The Paradoxes of Time and Time Travel
“In contradiction and paradox, you can find truth.”
A dictionary definition will tell you that a paradox is something that contains contrary or incompatible parts, rendering that something nonsensical. It will also tell you a paradox could be a seemingly absurd statement or proposition which, when investigated, may prove to be well founded or true. Interesting then that word itself is, well, paradoxical, having contrary meanings depending on how it is used.
But semantic linguistics aside, the question is: Should there even be any paradoxes in physics? Well, not according to Abramowicz and Lasota in their paper On Travelling Round Without Feeling It and On Uncurving Curves. “There are no paradoxes in physics,” they state, somewhat categorically, and if they do exist, they go on, it’s only because we attempt to understand physical ideas “by using inadequate reasoning or false intuition.” You may be tempted to reply to all this with the old line, ‘Oh, shut up and deal.’ Really though, where would the fun be in physics without paradoxes? Particularly Time Travel paradoxes. Aren’t these one of the main reasons people are interested in the concept of time travel in the first place? Or indeed reading academic papers entitled On Travelling Round Without Feeling It and On Uncurving Curves.
In 1931, Amazing Stories, published by Hugo Gernsback, certainly noticed that Time Paradoxes were becoming a feature of the stories in the magazine and so set a challenge to its readers entitled ‘The Question of Time-Travel’. One conundrum was put thus:
“Supposed I can travel back into time, let me say two hundred years; and I visit the homestead of my great-great-great-grandfather, and I am able to take part in the life of his time. I am thus enabled to shoot him, while he is still young man and as yet unmarried. From this it will be noted that I have prevented my own birth; because the line of propagation would have ceased right there. Consequently, it would seem that the idea of time travelling into the past, where the time traveller can freely participate in activities of a former age, becomes an absurdity. The editor wishes to receive letters from readers on this point: the best of which will be published in a special edition.”
One reader, a fourteen year old boy named James (Jim) Nicholson, wrote back asking “who the heck would want to kill his grandpa or grandma?” Young James then posed this question: “What if a man were to travel back a few years and marry his mother, thereby resulting in him being his own father?” Not surprisingly perhaps that boy went on to become president of American International Films, the company that made various science fiction classics, including THE TIME TRAVELERS (1964). Young James in his reply to the magazine also mentions a man travelling into the future and seeing himself killed in such an unpleasant manner that after returning to the correct time he commits suicide in order to prevent the more terrible way he was destined to die. Yet, he asks, if he did die, how could he have seen himself die in an entirely different manner in the future? Is Young James’ point an example of a future causal retro-paradox?
For many readers, Time Paradoxes and Thought Experiments are the primary reason, sometimes the only reason, for enjoying the story. Such tales appeal to people who can think round corners. They are the same folk perhaps who also enjoy solving Rubik’s cubes, crossword puzzles and Sudoku brainteasers. The unravelling, the deciphering and the resolving are the very point of the game. It’s not that empathy, emotion or even romance cannot also be enjoyed, but rather that these mind riddles have great intellectual and mental appeal. And they can be amusing too.
Larry Dwyer in his 1971 paper Time Travel and Some Alleged Logical Asymmetries Between Past and Future, published in the Canadian Journal of Philosophy and later reprinted by Cambridge University Press, had fun with some of the potential legal consequences of time travel. Should a time traveller who punches his younger self (or vice versa) be charged with assault? Should a time traveller who murders someone in the present and then flees into the past be tried for a crime that has not yet been committed? And if a married man leaves his wife and escapes into the past, if he remarries, is he still guilty of bigamy, even though his other wife will not to be born for a thousand years? These aren’t perhaps strictly speaking paradoxes, more ethical and legal questions for a jury to decide. That is, of course, if the jury doesn’t think when told about all this time travel nonsense that the man’s mad and belongs in a padded cell.
“If you try to fail, and succeed, which have you done?”
‘Yeah, but what if you went back and killed your own grandfather?’
He stared at me, baffled. ‘Why the f*** would you do that?’
