Time travel in sci-fi literature tends to be approached in two fundamentally different ways, and these two ways correspond to whether time is seen as objective or subjective. The brute force approach, as I’ll call it, ties in with our common sense intuition that time is an objective feature of reality, that it would keep ticking away regardless of whether or not anyone was there to measure it. In this approach, a machine or device is created (or discovered) that somehow allows its user to travel through time in a non-standard way. The mind travel approach, on the other hand, comports with Einsteinian and Kantian considerations about the mind-dependence of time; in it, travelling into the past is shown to be possible through a sort of rigorous mental training or discipline, with no recourse to technology required.
Personally I find the mind travel approach more compelling, but here I want to touch on and recommend two novels from each camp—and one curious outlier.
The Time Machine
The Time Machine by H.G. Wells is the ur-time travel novel; first published in 1895, it is (of course) where the term “time machine” originated, and is probably the strongest exemplar of the brute force approach. In it, an unnamed English scientist (simply called “the time traveller”) builds a machine that carries him over 800,000 years into the future—there he finds that humanity has split into two species: the effete, feckless, surface-dwelling eloi, and the vicious, light-shunning morlocks who feed on them. Filled with ruminations about the fate of civilization and the earth itself, and the long-term ramifications of class division, this book remains a thought-provoking and ultimately moving (and quick!) read.
11/22/63
11/22/63 by Stephen King is a more recent (2011) time travel story, one of the strongest in decades. In it, Jake Epping, an English teacher, uses a time portal to travel back to 1958 (the only year the portal opens onto), in an attempt to prevent the assassination of John Kennedy. The time portal is a naturally-occurring phenomenon (likened at one point to a bubble floating in ginger ale)—there’s no question of the user having to do anything but step into it; this tale is very much in the brute force camp. King’s initial description of Epping’s experience of 1958 is one of the most evocative pieces of writing I know of—you are transported, via King’s prose, as surely as Epping is. But King’s ultimate slap-down of the “everything would be fine if only JFK had lived” school of thought is what makes the book significant, and deeply haunting.
Time and Again
Time and Again (and its 1995 sequel From Time to Time) by Jack Finney (1970), was hailed as “THE great time-travel story” by Stephen King in the afterword to 11/22/63. It is the greatest exemplar of the mind-travel approach to time travel. Simon Morley, an illustrator in New York City in 1970, is recruited by government agents to participate in The Project—an experimental scheme to send people back in time through what amounts to self-hypnosis. The idea is: immerse yourself in the thinking of a period, don the dress, beliefs and attitudes of the period, and do these things in a place that has remained the same since that period, and—you will literally be there, and then. The Dakota apartment building overlooking Central Park is the “time machine” of the story—i.e., it’s the unaltered bit of New York architecture that allows Morley to convince himself that he’s in 1882, and thus to successfully appear there. It sounds crazy, but Finney’s meticulous description of the workings of The Project—and his beautifully evocative conjuring of New York in 1882—doesn’t just suspend disbelief; it annihilates it. An enthralling, amiable, and astonishingly researched classic.
Bid Time Return
Bid Time Return (1975) by Richard Matheson was made into the pretty good but somewhat syrupy movie Somewhere in Time (1980) starring Christopher Reeve, and subsequent editions of the novel bore that title. It is also very much in the mind-travel camp. In it, Richard Collier, a ’70s-era screenwriter with terminal brain cancer, decides to spend his dying days at an old California resort; once there, he becomes obsessed with a portrait of a 19th century actress who frequented the same hotel. Using a method very much akin to that described in Time and Again, he travels back to 1896, and meets and falls in love with the actress, notwithstanding difficulties created by her over-protective manager. It’s a beautifully written, heartfelt story of a love so powerful that time itself can’t impede it, but part of what makes it a standout for me is its fundamental ambiguity. The story is presented mostly in the form of Collier’s journal entries—what’s unclear is whether the events as depicted are really happening, or a fantasy being spun by a cancer-riddled, deteriorating brain. Matheson himself remains non-committal on this question, right to the last page—no mean feat!
