How Long Does it Take to Get to Valinor?

[Puddleglum]

Originally Posted by Inziladun

After that, how could time and distance be measured by a Middle-earth denizen, if one started to fly or passed through to another plane of existence?

Well, a Middle-earth denizen is still a creature existing within time. Even in Valinor, the Valar continue to watch the unfolding history of Arda as time flows on.

As such, someone traversing Ilmen on the straight-way to Valinor (if so gifted to find that path) would still experience the passage of time (be it short or long). Just as they would continue to experience the passage of time after arriving at Eressea (or Valinor beyond).

I don't think I would say that such voyagers are "traveling into another dimension (plane of existence)". That sounds too much like trying to shoehorn Tolkien's secondary (sub)creation into our own "current" primary-world "scientific" understandings which may actually be unnecessarily limited in scope.

Had Tolkien been writing a primary-world Sci-Fi novel, it might make sense. But as Eru (God) and pre-existing, self-incarnating spirits (Valar/Maier) are all REAL (within his secondary subcreation), I think there is basis for leaving things a bit more mysterious as Valinor was removed (and thus voyagers travel) "into the realm of hidden (tho still physical and real) things"