Tommy Tomorrow

Here is a 1949 comic, posted on Four Color Shadows, that nicely resolves all those temporal paradox/changing the timeline problems that vex Doctor Who, Starfleet officers, teenagers in DeLoreans, etc.  In this issue of Tommy Tomorrow, our hero travels back from the future (1989), to the present (1949).  Not understanding the dangerous consequences of telling humans their future, Tommy tries to convince them that he is from the future.  Fortunately for us, however, due to a series of coincidental entertainment events, the better than you might think technology of 1949, and human skepticism, no one believes him.  They all think he is a talented, but fake, publicity stunt for the aforementioned events.  Thus, we were all saved from the temporally paradoxical issues caused by time travel, thanks to our ancestors' ignorance.