Ripples in the Dirac Sea

by Geoffrey A. Landis

Short story about time travel with real physics.
About his award-winning short story, Geoff writes, "'Ripples in the Dirac Sea' was an experimental story for me. Quite a number of disparate threads wove into the final narrative. One important thread was my feeling that a story involving time travel should have a nonlinear narrative to reflect the discontinuous way the characters experience time. I also wanted to see if it was possible to write a story in which real physics is presented. Very little of modern SF goes beyond the early quantum mechanics of Heisenberg and Schrodinger, work which is admittedly remarkable and beautiful, but by no means the end of the story. Here I tried to invoke some of the strangeness and beauty— I might even say sense of wonder—of the physics of Paul Adrien Maurice Dirac. In 'Ripples' I decided to explore the inconsistency between Dirac's relativistic quantum mechanics and the mathematics of infinity developed by Cantor and others (as far as I can tell, a quite real inconsistency). The Dirac sea is also real, not an invention of mine— despite the very science-fictional feel of an infinitely dense sea of negative energy that surrounds and permeates us."

Genres: Science Fiction, Time Travel, Short Stories, Fiction, Speculative Fiction, Literature

20 pages, ebook

First published October 1, 1988

Reviews

[Timothy Ward · Rating 5 out of 5]

Review to come as part of my The Time Traveler's Almanac group read. This will post during the second week, September 10.

http://www.timothycward.com/2015/08/1...

Here's an excerpt:

This story is beautiful, scary, thought provoking and inspirational. It shows someone who's figured out time travel, shares what joys can be had by traveling back in time, but then ultimately says that us ordinary people have it far better. We don't know when we'll die, so the future is full of hope. This is a terrific story that does just about everything I'd want in a time travel tale.

[DJ · Rating 4 out of 5]

4/5 Rating Originally posted first at MyLifeMyBooksMyEscape as part of the Time Traveler's Almanac group read.
Follow along with #TimeTravelThursday

This is how you science a time-travel story!


This week in TTTA read along, we are reviewing the 1989 Nebula Award winner(!) for best short story. When I realized that, I raised my expectations. And you know what? I was not disappointed!

Our narrator is a physicist who has discovered time-travel. He starts off the story by telling us that "[his] death looms over [him] like a tidal wave..." He then goes on to explain how they had prepared for their time-travel trip, taking care to avoid any type of time paradoxes, but that they made one mistake. One mistake which is now obvious that they shouldn't have made.

We now follow the narrator along as he tell us how he came to find time-travel, some of the events and trips he been on with it, and what that obvious mistake was and what it has to do with his looming death.

I loved how this story was told; it has 2 different time lines that Landis weaves back and forth in telling the story: The narrator tells us the story line of how he first came to discover time-travel and what came from it; and a story line of when he travels back to a particular year in time, February 1965, where we meet a man named Dancer. There is also brief snippets of these "notes for time-travelers" where we are explained the science behind this technology.

It was great starting off knowing that narrator is about to die because of some mistake that was obvious now in retrospect. The whole time I was reading, I was trying figure out why that mistake he made was crucial, and how did it cause him to get to where he is now with that looming death; what is so special about the year 1965 that the narrator loves it so much, and, again, what it has to do with where the narrator is. Actually, we don't even know where he is at the start! All we know is that he is in some trouble.

As the story line of time-travel discovery goes on, the narrator verbally explains to us some of the rules of times travels and we also see him go on different trips in times to help explain - not the science behind time-travel - but to debunk certain theories about paradox and the whole time-continuum thing.

Between these two story-lines, there is that "Notes for a Lecture on Time Travel". They are a couple of paragraphs each (not even half a page), and this is where Landis has the actual science, physics, behind the technology. Doing this, I thought, made the story better. Landis breaks it down to basic stuff... however, I do not think it was explained well. I got the gist of how it worked with particles, but I didn't understand it, and that frustrated me. I would have liked more explanation of the basic theory, or break down even more into simpler science.

Time-travel, and science fiction stories in general, don't have to provide the science behind how their technology works and it doesn't hurt the story at all! But if you are going to bring the science into it, do it so the reader will understand it! Excluding giant info dumps - concise, coherent explanations will always make me enjoy the story more, and if there was just a few more sentences to tell me about the Dirac Sea, I know I would have loved this.

Character development, right? What about that? Well, I found most of the development for our narrator happened in the story-line of 1965. I didn't find anything that really stuck out to me about his character as unique, and think was a lot room for more development, but I did like and sympathize with him, and the character Dancer that shows up here I thought was pretty cool.