Stephen King’s 11/22/63
‘The Grandfather Paradox’
The most frequently discussed Time Paradox is ‘The Grandfather Paradox’, and that’s where we will begin. The originator of this term and concept is said to be Hugo Gernsback, publisher of the first science fiction magazine Amazing Stories. The paradox suggests that if you go back in time and alter the timepath of an ancestor, say by murdering your grandfather, you will naturally enough bring into question your own very existence. And obviously, that’s not a good outcome. Yet if you are never born, how can you kill anyone’s grandfather, never mind your own? And if your grandfather isn’t murdered, do you come back into existence again?
In TRAVELERS (using the American spelling of the series), there is The Oath that their journey back in time from the future is ‘At peril of our own birth.’ “If we successfully deflect asteroid Helios 685,” says Traveler 117, alias Mrs Bloom, “we alter the course of humanity so profoundly it’s highly probable that the time we come from, everything between then and now – the plagues, the wars – none of that will happen. Which means it’s also highly probable that neither will we.” Jonas and Martha in DARK face a similar existential question. The Grandfather Paradox, along with much else in time fiction, makes us confront our own mortality and even our potential non-existence. But whatever we may think of our lives at least those who lived did live, unlike ultimately poor Jonas and Martha in DARK. Yet perhaps saving the planet makes it all worthwhile.
On a more cheerful note, meeting ancestors can give us a new understanding and respect for those in our family tree who came before us. That’s certainly true in BACK TO THE FUTURE III set in the Wild West. Even in the first BACK TO THE FUTURE movie, where Marty has to stop a potential Grandfather Paradox by making sure his parents kiss at the Prom dance, Marty gains a new appreciation for his mum in seeing them so young. And Marty begins to understand too where his father’s lack of self-confidence came from.
But now let’s return to doom and gloom and death and self-sacrifice. IN THE SHADOW OF THE MOON tells the tale of a cop, Thomas Lockhart (Boyd Holbrook), chasing a time travelling serial killer called Rya (Cleopatra Coleman), but, as Rya is travelling backwards in time, she is killed at what for Lockhart is their first encounter. The twist in the tale is that the serial killer is his granddaughter and her motive in killing is to prevent a world changing disaster in the future. She probably knows she will die, but is this really the same type of self-sacrifice as ‘At peril of our own birth’ for where is the moral justification in what is essentially murder? Or it is OK to simply tell a crime Time Tale and leave out the exploration of moral complexities?
Rya in IN THE SHADOW OF THE MOON is Thomas Lockhart’s granddaughter from the future, but variation on the Grandfather Paradox is when the time traveller goes back in time and fathers a child, or indeed becomes his own ancestor in order for himself to be born (and in these scenarios it always is a man). This particular scenario is sometimes called the ‘Sexual Paradox’ and an example of this is THE FLIPSIDE OF DOMINICK HIDE, where the Time Traveller is indeed also his own great-grandfather. It’s there in a way in TERMINATOR as well. It’s John Conner in the future who sends Kyle back in time to protect John’s mother and in so doing protects himself, even though he is not yet conceived. But that’s the point, for John knows that in sending Kyle back in time, it is fact Kyle who becomes John Conner’s father. There is also an episode in RED DWARF where Lister is revealed to be his own dad. Lister thought he was abandoned as a baby under a pool table in a pub inside a box marked something like ‘our Rob’ or ‘our Ross’, however, when he becomes a Time Traveller Lister realises he is in fact his own parent. Lister uses the Time Drive to send himself and his baby back to the Aigburth Arms in 2155. There he explains to the baby that he isn’t being abandoned at all, he is simply keeping going a circular conceptual causation.
Ah yes, you say, but what about the biology of all this? After all, it takes two to tango. It is true that to be his own father, the baby Lister would have to have ended up with total replication of the time travelling Lister’s genome (the genome being the complete set of genes or genetic material present in a cell or organism). The chances of this happening are at the jackpot lottery-winning end of probability. But better not to worry about such things. And besides, it is just possible to win the jackpot. Even if it is never you.
Robert Heinlein took the Sexual Paradox to the N-th degree in ALL YOU ZOMBIES (1959), which is a Time Tale where everyone, as it were, is one. That is to say, the main characters – man and woman – are really the same person at different stages of their timeline. As Heinlein said to his literary agent, “I hope that I have written in that story the Farthest South in Time Paradoxes”. Yes, you have to admit, that’s pretty far south. Perhaps you could even say that Heinlein had in that story more or less fallen off the Antarctic upwards.
