posted
Reading the words "Time travel" got me thinking:
Time travel is a huge thing in literature and entertainment nowadays, but it's almost consistantly interpreted in a completely different way from place to place.
Sometimes, the character can move through time without having to worry about changing the present. This assumes that what happens in the past includes the changes time travellers could possibly make with future or present trips back in time. An example of this is time in the Harry Potter books: when Harry, Ron and Hermione go back in time in book 3 they already done what they go back to do. Presumably if they were stopped by someone, there would never have been any time travel in the first place. This seems to be a form of post-destined past in which everything relies on the final outcome somewhere infinitely far in the future.
The other form of time travel is the opposite and is the Back to the Future form of time travel. Marty, Einstein and Doc's major past actions can change their present and future. The past is not post-destined, although their minor actions seem to have no effect. Instead it is pre-destined, where everything stems from a distant set point infinitely far in the past. (In these movies though, especially the second two, there are major problems, but they deal with the future)
There are some that seem to mix the two forms of past. In Star Trek (IV) the Voyage Home the past seems to have both happened and not happened. Although it is clear that they do things to change the past (introducing Transparent Aluminum for example) that clearly, short of a miracle discovery that day without the interference of the Enterprise crew, haven't happened by the time that the crew goes back to, it has no apparent outcome on the future. Although this seems impossible this site gives a very detailed and extremely confusing description (towards the bottom of the page) of how this can possibly pan out. I still don't understand it myself.
So what is the state past? Is it a post-destined, unchangeable entity, a flexible completely pre-destined entity or an extremely complex both pre-destined and pre-destined looped series of events? If time travel is ever possible, which will be the past the we can wade through? If the post-destined and pre-destined "end" and "begin" points are infinitely far away/ago, what does that mean for time?
What are your feelings on the state of the past? What is the past for you? Is it fixed or flexible, complex or simple?
Interesting disections on the past can be found at this site which takes apart some of the movies I mentioned and many more that I haven't seen but you may have...
Posts: 8473 | Registered: Apr 2003
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posted
If I went back in time four years and burned the Florida ballot boxes, would Skippy still be president?
Posts: 279 | Registered: May 2004
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My feeling is that if time travel backwards is possible, it would be possible to "change the future." Of course, the future would have "always" happened the new way.
The problem is, we don't know how time travel might become possible, and we don't know what time travel actually means. Disrupting the past, vs completing the past. No one really understands how time works, and so we can't really have a good working theory on what time travel backwards would do to futureward events.
If anyone remembers my old handle, Everard, its from a series of stories by Poul Anderson that explores how time travel might work.
Posts: 4112 | Registered: May 2001
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When I was younger I remember standing on Bunker Hill and thinking that the only thing separating me from what happened there 200 years ago was time. Now I realize that in order to go back to 1776, I would also have to go backwards the distance the earth has hurtled through space in that time. Sure, you can sit in the same chair George Washington sat in--but in reality you are millions of miles away from the actual place where he sat.
I know this is a very simplistic way of looking at it, but it helps me understand just how unrealistic the concept of time travel really is.
Posts: 107 | Registered: Jan 2004
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posted
I was reading the Lewis & Clark journals the other day....
<----- Dork! Ha ha ha!
Hey, shut up, it was for work.
*snicker*
Anyway, and I read the accounts of their trips through our valley and realized that the geography and plant life were a lot different, and things changed drastically after settlers started irrigating. And this was just 200 years ago!
And this started me thinking that Place (I capitalize it because I mean the concept of) is really very impermanent. Whenever we like to feel inspired about walking the same ground as some famous general or an ancestor or Jesus walked... we're probably walking on ground 20 feet above or below the actual ground they walked on - the plant life and climate are all different... the only things the same are really prominent mountains, and in geologic time those are just as transitory.
And then I started thinking about how no cell in our body is older than 3 years, and how physically, I'm not the same person as I used to be... and then I wondered about us being digital entities.
And then my brain started to swell again...
Posts: 8504 | Registered: Aug 1999
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You know...if gravity keeps you on the planet no matter how you move around in three-space, why shouldn't gravity hold you to the ground while moving in time? So I would think that losing Earth, at least, wouldn't be a problem. (Of course, that's as much speculation as anything else.)
Maybe that's the explanation for the mysterious phone call when mom claimed I said I had to go because I was meeting some girl...whose name I'd never heard.