The actual plot? That was great. If you can pay attention very carefully(!) you might be able to see why that mistake was so huge, and how this time-travel story's time-continuum works ;)

Ripples in the Dirac Sea is well worthy of a Nebula Award. I would have like a little more something to our narrator's personality to make his stand out, but still found him sympathetic and felt his relationship with Dancer. Needless to be said, the time-travel aspect of this story is except! I just wished it was explained a bit more!

Be sure to check out my fellow time-travelers' reviews!
Alesha Escobar
H.M. Jones
Preston Leigh’s Leighgendarium
Timothy C. Ward

4/5 Rating

-DJ

[ola · Rating 5 out of 5]

The inventor’s first venture back in time brings him to San Francisco in the year 1965. Soon, this return into the past becomes a necessity after a fire is lit during the inventor’s stay at a hotel in the present day, and he leaps backwards in time to escape the flames. Through the years, he meets the enigmatic Dancer and Lisa, and the three embrace the ever-hedonistic lifestyle of the 1960s until Dancer meets his untimely death in 1969. The inventor lives on, creating a time machine and travelling back to the past. Always, he returns to 1965, and always, Dancer dies. Sometimes Lisa commits suicide out of grief for Dancer. Sometimes she lives and leaves the inventor, reaching out ten years later. It appears that no matter what happens, Dancer will die and the timeline will reluctantly shift around it.

Throughout the story, the inventor scorns the idea of time, believing himself above it, a theme subverted to taunt him by the end. The narrative is displayed in a nonlinear fashion, chronology leaping back and forth as fickle as the inventor’s own time travelling. Paragraphs dutifully open with, ‘To San Francisco, June 8, 1965’, ‘To the Cretaceous, to see the dinosaurs’, ‘To visit the crucifixion’, and he leaps possessively back and forth between Dancer and the hotel in flames. The discontinuity of the text mirrors the inventor’s own unravelling state of mind, past, present, and future occurring both in a grievous crawl and all at once. The more the inventor travels, the more timelines he creates and destroys, the less his dominion slips away.

Once, the inventor and Dancer observe the people of San Francisco and the inventor comments on their hurriedness, their frenzy to move throughout their day. Dancer replies that they are ‘trapped in the illusion of time’, an allusion of what is to come, of the lengths that the inventor will go to see him after his death. Again, the inventor returns to San Francisco in 1965, to Dancer and Lisa. Again, Dancer dies in 1969, the inventor returns to the future, to the fire, and travels backwards once more. He is no less trapped than the people of San Francisco, craving Dancer alive and travelling backwards just to see him, just to pretend that they can be together.

To travel through time is to reject nature. Through the invention of his machine, the inventor stakes a claim to this power, attempting to subjugate the force of time and manipulate it to his will. Once, the inventor describes himself as being ‘caught between omnipotence and despair’, the use of the word ‘between’ painting the two ideas as dichotomous; he is stuck in a compromise between the power he grasps and his indecision to wield it. However, Landis presents omnipotence and despair as opposites in irony; the inventor’s omnipotence is an illusion and he is in fact powerless, an idea only fuelling his despair.

He tells Lisa that she and the world do not exist, boasting that this timeline had only come into existence ‘because [he] was watching’, further gloating that it would ‘would disappear back into the sea of unreality as soon as [he] stopped looking’. His tone is haughty, vindictive—desperate to assert his agency over the timeline, he threatens Lisa with her nonexistence. He hubristically believes in his ability to force time to bend to his bidding, but his affirmation of Lisa’s existence and distress to prove himself to her reveals his insecurity.

Like clockwork, the inventor returns to 1965 again and again, unable to escape Dancer’s death or the hotel fire despite his self-proclaimed ‘omnipotence’. With all his supposed power, actions in the past cannot change the present and each timeline is erased as quickly as it began, a maxim established in his ‘NOTES ON THE THEORY AND PRACTICE OF TIME TRAVEL’. In asserting his omnipotence, he only forces himself to confront his insurmountable helplessness in changing the past or future, time machine or not.

‘My death looms over me like a tidal wave,’ the inventor mourns, ‘and yet I flee, pointless though it may be.’ The inventor compares his impending doom to the movement of the ocean, destined to crash down upon him and drag him under the surface when the time comes and not a moment sooner. At the inevitability of his death, he understands how his desire for power has backfired, and questions if his fight for autonomy was ever really his. Contrary to the beginning of the story where he celebrated his time machine, he is resigned by the end. ‘It is too late for me,’ he says as he grieves, ‘it makes no difference what I do.’ He grieves Dancer, grieves himself, and grieves everything he has done. He recognizes that his omnipotence was false, his power misplaced, and that he and Dancer are doomed to fall one after the other.

