Why is it dark at night?

When the sun sets below the horizon, darkness spreads over our heads. Why? Why is the sky dark at night? If you don't know, don't worry about it. Most people don't know that. Not only does she not know, she doesn't even know that she doesn't know, because she has never asked herself this strange question. However, the question "Why is it dark at night?" hasn't even been asked by stargazers themselves for centuries. It was not until the Renaissance that mankind realized that darkness is only self-evident in terms of our everyday, or rather nightly, experience. But in terms of the structure of the universe, it is a mystery. The book takes us through the complex journey of finding the answer. A road full of detours and false trails. Famous stargazers, physicists and philosophers have sought the answer. But it was a complete amateur, the famous poet and fantasist Edgar Allan Poe, who pointed the way. Was it just a coincidence? The problem of the darkness of night did not keep cosmologists awake even in the twentieth century. Is it still relevant today, in the twenty-first century?