Abstract
To travel in time.
“Hold infinity in the palm of your hand and eternity in an hour.”
—William Blake, writing in “Auguries of Innocence” (1863), with words that could quite well describe what it would be like to time travel
“I need a place to hide, that’s why I believe in yesterday.”
—The Beatles (Yesterday, 1965)
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Notes
- 1.
An excellent, book-length literary treatment of time travel is by David Wittenberg, Time Travel: the popular philosophy of narrative, Fordham University Press 2013.
- 2.
Marjorie Hope Nicolson (1894–1981) was a literary scholar of the first rank at both Smith College and Columbia University.
- 3.
T. J. Cottle, “Fantasies of Temporal Recovery and Knowledge of the Future,” in Perceiving Time, John Wiley 1976.
- 4.
T. Paul, “The Worm Ouroboros: Time Travel, Imagination, and Entropy,” Extrapolation, Fall 1983, pp. 272–279.
- 5.
J. W. Smith, “Time Travel and Backward Causation,” Cogito 1985, pp. 57–67.
- 6.
Among the many such tales, five particularly good ones are “Something for Nothing” by Robert Sheckley, “Mimsy Were the Borogoves” by Lewis Padgett (pseudonym of the married couple Henry Kuttner and C. L. Moore), “Child’s Play” by William Tenn (pseudonym of Philip Klass), “The Little Black Bag” by Cyril Kornbluth, and “Thing of Beauty” by Damon Knight. All can be found in various anthologies.
- 7.
The Fantastic Civil War (F. McSherry, Jr., editor), Baen 1991.
- 8.
Somewhat more pompous (but no less correct) was this observation by an academic: “The time-travel [film] romance is an attempt to reenchant the world, to regain a sense of belongingness, to reinstate the magical, autocentric Universe of the child and the primitive.” See W. Wachhorst, “Time Travel Romance on Film,” Extrapolation, Winter 1984, pp. 340–359.
- 9.
S. Deser and R. Jackiw, “Time Travel?” Comments on Nuclear and Particle Physics, September 1992, pp. 337–354.
- 10.
R. H. Wilson, “Out Around Rigel,” Astounding Stories, December 1931.
- 11.
W. Tucker, The Year of the Quiet Sun, Gregg 1979.
- 12.
A. E. Van Vogt, “Far Centaurus,” Astounding Science Fiction, January 1944.
- 13.
R. A. Sorenson, “Time Travel, Parahistory and Hume,” Philosophy, April 1987, pp. 227–236.
- 14.
R. Silverberg, “Ms. Found in an Abandoned Time Machine,” Beyond the Safe Zone, Warner 1986.
- 15.
R. Silverberg, “Many Mansions,” Beyond the Safe Zone, Warner 1986.
- 16.
R. Bretnor, “The Past and Its Dead People,” Magazine of Fantasy and Science Fiction, September 1956.
- 17.
L. Marlow, The Devil in Crystal, Faber and Faber 1944.
- 18.
A. Bester, “Hobson’s Choice,” Magazine of Fantasy and Science Fiction, August 1952.
- 19.
C. Willis, Doomsday Book, Bantam 1992.
- 20.
C. Sprague, “Time Track,” Startling Stories, January 1951.
- 21.
M. Leinster, Time Tunnel, Pyramid Books 1964.
- 22.
U. K. Le Guin, “April in Paris,” Fantastic Stories, September 1962.
- 23.
There are many excellent examples of such tales, a few of which are Clifford Simak, “Over the River & Through the Woods”; Ray Bradbury, “The Fox and the Forest”; Jack Finney, “Such Interesting Neighbors”; J. B. Priestly, “Mr. Strenberry’s Tale”; James Gunn, “The Reason Is With Us”; and H. B. Piper, “Flight from Tomorrow.” All can be found in various anthologies.
- 24.
R. F. Young, “Not to be Opened—,” Astounding Science Fiction, January 1950.
- 25.
C. Simak, “Project Mastodon,” Galaxy Science Fiction, March 1955.
- 26.