The discovery of fixed events in the timeline, in any timeline the inventor flees to, questions the role of human agency, including whether it even exists at all. Dancer’s death is inevitable, but the inventor returns to see him again and again, choosing to spend their remaining time together. To do so, he sacrifices the time it takes for him to burn in his hotel room, using up priceless seconds to appear within the flames, activate the time machine, and appear right back in 1965.

The inventor notes that he ‘[uses] up a little bit of time’ each moment that he jumps to visit Dancer, the phrase demonstrating the gentle erosion of his future, time travel chipping away at him bit by bit, until his own proclaimed ‘day [that he] will have no time left’. He has grown attached to Dancer, has become obsessive and hungry through the timelines as he watched him die hundreds of times; it is almost as if his inability to accept his lack of agency drives him to make decisions as opposed to his power to do so. Yet, he declares that Dancer ‘will never die, [that he] won’t let him’, as he travels back to 1965 yet again.

The inventor’s sense of denial and powerlessness gives way to his lack of control and his subsequent desperation. Dancer is dead, an event that is fixed to happen no matter the timeline. Even then, he speaks as if he himself can control lives and deaths, the simplicity and totality of his assertion speaking to hopelessly dictate Dancer and the timelines as if he were its god rather than a mere overseer.

It is through the inventor’s love for Dancer that Landis’ sense of humanity is able to shine through. The inventor’s mental fortitude is buried under Dancer’s hundreds of deaths that he stood by and watched. He allows himself to be consumed by the despair of it, leaping back in time over and over again in an act of hopeless rebellion to bring Dancer back, a lighter sentence than accepting his own powerlessness.

‘There’s so much time,’ the inventor tells Dancer in 1965, despite the weight of the future, to which Dancer, oblivious, responds with, ‘all the time there is’. This directly contrasts to the inventor’s admittance that he ‘live[s] on borrowed time’, using his precious few seconds to see Dancer yet again, stating that he knows ‘when and where [his] debt will fall due’. Both him and Dancer are fated to die, but he is ready to stake the permanence of his death on Dancer’s, to return to 1965 and San Francisco and Dancer until there is nothing but ashes.

Time in Geoffrey A. Landis’ Ripples in the Dirac Sea is presented as something beastly to be conquered, with time travel as the means to borrow energy from the Dirac Sea, let its antimatter spread in the negative direction, and conquer it. It is a concept so foreign and unnatural to the world yet able to drag individuals back to their most natural form, one that acts on instinct, on emotion, and one that threatens the very people who sought power with their own agency and efficacy. How much control does one truly have over their life, how can one battle the passing crawl of the clock? Through the discontinuity of time, Landis is able to explore the role temporality plays in a person’s thinking and decision-making, how individuals granted with great power grasp it, and the lengths that people will go to when faced with loss.

[Kamakana · Rating 5 out of 5]

if you like this review, i now have website: www.michaelkamakana.com

200906: years (decades...) since i first read this, it has special, heartbreaking effect on me because my father really loved this story. as scientist- chemical physicist/physical chemist- he was often dismissive of artistic attempts to deal with science but told me this one was excellent. his sisters were both artists. this is best time-travel story i have ever read. father is now six months four days passed and all i have left of him are stories like this...

story:

http://dirac-sea.weebly.com/ripples-i...

[Laurel · Rating 4 out of 5]

This is a time travel based on real science - the concept of the Dirac Sea. The essential notion being that one can only ever go back in time, never forward. And therein lies the trap. Although I'm not going to say more than that.

It is well written and vivid, which drew me in, and as events unfolded - or evidence became apparent - sympathy for the main character grew.

This is ultimately quite a sad story, but it also shows someone who is living life to the max - in so far as they are able.

[Jennivie · Rating 5 out of 5]

Wooooow.... And now I understand why I have seen this pop up as the best time travel story ever. I loved it!

