Why is the weather hot and cold?

Brothers ask questions, and brothers will definitely come to join us. Why is the sky hot and cold? The question is simple. If there is no difference between hot and cold, how can I prove that I am alive? People will feel when they are alive, and there will be cold and heat when they feel. Just like life, there are good and bad. If everything is good, how can it be bad? I remember when I was a child, my father told me that you saw how well the actors on TV played, so why couldn't you be an actor? I answered my father, why do you have to be an actor? People all over the world are actors. What is an actor if there is no audience? Hehe, just express your opinion and listen.