Time Travel discussion

"Ripples in the Dirac Sea" is a Nebula-winning story written by Geoffrey A. Landis.

*Story text available online: http://diracsea.net/ripples-in-the-di...
*Printed in The 1989 Annual World's Best SF
*Printed in Hugo and Nebula Award Winners From Asimov's SF (1995)
*Printed in The Best Time Travel Stories of All Time

The story explains the concept of the Dirac Sea, but it might be worthwhile to otherwise familiarize yourself with the theory before reading:
http://en.wikipedia.org/wiki/Dirac_sea. This phenomenon in the story allows for the time traveler to never be able to change anything in the future during his time travels. Therefore, nothing he does in the past has any consequences whatsoever.

Pre-Reading Question
1. If you could go to the past and return to the present multiple times with the knowledge that nothing you do can affect the future, what types of things would you do?

Post-Reading Questions
1. What do you think about this this theory?
2. What types of experiments would you perform under these circumstances?
3. How many stars do you give this story?

Pre-reading Question:

The only real change you could have on the present from the past would be the knowledge you brought back. I guess that opens the doors to time tourism without the risk of paradoxes etc. I think I would spend a lot of time reading in the past and still have all the time in the present.

I like the idea of a negative universe...I think its interesting and related to dark matter. Its out there we just can't see it. The theory of adding and taking away from infinity boggles my mind a bit but I can see the science in this clever science fiction.

I like to think of the universe more as a balanced equation. If you take away X on the past side of the equation, you also have to take X away on the future side o the equation. I can hold the theory of the Dirac Sea in mind for time travel just long enough to think it's beautiful nonsense.

Pre-reading:

Catching up on reading and other activities, if possible, sounds like a good idea. Also witnessing historical events, or spying on our parents when they were young, would be fun.

Pre-Reading Question:

I like the idea of catching up on reading and also having time for my other great passion - listening to classical music.

On a not so selfish note to try and make a difference for those I came into contact with - whether voluntary work or using the time in the past to train for a different career.

Post reading Question 1:

What do you think of this theory?

I came across the Dirac Theory and the discovery of the positron which gave experimental proof of the Dirac equation when studying for my degree. However, I think it is stretching the theory a lot to postulate time travel into the past from it.

Landis's story however is where in my opinion good science fiction goes - it uses scientific fact and extrapolates to ask the what if question.

Being written over 25 years ago it was in a sense state of the Art then and recognised as such by the SFWA in that they awarded it the Nebula for short story in 1989.

Post reading question 3:

I would give the story 4 and a half stars reading it today, but if I'd read it in 1988 when it was first published in Asimov's Science Fiction Magazine I have a feeling I may have given it 5 stars.

I thought it was a really good story - lots going on, a plausible scientific theory. It's also somehow believable that you could only go back in time and return to your present moment.

I particularly enjoyed (view spoiler)[the scene where he want back to try to see the crucifixtion and got beaten up and left pretty much for dead. Waiting days to see a dinosaur in the age of the dinosaurs also felt real. (hide spoiler)]

If I could go back in time without affecting the outcome of the future, I would go back to do loads of things, and probably some pretty stupid ones simply because I could and there would be no consequences. I could become the town slut or try every drug I could get my hands on or get revenge against my enemies or rob people or whatever I wanted to do. When I first read (view spoiler)[that the narrator went back and killed his own father just to do it, I was shocked, but when I thought about it, it makes sense to experiment by doing crazy things, because he wouldn't have to answer for his actions, other than in his own mind. (hide spoiler)] The only thing I wonder about is if you went back in time for too long too many times, wouldn't you age in the future? Could you die in the past, or would you always return to the present?

I had a hard time wrapping my head around this theory entirely, but I think it is a very creative and logical way of presenting time travel. I enjoyed this story and would give it 4 stars, possibly 5 depending on whether it lingers with me over time. I didn't just enjoy the time travel experimentation but the complexity of the characters in spite of the small amount of exposition.

Loved this story. Loved the theory behind it. A theory that does not come in much in time travel yet makes a beautiful kind of sense to it. Four and half stars for what I thought was absolutely brilliant story. I love the predicament our time traveller falls into (Trying to be spoiler free) and essentially traps him. Fantastic.

Hmm. I, personally, found it a bit pretentious, going into all that depth describing Dancer's decor, for example. It came across to me as one of those 'extended metaphor' devices that just don't appeal to me.

Otoh, I did like the mechanic of nothing you do in the past changes the present that you return to.*

I think probably three stars.

*Questions for clarity, though. Well, clarity w/in TT, fwiw.

What if he'd stayed in the past years and years and 'caught up to' the present? Or did he try that and I missed it?

Did he take Dancer into the farther past? I simply couldn't untangle all the pasts.

Good Questions Cheryl,

dont think he attempted living into the present and past. I think he probably should given the alternative.

But given the laws of conservation of energy he can't be two places at once...but than again we are talking about making room from infinity so why not?

If he couldn't be in two places at once, how did he keep going back and trying to prevent (view spoiler)[Dancer's death? Or going back to relive their first meeting (hide spoiler)]?