[harley · Rating 5 out of 5]

the fatal flaw of a scientist is faith in his own inhumanity. emotion as an encumbrance. subjectivity as a sin. it’s easy then, to say that the progress spilling from your fingers into a page of equations into a machine is just as inhuman as you are. in the wide dirac sea of forward-time-flowing electrons and backwards-time-flowing anti-electrons, you push inhumanity to its limits.

your actions itself are inhuman. no, maybe not your actions. but when you dip your fingers into water, are we wrong for expecting to see ripples? we’re supposed to leave traces of ourselves, so perhaps you’re right, your sciences are inhuman. the dinosaurs, the san fransisco fires. you laugh, vindicated. fine, where to next?

off you go then, living your anti-matter fuelled joyride. and honestly, with your particular flavour of disregard, it’s surprising that you found someone. you, Dancer, Lisa; motes crashing together living a feynman diagram of life. and you enjoy it don’t you? where’s your objectivity now, scientist? your omnipotence? can you continue to claim the sciences as inhuman?

you’re different now aren’t you, backwards-time-flowing anti-scientist? holding onto your backwards-time-flowing anti-inhumanity. are you just a man now? have you been thwarted by the concepts you tried to control?

because what you don’t realise is that time is our social construct, life is the constant. we’re sure you’re familiar with relativity, are you not? time flows in the way humanity frames it. and the way you frame it, 1965-1969-now-1965, you’re chained. you’re doomed and you’re in love and in a way, they’re synonyms because the framework of love begets an ending. and yet still you fight it. where’s your objectivity now, sailor? you flail against the rip currents of his death. and maybe just once you hope, even though you know it does not matter, that the tide abates and sand appears beneath his feet; he stands. and even as you’re pulled back into the sea, you can think for a minute that everything’s ok; and the waves crash down again.

dear scientist, if time is an ocean, instead of how wide, may we ask, how deep?

how deep can you sink?

[Glen Engel-Cox · Rating 5 out of 5]

One of the best time travel stories that honestly deals with the paradox with a simple physics explanation: what you borrow, you must return. So, yes, you can travel into the past, but nothing you do there will cause any change to the future. The plot that Landis hangs on this is nicely done, too, in a sense the ultimate nostalgia trip—for what else would being able to visit the past without making a change be?—with a very definite conclusion, even if it’s drawn out. To say more would take away from this clever and well-written story. Recommended.

[Andy Hickman · Rating 3 out of 5]

“Ripples in the Dirac Sea” by Geoffrey A. Landis

“My death looms over me like a tidal wave, rushing toward me with an inexorable slow-motion majesty. And yet I flee, pointless though it may be.”

Notes On The Theory And Practice Of Time Travel:
1.)  Travel is possible only into the past.
2.)  The object transported will return to exactly the time and place of departure.
3.)  It is not possible to bring objects from the past to the present.
4.)  Actions in the past cannot change the present.

“My professor in transfinite math used to tell stories about a hotel that had an infinite number of rooms.  One day all the rooms are full, and another guest arrives.  “No problem,” says the desk clerk.  He moves the person in room one into room two, the person in room two into room three and so on.  Preston!  A vacant room.
A little later, an infinite number of guests arrive. “No problem,” says the dauntless clerk.  He moves the person in room one into room two, the person in room two into room four, the person in room three into room six and so on.  Presto!  An infinite number of rooms vacant.
My time machine works on just that principle.”

“He had…as much wisdom as it has taken me a hundred lifetimes to learn.”

“Time travel is subject to two constraints:  conservation of energy, and causality.  The energy to appear in the past is only borrowed from the Dirac sea, and since ripples in the Dirac sea propagate in the negative direction, transport is only into the past.  Energy is conserved in the present as long as the object transported returns with zero time delay, and the principle of causality assures that actions in the past cannot change the present.  For example, what if you went in the past and killed your father?
Who, then, would invent the time machine?
Once I tried to commit suicide by murdering my father, before he met my mother, twenty-three years before I was born.  It changed nothing, of course, and even when I did it I knew it would change nothing.  But you have to try these things.  How else could I know for sure?”

[k · Rating 5 out of 5]

the best friend beat me to it so now my comment will read like a crappy paraphrase of hers... the way this actually rewired my brain though.. time machine stories are soo perfect because it's essentially a retelling of the prometheus complex (actually, all of sci-fi is just a variation of the prometheus theme, and this is a hill i will die on) (i lie it's not really but all the sci-fi /i/ like to read is) <333 the paradox of time travel is that it represents man's ability to subdue subjugate enslave time, to bend it to our will, but this sense of omnipotence is in fact an illusion because time is a tidal wave, and there is no way a single individual -- a mere drop in the vastness of the ocean, a pearl-diver stealing borrowed moments in the dirac sea -- can overpower such cthonic forces that came long before we were ever conceived into existence and will remain long after we die and there is no one to remember us at all... the moment of anagnorisis when we realise all we do is futile and nothing we do in the past can change the present really is the fruit of our hubris... one day i will stop trying to superimpose the tragic model onto everything i read but it is not this day xoxo

tldr: we are all slaves of time; resistance is futile, but the act of resistance itself is not

[Tobias · Rating 4 out of 5]

This one is a solid 4 star. Dude gave an introduction to Cantor's proof of "countability" and I'm all for it :)

I have a sense that it might be the intellectual predecessor of Steins;Gate. It certainly exudes a certain mono-no-aware in its style and frankly it's surprising for me to see an American achieving that.

