Coffee, when poured into a mug and consumed, delivers a strongly desired boost of energy through caffeine. The same coffee, when poured onto the laptop, can be ruinous. The question of usefulness or harmfulness, applied to coffee, is answered by the use.
The same can be true for light, especially outside. But indulge me a moment as I continue to explore analogies along these same lines.
Gasoline, when used in the engine of a large truck, provides something useful: propulsion. That same gasoline, when poured into our community’s reservoir, poisons the water we need to drink and causes serious harm to our bodies. Coffee is not quite so toxic, though too much can be hard on us.
It is a good thing we know better. But when it comes to light, we mostly do not know better.
Gasoline may be useful in trucks, but for a number of reasons we want to use as little as possible. Gasoline in our water supply is harmful and ridiculously wasteful. Why would we drill or frack or dig for oil, refine it into gasoline, and then dump it in such a way that it will be harmful to our health and wellbeing?
Darkness, like clean water, is also important for our wellbeing (read more on the important of darkness HERE). The truck’s headlights in this image provide useful light that helps the driver get there safely. The lights on the reservoir sign may serve a minor function in helping people find the reservoir at night, but I suspect that is rarely, if ever, needed. Most of the light, and most of the year, the light shines up into the sky where it causes all kinds of havoc for our natural environment. And, just like refining gasoline to pour into our water supply, the overwhelming majority of light that goes up is using resources like copper and electricity and coal that are simply wasted.
We are paying good money to pollute the skies simply because we don’t know any better.
The next time you are out at night, take a look around. Are there porchlights wasting money and brightening the sky? Are there empty parking lots brightly illuminated, a large amount of that light reflecting off empty parking spaces into the night sky?
We need to stop pouring coffee on our laptops and start pouring it into our mugs.
We need to stop pouring light into the skies and keep it contained in useful fashion.
Is light useful, harmful, or both? Depends on how you use it.