Kindred
Kindred (1979) by Octavia E. Butler is the outlier. It is often classified as science fiction simply because it is a time-travel story; probably it is best thought of as time-travel fantasy (Mark Twain’s A Connecticut Yankee in King Arthur’s Court would be another example of this). A young African-American woman named Dana Franklin is a writer living in present-day Los Angeles. One day she suddenly feels strange, swoons, and finds herself transported back to a plantation in antebellum Maryland, where she has to live as a slave—until she just as suddenly jumps back to the present and normality. Her life becomes a nightmare as these time-shifting leaps continue to happen—she never knows when they are going to happen, or for how long she’ll be trapped in this particularly hellish past. At one point her white husband, Kevin, goes back with her—he becomes trapped in the past for five years. The question of how the time leaps are being accomplished (are they somehow being caused by Dana’s mind? Are they a natural phenomenon? Has Dana been chosen for some inscrutable reason?) is never addressed—and it really doesn’t matter; that’s not what the book is about. What the book is about (among other things) is the hideousness of slavery—how it blighted the lives of the slaves, of course, but also the ruinous and degrading effect it had on the slaveholders. It remains an enthralling, disturbing modern classic.
Prentis Rollins has over twenty years of experience working as a writer and artist in the comics industry. His previous titles include How to Draw Sci-fi Utopias and Dystopias, The Making of a Graphic Novel, and Survival Machine (Stories). He has also worked for DC Comics between 1993—2013 for titles such as Batman, Superman, Green Lantern, JLA, and dozens more. The Furnace is his debut full-length graphic novel. He lives in London with his wife and three children.
Gregory Benford’s Timescape.
Benford’s Timescape
Robert Silverberg’s Up the Line
Connie Willis’s The Doomsday Book
Michael Moorcock’s Behold the Man
I have problems with 11/22/63. The whole middle romance section goes on wayyyy too long.
“The Anubis Gates” by Tim Powers (mind-boggling example of “bootstrap paradox”)
Blackout and its sequel All Clear by Connie Willis
Connie Willis’s Blackout/All Clear seems to deal a bit more with the metaphysics of time travel than The Doomsday Book, although the latter is surely her masterwork. The earlier novel deals mostly with the period that time traveler Kivrin is sent to and with the effects of the Black Death.
Definitely check out The First Fifteen Lives of Harry August by Claire North.
It definitely had to be a big challenge to get down to 5 books!
Some possibly less literary choices, but still enjoyable:
Heinlein’s “By His Bootstraps” or _Door Into Summer_.
Frankowski’s Conrad Stargard series, starting with _The Crosstime Engineer_.
In a sorta-kinda way, the Paratime books by H. Beam Piper, especially _Lord Kalvan of Otherwhen_ – not really time travel, but it FEELS like it.
2 very similar setups, but very different stories: SM Stirling’s _Island in the Sea of Time_ books, and Eric Flint’s _1632_ series.
In the “haven’t read, but heard good things about” category:
Ken Grimwood’s _Replay_
L. Sprague de Camps _Incomplete Enchanter_
All of Connie Willis.
Heinlein’s Time Enough for Love (when LL goes back in time, befriends his family, and sees himself as a child)
LOVE Time and Again, and so many of the additions in the comments. Another overlooked book (and film) that to me has that same sensibility as Time and Again is Portrait of Jenny by Robert Nathan. (I also like his The Elixer, but it doesn’t quite fit here.) But I always wondered, what do the people overseeing The Project see when someone transitions?
It’s worth mentioning John Crowley’s unique novella “Great Work of Time.”
The Company series by the late, great Kage Baker is, warts and all, my favorite time travel epic of all time.
A recent-ish and very original take on time travel is The Rise and Fall of D.O.D.O. by Nicole Galland and Neal Stephenson. It’s an occasionally hilarious vision of what time travel would look like if a military/government bureaucracy gets a hold of it. It’s far from perfect but still a blast to read.
Perhaps Asimov’s End of Eternity hasn’t been mentioned simply because it’s such an obvious choice. But it is notable for actually being a story about time travel, rather than merely using time travel as a holodeck or plot device.
