Hi, Quantum Mechanics is a such big topic in physics. And more important, it is the topic try to describe ALL physics system at microscopic scale. The word "predetermined" in physics, most likely means, if you have a input, then you can compute the output. The randomness in quantum physics is because of the daul features of small particles. I guess you mix the true physics with science fiction. Besides, physicists are also try to make the randomness less random. To them, the randomness is not random, it is just something they still cannot formulize yet. When you talk about predict the future and undo the past, it sound more like time travel. By right now, no one konws it can be done or not. It is only theoretic. There are something called Novikov self-consistency principle and parallel universes. You may want to read. I personally more prefer parallel universes. Regards.