Sunday, 25 November 2012

Dark skies vs. light pollution: trying to keep in touch with the cosmos

A few minutes after witnessing the recent solar eclipse - reaching an 87% maximum here in Auckland, New Zealand - I was astonished to overhear the account director of an international advertising agency disparagingly state that all the people on the streets he had just seen staring at the sky would probably have been eaten by dinosaurs a few thousand years ago. I was so shocked by his lack of wonder (and this from the representative of an agency that claims to appeal to the heart as much as to head) that I couldn't even bring myself to ask if he was a creationist, considering his evolutionary timescale differed by approximately sixty-five million years from the scientifically accepted one. As much as the impression he gave of being a follower of the Sarah Palin school of history, what really got to me was his lack of wonder: have many first-worlders become so surrounded by electronic gizmos that they are immune to the marvels of nature?

One of the great natural sights anyone can enjoy is the night sky, but with more than 50% of the human race now living in conurbations we are rapidly cutting ourselves off from view that helped inspire our earliest mythologies. Could an argument be made that as our ability to observe the rest of creation declines, so does our ability to awe? Although my home city of Auckland is less light polluted than my last place of residence, London, a brief visit to rural Queensland, Australia earlier in the year reminded me just how much us city dwellers are missing: for example, Mars really is an angry 'Bringer of War' red whilst the Milky Way does seem like a river cutting through the sky. I also recall that once during a holiday in Cyprus I saw an extremely bright, eerie glow radiating from behind hills near our rural villa, only for the full moon to eventually rise as the source of the light.

Although Auckland isn't bad by the standards of some cities - it's dark enough in my back garden for even a half full (First Quarter) moon to cast strong shadows - the view directly west, currently home to interesting sights such as Mars, Mercury and Venus, is pretty much ruined by the stadium lights used in the local shopping centre car park, which remain on until very late. In addition, there is enough general light pollution from buildings and to a lesser extent street lamps that even a modicum of cloud is enough to reflect a diffuse glow and severely impact astronomical 'seeing'.

Crater Copernicus via a Skywatcher 130P telescope
The crater Copernicus, as seen from Auckland via a Skywatcher 130P reflector using a QHY5V camera.

With numerous forms of contamination now known to be causing environmental degradation it's hard to see where support can be garnered for this most poetic of forms of man-made pollution. After all, astronomers are hardly an endangered species and with professionals able to use the likes of the Very Large Telescope in Chile and plans afoot for the European Extremely Large Telescope to be operational by 2022 things are looking up for the discipline (an old astronomical pun, if you weren't aware). But as for us city-bound amateurs, we're stuck with poor viewing conditions thanks to all the artificial lighting, never mind the turbulence caused by heat radiating from asphalt and the like.

Research suggests that the USA alone loses billions of dollars per year on night lighting commercial and corporate premises. So why are shops lit up outside of opening hours: to advertise the company logo and wares for any passing punter, just on the off-chance it triggers a bell in the consumer's head? And what about office buildings? Since movement detectors have been installed in most office tower blocks I've worked in, why do companies still feel the need to have dozens of floors lit up like a Christmas tree? The USA currently imports over 20% of its energy so wouldn't make sense to for the largest consumers to cut down on usage rather than become increasingly beholden to other nations? The lifespan of most fossil fuels deposits is now understood and makes for grim reading, especially with regards to oil. European energy reserves for example are known to be extremely low, so how can non-practical nocturnal lighting be anything other than ridiculous?

And then there are street lights, which in most designs seem to radiate light in all directions. There are models that aim their light where it's needed, i.e. downwards, but the vast majority just aim their beam everywhere. I'm assuming that any street light that channels its light downwards in a tighter beam can utilise lower power bulbs than other styles but even with the obvious eventual power savings I can't see much chance of upgrades en masse; there are an estimated 35 million street lamps in the USA alone, so conversion wouldn't be an overnight process. What about tasking local authorities with switching to more efficient models as and when individual lamps require replacements? You would have thought any opportunity to save energy would be a basic tenet of legislation by now. Or is there a naïve belief that science will come up with a miracle solution in our darkest hour? Personally I'm not sure that nuclear fusion is going to be ready any time soon!

So apart from annoying amateur astronomers there are several strong arguments in favour of reduced nocturnal light pollution. A biological rather than economical one has been suggested by several studies investigating the effects strong nocturnal light levels may have on human health, such as reduced melatonin levels. In addition, various types of wildlife from hatching amphibians to migrating birds are affected by artificial night lighting, and as we are becoming increasingly aware, one small change in the ecosystem can rapidly cause a chain reaction up the food pyramid. As if these problems weren't enough, another issue that seems to have garnered minimal media attention is that artificial lighting at night may break down the nitrate radical NO3, which would otherwise help to neutralise other, smog-contributing, nitrogen oxides. All in all, there seems to be very few areas of concern to humanity that are not affected by nocturnal light pollution. By comparison, the inconvenience to us amateur astronomers seems like small fry!

However, it is not entirely doom and gloom. The International Dark-sky Association (IDA) was formed in 1988 to fight light pollution at a grass roots level and has put together information packs as well as organising the International Dark Sky Places programme. There are to date nearly twenty parks and reserves around the world that have qualified for this status, the majority to be found in Canada and the USA. The largest however is the Aoraki Mackenzie International Dark Sky Reserve on South Island, New Zealand, so I intend to get down there at some point in the next few years...

Another campaign that relies upon public participation is the GLOBE at Night programme, which has collated nocturnal light pollution levels using data supplied by volunteers from 115 countries. It has a family-friendly website with items in up to 14 languages, so for any parents looking to involve their children in an important global experiment, this is the place to go. It even includes instructions on making that essential tool for all night-time observations, a red light, so that you can view documentation without ruining your night vision sensitivity. Incidentally, I know the problems of ruined night vision all too well, since although the superb planetarium freeware I use has a night mode, my telescope camera software does not; I suppose I'll just have to find somewhere that sells sheets of red gel to tape over the laptop screen.

It would appear that the ever-increasing difficulty of viewing at first hand the stars, planets, nebulae and everything else that makes the observable universe is just the tip of the iceberg when it comes to the problems caused by too much artificial lighting at night. But thanks to the likes of the IDA and GLOBE at Night programmes there is now an opportunity for anyone to get involved, both to promote conservation of energy and our fragile ecosystem whilst preserving something of the wonders that previous generations took for granted. As the physicist Brian Greene, author of The Elegant Universe (that's the book with all the tricky stuff about Calabi-Yau spaces) puts it: "I have long thought that anyone who does not...gaze up and see the wonder and glory of a dark night sky filled with countless stars loses a sense of their fundamental connectedness to the universe. And as the astounding vastness of the universe becomes obscured, there is a throwback to a vision of a universe that essentially amounts to earth, or one's country, or state or city. Perspective becomes myopic. But a clear night sky...allows anyone to soar in mind and imagination to the farthest reaches of an enormous universe in which we are but a speck. And there is nothing more exhilarating and humbling than that."

If that's not a call to action, I don’t know what is: come on Brian Cox, please get the ball rolling!