I have followed XKCD for years. His What If? blog (and book) is really good as well. He walks step-by step through the inputs and effects of the questions. The What If for the video below is Relativistic Baseball.
If the video does not load, then try Randall Munroe: Comics That Ask What If?
From TED Talk: Randall Munroe published July 05, 2016 at 07:41AM.