An Experiment with Time is a long essay by J. W. Dunne on the subjects of precognition and the human experience of time. First published in March 1927, it was very widely read, and his ideas promoted by several other authors, in particular by J. B. Priestley. Other books by J. W. Dunne are The Serial Universe, The New Immortality, and Nothing Dies.
Appendix to the third edition:
Dunne's theory, elaborated from years of experiments into precognitive dreams and induced precognitive states, is that in reality all time is eternally present, that is, that past, present and future are all happening together in some way. Human consciousness, however, experiences this simultaneity in linear form. Dunne posits that in the dreaming state this way of interpreting time ceases to be as concrete as when we are awake. Thus we are capable of having what we call precognitive dreams as consciousness finds itself free to roam across past, present and future. From this Dunne posited that we exist on two levels ourselves, both inside and outside time, thus suggesting the notion of Immortality contained in his later books The New Immortality and Nothing Dies.
The idea that time (and, by extension, humanity) exists both simultaneously and linearly is a difficult one to grasp. One analogy is that of a book. At any given moment the entirety of a book exists in itself but at any given moment we can only read one page at a time. The other pages, while existing simultaneously with the one we are reading, remain outside our consciousness. If we could somehow read every page of the book at once, or be able to experience the book in its entirety in a single moment then we would be closer to a real experience of it. Similarly in our lives we are conscious of only one moment in time, the present, rather than our past, present and future together. The past is remembered but not physically experienced, the future remains unknown. In some respects this is comparable to Thomas Aquinas's description of God seeing all things past, present and to come in the "now" of eternity: likened to a watchman looking down from the top of a valley and apprehending at a glance all the events taking place in worldly time — the valley — from a perspective outside of time.
To achieve the simultaneous awareness of past, present and future would mean a complete reevaluation of the nature of our existence in terms of consciousness, time and physical reality, something which Dunne argues is the logical conclusion of his work.
In An Experiment with Time, Dunne discusses how a theoretical ability to perceive events outside the normal observer's stream of consciousness might be proven to exist, and some of the possible other explanations of this effect, such as déjà vu.
He proposes that observers should place themselves in environments where consciousness might best be freed, and then, immediately upon waking, note down the memories of what had been dreamed, together with the date. At a later time these notes should be scanned, and possible connections drawn between them, and real life events which occurred after the notes had been written.
While the first half of the book is an explanation of the theory, the latter part comprises examples of notes and later interpretations of them as possible predictions. Statistical analysis was at that time in its infancy, and no calculation of the significance of the events reported was able to be made.
Dunne's theory of time has parallels in many other scientific and metaphysical theories. The Aboriginal people of Australia, for example, believe that the Dreamtime exists simultaneously in the present, past and future, and that this is the objective truth of time, linear time being a creation of human consciousness, and therefore subjective. Kaballism, Taoism and indeed most mystical traditions have always posited that waking consciousness allows awareness of reality and time in only a limited way and that it is in the sleeping state that the mind can go free into the multi-dimensional reality of time and space (e.g., "Dreams are the wandering of the spirit through all nine heavens and nine earths," The Secret of the Golden Flower, trans. Richard Wilhelm). Similarly, all mystery traditions speak of the immortal and temporal selves which exist simultaneously both within time and space and without.
If Dunne's theory were true it could provide an explanation for religious experiences of "eternity" or "timelessness" recounted in the works of religious ecstatics and mystics the world over.
J. B. Priestley used Dunne's theory directly in his play Time and the Conways, professing in his introduction that he believed the theory to be true. Other writers contemporaneous to Dunne who expressed enthusiasm for his ideas included Aldous Huxley, who was also interested in the expansion of human consciousness to experience time.
The idea that time might be experienced differently in enfolded space is one posited by quantum physicist David Bohm, who also believed that consciousness defined how we perceived the world. Bohm, who called for a revolution in human consciousness to free us from the old, Newtonian, mechanistic understanding of the universe, even posited that through a transformation of consciousness Time could possibly cease to exist in the way we perceive it now (cf., "The Ending Of Time" by Jiddu Krishnamurti and Dr David Bohm).
In his book Is There Life After Death? (2006), British writer Anthony Peake attempts to update the ideas of Dunne in the light of the latest theories of quantum physics, neurology and consciousness studies.
The 1964 novel FROOMB! by British writer John Lymington refers to and is inspired by some of Dunne's concepts. The protagonist, intended to be scientifically "killed" and revived to bring back an account of Heaven, is instead physically transported into the future, a parallel "time-band." He attempts to communicate with the controller of the experiment through dreams.
In the 1970 children's TV series, Timeslip, a time bubble allows two children to travel between past, present and future.
In the 2002 French movie Irreversible, one of the characters is seen reading the book by Dunne. The movie also investigates the aspects of the book through the style of filming, in that the story is told backwards, with each sequence starting at that moment where the next sequence in the film ends. Furthermore, the tagline is Le temps détruit tout meaning "Time destroys everything" -- it is the is the first phrase spoken and the last phrase written.