14 DAY TRIAL // The sky we see today is very distinct from the sky one could see one century ago, especially in the big cities. This is due to the light contamination, an increasing nightmare for the astronomic observatories. The signals of the mobile phones and of the satellites cover the molecules and waves present in the interstellar space and the stars and galaxies themselves, an impediment in the study of the Universe. The cloud of electromagnetic waves isolates humankind.
The light contamination is wasted, the energy lost lighting up the sky, not the ground. A classical example are the ball lampposts, still found in most cities. Or the lighting of the monuments during the night: who is admiring them after midnight?
In US a third of the light produced annually is wasted, with a yearly cost of 30 million oil barrels and 8.2 million carbon tonnes, a total of 2 billion dollars.
But the light contamination does not affect only humans. Amongst its victims, there are reptiles, amphibians, insects and birds.
The nocturnal birds that use the Moon and the stars to orientate during their migrations, get confused and collide against towers or illuminated buildings. The turtles that lay eggs on the beaches of the coast, will give up when the coast is too lit and if they have already laid the eggs, the offspring, instead of heading towards the sea, are attracted by the light, getting exposed to predators.
There are frogs that only croak, calling for a mate, only in the total obscurity. If there is not such obscurity, they cannot reproduce. There are frogs that go out for a hunt only when the sun sets. In some areas, they start to go out later than usual, when the food is already scarce.
Many insects die attracted by the luminaries, and this is important, as they are the base of the terrestrial food chain.
In humans, night light is known to induce changes in the levels of the melatonin hormone, implied in the biological clock, antioxidant and immune system and sleep.