P. Anderson, “Wildcat,” Magazine of Fantasy and Science Fiction, November 1958, and W. Jeschke, The Last Day of Creation, St. Martin’s Press 1982.
- 27.
L. Niven, “The Theory and Practice of Time Travel,” in All the Myriad Ways, Ballantine 1971.
- 28.
A. Boucher, “Elsewhen,” Astounding Science Fiction, January 1943. Partridge’s dream is shattered, however, because he overlooks a few details about time travel, ones that he wouldn’t have missed if he could have read this book. We’ll come back to this classic story, which merges a time machine with murder, later in the book.
- 29.
This is a popular science fiction scenario, and three of the best stories playing with it are P. Anderson, “My Object All Sublime,” Galaxy Science Fiction, June 1961; I. Watson, “In the Upper Cretaceous with the Summerfire Brigade,” in Stalin’s Teardrops, Victor Gollancz 1991; and R. Silverberg, “Hawksbill Station,” Galaxy Science Fiction, August 1967.
- 30.
S. Gansovsky, “Vincent Van Gogh,” in Aliens, Travelers, and Other Strangers, Macmillan 1984.
- 31.
J. Finney, “The Face in the Photo,” in About Time, Simon and Schuster 1986.
- 32.
W. Tucker, The Lincoln Hunters, Rinehart 1958. See also A. Bitov, “Pushkin’s Photograph,” in The New Soviet Fiction, Abbeville Press 1989.
- 33.
M. Shaara, “Man of Distinction,” Galaxy Science Fiction, October 1956.
- 34.
L. A. Frankowski, The Cross-Time Engineer, Del Rey 1986. The same idea is in the 1991 film comedy The Spirit of ’76, in which time-traveling historians from 2176 visit the past in an attempt to reconstruct the lost records of the founding of America.
- 35.
J. C. Graves and J. E. Roper, “Measuring Measuring Rods,” Philosophy of Science, January 1965, pp. 39–56.
- 36.
H. M. Sycamore, “Success Story,” Magazine of Fantasy and Science Fiction, July 1959.
- 37.
C. Simak, Mastodonia, Ballantine 1978.
- 38.
Two are B. W. Aldiss, “Poor Little Warrior,” in The Science Fictional Dinosaur, Avon 1982, and a famous one by Ray Bradbury, “A Sound of Thunder,” in The Stories of Ray Bradbury, Alfred A. Knopf 1980.
- 39.
C. Simak, “The Loot of Time,” Thrilling Wonder Stories, December 1938, in which a time machine inventor raises money for his research by transporting hunters back 70,000 years to the Old Stone Age.
- 40.
Three such tales are R. Silberberg, Up the Line, Ballantine 1969 and “When We Went to See the End of the World,” in Beyond the Safe Zone, Warner 1986; and G. Kilworth, “Let’s Go to Golgotha!,” in The Songbirds of Pain, Victor Gollancz 1985.
- 41.
B. Tucker “The Tourist Trade,” in Tomorrow the Stars, Doubleday 1952.
- 42.
L. Laurence, “History in Reverse,” Amazing Stories, October 1939.
- 43.
H. Harrison, The Technicolor Time Machine, Doubleday 1967.
- 44.
A. Derleth, “An Eye for History,” in Harrigan’s File, Arkham House 1975.
- 45.
A skeptic’s reaction to the idea of time travel in J. McDevitt’s story “Time’s Arrow” in The Fantastic Civil War (see note 7).
- 46.
Arthur C. Clarke, “About Time,” in Profiles of the Future, Warner 1985. A story that I recall once having read (but cannot now remember either the author or the title) wonderfully illustrates Clarke’s point. A time traveler in disguise at Golgotha for the Crucifixion has a camera hidden beneath his robe to avoid attracting attention. All goes well until he notices odd, clicking noises coming from all those standing near him. It is then he realizes the entire crowd is nothing but time travelers, from all through the ages, all with hidden cameras!
