By Dr. Smriti Mahajan
Well-lit roads and parking lots are synonymous with safety. Skyscrapers made of glass and steel, shining brightly all through the night, define a city’s skyline and announce its status in the national and international arena of development. The wealthiest house on the block has the brightest porch. And yet, the inhabitants of that home find it difficult to fall asleep. City dwellers fall prey to criminal activities and yearn for the quiet, peace, and darkness on their vacations away from their illuminated city life.
It is ironic that as citizens of a fast-developing, energy-starved nation, most of us living in urban areas have walked through neighborhoods with more lights than the number of stars we can count in the night sky.
Impact of Light on Our Lives
Modern research shows that we need darkness to lead a healthy life, and yet, in ignorance, we continue to hamper the most crucial component of our well-being by blue light emerging from the LEDs surrounding us and digital devices that are part of our days—and unfortunately, our nights.
On the contrary, humans have actually evolved to savor darkness. For thousands of years, our hunter-gatherer ancestors led lives in tune with the cycle of light—they woke up with sunrise and wound down their day at sunset. The only light available to humans after sunset was the soft glow of the Moon or yellow light from the embers left after cooking and wood fires burnt to keep warm.
It is therefore not surprising that our hormones, brain activity, digestion, sleep cycle, and energy levels—controlled by various complicated emotional, chemical, and physiological processes in our bodies—are linked to the 24-hour cycle of the Sun, known as the circadian rhythm.
Our bodies produce many hormones such as melatonin, which induces sleep, and growth hormone at night. It is a well-known fact that people with insufficient sleep produce less growth hormone. This is extremely important for children because lack of growth hormone can hinder their growth and is linked to behavioral issues.
Darkness and Intellectual Growth
In the absence of modern-day entertainment sources such as television and the internet, for centuries our ancestors stared at the night sky. They imagined patterns among the points of light overhead and named them for reference and discussion. They recorded time and important events based on the setting and rising of these constellations and other key objects visible in the night sky at particular times of the year.
The sowing and harvesting seasons, and in some civilizations floods (i.e., the onset of monsoons), were predicted based on the appearance of the night sky. Even today, it is mandatory for sailors to learn navigation aided by stars and other celestial objects so that they have the ancient knowledge guiding them even if all else fails.
Humans evolved because they looked up at the sky, but unfortunately, that growth and development are now hindering our view of the night sky itself.
Light and Other Species
Many plants, insects, and even fungi have been shown to follow the 24-hour rhythm of the solar cycle. It was intriguing for scientists to learn that the leaves of a plant kept in a dark basement dropped at night, just like they would in a lighted balcony—evidently suggesting that they were governed by the plant’s internal clock.
Several behavioral studies of migratory birds, insects, and sleep patterns in other animals show a clear need for darkness for their well-being and reproduction. Carnivores rely on darkness to fetch their prey, while many birds have their mating instincts tuned to the phases of the Moon. Female sea turtles come out of the water to lay eggs on the beach in the dark of night, while migratory birds follow the Moon to navigate.
But the unhindered presence of light from various manmade sources confuses migratory birds, who die of exhaustion because they lose their path and often collide with brightly lit buildings. The bright lights on beaches confuse sea turtles, who lose their way and are run over by fast-moving vehicles on nearby highways.
The seemingly harmless artificial lights illuminating the night are supposed to make us feel safe and happy but are actually disturbing our circadian rhythm and are life-threatening for our co-inhabitants.
Types of Light Pollution
Light pollution can be broadly classified into four categories:
Skyglow: It is the ever-pervasive brightening of the night sky, especially in densely populated areas. This is what prevents us from enjoying the night sky from our balcony.
Glare: Bright lights causing visual discomfort. Anyone who has driven a car at night must have encountered at least one other vehicle with its headlights on high beam. That uncomfortable feeling is what this form of light pollution is all about!
Light trespass: Any form of light entering premises where it is not required—for instance, a streetlight shining brightly outside your bedroom window.
Clutter: Too many bright lights shining together, causing confusion.
Rise and Role of Astro-Tourism
Astro-tourism is a niche industry aiming to combine human yearnings for exploration, knowledge, and adventure with their need for darkness. It encourages low-impact tourism in dark locations, often combining stargazing and astrophotography sessions with nature-themed activities such as camping, bird watching, safaris, and trekking. The fascination for astronomy, coupled with ease of travel and affordable digital photography instruments, has provided a boost to this industry, which is expected to hit the $400 million mark globally by 2030.
As travel becomes easier and demand for memorable experiential tourism surges, more tourists seek out remote, dark destinations to appreciate the night sky. As a consequence, astro-tourism ventures are ideal ambassadors for spreading awareness about light pollution.
The Corbett National Reserve recently witnessed one such initiative undertaken by the Uttarakhand Tourist Development Board in collaboration with an astro-tourism venture called Starscapes. Stakeholders from various walks of life—astronomers, science communicators, naturalists, architects, and representatives from social and traditional media—gathered together at the “Nakshatra Sabha Dark Sky Conclave” to discuss possible steps that can be undertaken to combat light pollution on personal, social, and state levels.
Steps to Combat Light Pollution
Unlike others in its class, light pollution can be reduced with simple steps adopted in our daily routine. These steps can help us build better infrastructure and lead healthier lives without traveling to dark locations to reset our circadian clock. Streetlights should be designed to illuminate the road by pointing their beams downward. The traditional designs pointing upward were created for gas lamps, which were neither as efficient nor as bright as the latest technology we use today.
We need to think rationally and illuminate shopping malls, petrol pumps, and streets accordingly. A mindset shift is required to accept that bright is not always safe! If that were the case, no crimes would ever have been committed in well-lit alleys, parking lots, jewelry shops, and 24-hour departmental stores. But that is not the case because even criminals need light to accomplish their tasks!
The illuminance of streetlights—and in most cases, parking lots and petrol pumps—can be reduced to 60% or less past 11 PM. This will not just save energy but will be relatively healthier for the people involved.
Use orange or yellow light inside the home and out on the porch (if needed). This is our closest substitute for the orange glow of the wood fire burnt by our ancestors. The soft orange glow is aesthetically pleasing and calms the mind. That is why your favorite restaurant has dim orange lights, and that candlelight dinner with a loved one puts you in a good mood even before you lift the spoon.
Try to minimize the use of digital devices—mobile phones, TVs, and laptops—after sunset. Aim to stop using them at least an hour before bedtime. Use the nighttime mode setting available on most digital devices nowadays, which automatically reduces the glaring colors and white screen on devices after sunset. Basically, the idea is to limit white light after dark, overexposure to which hampers sleep and accelerates disorders such as ADHD, anxiety, and Alzheimer’s disease.
As the most intellectual beings on the planet, it is our duty and the need of the hour to conserve other species, the environment, and moreover our oldest natural heritage—the star-studded skies, which are hardly visible to 40% of our population in urban areas. By losing the dark sky, we are losing touch with our culture connecting us to our ancestors with whom we share the legacy of the night sky. We are losing out on the feeling of awe and wonder that the study of astronomy offers and the precious sleep required for our growth and well-being.
About the Author
Dr. Smriti Mahajan is an astronomer, science communicator, and content creator promoting STEM education through astronomy.
Email– theastronomyclass@gmail.com
Author: Prakriti Parul
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