Douglas Adams in THE HITCHHIKER’S GUIDE TO THE GALAXY and THE RESTAURANT AT THE END OF THE UNIVERSE has fun with Time Paradoxes and the Sexual Paradox in particular. In THE RESTAURANT AT THE END OF THE UNIVERSE, for example, Adams offers this advice:
“One of the major problems encountered in time travel is not that of becoming your own father or mother. There is no problem in becoming your own father or mother that a broad-minded and well-adjusted play can’t cope with. There is no problem with changing the course of history – the course of History does not change because it all fits together like a jigsaw. All the important changes have happened before the things they were supposed to change and it all sorts itself out in the end.”
Yes, it’s good to know these details before hopping into that truck that stopped to give you a lift on the A42. But is there an actual solution to the Grandfather Paradox? Well, maybe it’s not that difficult. Just make a rule that time travel is only made available to those time travellers who go into the past and solemnly swear not to kill their grandfathers. There you are, problem solved!
“Paradoxes are just scar tissue. Time and space heal themselves up around them and people simply remember a version of events which makes as much sense as they require it to make.”
DIRK GENTLY’S HOLISTIC DETECTIVE AGENCY by Douglas Adams
“In the world of words the imagination is one of the forces of nature.”
The science fiction writer Larry Niven is known for his many ‘Laws’. Here are a few on writing:
“Never be embarrassed or ashamed about anything you choose to write.”
“It is a sin to waste the reader’s time.”
“If you’ve nothing to say, say it any way you like.”
“There is a technical, literary term for those who mistake the opinions and beliefs of characters in a novel for those of the author. The term is ‘idiot’.”
Larry Niven’s Law on Time Paradoxes could be called The Law of The Conservation of the Past. For example, if a message is sent to the past, it naturally follows that message will change history, but this will ultimately include the decision to send the message and what was put in it. A ‘new’ message will then be sent instead, and this too will change the past, only in a different way, and so on, and so on, until some sort of equilibrium is achieved – the simplest being the message isn’t even sent at all. Hey Presto! Issue resolved!
The scientist Igor Novikov put this concept it a different way in Evolution of the Universe where he wrote, “The closure of time curves does not necessarily imply a violation of causality, since the events along such a closed line may all be ‘self-adjusted’ – they all affect one another through the closed cycle and follow on in self-consistent ways.” Self-consistency, a new equilibrium or just a belief that it will, as Douglas Adams put it, ‘sort itself out in the end’. Well, it must be right. We are here after all.
“The gods do not protect fools. Fools are protected by more capable fools.”
“Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing it is stupid.”
“When you sit with a nice girl for two hours, it seems like two minutes; when you sit on a hot stove for two minutes, it seems like two hours. That’s relativity.” The words of Albert Einstein. Not quite a paradox but close, in that we all experience seemingly contradictory notions as we are subject to the passage of time. Summer days are maybe long, yet they often seem to go so quickly, while those dark winter nights never seem to end at all.
“Imagination is everything. It is the preview of life’s coming attractions.”
“The best way to predict the future is to invent it.”
The Future Paradox and Changing the Future
Is there such a thing as a Future Paradox or are paradoxes limited to time travel in the past? The answer in a way depends on whether you believe in free will, the point here being that knowing what will happen tomorrow or whenever, gives you enormous power, but ironically it is that very knowledge which may force you to follow the path that leads to whatever that future is said to be. In effect, knowing the future renders you powerless by removing alternative choices, and so, ultimately, free will. Put simply, what you are told becomes a self-fulfilling prophecy. A quick example of this can be found in a play called THE JEST OF HAHALABA by Edward John Moreton Drax Plunkett (better known as Lord Dunsany). In it a man reads his own obituary in tomorrow’s newspaper and as a result drops dead with the shock, resulting in the very obituary he just read. And think here, perhaps of Shakespeare’s MACBETH. Would Macbeth have made the choices he did without the interference of those pesky witches?