- 47.
G. Fulmer, “Understanding Time Travel,” Southwestern Journal of Philosophy, Spring 1980, pp. 151–156. The modern view of this ‘paradox’ is not that it describes a situation so absurd that time travel must be impossible, but rather that all the time travelers who were (will be?) at the Crucifixion are in the historically recorded crowd (see note 46 again). The Crucifixion happened just once, not over and over. I’ll return to this point later in the book.
- 48.
D. Plachta, “The Man from When,” Worlds of If Science Fiction, July 1966.
- 49.
R. H. Wilson, “A Flight Into Time,” Wonder Stories, February 1931.
- 50.
P. S. Miller, “The Sands of Time,” Astounding Stories, April 1937.
- 51.
M. A. Burstein, “Cosmic Corkscrew,” Analog, June 1998.
- 52.
P. Anderson, “Flight to Forever,” Super Science Stories, November 1950.
- 53.
Turning this idea on its head is the approach of the 1978 novel The Way Back (DAW) by A. B. Chandler. Its characters return from the past to their own time by traveling even further backward, right through the Big Bang and into the previous (and identical) cycle of time.
- 54.
S. W. Hawking, “Chronology Protection Conjecture,” Physical Review D, July 15, 1992, pp. 603–611. See also J. F. Woodward, “Making the Universe Safe for Historians: Time Travel and the Laws of Physics,” Foundations of Physics Letters, February 1995, pp. 1–39.
- 55.
J. Queenan, “Time Warp: Or, Investing in the Future Is a Bust,” Barron’s, January 8, 1990, p. 46.
- 56.
M. R. Reinganum, “Is Time Travel Impossible? A Financial Proof,” Journal of Portfolio Management, Fall 1986, pp. 10–12.
- 57.
L. Jones, “Sunday is Three Thousand Miles Away,” Thrilling Wonder Stories, June 1950. A more recent, two-novel treatment of historians tinkering with history is by Connie Willis (Blackout and All Clear, both published in 2010).
- 58.
Stephen Hawking, My Brief History, Bantam 2013, p. 113.
- 59.
Matt Visser, “The Quantum Physics of Chronology Protection,” in The Future of Theoretical Physics and Cosmology, Cambridge 2003. This paper was Visser’s contribution to the celebration of Hawking’s 60th birthday, held in January 2002.
- 60.
This may seem like something new, but it really isn’t. General relativity has causality built into it on a local level (where it belongs); a failure of causality (that is, time travel—see J. Sharkey, “The Trouble With Hyperspace,” Fantastic April 1965) occurs in general relativity only when one studies global regions of certain spacetimes. Forcing a physical theory to have a prescribed global behavior would be to undo all of physics since the development of local field theories, along with all their amazing successes in explaining nature.
- 61.
M. Shaara, “Time Payment,” Magazine of Fantasy and Science Fiction, June 1954.
- 62.
W. B. Pitkin, “Time and Pure Activity,” Journal of Philosophy, Psychology and Scientific Methods, August 27, 1914, pp. 521–526. Pitkin’s essay was a critique of time travel as presented in Wells’ The Time Machine, which Pitkin called “one of the wildest flights of literary fancy.”
- 63.
Making its first appearance in 1748, Enquiry has been reprinted numerous times since. I used the 1963 edition published by Open Court.
- 64.
What Hume is alluding to here should be plain; as expressed in P. Heath, “The Incredulous Hume,” American Philosophical Quarterly, April 1976, pp. 159–163, Hume was “an exposer of bad arguments in rational theology.” For Hume, second-hand (or even more remote) tales of the return of a man from the dead—the claim that literally kept Christianity alive after Christ’s execution—were suspect.
- 65.
