Gazing up at twilight sky | Sunday Observer

Gazing up at twilight sky

22 January, 2023

Light is a magic element. The great builders of the past used it masterfully to manipulate almost everything. The Egyptians cut the temple at Deir el Bahri from the rocks on the West bank of the Nile so that the morning sun would stain it an awesome purplish-bloody red.

The Byzantine architects covered their domes with glistening mosaics, so light would reflect dizzyingly and dazzlingly back and forth, obscuring form with mystery. The Gothic builders filtered light through coloured glass, to set it dappling and dancing on the grey stone.

They are the wonders of light coming from the sun. Today, science has advanced to such an extent that man has been trying to use artificial light created by electricity to create wonders. However, scientists are now trying to find ways and means to mitigate the adverse effects of artificial lights on humans. They fear whether a new light pollution is invading the environment.

The environment is what sustains human and animal life. We cannot live without breathing the air or drinking water. We cannot survive if the soil is infertile and we cannot grow sufficient food to feed humans and animals.


Man has been polluting the earth as if he holds it on lease. Factories release industrial waste into the earth and waterways. They also emit noxious gases into the atmosphere polluting the air. As such we have been grappling with the pollution of the air, water and soil. Now we have light pollution to deal with.

Light pollution causes unintended harm to humans and animals. Those who are living in big industrial cities are becoming aware of the dangers of bright lights that make it impossible for them to see the twinkling stars in the night sky. The glow of street lights, searchlights, office lights and neon lights have been designed to dispel darkness.

Today, scientists are investigating the serious impact of light on human health. Light pollution will increase the incidence of breast cancer, depression and many other ailments. On the other hand, light pollution has adversely affected wildlife. Alan Outen, a British ecologist said, “People are beginning to take light pollution seriously.” He said the implications are bigger than what they have realised.

According to a recent survey, two-thirds of the world population live under night skies polluted by light. The illuminations of big cities are so powerful that they do not become dark at night. Satellite images reveal that in the United States, Germany, France, Japan and South Korea, night has become more or less twilight.

As a child I used to gaze up at the night sky and count the stars. It is said that you can see nearly 3,500 stars and planets in the sky with you naked eyes. The night sky has inspired writers and poets. Many poems and essays have been written describing the natural beauty of the night sky.

However, in large industrial cities, the number of visible stars has dwindled due to light pollution. Due to this latest malady, your eyes will never get to the stage where they are fully adapted to darkness. In a way we have lost our night vision due to the light pollution.

Impact on animals

Apart from humans, migratory birds have been adversely affected by the light pollution. Millions of birds in the United States die as a result of crashes. Even well-lit skyscrapers have injured or killed a large number of birds. On the other hand, artificial lights along ocean beaches in Florida have confused baby sea turtles.

More than a million hatchings have been adversely affected. Turtles are usually attracted to light coming from stars and the moon. When beaches are brightly illuminated they crawl towards the road only to be crushed by speeding vehicles. Some turtles wander about on the beach and are baked by the rising sun.

Bryant Buchanan, a biology professor at Utica College in New York, said even the dim light is sufficient to blind nocturnal frogs. According to biologists, strong light at night can cause habitat loss for certain wildlife. Light can also cause mental distress and impairment in many animal species.

Although the immediate cause is still unknown, a possible cause may be the evolutionary presence of alternating darkness and light. Nobody can survive either in total darkness or total light.

Richard Stevens, an epidemiologist at the University of Connecticut Health Centre said light at night can disrupt critical hormone levels. According to him, the cancer risk is five times higher in developed countries than in developing countries. However, there may be other causes for breast cancer such as fatty foods, genetics or exposure to toxic chemicals.

In his research studies, Stevens concentrated on the 24-hour biological clock that guides our bodily functions. Melatonin is a hormone most living creatures produce only in darkness. As a result, even a small light can affect the production of melatonin. According to scientists, we should sleep in complete darkness. Stevens said, “There is mounting evidence to suggest that disruption of the melatonin rhythm may lead to chronic fatigue, depression, reproductive anomalies and even cancer.


Stevens said female nurses who are compelled to do night duty run the risk of contracting breast cancer. According to him, blind women have a lower risk of cancer. The key is that melatonin is produced in the brain when the eyes signal when it is dark. The production of melatonin begins around midnight and shuts off during the day. As a result there can be a drop in the production of melatonin in those who work at night.

Scientists do not expect you to turn off lights and sit in darkness for health reasons. They advise you to limit your exposure to bright lights at night.

[email protected]