I would love to see the aurora, who wouldn’t? And yet I have this spectacular ability to miss them time and again. I don’t live far enough north to see them often, but there have been several times when they have been viewable from where I live, but I’ve missed them. This, even though I have signed up to the University of Central Lancashire’s Aurorawatch service and even received a Red Alert one night and ignored it, only to find in the morning that a spectacular display had occurred overnight and I’d slept through it. Typical. So when I saw this book by plasma physicist Melanie Windridge I absolutely had to read it. I might not have seen the Northern Lights, but at least I could learn about them.
The book is structured around 6 different locations, each of which are critical to the development of our understanding of the aurora. Windridge begins in Sweden, the first place she saw the aurora. Through each location Windridge expands on and develops the story of the aurora: what we know about it, what we don’t know, misunderstandings, instrumentation and technology, and the sacrifices and challenges of the scientists and enthusiastic amateurs (who contribute as much, if not more, than the qualified scientists) who have made it their life’s work to understand the lights. Sweden is a gentle introduction, with quite lyrical descriptions of the aurora (I imagine seeing them must simply be so otherworldly that it inspires these wonderful descriptions) like this:
“To the west, the mine looked almost ethereal, dripping white light and with three plumes of smoke billowing into the sky, illuminated from below. I turned my back on the industry and looked north, where a very quiet aurora was beginning to appear as a green, arcing haze. Over time it grew in colour and clarity, the arch becoming more defined, then breaking and twisting into an S-shape. Other parts of the sky were brightening too, but in different ways. To the right the light seemed a whiter gree and more diffuse, but had a semblance of linearity, like faint rays.”
Then we move to Norway, and much of the history of the scientific exploration of the aurora, and in particular the activities of Kristian Olaf Birkeland who was instrumental in the work of understanding how the aurora work. Given Norway’s position in relation to the aurora this small country has made quite a significant impact on our understanding both of the aurora and the sun, as it is known to be events on the sun which cause the aurora to occur, though much of the actual mechanics remain unclear.
In Iceland we learn of the way in which photography has aided the development of an understanding of the aurora, as well as spreading the love and awe of the event to communities which might never experience it directly. It is in this chapter that Windridge begins to open up about plasma physics, her speciality, and it was here that I almost became lost. I realise that as an amateur the pure science was always going to be more difficult to follow, but I think Windridge strikes a good balance between hard science and layman’s science and whilst there were times when I found myself scratching my head a bit, it also left me with enough of an interest that I will be following up on plasma physics in more depth. There’s also plenty of human story in the exploration of the scientists who have aided in the understanding of the aurora, and the people who still work in this field bringing it to life.
The book then flows through Canada – where we learn about space technology, auroral image capture and the volunteers helping to spread the word about the aurora using the internet as their medium; as well as electromagnetism (also a fascinating subject), more about spectroscopy and the Earth’ magnetic field. In Scotland we learn about space weather and the very real threat this poses to an electrically dependent society, and the attempts that are being made to improve our ability to forecast. Then in Svalbard Windridge encounters the aurora again, explaining how the different shapes of the aurora arise and how science is working to develop an even better understanding of the phenomena.
It is a fascinating book, filled with interesting facts like this which are the kind of thing that really set my mind racing:
“The photon of light released in a fusion reaction in the centre of the Sun then begins its long journey out from the core, passing though the radiative zone and the convection zone before it reaches the solar surface. The photon can get trapped in the radiative zone for quite some time. It bounces off atoms at random like a puck in a pinball machine, being absorbed by one atom and then re-emitted to be reabsorbed by another. This seriously impedes its ability to exit this zone, which is the thickest layer in the Sun, stretching from around 20-70 percent of the distance from the centre of the Sun to the surface – about half of the solar radius. It can take up to 200,000 years for a photon to cross the radiative zone travelling along this random, bouncy path.”
It is a science book, it has lots of science in it so if you’re not keen on science, particularly physics, then perhaps this isn’t a great book for you. But it is about more than just the science; it is about the spirit of human endeavour, the need to know even the unexplainable. It covers aurora superstition and spirituality, emphasising how the empirical knowledge that science brings does not detract from how seeing the aurora makes people feel. In the end, most science is fuelled by the same fascination that draws people to view and spiritualise the phenomena, it comes from a place of joy and curiosity, and this very much comes across in Windridge’s book. It has given me a thirst to know more, and further fuelled my desire to actually see these beautiful lights.
Aurora is published by William Collins