This skeptical reaction was nicely captured in the story “E for Effort” by T. L. Sherred (Astounding Science Fiction, May 1947). As one character laments, “I’ve watched scribes indite the books that burnt at Alexandria; who would buy, or who would believe me, if I copied one. … What sort of padded cell would I get if I showed up with a photograph of Washington or Caesar? Or Christ?” The padded cell was indeed the fate of the time traveler in “The Ambassador from the 21st Century” (Startling Stories, March 1953) by H. J. Shay, the story of a man who journeyed from A.D. 2007 back to 1952 to warn of a future war; he was committed to a mental institution to receive help for his “illusion.”
- 66.
J. Haldeman, “No Future In It,” Omni, April 1979.
- 67.
G. Gor, “The Garden,” in Russian Science Fiction (R. Magidoff, editor), New York University Press 1969.
- 68.
P. Bolton, “The Time Hoaxers,” Amazing Stories, August 1931.
- 69.
Robert Sheckley, “Something for Nothing,” in Citizen in Space, Ballantine 1955.
- 70.
The word known is important. As a character in one early science fiction story puts it, “These things [four-dimensional object] sound like miracles; but, after all, what are miracles but phenomena which, on account of our ignorance [my emphasis], we cannot explain?” See B. Olsen, “The Four-Dimensional Roller-Press,” Amazing Stories, June 1927.
- 71.
D. M. Ahern, “Miracles and Physical Impossibility,” Canadian Journal of Philosophy, March 1977, pp. 71–79.
- 72.
In Lewis’ eerie, unfinished story “The Dark Tower,” a tale of the ‘chronoscope,’ a gadget that “does to time what the telescope does to space,” the persistent skeptic in the story is a Scot, surely created in the image of Hume. See C. S. Lewis, The Dark Tower and Other Stories, Harcourt 1977.
- 73.
C. S. Lewis, The Grand Miracle, Ballantine 1986.
- 74.
H. Putnam, “It Ain’t Necessarily So,” Journal of Philosophy, October 1962, pp. 658–671.
- 75.
J. Earman, “On Going Backward in Time,” Philosophy of Science, September 1967, pp. 211–222.
- 76.
R. Weingard, “On Travelling Backward in Time,” Synthese, July–August 1972, pp. 117–132.
- 77.
Arthur Conan Doyle, “The Disintegration Machine,” The Strand Magazine, January 1929. Professor Challenger is nothing like Wells’ thoughtful Time Traveller; in the original 1912 Challenger novel The Lost World, he was described as a “primitive cave-man in a lounge suit.”
- 78.
R. Silverberg, “What We Learned from This Morning’s Newspaper,” in Beyond the Safe Zone, Warner 1986.
- 79.
J. D. North, The Measure of the Universe, Oxford University Press 1965.
- 80.
C. T. K. Chari, “Time Reversal, Information Theory, and ‘World-Geometry’,” Journal of Philosophy, September 1960, pp. 579–583.
- 81.
Groff Conklin, editor of Science-Fiction Adventures in Dimension, Vanguard 1952.
- 82.
H. L. Gold, editor of The Galaxy Reader of Science Fiction, Crown 1952.
- 83.
In his introduction to Robert Heinlein’s classic time travel tale (to be discussed later) “All You Zombies—,” in The Mirror of Infinity, Canfield 1970.
- 84.
F. Leiber, “The Oldest Soldier,” Fantastic, May 1960.
- 85.
G. C. Eggleston, “Who Is Russell?” American Homes, March 1875.
- 86.
A science fiction physicist receives harsh criticism from a colleague in L. A. Eshbach’s “Out of the Past,” Tales of Wonder, Autumn 1938.
- 87.
Both of these notions still routinely appears in science fiction, however, because they are ‘just too neat’ to let ‘mere physics’ get in the way of a good tale. I use one, without apology, in my own story “Newton’s Gift” in Appendix B.
- 88.
Three such tales are M. J. Breur, “The Time Valve,” Wonder Stories, July 1930; F. J. Bridge, “Via the Time Accelerator,” Amazing Stories, January 1931; E. Binder, “The Time Cheaters,” Thrilling Wonder Stories, March 1940.
- 89.