Diana Gabaldon with her “Outlander” series. Very thought out timeline with rich history and a female forward leading lady.
1. Dr Who tie-in novels
2. Ben Elton, ‘Time and Time Again’. Excellent time travel story with a killer twist.
The Map of Time is a nice spin on the Time Machine and H.G. Well.
The obligatory Discworld book – Night Watch.
The mind travel approach, on the other hand, comports with Einsteinian and Kantian considerations about the mind-dependence of time
I’ll admit I have no idea what this is supposed to mean, and what Einstein and Kant are doing in the same sentence. (OK, sure, there is a sort of “mind dependence” for concepts of space and time in Kantian epistemology, but there’s nothing resembling “mind dependence” in general relativity, at all.)
If there’s a Heinlein story I’d nominate for this thread, it’d be “Elsewhen”, as it’s kind of a blend of the brute force/all in your mind models. And I’d suggest Jane Yolen’s The Devil’s Arithmetic* as another outlier.
*not Briar Rose, as I mistakenly said, which would be silly, as cecrow kindly doesn’t say in #34 below
Michael Moorcock’s Dancers At The End of Time. There are multiple time-travel machines, and none of them work very well.
John Varley’s Millennium. There is only one time-travel machine, and God made it.
Those both show the limitations of the brute-force approach to time travel – as does the time travel thread in Harry Potter and the Prisoner of Azkaban, in which Hermione Granger makes use of a time-turner to do her homework, surely the most bizarre conflation of fantasy and British school story, and the time-turner never appears again because it would resolve too many other plot holes in future books.
Time travel in the mind is often weirdly more interesting – someone mentioned Doctor Who tie-in novels, but the Doctor (and the crew of the Enterprise, who also time-travel…) use a brute-force approach. Probably the TARDIS wouldn’t care for being described that way, though.
Quantum Leap‘s tie-in novels have Sam Beckett’s mind jumping in time (the TV series sometimes played with the idea that it was Sam’s actual body that jumped, but just the fact that Sam could wear the shoes and clothing of whoever he Leaped into, I think proved that it was his mind leaping, not his body).
I love Octavia E. Butler’s Kindred, but the time-travel is a mcguffin, not really an essential element to the story – Diana Wynne Jones uses a similar twist in The Crown of Dalemark.
For me the strangest and most compelling time-travel-in-the-mind novel is Marge Piercy’s Woman On The Edge of Time. We never know – we literally have no idea – whether Connie is projecting herself forwards in time to meet the people of a future America where the land and the water are healed: or if she is a hallucinating schizophrenic whose fantasies become more real to her than the grim hospital she’s trapped in. I know which way I’ve always liked to read it, but I have to admit, there’s nothing either way to prove that reading’s true.
@PeterErwin: I am guessing the author was referring to Special Relativity and the time dilation effect, in which the passage of time depends upon the observer’s frame of reference (see also: twins paradox, which has been used by multiple SF writers). I suppose it’s “mind dependent” in the sense that the observer’s mind is making the observation about the clock’s speed. However, it is ultimately not the observer’s mind that affects the perceived speed of the clock; it is whether or not the observer is in an inertial reference frame.
I found that a little perplexing too.
Willis’s short and funny works are also excellent on time travel (to say nothing of the dog, Fire Watch, etc).
Kage Baker’s Company work is about as elaborately considered as time travel comes. That would be my top recommendation, though the later works not as compelling. Start with the garden of Iden.
I like the paradox presented in the 2002 film version of The Time Machine. The time traveler’s fiance dies, which spurs his invention of the time machine. He tries several times to save her but never can. Jeremy Iron’s Uber-Morlock finally reveals to him the paradox of his situation: that since he invented the time machine to save her, he can’t go back and save her, as he would no longer invent the time machine, which would prevent from going back to save her…
Glad to see that Matheson made the list. And, yes, I’ll cop to putting the movie title on all the Tor editions, since SOMEWHERE IN TIME long ago eclipsed the original book title in the public mind.
