Light is the source of life
Its energy allows plants to carry out photosynthesis and conditions the biological cycles of most living beings, among which is our species. Until the early nineteenth century, when Humphry David placed a thin strip of carbon between the two poles of a battery, giving rise to the first light bulb, and later Edison patented it in 1880, our only source of light came from the Sun and, in the night, of lamps and bonfires.
Technological advances in barely a century have made light even a problem, not only for the environment but for our own health. Light pollution affects urban and industrial areas and it is estimated that more than 80% of the world’s population lives under skies with light pollution. In some cities the possibility to see a few more than a dozen stars is minimal and this scenario is presented in countless cities throughout the planet.
”The light bulb was invented by Humphry Davy but it was not stable, Thomas Edison improved it
When we talk about light pollution we are talking about the brightness that is seen in the sky at night derived from an inefficient use of light. Instead of sending the light towards the ground, it is emitted towards the sky. Its incorrect use is also a waste of energy, alters and unbalances flora and fauna in general, disturbs our sleep cycles, increases glare on the road, hinders air and maritime traffic, and increases CO2 emissions.
About half of the insects live at night and their reproductive cycle and that of other nocturnal animals is altered by light pollution. Take for example moths, which use the light of the Moon to orient themselves, since they balance their flight path according to the rotation of the earth. Or in the fireflies, whose female emits light to attract the male and who sees how his effort cannot compete with the light of a street lamp. By reducing the number of insects, the birds whose diet depends on them are not able to raise their young due to lack of food, thus also reducing the livelihood of carnivorous animals.