The cosmic block

Once, on a trip to the Sundarban forests, I woke up to stargaze after the moon had set. My first thought was to check the time but my phone was dead and my friends' phones were locked inside the mosquito nets with them. So, I went outside, spotted Orion high in the sky and was fairly certain it was around 2 am. To clarify, I did not calculate the time somehow by looking at a star map, I had simply grown familiar with the sky from regular stargazing. I thought nothing of this at the time but my friends found this story endlessly hilarious and still bring it up today. 

I guess it's fair, telling time by the stars is not usually expected of anyone these days. Is that natural though? Would it be second nature for our ancestors to tell time by the stars before clocks were invented? I am not enough of a historian to answer this question directly but this disconnection from the cosmos is worth exploring, and that I can certainly do.

I once took this picture from my balcony. It is the Orion Nebula as seen in the Delhi night sky shortly after some rain showers. It is a special picture because usually the night sky in Delhi is a grey slate with a hue of reflected street lamps. Of course, Modern city life would simply be impractical without street lighting. Humans are afraid of the dark for good reason. It used to be the threat of venomous bites from below or a nocturnal predator from the shadows. 12000 years later we are obsessed with eliminating darkness wherever it lies. Sounds like an excerpt from a fantasy novel but the benefits of street lighting are entirely non-fictional. The infrastructure built for street lights is seen as a major sign of development, bringing greater access to electricity, better roads and improved safety to neighbourhoods. Re-imagining city life without lighting to eliminate light pollution is a bargain that everyone will refuse and so we just have to live with the consequences. 

Other components of light pollution do not have the nuance of social and economic positives. My home town of New Delhi has been in the news every year for having the most polluted air in the world. Especially in the pre-winter season when atmospheric trapping accumulates all the pollutants produced by the city and the stubble-burning farmlands that surround it on all sides. The result is that the capital city of about 32 million people suffocates in the worst air quality available anywhere in the world. Its residents celebrate this achievement by setting light to 1000s of crore rupees of firecrackers. Light that would have otherwise escaped the atmosphere or been absorbed at higher altitudes is scattered off of particulate matter in the air making the sky brighter. The exact impact of air pollution on light pollution depends upon the concentration and size of particles, distance from, colour and angular spread of the light source. Doing a controlled experiment to study all those variables in a real city is largely impractical.

Looking back I can understand the reason why I had fallen in love with the stars. Think about it, for most of human history we have lived under a constant reminder that more of the universe is above us and out of reach than is below us. Virtually every mythology and system of beliefs places great importance in the creation and behaviour of the Sun, the moon, the planets and the stars. We consider them gods. Events like eclipses, comets and supernovae have been considered harbingers of great or terrible times, changing the fates of entire kingdoms and wars. Questioning cosmological philosophies was reason enough to send heretics to the gallows. This stuff was deeply important to people. Even today, large portions of the population across many cultures arrange their lives around the motions of these heavenly bodies. I have to believe that these convictions and beliefs are hangovers of a distant past. If I were to ask someone in a city to point to the constellation of their zodiac they would look at me as if I had asked an impossible question. Either because they had never considered that concept before or more likely because the sky would be a grey slate of nothingness.