Why is the sky dark at night?
Because there is no Sun - is no good an answer. As a school going kid that kind of answer felt good to live by. But now, if you think the answer to this question is obvious, think again. The best minds of physics have studied this question for over a century, and the current answer may surprise you.
If you haven't read about it earlier, the world of science will help you understand why even though we have so many stars and galaxies all around us, we still have a pitch dark background across the sky at night.
Check out this 3-minute video -