And I’ll second the recommendation for THE ANUBIS GATES by Tim Powers.
One that I found memorable was “Bring the Jubilee” by Ward Moore.
Jack Finney’s Time and Again served as the basis for the movie Somewhere in Time starring Christopher Reeves as a young man trying to hypnotize himself back to a resort in 1889 in order to pursue a young woman whose portrait he fell in love with. Reeves dresses the part, learns everything he can and successfully transports himself back. However, he’s undone by viewing the date on a modern penny.
A Scientific Romance by Ronald Wright: HG Wells time machine and a dark arrival to a vastly climate alterted future. Literary, brilliant, beautiful, immersive, poetic.
The Mirror by the late Marlys Millhiser: Grandmother and granddaughter exchange places in time. Excellent, realistic portrayal of culture shock, coping, living out another’s life. Exceptional characterization. Also The Threshold by the same author.
Kage Baker’s entire Company series – mentioned already, phenomenal wonderful.
David Gerrold’s The Man Who Folded Himself.
Seconding The Anubis Gates, also Three Days To Never, also by Tim Powers. Also The Rise and Fall of D.O.D.O., by Neal Stephenson.
Although not a time travel book, I just finished Ken Grimwood’s Replay about a man who dies and wakes up again and again as a college freshman in the 1960s, and relives his life over and over. It’s a classic, and very thought provoking. I also really like Time On My Hands by Peter Delacorte, about a plot to go back in time and assassinate Ronald Reagan before as a young actor, so he can’t live to be president; I bought a used copy and plan to re-read it soon.
I’ve mentioned Time Travelers Never Die somewhere before on Tor, but it is still the best thought-out exploration of time travel I’ve read. It doesn’t use time travel merely as a plot device but actually makes it the plot, while pointing out the tropes of the genre along the way, especially how often our linear view of time gets in the way of the full implications of such a technology.
I will always love the time machine, the 1960 movie is a classic.It actually wasnt time travel but the new theory of evolution that got wells thinking about the human race evolving into two seperate species, this is why the time traveler has to go that far into the future.
I always rather liked Thrice Upon a Time by James P. Hogan, in which information could be sent through time but not people or things.
Pebble in the Sky (Asimov) is my easy choice. Plus all of LeGuin’s transilience stories, led by A Fisherman of the Inland Sea.
My surprise choice: Lightning (Dean Koontz).
Can’t think of any fiction offhand that I enjoyed time travel in (I generally avoid the trope, probably why). But I was impressed with the movies “12 Monkeys”, “Source Code” and “Looper”.
Re 18, above: “I’d suggest Jane Yolen’s Briar Rose as another outlier.” I’m stumped how you see time travel as a factor in that novel.
cecrow@34: That’s because I stupidly confused Briar Rose and The Devil’s Arithmetic. I’ll fix the original–thanks!
@34 Yep I enjoy most Sci-Fi but time travel I avoid because I just can never get past the basic paradox flaw.
11/22/63 is a perfect example. I really like reading most of King’s stuff, this is the one his books I had to force myself to finish. Even his Dark Tower series, which I did enjoy, uses time travel in parts, he alters the time travel ‘rules’ to fit the plot and it never worked for me.
@36,
Asimov’s End of Eternity manages to avoid most paradoxes because the time-travelers themselves remain outside of time, in a separate place called “Eternity”. But naturally the destructive effects of paradox eventually come into play.
@36
The wiki page https://en.wikipedia.org/wiki/Lightning_(novel) at the bottom explains how Koontz deals with it. Dangerous read though, full of spoilers!
In his story you can only move forward, to a time that you haven’t traveled before. And you always return 11 minutes after you leave, curiously enough.
Before “Time and Again,” Jack Finney did numerous short stories involving the same sort of “time-slip” initiated by being in a location that has existed largely unchanged through time, or through some artifact or artifacts from that time. They were collected in two volumes, “I Love Galesburg in the Springtime” and “The Third Level.”
@38 for me it goes beyond “if I go back in time and kill an ancestor thus I am never born, then I can’t go back in time and kill him paradox.”
