I lean more towards there being more than one timeline. So at the point where you go back, another timeline starts to diverge from your original one, to a greater or lesser extent depending on your actions and their ramifications.

But, if there's only 1 timeline, if you are able to travel back in time, I think that makes the timeline fluid.

Right. The reason I don't believe in time travel is because no time travelers have ever shown up. (Unless you listen to Art Bell's radio show.)

Unless all the time travlers have done their traveling secretly and haven't announced themselves. Paul Auster's last book Oracle Night includes a subplot of sorts where the novelist character is asked to write a screenplay update of Wells's Time Machine. He comes up with some really cool scenario involving folks in the future going back in time once, on their 20-somethingth birthday, but they're not allowed to change anything or interfere with time. If they do, there is a whole team of people poring over history books and things in the future waitint to see if they change. If they do change, they can remotely terminate the lives of the time traveler.
Two travelers decide to prevent JFK's assassination, and they had some way of either facing their own death as a result or of getting out of it somehow. I forget how the whole thing plays out, but it sounded pretty cool.

If you haven't already, read Timeline by Michael Crichton. The book is so much better than the lame movie adaptation.

The finest novel I have ever read about time travel is The Man Who Folded Himself by David Gerrold (best known for his episode of the original Star Trek, "The Trouble with Tribbles.") I do not believe it is print, but it should be. It's a must read.

Anyway, Gerrold goes well beyond either Rule 1 or Rule 2. Can't explain, you must read it. There are some major questions, some unsettling, that the author raises--this is not a book for the immature--making this more cerebral than most of today's sci-fi, too.

Again, great book.

A great book not necessarily about time travel, but about being "unstuck in time", i.e., living in four dimensions: Vonnegut's Slaughterhouse Five - which definitely follows Rule 2

"(Unless you listen to Art Bell's radio show.)"

DUDE! Art Bell is crazy weird. There's some funny stuff on his site, if you can find it. I once found a linked site claiming that David Hasselhoff is the antichrist.

Here's the link!

I read one short story that *sort of* combines the two concepts. In it, time travel was just being discovered at a certain university high-tech lab, and was restricted by the extreme complexity and expense of the necessary equipment. At several critical junctures in its development, the main characters notice a strange temporary shimmering/waving effect in their surroundings. Eventually they realize that each one of these events is the indication of a major fork in the path of possibilities, and they notice its effects most strongly because they are near the 'epicenter' of the critical decisions. So they theorize that the structure of space-time is like a tree, with branches that represent all possible timelines.

p.s. My description doesn't do justice to the subtleties of the story. It has been several years since I read it, and I don't remember the title...

I subscribe to the many worlds theory of quantum mechanics proposed by Everett in the 50s (Everett is the father of E from Eels, if anyone cares about pop trivia).
In this model every outcome from a quantum event is persued, but I only experience one of them. In the endless cascade of quantum events, "I" follow just one of an extraordinary number of paths.

The upshot of this in a time travel scenario would be as Robert described in the first comment. I would backtrack through my set of events then optionally follow a new path from then on. It would appear to be a fluid timeline (like in Back to the Future -- except that Marty wouldn't disappear in the 1950s, he would just be a weird orphan; and his photograph wouldn't fade).

What you describe sounds a lot like the Star Trek episodes where Kirk crosses over into a parallel universe, that has the same people, yet it's different. Star Trek: Deep Space Nine did some crossover episodes into the same universe Kirk had gone to.

Yes, I think the original startrek may have been consciously exploring Everett's idea.
Has anybody seen the futurama episode "the Farmsworth Paradox"? Not strictly time travel but an excellent romp through multiple universes.

Relativity gives us another way to view time travel, which I think leads one more towards the fixed time-line point of view. Under this kind of physics, we would need to build some kind of device to receive visitors from the future -- which would explain why we haven't met our future selves, since we haven't built that device yet. I prefer many-worlds because I understand qm better than relativity.

The problem I have with most time travel stories bound to Earth, is that the earth does not keep still -- the time traveller would need to work out the position of the Earth at the time he wants to emerge. I try not to let that get in the way of a good story though.

Time Travel
Thinklings have posted the question, What If Time Travel Were Possible?
If you have ever read any sci-fi dealing with time travel there are normally two possible outcomes from going back in time. You either directly influence your timeline or you cre...

I'm not sure how the in-between option is really a view about time travel. It's fatalism. There are certain things that happen no matter what and others that don't. The static time view says you can only fulfill the past but not change it, because it's already true that it happened that way. (I'd say the same about the future, by the way. It's true what I will do, and I can't change that. I can and will affect what will happen, but I can't change what will happen.) Fatalism is a very different idea, that only certain things are guaranteed to happen. This seems to be what the Terminator movies have gone with by the third film. The only way I can make sense of such an idea is if a divine-like being is ensuring certain events without caring about others, but it also requires the first view of time where the past can be changed (which I don't understand philosophically at all to begin with, but that's irrelevant to my point here). In other words, the in-between view is basically view 1 + fatalism, not something between the two views.

Jeremy: I hadn't thought of it in those terms. Very interesting.

Jeremy,
Thanks. I think we agree. I hadn't quite thought of it that way before either. I think you're right.

If you enjoy time travel in fiction, Check out "To Say Nothing Of the Dog" by Connie Willis. IMHO, the best treatment of time travel I've seen in fiction (plus, it's very well written and amusing). Definitely leans toward rule #2, but not 100%.

Also, "The End of Eternity" by Issac Asimov and "Pastwatch" by Orson Scott Card are pretty good. Both lean more toward rule #1.

But in Back to the Future -- and in Bill and Ted's Excellent Adventure -- they don't break the rule set forth in the adage. I think it's great when they DO meet themselves, especially when it happens in the beginning, before they even know that they're going to be time-travelling. I like the combination of Rule 1 and 2, where people try to change the future by going to the past, but find that the present they had occupied before had always been affected by their time travel anyway.

But the all-time best was Homer Simpson with the time-travelling toaster in Treehouse of Horrors.

Warren

Shanti Shop

If time travel were possible,where would you go,and when?

Peter, Thanks for stopping by. Here are just a few:
1- Jesus' time and place
2- AD 70 Jerusalem (if I could be invisible and not subject to slaughter)
3- 312 AD- Battle at Milvian Bridge- to see for myself what Constantine saw.
4- Time of Noah- if I could get a ride on the ARK, to see if flood was worldwide or not.
5- Time of Jonah- to see him get puked out, and to hear his sermon.
6-October 31st- Church at Wittenburg, Germany, to see the look on Martin Luther's face
7- Church service where Jonathan Ewards first preached "Sinners in the hands of an Angry God".
8-1941, Roswell, New Mexico- Aren't you just a little bit curious? I'd want to see what really happened. :)
9- 1972- hospital room where I was born - to see and hear my parent's reaction when I was born.

What about you, Peter?

#6 above- year is 1517.

I think I'd want to solve all the mysteries. So how about Dallas, November 22nd, 1963? I'd be sitting in the grassy knoll with camcorder.

(Note: in all of the above my assumption is that I can't change history. I could only observe it.)