J. Lafleur, “Time as a Fourth Dimension,” Journal of Philosophy, March 1940, pp. 169–178, and “Marvelous Voyages—H. G. Wells’ The Time Machine,” Popular Astronomy, October 1943.
- 90.
Philosophers seem to be becoming more aware of the collison problem (which they have dubbed “the double occupancy problem”), and at least three papers published since the second edition of Time Machines discuss it: W. Grey, “Troubles With Time Travel,” Philosophy, January 1999, pp. 55–70; P. Dowe, “The Case for Time Travel,” Philosophy, July 2000, pp. 441–451; R. Le Poidevin, “The Cheshire Cat Problem and Other Spatial Obstacles to Backward Time Travel,” The Monist, July 2005, pp. 336–352. Physicists don’t concern themselves with the collison problem simply because they aren’t interested in Wellsian time machines; I’ll explain why I say this by the end of this section.
- 91.
M. Jameson, “Dead End,” Thrilling Wonder Stories, March 1941. The “cosmic rays” are presumably the cause of the interference.
- 92.
Actually nuclear, but don’t forget when Wells wrote his novel.
- 93.
F. Brown, “Experiment,” Galaxy Science Fiction, February 1954.
- 94.
M. Cook, “Tips for Time Travel,” in Philosophers Look at Science Fiction, Nelson-Hall 1982. One modern story that gets Cook’s point right is by I. Watson, “The Very Slow Time Machine,” in The Best Science Fiction of the Year (T. Carr, editor), Ballantine 1979.
- 95.
M. Jameson, “Murder in the Time World,” Amazing Stories, August 1940.
- 96.
This little story I’ve just told you involves what is called a bootstrap paradox (just where did that solution come from, that is, who thought it up?) and it is one of the real puzzles of time travel. I’ll say lots more about such curious doings later in the book.
- 97.
There is a hint of this in one prescient science fiction story, in which the inventor of a time machine, when asked about how it works, replies “An electromagnetic warping [my emphasis] of the spacetime continuum.” See N. Schachner, “When the Future Dies,” Astounding Science Fiction, June 1939.
- 98.
A wormhole is featured in the 2014 film Interstellar, whose Executive Producer and technical advisor was Thorne. The film’s special effects are relativistically correct (not the typical Hollywood ‘fantasy physics’), and you can read how that was achieved in Oliver James, Eugénie von Tunzelmann, Paul Franklin and Kip S. Thorne, “Gravitational lensing by spinning black holes in astrophysics, and in the movie Interstellar,” Classical and Quantum Gravity, February 2015. See also (same authors) “Visualizing Interstellar’s Wormhole,” American Journal of Physics, June 2015, pp. 486–499.
- 99.
As you can see from this, science fiction writers have had fun with the Möbius strip. Two early examples not involving time travel are N. Bond, “The Geometrics of Johnny Day,” Astounding Science Fiction, July 1941, and W. H. Upson, “A. Botts and the Möbius Strip,” The Saturday Evening Post, December 1945. The use of the Möbius strip for time travel occurs, for example, in M. Clifton’s “Star, Bright,” Galaxy Science Fiction, July 1952.
- 100.
If he had lived, perhaps the well-known science fiction writer James Blish (1921–1975) would have written such a tale. In David Ketterer’s biography of Blish (Imprisoned in a Tesseract, Kent State University Press 1987), there is this comment from a 1970 letter written by Blish: “I am especially intrigued by the spinning-universe form of time travel, especially since … nobody has touched it … But I should really stop mentioning the spinning-universe in public, or somebody will nobble onto it before I can get into it!”
- 101.
N. Hebert, Faster Than Light: Superluminal Loopholes in Physics, New American Library 1988.
- 102.
H. Kragh and B. Carazza, “From Time Atoms to Space-Time Quantization: the idea of discrete time, ca 1925–1936,” Studies in History and Philosophy of Science, June 1994, pp. 437–462.
- 103.
S. Weinbaum, “The Ideal,” Wonder Stories, September 1935.
- 104.