The Future Paradox in terms of free will is there in the earliest of all human dramas, namely OEDIPUS REX by Sophocles. Oedipus famously went to Delphi to ask about his parentage, but instead of answers he was given a prophecy that one day he would murder his father and have sex with his mother. Not surprisingly, he resolved to leave his home of Corinth and never return, only it’s this very action that leads to him killing his father and sleeping with his mother. Oedipus thought he was escaping his destiny, but in fact he was bringing it about. And ideas around destiny have never really left the creative stage for you can find its essence in many novels, movies and television series which ask the questions: Do we truly have agency over our future?
On the other hand, there is the question: Does knowing your future change your actions in the present? Cris Johnson in NEXT (2007), based on the Philip K. Dick short story THE GOLDEN MAN (1954), thinks more in terms of possibilities than a single destiny when he says, “Here’s the thing about the future. Every time you look at it, it changes, because you looked at it, and that changes everything.” Note the word ‘everything’. And isn’t that true in a way even if, as with Chris Johnson, you cannot see two minutes ahead in time, for aren’t we always considering future possibilities and scenarios? We weigh them up and try to work out which suits us best.
Besides, if in a Time Tale you can change the past, why shouldn’t you be able to alter the future? Nothing is bound to happen, it’s only ever us that bound it. This idea is at the heart of the questions Ebenezer Scrooge asks The Ghost of Christmas Future when Scrooge is shown his own grave:
“Before I draw nearer to that stone to which you point,” said Scrooge, “answer me one question. Are these the shadows of the things that Will be, or are they shadows of things that May be, only?”
Still the Ghost pointed downward to the grave by which it stood.
“Men’s courses will foreshadow certain ends, to which, if persevered in, they must lead,” said Scrooge. “But if the courses be departed from, the ends will change. Say it is thus with what you show me.”
Of course those who know the future, or a potential future, don’t always wish to reveal what it is. Tiresias in OEDIPUS REX wisely refuses to tell King Oedipus what he knows. In a much more recent tale, TRAVELERS (using the American spelling of the series), there is Protocol 2H for the Historians which states that ‘Updates are not to be discussed with anyone. Ever.’ Oedipus is determined to find out why the gods have sent a plague to Thebes, but in asking that question, he discovers that he himself is the tragic answer. It his unnatural actions of patricide and incest which so offended the gods and for that reason it was they brought about the plague. But there is a difference between OEDIPUS REX and TRAVELERS and that is the ‘updates’ that the Historian Philip receives lead only to ‘projections’ of one or more alternate timelines as opposed to pre-ordained destiny. The future isn’t necessarily as fixed, for our philosophy of life differs greatly from that of the ancient Greeks. At least for many people.
Being aware of what may come can give us hope as well as trepidation. But it does raise the very philosophical question: If we knew how things would end on our journey, would we still make the same decisions? Would we choose a different route? Content is the person who is happy to keep to the path already trodden.
Forest (Nick Offerman) in DEVS, like many characters in Time Tales, is suffering from bereavement, in his case the death of his young daughter. It is the sort of loss where a man tortures himself with guilt in a belief that there was something that could have done to prevent it. Forest seeks absolution and the machine, he hopes, will give it to him. You see, the Devs computer is programmed to examine all possible permutations of history and so through it, Forest will discover if there was indeed anything more he could have done to save his daughter’s life.
As the story progresses, Lily Chan (Sonoya Mizuno) becomes a bit of a fly in the ointment at the secret world of Forest and Devs. Her inquiries and investigations into what is really going on there begin to cause Forest and his political and financial backers problems and eventually all is uncovered and revealed. In their final confrontation, however, Lily is offered through Forest and Devs an opportunity to view her own future, for it becomes apparent the computer can predict what is to come as well as retrospectively generate what has been. These simulated images are only seconds ahead of real time, but they are enough for her to know how the battle will end. Or rather how this seemingly infallible computer predicts it will end.
The question becomes will the Future Paradox force her into making that predicted decision or will she choose another path? In other words, will the determinist computer be wrong and her actions show that she does after all have the free will to ultimately choose what she will?