I am a firm believer that there is a natural balance to all things and if I suddenly remove matter and energy from this universe it creates an imbalance, in other words it changes the entire universe. Now if I take that same matter/energy and place it back into the universe, does not matter if it is past, present or future I once again upset the natural balance.
Even King in the mentioned book 11/22/63 early on talks about how the main character changes things just by going back, he does not have to interact with anyone, just by being there it changes everything.
If I would go back in time I would be breathing in air, changing it, my body heat would be changing the natural temperature of the air surrounding me just by being there and that is only considering the changes I make on a molecule level what about on the atomic and sub atomic levels?
I am not saying time travel is impossible, I am just saying I can not wrap my mind around it thus any time travel story, for me, is flawed from the start.
You might like Company of the Dead by David Kowalski. Time travel, the Titanic, and some high weirdness. I agree with all of those who have mentioned Tim Powers’ The Anubis Gates, one of my favourite books. As for 11/22/63, there were good bits, including the man in the hat driven mad by all of the shenanigans, and the visit to Derry, but I found it hard to accept that Oswald basically saved the world by killing Kennedy.
@40/sdzald,
I think you have the makings of an article there – “5 sf novels that don’t violate the laws of physics.” :)
@42 I hear you :) To be honest its a personal thing, I have several friends laugh at me over it, one even basically said “So it’s ok with you that wizards can shoot fireballs out their arse and spaceships routinely violate the rules of physics but you can’t get past the time travel paradox?”
The best way I can explain it is, I like dogs, lots of different kinds of dogs, but when it comes to poodles UGGGGG. Like I said its a personal quark I just can’t seem to get around no matter how much I would like to ‘suspend disbelieve.’
Andre Norton’s “time trader” series had some fun adventures, and they may be the first time travel books I ever read. And they had mysterious alien invaders as well as time travelers. Who could ask for more?
@43
In my youth I was fascinated by anything that challenged the ‘status quo ante dominant paradigm’ – stories about time travel, telepathy, immortality, psychokinesis, superintelligence, whatever. Now that I am nearly 60, I’d rather see (for example) a realistic version of The Expanse that is focused on the challenges of getting along and keeping our humanity in a future that is at least livable if not utopian – while losing all the stuff about all-powerful aliens, hyperdrive, etc.
Even so my favorite sf novels remain the Dune Series, and I even have a special fondness for Dune Messiah, although at a certain point it goes beyond sf and ventures into the occult, something I’m otherwise not a fan of. The writing is so good I find myself willing to go along.
(No offense to any of you poodles out there, but you are obviously not supposed to exist.)
How to Live Safely in a Science Fictional Universe
by Charles Yu
I think my first time travel book was “Time at the Top” by Edward Ormondroyd in 5th grade, and then I did not find it again for years. Ordinary girl Susan helps an old lady on the streets of NYC, and is told she gets “three”. Not wishes, although she tries and then feels silly… And then the elevator in her apartment building takes her, not to the top floor, but to the second story of a house in the 1890s! She makes friends, there is some treasure hunting, and even some matchmaking…
It was doing a search for “magic elevator” that brought it back! There’s also a sequel, “Time and Again”, which is fun but not as perfect.
There was a short story, it might have been by Asimov, which told what happened to the traveler in “The Time Machine” after he took off at the end of the book. Basically he got trapped, his machine broken, in the time of the plague… but it was really well written.
Connie Willis – I have a love-hate with her books. I find them fascinating but her characters get put through so much I find it hard to enjoy. The exception, of course, is the absolutely silly romp “To Say Nothing of the Dog”.
I know he’s problematic, but Orson Scott Card has written two amazing time travel books. The first is “Enchantment”, which is actually fantasy – a twist on Sleeping Beauty which also includes Baba Yaga, who gets her idea for the “house on chicken feet” from her encounter with modern airplanes!
And “Pastwatch: The Redemption of Christopher Columbus”. Nearly the entire book involves time viewing, in order to make the crucial decisions involved in the actual time travel at the end – to change the course of history in the Americas by interfering with the man who “discovered” them. It’s really amazing. Also notable for being one of few books that my entire family was able to enjoy – we all have different tastes in reading. “Enchantment” was another.