This is the constant in Newton’s famous inverse-square law for gravity; the attractive force F between two point masses m 1 and m 2, distance r apart, is \( F=G\frac{m_1{m}_2}{r^2} \).
- 105.
By comparison, the density of a neutron star is on the order of a ‘mere’ 1016 grams/cm3.
- 106.
Perhaps not so well-known, however, is that science fiction was there long before Wheeler. In one classic tale (M. Leinster, “Sidewise in Time,” Astounding Stories, June 1934) a scientist explains at the end, “We know that gravity warps space … We can calculate the mass necessary to warp space so that it will completely close in completely … We know, for example, that if two gigantic star masses of certain mass were to combine … they would simply vanish. But they would not cease to exist. They would merely cease to exist in our space and time.” And then, as another character sums it up, “Like crawling into a hole and pulling the hole in after you.” The explicit use of the complete term black hole for a region of weird spacetime also appeared in science fiction before Wheeler (P. Worth, “Typewriter from the Future,” Amazing Stories, February 1950).
- 107.
P. C. W. Davies, The Edge of Infinity, Simon & Schuster 1981.
- 108.
S. Hawking, “Breakdown of Predictability in Gravitational Collapse,” Physical Review D, November 15, 1976, pp. 2460–2473.
- 109.
S. W. Hawking and R. Penrose, “The Singularities of Gravitational Collapse and Cosmology,” Proceedings of the Royal Society A, January 27, 1970, pp. 529–548. Ironically, one of the ‘realistic’ assumptions made in this paper, which appears to force singularities to exist, is that time travel is impossible!
- 110.
A naked singularity, with no event horizon behind which to hide, would be particularly bothersome to physicists who don’t like the idea of the breakdown of physics being on full display. What they think they’d then see would be completely unpredictable. Whether such a situation can actually exist is still open to debate, but there are both analytical solutions and computer simulations (incorporating realistic equations of state on the pressure response of matter as it is compressed) that seem to allow it (as in the gravitational collapse of an infinitely long, non-rotating cylinder that appears to result in an axial, thread-like, naked singularity).
- 111.
The word charge means either electrical or magnetic charge, although from a practical point charge probably does mean just electrical, as the theoretically possible magnetic monopole has yet to be observed and, in any case, it is thought that black holes will not have a significant electrical charge.
- 112.
Even Einstein hadn’t yet solved them, and he apparently thought they were too complicated to be solved; when he saw Schwarzchild’s result, he was so impressed that Einstein wrote to say “I had not expected that the exact solution to the problem could be formulated. Your analytical treatment of the problem appears to me splendid.”
- 113.
Two years later, the University of Pittsburgh physicist Ezra Newman finally solved the field equations for the realistic, general case of a rotating and charged black hole.
- 114.
You can find discussions on how this is imagined to work in two papers by R. Weingard: “General Relativity and the Conceivability of Time Travel,” Philosophy of Science, June 1979, pp. 328–332, and “Some Philosophical Aspects of Black Holes,” Synthese, September 1979, pp. 191–219. See also M. Calvani et al., “Time Machine and Geodesic Motion in Kerr Metric,” General Relativity and Gravitation, February 1978, pp. 155–163. I won’t pursue black hole time machines in this book, as it is not what modern physicists consider a plausible means of time travel (How are you going to gain access to a black hole?!!!) For how one science fiction writer did use the idea, however, see L. Niven, “Singularities Make Me Nervous,” in Stellar 1 (J.-L. del Rey, editor), Ballantine 1974. Black holes are bizarre objects—nearly as bizarre as time travel—and it seems risky to try to understand one in terms of the other (recall Professor Challenger’s observation!).
- 115.
