Light, as we all know, is very important in human life. Imagine a sudden absence of all form of light (the sun, the moon, electricity, solar, etc) in the whole world. What do you think? A beautiful dark world or a disgusting and awful dark planet to live in? I guess your answer is as good as mine: The world will be a miserable place to live in! Sorrow will not be uncommon! The future will be gloomy! And death will be commonplace.  Believe me or not, such is the situation with everyone who doe...