Can I count the Pern books? There’s quite a significant bit of time travel in that very first one…
Connie Willis’ Doomsday Book knocks me sideways every time I read it. It is one of my favorite books of all time,
For a truly surreal time travel novel, I recommend The Iowa Baseball Confederacy by W.P. Kinsella (author of Field of Dreams). When the Cubs were finally winning the World Series, a couple of months after Kinsella’s death, many people noted the similarity between that game and the one the Cubs played in that novel.
The Chronicles of St Mary’s by Jodi Taylor are more fun time travel, though not always light (and a few times genuinely heartbreaking). St Mary’s Center for Historical Research has a staff of eager historians keen on recording the truth of historical events by visiting and observing only. No interference is allowed. Only, things happen, and then more things need to happen to set those things straight before everything falls into chaos. The first is called Just One Damned Thing After Another.
@47 I’m glad to see someone else remembers Time at the Top. There are a number of children’s/YA novels that deal with time travel.
Although not as important as the book portal machine, time travel and the Chrono Guard are important in Jasper fforde’s Thursday Next novels.
Roswell That Ends Well, by J. Stewart Burns.
Solves the Grandfather Paradox.
Check out Elan Mastai – All our wrong todays
One of the best books featuring time travel I have ever read, not least because of the highly sympathetic protagonist who frequently refers to himself as a “loser”. And an awesome love story, as well.
Mark Twain’s A Connecticut Yankee in King Arthur’s Court
L. Sprague de Camp’s Lest Darkness Fall was the first modern SF story of someone dumped in the past, and attempting to change history.
Heinlein’s All You Zombies. It’s the ultimate I’m my own grandpa story. By His Bootstraps is of similar ilk.
Ray Bradbury’s A Sound of Thunder is of the you-can-change-the-past school.
Isaac Asimov’s The Ugly Little Boy is a gripping though nonsensical story.
In H. Beam Piper’s Time and Time Again, a 43-year-old man dies in the Third World War. Then wakes up in his own 12-year-old body, at the end of WWII. He may be 12, but he has all his adult memories and skills. He and his dad set out to prevent WWIII. Which is now decades in the future.
In Poul Anderson’s wonderful Time Patrol stories, the Patrol protects reality from accidental or deliberate changes in the past. When one happens, a new universe replaces the old. The protagonists continue to exist even though the universe that engendered them does not.
In Harry Turtledove’s Guns of the South, time travelers equip Robert E. Lee with AK47s.
David Drake’s Travellers features a dirigible from the future, crossing 1890s America.
Mack Reynolds’ The Other Time (with Dean Ing), in which the protagonist is out in the Mexican desert, feels dizzy, and finds himself in the time of Cortez and Montezuma. Luckily his name is Don Fielding, so the Spaniards take him as a noble, and he’s fluent in Spanish and Nahuatl. He doesn’t like the way the Spaniards are treating the natives, and changes history.
David Gerrold’s The Man Who Folded Himself, I concur, is the quintessential time travel novel. Whenever the subject comes up, it is the first example I think of. Gerrold’s work considers and engages every imaginable paradox and its consequences; and the book is stunningly well-crafted for its subject, from a writer’s perspective. As Tor author Douglas Lain wrote for Tor.com in 2012, “(Gerrold) writes the whole story in the second person without alerting you, the reader, directly to this fact. You’re brought inside the book without really knowing it.” Both Mr. Lain’s article and Mr. Gerrold’s book are worth a second reading in regard to this subject. See: https://www.tor.com/2012/03/19/time-travel-in-the-second-person-the-man-who-folded-himself/
@54 +1 on both Lest Darkness Fall and Sound of Thunder. I also like David Drake’s To Bring The Light, the last of the extras added in this edition of the deCamp… https://en.wikipedia.org/wiki/Lest_Darkness_Fall_and_Related_Stories
While not a novel, I’m surprised that Ted Chiang’s multi-award winning novelette, The Merchant and the Alchemist’s Gate, has not been mentioned at all. I don’t want to spoil any of the fun twists in the book, but he approaches time travel (and the period/location) with the same rigor and thoughtfulness as any of his other stories. A true gem.
