Even our earliest ancestors recognized that sunlight, longer daytime, and higher temperatures in spring marked the beginning of a new vegetative cycle. These observations led them to perceive light as the fundamental source of life. While this perception holds true, it only represents a portion of the whole picture. As we delve further, we will discover that darkness, night, cloudy periods, and other factors are equally indispensable to sustaining life. The crucial point to acknowledge is that all organisms operate within specific cycles and rhythms, which can only be achieved when darkness alternates with light.
Light and darkness – one-sided cultural perceptions vs scientific truth
Every individual is influenced by the internalization of cultural models, and virtually every culture symbolically distinguishes between light and darkness. Light is often associated with concepts such as day, goodness, and life, while darkness is commonly perceived as “evil”. How does this relate to ecology? Today, we have evidence to substantiate that life on Earth requires both light and darkness. This fact stands on its own, requiring no further arguments for support. However, it is beneficial to highlight scientific findings that can fully rehabilitate our perception of darkness and underscore its importance in ecological contexts.
Equilibrium and complementation
Bats once inhabited a historic church in Sweden. The city authorities, considering the impressive appearance of the building, made the decision to illuminate it with floodlights continuously throughout the day and night. Unfortunately, this choice had dire consequences as all the bats that sought refuge there perished. They were unable to survive the adverse effects of what we now recognize as “light pollution.”
This serves as a small-scale example, but it emphasizes a larger truth: all organisms on Earth, particularly plants which form the foundation of the food chain, have evolved within the framework of the daily cycle of light and darkness. If our planet were to suddenly alter its orbit, disrupting the regular alternation of these periods, the functioning of nature as we know it would be severely impaired. Vital processes such as efflorescence, pollination, and growth would be impeded.
Humans, too, have an inherent rhythm tied to the ebb and flow of light and darkness. The absence of sleep ultimately leads to death. We cannot remain awake indefinitely; we require periods of rest to rejuvenate. This physiological necessity is crucial for sustaining our well-being. Darkness stimulates our brain to produce melatonin, aiding in wound healing and cellular regeneration. Sleep is vital for our mental state, and during our formative years, our bodies predominantly grow while we sleep, among other essential functions.
What is “light pollution”?
Light pollution is a consequence of human activity, predominantly observed in densely populated urban areas where specific regions remain illuminated around the clock. Unfortunately, this situation is unfavorable for numerous species, including humans. The human brain relies on darkness to produce essential hormones vital for proper functioning. Similarly, creatures such as hedgehogs in city parks, various bird species, plants, and others require darkness in accordance with their natural behaviors, such as nocturnal feeding or tissue regeneration. Continual exposure to light disrupts their ecological balance, displacing species adapted to shade and darkness from their respective ecosystems.
Rehabilitation of darkness and conclusions for further actions
It is evident that both residential and public spaces should be equipped with smart lighting systems that automatically turn off when not in use. We recognize the importance of conserving natural resources. However, what may not be as apparent is the necessity for comprehensive city lighting designs that prioritize the well-being of people, animals, and plants. Lighting in urban areas, for example, should be carefully planned to align with natural rhythms, ensuring the protection of all species and maintaining a harmonious balance that caters to their specific light and darkness requirements. Darkness complements light, and it is crucial to uphold this equilibrium in our actions and strive to organize our world in a manner that does not disrupt it.
