Apparently all the rules of physics are valid in reverse. Consider that time moves forward but what's happening is the past in reverse. So the universe reverses as time moves forward. Note that if the universe stops reversing and starts moving forward again then it does not move forward exactly as it did last time as the universe is chaotic and the uncertainty principle means you can't replicate the starting conditions perfectly. Now you would have to figure a way to smuggle yourself unchanged as the universe reverses. If you did all this the grandfather paradox would not apply. Even if you didn't murder him you would never be born anyway as human creation is also a chaotic process so no exact same human being would be born as the universe moves forward again. Essentially you would destroy each person as you reverse past their date of birth.
Apparently all the rules of physics are valid in reverse. Consider that time moves forward but what's happening is the past in reverse. So the universe reverses as time moves forward. Note that if the universe stops reversing and starts moving forward again then it does not move forward exactly as it did last time as the universe is chaotic and the uncertainty principle means you can't replicate the starting conditions perfectly. Now you would have to figure a way to smuggle yourself unchanged as the universe reverses. If you did all this the grandfather paradox would not apply. Even if you didn't murder him you would never be born anyway as human creation is also a chaotic process so no exact same human being would be born as the universe moves forward again. Essentially you would destroy each person as you reverse past their date of birth.