Bio: Perhaps no creator's appearance in comics was quite so essential as that of Gardner Fox. Indeed, he was the initial "bridge" between Earth 1 and Earth 2. In the pages of The Flash, Barry Allen discovered that the comics he read as a kid--All-Star and the like--were a key to understanding a strange new Earth that he accidentally found. Why? Well, All-Star's most prolific author, Gardner Fox, essentially "channeled" his way to Earth 2 through his dreams. When he dreamt, he actually saw the events transpiring on Earth 2, and then wrote them down in comic book form.
Notes: Another way of looking at the importance of the character of Gardner Fox is that you can have multiple earths without Fox--but you can't have Earth 2.