@Ticce Some humans do say they know something about a version of it. They say that time and perceived physical reality are illusions, and you (that is, your conscious present attention) can and does go back, over and over. And/or that reality is a projection of something else.
As far as conventional physical notions, what would it mean to “go back in time”? Would you “rewind” everything that happened in the universe? How would you even begin to accomplish that from a physical technological standpoint?
If you mean relativistically, we can reverse direction only by applying kinetic energy on other objects, and while this may from certain points of reference seem to affect time, in no case does it involve moving backwards in time.
What would be implied for cause and effect if it were possible? As soon as you allow the possibility, all notions of causality are out the window, unless perhaps it is a matter of either rewinding everything, or only moving attention/awareness/consciousness, or if there are infinite multiverses, or new timeline threads that get created by reverse “time travel”.