Pre-Reading Question
I would visit famous events that are the subject of controversy. Like famous killings (Jack the Ripper) or events. You could save the Library of Alexandrea, over many lifetimes of time traveling, by this method and scanning of books into digital.

1. What do you think about this this theory?
The problem is that, as I understand it, time is an element that is added to equations, but is not necessary. Given that, I don't think the conservation of matter issue is even relevant.

But the entire poof-it's-gone effect on a timeline seems a bit... well... magical. It certainly doesn't seem scientific, so much as: well, it's gotta be something.

3. How many stars do you give this story?

I hate objective scales of subjective experiences. However, when in Rome...

3.5 out of 5 seems good.
I enjoyed it, and that was a nice twist that I'd never seen, before.

(view spoiler)[Note: not the need to return to the place you left, which I've seen, but the fact that you have only seconds to live and must always return to that moment (hide spoiler)]

I have to admit it loses, a tiny bit, by being fatalistic about choice. Downer and philosophically annoying, to me.

I also just realized that there's no reason to assume that he could even die, in the past.

Coming to the present means that all changes in the past are restored and nothing he does in the past can change the present, thus he can not have died and is still alive.

Imagine the holiday pitch:

Historical Death Tours!
Experience what it was like to die on the Titanic, the Hindenberg, the Lusitania! Have your head chopped off during the French Terror, be burned as a witch, by the Inquisition! You die the way you want to die. As often as you want!

Also (and pardon the volley of posts), the fact that you can bring back images and memories tells me that the theory is bunk... even in the world of the story.

If the story world were consistent, then he would never remember a single trip and the camera would have come back blank.

Gosh James. I almost liked the story - until you pointed out all those problems with it! I love the idea of the Hist. Death Tours... lessee, I want to be guillotined with the French nobility - not!

Heh. I still enjoyed it, though. All time travel stories have problems. Nature of the beast.

I really enjoyed this one. Even if the time travel theory doesn't hold water, few do, so I give that a pass. What I really liked was that the author contained the story so well. Short stories are tough and when you give the character seemingly infinite time, you have to counterbalance that with limitation. It's a hero's limitations that make him or her interesting. Superman is a boring hero without Kryptonite.(even then he's a bit dull because we know he'll win) We need to know what the hero authentically fears and how make them face it. The genius of this story is that what makes this particular hero powerful is the exact same thing that limits him. Time. I think that was brilliantly done. What is nice is that the same thing that limited the character also ends the story. It has the same symetry. All the time in the world is competing against fleeting seconds that can never be got back. We don't need to play the rest of the moves, we've already seen the checkmate.

Solid writing. The structure alone warrants 5 stars from me.

Well, yes, I see your point, Nathan.

But, and I'm speaking strictly for myself here, I have to be frank: often when I read something that other good writers vocally admire, it's turns out to be something I don't particularly enjoy. Telling a story skillfully isn't enough, for me, I've found.

Pre-reading question answer: As long as I could remember my visits, I think I would like to go back and learn to play lots of instruments. I currently play the Ukulele and enjoy music immensely. I also would like to go and see some historic concerts, maybe attend the opening night of Stravinski's Rites of Spring (the one where the audience rioted!) That would be fun. :)

Cheryl wrote: "*Questions for clarity, though. Well, clarity w/in TT, fwiw.

What if he'd stayed in the past years and years and 'caught up to' the present? Or did he try that and I missed it?

Did he take Danc..."

Hi Cheryl. I had to read the story twice to unravel some of my confusion. Still confused about 1 thing but as far as catching up to the present, he can't do that. (view spoiler)[Wherever he is, when the instant he left the present approaches, he vanishes and returns to that moment. He can't go beyond it. (hide spoiler)]

Post reading question answers:
1. An interesting theory. Can' say I understand it but interesting.
2. No idea what kind of experiments to perform. Maybe send a worm back an hour and dissect it in the past? :(
3. I read this story twice. The first time I would have given it 3 stars but after reading all the comments on here and then re-reading he story, I would give it 4 stars. I liked the descriptions of (view spoiler)[the time period of the 60s-70s.Having lived during that time it rings true for me. (hide spoiler)]

Some confusion about the story:
(view spoiler)[
1. It is mentioned by Lisa that the time traveller caused Dancer's death. How?
2. Why is the time traveller running out of time? He says he has only about 10 seconds left and it gets less each time he returns. I don't get that.
(hide spoiler)]

Thanks for clearing one confusion for me, Glynn, and adding another. I know TT can't *really* make sense, but I'm just not happy with this story. Maybe I should reread it again, now that I've seen discussion and time has passed. Or maybe not.

Glynn wrote: "Some confusion about the story:

1. It is mentioned by Lisa that the time traveller caused Dancer's death. How?
2. Why is the time traveller running out of time? He says he has only about 10 secon..."

Each time he returns he just sets the machine again to travel into the past. I think eventually he has to go back to the present and when he does he just skips back somewhere else. Each time he is in the present in the hotel room he has to set the machine and that is what's using the time. That was my interpretation anyway.

I agree about him setting the machine in the present uses up valuable seconds each time. Psychologically this must play on him as he approaches the time when he will be in the hotel room.