People are not interchangeable, Miss Rita. They aren't apples in a basket, with one bushel bought as easily as another. The matter of changing a world comes down to...you don't have good words for it, but you might say, inflection points. Events that are bound together, that are in resonance, can all be moved with a single lever at the correct point. Many separate incidents on separate worlds cannot. One planet is a magnitude of one. Insulating each universe we visit from any perturbations we may cause is a magnitude of infinity.

But even if I could do it, I wouldn't. You are all just as capable of taking the opportunity to make positive changes in these worlds as you are capable of doing harm. I do encourage anyone who is concerned about this to take that responsibility seriously.