My recent favorite, not mentioned here I think, is Bee Ridgway’s River of No Return. The jump is forward in time, not backward. While somewhat reminiscent of Kage Baker’s The Company novels, Ridgway’s style is different. I found the description of the transition (something usually skipped over) between times really fascinating. I hope she writes more novels!
Echoing Shawn Thrasher above, who mentioned Peter Delacorte’s Time On My Hands. As in the book 11/22/63, the protagonist wants to go back and change the course of a U.S. presidency. Only, of course, it all goes wrong… Great book.
There’s a particular sub-sub-genre of time travel/body-exchange-across-time novels that offers some good reads; namely a girl on the cusp of adolescence travels to the past or changes places with someone from the past. Things happen, hard lessons are learned, she does some growing up, and returns to her present. The ones I can think of offhand are:
• Charlotte Sometimes by Penelope Farmer
• Playing Beattie Bow by Ruth Park
• The Freedom Maze by Delia Sherman
• Saturday, the Twelfth of October by Norma Fox Mazer
Personal favourite’s.
Things undone John Barnes short story.
The two classic novels by Barrington J Bayley.
Collision with Chronos.
The Fall of Chronopolis.
Please read them
@7: I protest the inclusion of The Incomplete Enchanter ; the authors(*) are clear from the start that the characters are traveling to mythic lands where the very laws of ~science are radically different (i.e., magic works), not to our own history (or even across alternate histories as in Lord Kalvan).
@0: tastes vary; I found the Finney a horrible slog. Perhaps the issue was the substitution of historic detail for plot (cf Willis’s apparently stuffing everything she knew, and some things she didn’t, into Blackout and All Clear), or maybe it’s just that his endless whinge about how much better things were in the past is amusing at short lengths (e.g., “The Third Level”) but tiresome in a novel.
(*) I also protest the failure to credit co-author Fletcher Pratt.
#54 and others included some old favorites of mine. I have a few to add:
L. Sprague de Camps series of short stories published as Rivers of TIme, that I believe started with A Gun for DInosaur.
2. Fritz Leiber wrote a series of time travel stories (mostly in Galaxy) with the theme Try and Change the Past, and included the short novel Big TIme (all published as an Ace Double in the early 1960s.
3. John Brunner’s Times Without Numbers (also part of an Ace Double)
4. Larry Maddock’s series for Ace, Agent of TERRA (3 or 4 books in series). Pen name for Robert (/) Jardine.
R. A. MacAvoy’s work is a mixed bag. The Book of Kells is one of her better tales. It involves a time portal between modern Ireland and the Ireland of 1,000 AD, when Dublin was a Viking settlement.
@40, I have bad news for you: one interpretation of general relativity has it that the universe itself is removing matter and energy from itself at a titanic rate, everywhere. This is not a small thing. If it hadn’t been for this continuous removal we would be enclosed in a bath of radiation at least as hot as the surface of the Sun: *most* of the energy not bound up in matter in the universe has been lost. The background radiation field contained about a billion times as much energy as did its particles when it was born: it doesn’t nowadays. (You could also interpret it as soaking into the structure of spacetime as spacetime expands, but since there is no property in spacetime which ‘increases’ to allow for that, this would just be a different form of violation of conservation of energy: you could also interpret it as going into the universal gravitational potential, but if anything that is even *less* useful and even further from true. Sure, you’d get it all back if spacetime recollapsed, but it doesn’t seem that it’s going to do that.)
So there is no balance regarding the amount of mass-energy in the universe. It’s dropping all the time, and it’s had a long time to drop. You just can’t see this happening except on the very largest scales.
(Another way of putting this: the expansion of the universe breaks time-translation symmetry, forcing conservation of mass-energy to be violated.)
Time travel remains ridiculously hard verging on impossible, but conservation of mass/energy is certainly not grounds for finding time travel unlikely. It’s unlikely for entirely different reasons!