In the developed world we take light for granted. Whenever there is darkness, we can flick a switch and it is gone. Thus we can work productively at night or in enclosed spaces. We can read and study too. Light is key to our enlightenment. Light dispels the shadows where danger might lurk. Light not only illuminates, it also protects.
All our fossil fuels derive directly from light. The sun’s rays are fixed by photosynthesis in plants which are then slowly transformed into the coal, oil and gas that are currently essential for our energy needs. The sun obviously provides us with solar power too, but also heats the atmosphere and oceans providing us with renewable energy from wind and waves. Without light we would be powerless as well as blind.
But light is even more fundamental than this. Over the last decade, astronomers have exploited huge advances in instrumental technology to detect incredibly faint light from stars in unimaginably distant galaxies, so distant in fact that light has taken billions of years to reach us from them. Light has helped us understand our place in the universe by assembling a model of creation called the Big Bang theory, according to which the entire cosmos was once much brighter and hotter than a star. All the matter from which our planet, our sun, and ultimately ourselves, are made was born in an intense flash of light.
Physicists are rightly proud of the giant steps that have been made towards a fuller understanding of the interactions between light and matter, and how this knowledge has been used to probe both the deepest depths of space and the tiniest subatomic particles. But because all these great advances depend so crucially on energy, and especially light, they can’t fail to remind us also of how poorly we manage our meagre energy resources on earth.
For example, data on the population fraction with access to electricity show a rise from about 50 per cent in 1970 to over 75 per cent in 2005. However, this progress has been very unequal across regions. Even today, nearly 75 per cent of the population of sub-Saharan Africa and 50 per cent in South Asia lack access to electricity. International Energy Agency estimates suggest that the number of persons without electricity access will continue to rise in South Asia until the end of this decade, and in sub-Saharan Africa until 2025.
This growing energy disparity may result in greater levels of deprivation, alienation and social unrest but it can only be tackled if the developed world accepts that it is wrong for energy to be distributed so unevenly when its supply is so essential in so many ways to our past present and future on this planet.
Olafur Eliasson’s Little Suns are practical devices that can make a real difference to real lives. But they are also symbols of that bigger sun to whose light we owe our collective existence. Energy doesn’t belong to anyone. We all belong to it.
Head of Mathematical and Physical Sciences, University of Sussex, UK