The philologist and author J. R. R. Tolkien set out to explore time travel and distortions in the passage of time in his fiction in a variety of ways. The passage of time in The Lord of the Rings is uneven, seeming to run at differing speeds in the realms of Men and of Elves. In this, Tolkien was following medieval tradition in which time proceeds differently in Elfland. The whole work, too, following the theory he spelt out in his essay "On Fairy-Stories", is meant to transport the reader into another time. He built a process of decline and fall in Middle-earth into the story, echoing the sense of impending destruction of Norse mythology. The Elves attempt to delay this decline as far as possible in their realms of Rivendell and Lothlórien, using their Rings of Power to slow the passage of time. Elvish time, in The Lord of the Rings as in the medieval Thomas the Rhymer and the Danish Elvehøj (Elf Hill), presents apparent contradictions. Both the story itself and scholarly interpretations offer varying attempts to resolve these; time may be flowing faster or more slowly, or perceptions may differ.
Tolkien was writing in a period when notions of time and space were being radically revised, from the science fiction time travel of H. G. Wells, to the inner world of dreams and the unconscious mind explored by Sigmund Freud, and the transformation of physics with the counter-intuitive notions of quantum mechanics and general relativity proposed by Max Planck and Albert Einstein. In 1927 J. W. Dunne wrote an influential book proposing a theory that time could flow differently for different observers, and that dreams gave access to all of time. A network of writers who were influenced by Wells, including Henry James, Dunne, and George du Maurier created a literary environment that enabled Tolkien to explore time travel in his own way, first in the unfinished The Lost Road, then in the unfinished The Notion Club Papers, and finally in The Lord of the Rings.
Tolkien mentions both the mortal desire to escape from death, and the Elvish desire to escape from immortality. The Tolkien scholar Verlyn Flieger suggests that these illustrate a Christian message, that one must not attempt to cling to anything as worldly things will change and decay; instead, one must let go, trust in the unknown future, and in God. This theme is, she argues, demonstrated in the protagonist Frodo Baggins, who is saved by having the courage to face loss, to move, and to change.