Two articles by Mark A Golding, "Shortcuts Though Space in Star Trek" and "Subspace Radio and Space Warps" advocate the theory that much interstellar travel in Star Trek is done through wormholes or other space warps that allow instant travel between stars, thus explaining many of the problems with the duration and distance of various interstellar trips in Star Trek.
They were published in Trek: The Magazine for Star Trek Fans number 11, July 1978, and number 14, Fall 1979, and in The Best of Trek, 1978, and The Best of Trek 2, 1980.
Those articles also mention a theory that explains some problems in Star Trek chronology by saying that Earth invented forms of rapid interstellar travel twice in Star Trek history - once by a secret group unknown to the rest of humanity and later by the rest of humanity - and the two groups reunited by the era of TOS.
I would be grateful if anyone who has access to Trek and the Best of Trek books could confirm that those articles do include the theory that in Star Trek Earth developed forms of rapid interstellar travel twice.
I would also like to know if anyone knows of any other discussion of the idea that Earth might have developed forms of rapid interstellar travel twice in Star Trek.