Of course, seeing your future, even if only for a few seconds ahead, as is the case with DEVS, could be a double-bluff. In the Future Paradox there is always the possibility that telling you that doing X and not Y will bring about Z may well be what makes you do Y, which is what actually was going to bring about Z along. Anyway, in the event, Lily does not do as the computer predicted. The chain of cause and effect is broken just as it was in the German television series DARK. You could say then that the ‘Future Paradox’ is broken as well. The good news is that free will is a possibility. The bad news, however, in this story, is that both Lily and Forest die. Well, sort of. You see, there’s another twist and more good news: Lily and Forest somehow become part of the computer simulation in a world as real as reality itself.
DEVS is a many layered series. It explores bereavement (both Forest and Lily are recovering from loss of loved ones), voyeurism (the Time Window is used to generate images of Marilyn Monroe and Arthur Miller having sex) and even God is there in the mix too because in Latin the letter V is an allograph and so Devs is really Deus, the Latin word for God. Ultimately though the focus of the series is exploration of those perhaps unanswerable questions about the nature of predetermination and its relationship with our belief in free will. And an imaginative and fascinating exploration it is too.
Knowing the future or having a sense of it is sometimes there in Time Tales that deal with crime. The film MINORITY REPORT, again from a short story by Philip K. Dick this time set in 2054, features Delphic-like ‘PreCogs’, mentally-altered humans who are now able to predict the future to such an accurate degree that special cops are tasked with arresting killers before a crime is even committed. FIVE DAYS TO MIDNIGHT also has a crime element as it centres on a physicist who discovers post-dated documents indicating that he will be murdered in five days time and TIME LAPSE, a murder mystery of sorts, deals with a strange machine that takes pictures of events twenty-four hours before they occur.
We all know the old line, ‘It’s difficult to make predictions, especially about the future.’ But do we know who said this first? Niels Bohr? Samuel Goldwyn? K. K. Steincke? Robert Storm Petersen? Yogi Berra? Mark Twain? It has been traced to a Danish parliamentary debate in 1937, but with no attribution specified. It seems it made its first appearance in English in a 1956 academic publication called the Journal of the Royal Statistical Society where it is said to be an aphoristic joke of Dutch origin. But again, no name is given. Ironically, even with the most famous gag about predicting the future, nothing is known for sure. And isn’t that in a way quite appropriate?
There was an irony too in the making of FLASHFORWARD, the American television series based on the 1999 novel by Robert J. Sawyer. The show revolves around a mysterious event which causes nearly everyone on the planet to simultaneously lose consciousness for two minutes on October 6th 2009 and in this blackout people see what seems to be visions of their lives six months hence. The final episode of Season One of FLASHFORWARD showed visions of happenings twenty years into the future, only it was filmed before it was known the show would be cancelled. In the future, perhaps even in 2030, the twenty year anniversary of the show, someone will re-commission FLASHFORWARD to see if those visionary predictions were correct.
In the SWIDGERS book series, William meets a character, Alicia, who can see into the past, indeed she shows him in detail what he must know and understand to move on in the present. Yet the individual who seems to know of William’s future is more elusive. Without revealing too much, this person’s brief ‘missives’ are as cryptic as the Delphic oracle. But isn’t that the truth, in a way? We have a vague idea we may know what could happen, but exactly how it will work out, well, that’s always a little misty, until the event itself occurs. And it’s only when it does that those mysterious foretelling begin to make sense. Or at least we find a sense in them. And that’s certainly true of William in SWIDGERS.
But not everybody wants such knowledge. Isn’t it cheating in a way? As Liz Cooper (Jessica Biel) in the movie NEXT says “I don’t think I want to know. I mean, if every move we make is preordained, then what is the point of that? I mean, life is supposed to be a surprise.” But knowing something of the future isn’t all bad news, after all, in NEXT it’s Cris’s ability to see into the future that saves Liz’s life. But perhaps the last word should be left to Doc Brown. In BACK TO THE FUTURE he says, “Nobody should know too much about their own destiny.” The future really should be a blank page:
JENNIFER PARKER: Dr Brown, I brought this note back from the future and – now it’s erased.
DOC BROWN: Of course it’s erased!
JENNIFER PARKER: But what does that mean?
DOC BROWN: It means your future hasn’t been written yet. No one’s has. Your future is whatever you make it. So make it a good one, both of you.
MARTY: We will, Doc.
“I never think of the future, it comes soon enough.”