so they say we cant travel back n time because it would create a paradox. Theres a line of thought thats says it may be possible i we select the history that does not cause a paradox. However it seems to me that quantum physcics also says that all historys exsist until we collapse the wave. This means we cannot create a paradox that doesnt already exsist as a possible history. The paradox problem also seems to imply that a paradox is only a paradox because it creates a new timeline, but given that we know a timeline only exsists because its the line of entropy, then theres nothing special about timeline paradoxs, its more to do with our abaility to think past that timeline we cannot currently move out of.