S. W. Hawking and J. M. Stewart, “Naked and Thunderbolt Singularities in Black Hole Evaporation,” Nuclear Physics B, July 1993, pp. 393–415. As bizarre as is the thunderbolt, it was anticipated in science fiction by more than half a century. In the story “The Tides of Time” by R. M. Williams (Thrilling Wonder Stories, April 1940), the universe is collapsing at faster than the speed of light. Human scientists learn this when fleeing aliens stop their faster-than-light space ships to warn them. One of the human characters then looks out into the night sky and, in words that sound like those of Hawking and Stewart, “There would be no warning, for the rolling tide was traveling faster than light … It would come faster than the flicker of an eye. No one would see it come. One instant the world you knew would be around you. The next instant, there would be nothing. You would not even have time to know what had happened. Death, faster than the lightning flash!” This story may have been inspired by a tale published decades earlier, by the Canadian writer Frank Lillie Pollock (1876–1957). In his “Finis” (The Argosy, June 1906), written long before the concept of a super-nova, the light of a huge, distant star finally arrives to cook Earth into oblivion.
- 116.
See, for example, R. Geroch, “What Is a Singularity in General Relativity?” Annals of Physics, July 1968, pp. 526–540.
- 117.
See, for example, I. Novikov, “Change of Relativistic Collapse Into Anticollapse and Kinematics of a Charged Sphere,” JETP Letters, March 1, 1966, pp. 142–144, and V. P. Frolov, et al., “Through a Black Hole Into a New Universe?” Physics Letters, January 12, 1989, pp. 272–276. Igor Novikov is a Russian physicist at the University of Copenhagen, and he will appear later in the book when we get to the paradoxes of time travel to the past.
- 118.
V. De La Cruze and W. Israel, “Gravitational Bounce,” Nuovo Cimento A, October 1, 1967, pp. 744–760.
- 119.
S. Hawking, “Black Hole Explosions?” Nature, March 1, 1974, pp. 30–31, and “Particle Creation by Black Holes,” Communications in Mathematical Physics, 1975, pp. 199–220.
- 120.
The uncertainty principle has long been used in time travel science fiction. In one story, for example, a character is transported from 1950 to 2634 by a scientist of the future. Once there, this character decides he’d like to remain permanently in the 27th century. He is told that he can’t because he is like an atom excited into an elevated energy state and, just as quantum mechanics says that eventually an electron in such a state will drop back down into a lower energy state, so do the “laws of time travel” require that he drop back to his normal time. How long can he remain in future, he is told, “depends on the mass [energy] of his body and the number of years the mass [energy] is displaced.” That is simply the uncertainty principle. See W. Bade, “Ambition,” Galaxy Science Fiction, October 1951.
- 121.
S. Hawking, “The Quantum Mechanics of Black Holes,” Scientific American, January 1977.
- 122.
E. P. Tryon, “Is the Universe a Vacuum Fluctuation?” Nature, December 14, 1973, pp. 396–397.
- 123.
See Richard Feynman’s Nobel lecture, reproduced in Science, August 12, 1966, pp. 699–708, where he recounts Wheeler’s ‘proof’ for why every electron in the universe has exactly the same charge (‘there is only one electron, weaving its way back-and-forth in time, with positrons being the electron when traveling backward-in-time’).
- 124.
Will Stewart, “Minus Sign,” Astounding Science Fiction, November 1942. ‘Will Stewart’ was a pen-name for John Stewart Williamson (1908–2006).
- 125.
S. Lem, “The Eighteenth Voyage,” in The Star Diaries, Seabury Press 1976.
- 126.
G. Fulmer, “Cosmological Implications of Time Travel,” in The Intersection of Science Fiction and Philosophy (R. E. Meyers, editor), Greenwood Press 1983. Isaac Asimov used a similar idea in his story “The Instability,” The London Observer, January 1, 1989.
- 127.
J. R. Gott and L.-X. Li, “Can the Universe Create Itself?” Physical Review D, 1998, 023,501.
- 128.
N. D. Birrell and P. C. W. Davies, “On Falling Through a Black Hole Into Another Universe,” Nature, March 2, 1978, pp. 35–37.
- 129.
T. M. Helliwell and D. A. Konkowski, “Quantum Singularities in Spherically Symmetric, Conformally Static Spacetimes,” Physical Review D, May 13, 2013, 10404.
