Although time journey has been a standard plot device in science fiction because the late nineteenth century and the theories of particular and common relativity allow methods for types of one-method journey into the long run through time dilation , it is presently unknown whether the legal guidelines of physics would permit time travel into the previous. Such backward time travel would have the potential to introduce paradoxes related to causality , and quite a lot of hypotheses have been proposed to resolve them, as mentioned within the sections Paradoxes and Rules of time journey beneath.

Great hub. I do surprise if your conclusion that trigger and impact preclude journey again in time is airtight. I seem to dimly remember that some discoveries in sub-atomic physics carry the precept that impact can’t precede trigger into question. Would or not it’s on extra sure footing primarily based on conservation of matter …