory. Reluctantly, Norway agreed, and Birkeland chose a site in Finnmark, the northernmost province of the country, on the peak of Haldde mountain. In the summer of 1899 a small stone building was erected, some 1150m above sea-level, within the Arctic Circle, in an atmosphere entirely free of light pollution and factory smoke. From here Birkeland, if he survived the freezing tempests of a five-month sojourn in the Arctic winter, hoped to solve the many riddles of the Aurora Borealis.
At the end of the nineteenth century no one knew whether the Lights originated in Earth or space. Did they touch or emanate from the peaks of mountains? How low did they reach? Could they singe hair or even kill? Did they affect the weather and cause crackling noises? How far into space did they penetrate? The first written account of a probable aurora dates from the 12th March 567 BC, during the reign of King Nebuchadnezzar II, and mentions an unusual ‘red glow’ in the night sky. Aristotle, in his fourth-century BC work Meteorologica, describes aurora looking like flames of burning gas that, when sending out sparks and rays, resembled ‘jumping goats’.
Scandinavian folklore provided many poetic explanations. The Aurora were created, for instance, by sunlight reflecting off shoals of herring, rocking icebergs or the wings of migrating geese. Birkeland’s own favourite theory came from a Swedish man of letters who, in 1740, shone a beam of light through a prism suspended over a glass of cognac, to create swirling patterns in the alcohol fumes — thereby proving his theory that the Lights were produced by sunlight falling onto ‘vapours’, though not necessarily alcoholic ones.
In October 1899, Professor Birkeland and four student volunteers left the Royal Frederick University and travelled the length of the country by boat and horse-drawn carriage to the base of Haldde Mountain, where their cases of instruments and supplies were piled onto sleds pulled by reindeer. They set off up the mountain following a reluctant guide, a Sami reindeer herder turned postman, who muttered continuously that the Lights would seek revenge for the scientists’ curiosity. Indeed, during what should have been a six-hour trudge, a violent blizzard engulfed the party and nearly killed them all. They reached the summit just before nightfall the following day, and the first victim of the expedition had been claimed: the hands of one of the volunteers, a trainee surgeon, were frostbitten and all his fingers were amputated.
One hundred years to the day after the disastrous launch of Birkeland’s expedition, I flew over the northern coastline of Norway, looking down on a landscape devoid of colour: white snow, black cliffs, the deep, dark water of the fjords flecked white with ice and the tips of small waves. By extraordinary luck, I met a scientist at Alta airport who had been granted permission to ascend Haldde on a skidoo to mark the anniversary. He invited me along and we rushed over sunlit snow for an hour, reaching the summit forty times faster than had Birkeland.
I could see all that Birkeland had seen a century before. To the north is the Pole, unconquered when Birkeland was on Haldde. To the west and east stand the sharp peaks of the Kvænangen and the softer outlines of the Porsanger Mountains. The plateau to the south provides the winter pastures of the Sami reindeer herds, while below is the dark, branched channel of the fjord in the Alten valley. The observatory itself is small, with a squat tower to one side, anchored to the mountain with thick, steel cables to prevent it being blown away. For Birkeland, it was both shelter from the worst that the Earth could throw at him, and a doorway to space.
Although the observatory is no longer used for science, and is simply a place where visitors who brave the climb can stay the night for free, it began life bristling with instruments to measure and record changes in the Earth’s magnetic field, electric currents in the ground, wind speed, air pressure, temperature, cloud formation and auroral forms. Birkeland and his students worked around the clock in shifts, collecting the most valuable data between the hours of 6pm and 2am, when the Lights are at their most active. Birkeland observed that the Lights appeared only when his instruments indicated a disturbance in the Earth’s magnetic field, and that they were most brilliant when large sunspots were active on the Sun’s surface. He called them the Aurora Polaris, or Polar Dawn.
The team celebrated the dawn of the twentieth century in the permanent darkness of Arctic winter, battered by winds of nearly 140km per hour. They were trapped inside for three weeks, in January 1900, by a particularly violent storm — but were undeterred. Birkeland became convinced that the Lights occur when charged particles, streaming from the Sun in narrow beams called cathode rays, hit the Earth’s magnetic field and are drawn along field lines down towards the poles. As the particles collide with atoms in the atmosphere, mainly of nitrogen and oxygen, the energy created is emitted as light. He suspected that at the South Pole, the Aurora Australis would be an exact mirror of those at the North, the same patterns, at the same time, in reverse.
Birkeland’s theories about the Aurora were long denied the credit they deserved largely because British scientists were convinced that space is a vacuum and that no particles from the Sun could reach the Earth. The influence of the Royal Society in London was far greater than Birkeland’s, and it took more than half a century for him to be proven right, long after his death. In 1966, one of the first satellites sent into space collected evidence of charged particles streaming from the Sun, a phenomenon now called the Solar Wind.
Perhaps the superstitious Sami postman had been right to fear the Lights. In the final days of their expedition to Haldde, an avalanche killed the youngest assistant of the party. Professor Birkeland himself died alone, in a Japanese hotel room in 1917, of an overdose of sleeping powders with a pistol on his bedside table. He had told a friend the day before that spies were trying to steal his designs for an electromagnetic cannon. This might have been true; a war was raging in Europe. His effects and final thesis, on research he had carried out in Egypt into the Zodiacal Light to further prove his ideas about cathode rays, went down in a storm with the ship carrying them home.
The night I visited the Observatory I lay in the snow and gazed up into space. It was minus 30 degrees Celsius but there was no wind, moon, light pollution or cloud. As if to my call, the Aurora appeared over the mountains to the east. At first, one string of fluorescent, whitish green light snaked slowly across the entire dome of the sky, not as bright as lightning but powerful enough for me to see the landscape around. Other lights followed and intertwined, always moving forwards, at times brightening and growing faster, at others dimming and slowing down. Then thinner rays streaked downwards so fast that I could not tell when they began or ended, to create a gauzy curtain of light, blown by the solar wind.
For a full hour I watched the ever-changing display, profoundly delighted and grateful to the living scientists who had patiently and generously dispelled my ignorance of physics to allow me to understand the prophetic genius of Birkeland and to start my life as a writer. I imagined the Professor lying beside me in the snow, wrapped head-to-toe in reindeer skin, smiling too.