And God said, Let there be light: and there was light. And God saw the light, and it was good, and God divided the light from the darkness. So the Bible tells us how God created light in the World. For something that God created, the truth is there isn’t very much of it. Even the sunniest place gets 11 hours worth, and some cloud-covered areas get only 3 hours per day. Also the rest of the Universe, most of the stuff between planets and stars is dark. In what is known as the Olbers paradox, despite bright stars, space is dark.
On earth, humans created workarounds. The work of Benjamin Franklin and Thomas Edison has left the world we know bathed in light. At the switch of a button. We now have Earth Hour where we turn it off. Living in artificial light for between sixteen and twenty hours is not the norm for humans, having spent most of humanity in darkness.
Some scientists believe that constant exposure to light is one of the reasons we find it hard to sleep. In a study conducted by Thomas Wehr, a group of participants was asked to spend fourteen hours in darkness each day for a month. In doing so, they began to sleep for fourteen hours per day. Subsequently, they migrated to eight hours but these eight hours included two hours of a mode of awareness that was neither active consciousness nor actual sleep. The capacity to experience this state had withered away and now only existed in ashrams or monasteries due to constant exposure to light. Fuelled by caffeine, exposure to gadgets and artificial light, humans spend a large part of their lives in what is known as a hyper-alert state. Your brain is not used to this and soon experiences fatigue. You experience this as lack of sleep.