As for non-linear narrative — it might be striking back in its days but nowadays it's hardly a merit. I mean, have you seen Garden of Sinners?

Character-wise, Ghost in the Shell remains my personal GOAT. It's a great sin of modern female not living up to the standard of Major Kusanagi Motoko and we are only 5 years away from 2029. It's also a great sin that the script of Ghost in the Shell SAC S01E02 didn't win a Nebula award.

I just realized how profoundly Japanese sci-fi and fantasy genre has shaped my taste in sci-fi, and I am proud of it. Despite the villainization of anime-watchers in current anglosphere political discourse.

[Gea Starling · Rating 5 out of 5]

设定也太棒了！好奇是不是在那个年代量子力学界的频繁突破给了太多营养，让基于它们的科幻作品繁荣绽放。

有着无限的时间却一点时间都没有。无论回到过去做了什么都无法影响当下，无法改变那条真正存在的时间线，却为了躲避死必须徘徊于过去。因为每次回到现实都无法避免用掉仅剩的一点点时间，所以就算是在时间机器给的无尽的可能性里也无法为所欲为。

Dancer什么都不知道却在一切事情上说的都是对的。之前从外部看我可能把它归因为那个年代嬉皮士们的特有文化，但是这个时间点恰好在我切身体会过通感和unity of everything之后，用zzf的话讲还是很有宿命感的。也是在zzf的事情上，"That won't solve your problem, you know".

人和人之间关系的细枝末节都被捕捉到了，像不知道是对Dancer还是Lisa的妒忌、Dancer的包容性、和Lisa对他预言Dancer死亡的责怪。我在搜索狄拉克之海的时候也顺便重温了一下Feynman diagram的优雅样子，虽然故事被我切割成了两半，去旅游之前和回程后的两天，整体读下来还是很让人幸福的。

[ran · Rating 4 out of 5]

that was so gay i felt like i was watching sk8 the infinity. some of the writing "i didn't know who i was jealous of" when dancer and lisa cuddled and "i'm living on borrowed time" ok just say you're an ao3 reader. like ten months into an obsession bc the writing wasn't that good but it was getting there. it was giving tags: 60s au, time loop, mcd, angst, like oookkkk landis

[hana · Rating 2 out of 5]

read for eng102

pretty writing but kinda boring im sorry

"that was when LSD was blooming onto the scene like sunflowers, when people were still unafraid of the strange and beautiful world on the other side of reality."

[Nicole · Rating 5 out of 5]

NOTES ON THE THEORY AND PRACTICE OF TIME TRAVEL:
1) Travel is possible only into the past.
2) The object transported will return to exactly the time and place of departure.
3) It is not possible to bring objects from the past to the present.
4) Actions in the past cannot change the present.

[Deborah · Rating 4 out of 5]

In The Time Traveler's Almanac.

[Marcus · Rating 5 out of 5]

A very scientific approach to science fiction. New and interesting view on the topic of Time travel.

[Tate Quinton · Rating 5 out of 5]

Best time travel short story I've ever read.
And I've read them all. Actually not all but
a lot.

[Riju Ganguly · Rating 2 out of 5]

A painful read, with all its speculations eventually going up in flames.

[s · Rating 4 out of 5]

read for uni

[Shuchi · Rating 4 out of 5]

“Time travel. It’s not immortality, but it’s got to be the next best thing.”

[Abhilash · Rating 4 out of 5]

Another neat little time travel story that speaks for fatalism and the futility of trying to change the past. I'm not building a time machine anyway.

[stelly welly]

Doomed yaoi

[Ella · Rating 5 out of 5]

also read for class. this one was really cool! talks about ideas of time travel and quantum physics relating to the modern world

[Jari Meevis · Rating 5 out of 5]

beautiful short story on futility and meaning.

[Heidi · Rating 5 out of 5]

I read this in The Time Traveler's Almanac. A very sad story, but I loved it.