So why does this force need to be fine-tuned? If the strong force was two percent weaker, then hydrogen atoms would repel one another, and there would only be hydrogen atoms in the universe. But if the strong force was two percent stronger, then all of the hydrogen atoms would quickly attach to one another, and there would just be helium. Without free hydrogen you can’t make atoms like H20, or water. This would make life’s existence highly unlikely, if not impossible.223
