Why time travel in the past is not possible. (Theory #1)

Time travel to the past is not possible because if we want to travel into the past, and we change something, anything at all, the butterfly effect will ripple across the universe and you will cease to exist. On the other hand, if you plan on travelling back in time just to change something, in the future, you would have no need to travel back in time. This would create a paradox that fuels itself. (to be continued)