Light pollution is the artificial lightthen emitted by humans, which is generated without a criterion of efficient lighting.

The word "pollutionhighlights the fact that it is an excess, something in the environment that is detrimental to it. "Light", which is sometimes used in a positive sensehere understood as the scattering of light and causes unnecessary pollution.

The evolution of our cities requires us, for commercial reasons and securityto illuminate streetsparks, businesses, shop windows and whatnot, but the misapplication of an efficiency criterion in this lighting results in the spread of light to excessive that does not serve to illuminate (the skythe trees).

To understand what it isjust think of the classic "balls," lighting the drive way or public parks.



These generate a large portion of their light (over half) to the other, toward the skywhich of course is not to be illuminatedIn addition therefore to unnecessary waste of energywe are leading, slowly, the loss of that which is the spectacular starry sky.

Just use light sources that light only downward, there are already enough to use it!