- 130.
F. J. Tipler, “Rotating Cylinders and the Possibility of Global Causality Violation,’ Physical Review D, April 15, 1974, pp. 2203–2206.
- 131.
See, for example, C. Cloukey, “Paradox,” Amazing Stories Quarterly, Summer 1929. Later in the book I’ll discuss even earlier literary occurrences of bootstraps (that is, of information on closed loops in time).
- 132.
K. S. Thorne, “Nonspherical Gravitational Collapse: Does It Produce Black Holes?” Comments on Astrophysics and Space Physics, September–October 1970, pp. 191–196. What “asymptotically flat” means will be discussed in Chap. 3.
- 133.
W. B. Bonner, “The Rigidly Rotating Relativistic Dust Cylinder,” Journal of Physics A, June 1980, pp. 2121–2132. Tipler was not the first to study rotating cylinders in the context of general relativity. Such cylinders had been around for decades, going back to 1932. A good reference is M. A. Mashkour, “An Exterior Solution of the Einstein Field Equations for a Rotating Infinite Cylinder,” International Journal of Theoretical Physics, October 1976, pp. 717–721. The first-analyzed configuration of matter that generates closed timelike lines, solved in all its general relativistic detail, was the infinite rotating cylinder studied by W. J. van Stockum, “The Gravitational Field of a Distribution of Particles Rotating About an Axis of Symmetry,” Proceedings of the Royal Society of Edinburgh, 1939, pp. 135–154. This is particularly interesting because, while Van Stockum didn’t spot the presence of closed timelike lines in his solution, his cylinder is made entirely from ordinary matter.
- 134.
F. Tipler, “Singularities and Causality Violation,” Annals of Physics, September 1977, pp. 1–36. See also his earlier paper “Causality Violation in Asymptotically Flat Space-Times,” Physical Review Letters, October 1976, pp. 879–882, where he wrote “There are many solutions to the Einstein equations [of general relativity] which possess causal anomalies in the form of closed timelike lines (CTL). It is of interest to discover if our Universe could have such lines. In particular, if the Universe does not at present contain such lines, is it possible for human beings to manipulate matter so as to create them? [That is, to construct a time machine.] I shall show in this paper that it is not [Tipler’s emphasis] possible to manufacture a CTL-containing region without the formation of naked singularities, provided normal matter is used in the construction attempt [my emphasis].”
- 135.
A. Ori, “Must Time-Machine Construction Violate the Weak Energy Condition?” Physical Review Letters, October 1993, pp. 2517–2520. The weak energy condition is the seemingly ‘obvious’ requirement that the observed local mass-energy density should never be negative. Quantum mechanics predicts (and it has been experimentally confirmed) that there are exceptions.
- 136.
M. P. Headrick and J. R. Gott, “(2+1)-Dimensional Spacetimes Containing Closed Timelike Curves,” Physical Review D, December 15, 1994, pp. 7244–7259. The ‘(2+1)’ refers to a toy spacetime with just two spatial dimensions and one time dimension.
- 137.
O. Saari, “The Time Bender,” Amazing Stories, August 1937. In this story we read that the time traveler “could not travel into the past for the plate had to exist in all ages traveled, and it had not existed before he made it.”
- 138.
E. L. Rementer, “The Time Deflector,” Amazing Stories, December 1929.
- 139.
K. S. Thorne, “Do the Laws of Physics Permit Closed Timelike Curves?” Annals of the New York Academy of Science, August 10, 1991, pp. 182–193. Science fiction writer Damon Knight (1922–2001) anticipated Thorne’s rebuttal in his story “Azimuth 1, 2, 3, … ,” Isaac Asimov’s Science Fiction Magazine, June 1982.
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Nahin, P.J. (2017). A Broad Look at Time Travel. In: Time Machine Tales. Science and Fiction. Springer, Cham. https://doi.org/10.1007/978-3-319-48864-6_1
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