Posts: 1114 | Registered: Mar 2004
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posted
Losing earth wouldn't be a problem--getting the earth to "go backwards" with you would be. If you went back in time alone, and everything else didn't, then the earth would already be gone. Make sense? My point is that space and time are so intertwined that in my opinion you would need the ability to move very large objects very long distances at a impossibly rapid rate to get it to work.
Not only that, but the earth would have to be in two places at the same time. Could you take the earth back to the past without destroying the future?
posted
What if there is no time to travel back into?
Causualty without time is being postulated now, but I have no linky to support it.
Also without support, I read a few years ago about a technique involving singularities that would work, but should anyone do it, it would destroy the universe.
We really don't know what time is.
However, as a literary device, the sub-genre was almost inevitable. Science Fiction is often an excercise in extrapolation. Most time travel stories are extrapolations from changes in events, and rather than physics and astronomy, relies on history and sociology as the science. Although I couldn't describe how it could be done, the idea of writing these plots becomes very appealing.
Posts: 1843 | Registered: Aug 2003
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posted
as for the movement of the planet in time travel, check out (can I say this here?)Piers Anthony's Immortality series novel on Chronos. It gave an interesting explanation that (very basic summary) you have to compensate for the motion of the planet when you travel back in time, becuase the universe is constantly expanding. It's more detailed than that, but I have a liberal arts degree and I'm not allowed to elaborate or postulate further... Posts: 262 | Registered: Jun 2004
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posted
What I'm saying, Shepherdess, is that the Earth exists in the past (if there is any past to exist in, anyway) and is continuous with the Earth of the present. Maybe if the method of time travel involved a discontinuous "jump" back to whenever, that would be a problem. But if you are moving continuously into the past, then the Earth remains beneath you at all times. Unless you're traveling back so fast that the Earth recedes from you/you from the Earth at escape velocity, why should you get disconnected?
Posts: 1114 | Registered: Mar 2004
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posted
Mabus, I guess we view the earth a little differently. I believe that the earth did exist in the past, but that it no longer does. If you traveled back continuously to the past, along with the earth, then what about everyone else on earth? Do they travel back with you? So, when you get to the past, are they there with you? Then that would just be the future, wouldn't it? The way I see it--there is only one earth, and it only exists here right now. It came from the past, and its travelling to the future, spatially as well as chronologically, because they're really both the same thing.
I'll admit, these conversations make my head hurt--but then I'm not an astrophysicist, so my understanding of this is superficial at best.
Posts: 107 | Registered: Jan 2004
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posted
Well, viewed that way I can see why you would arrive to empty space--from that perspective nothing actually exists in the past at all. But then motion would have nothing to do with it.
I imagine the past as a continuous set of frozen moments, myself. That is, somewhere in it there is everything I have ever done, along with the whole setting, including the planet. Only my consciousness is moving toward the future.
Posts: 1114 | Registered: Mar 2004
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posted
Mabus, I think I understand what you're saying, it's just a completely different perspective from mine. The way I view the universe, the only way you could travel in time would be to be so big that you could defy space itself. I can't separate time and space in my mind.
Oh, and Gryphonesse--I haven't read Chronos yet, but I'll definitely look it up. I'm always up for "very basic summaries!"
posted
my guess is we will never see Time travel, even if was possible, governments would not allow it to exist. If anyone started messing with it, the government would take it over and kill the person before they could announce their discovery. It would just be to dangerous to governments if you could alter events in the past
Posts: 1901 | Registered: May 2004
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posted
Are we three dimensional entities moving through a 4th dimension time, or are we static, 4 dimensional entities, and our perception of time is merely a curious effect of our current inability to precieve the 4th dimension upon which we think we're traveling, but in reality, have already arrived?
Point a, represented by an astrix, is living in a 1 dimensional world, it can only move along a line. Here's our poor, restricted point a:
code:
-*--------
That's him on his single line at a specific point in time. Only he decides that even if it isn't much differen't, he's like to check out the other end of the line, so he moves (taking time to move of course, he's no instantaneous) and now here he is:
code:
---------*
We can see his movement either as a series of one dimensional movements, or we can put them together to create a two dimensional world, where time is the second dimension like this:
That's his two dimensinal view, entirley static since instead of viewing a series of time-frames, we're seeing time represented as an actual phsyical dimension. the thing is, we're 3D, so we can see those two dimensions, but poor, repressed point a can only see in his one dimension, that's why he sees himself as one dimensional (and why the girls don't like him), he can't see the time dimension, so he has to see a series of one dimensions to approximate the 2nd dimension. So really, if he saw our little 2 dimensional plot of his one dimensional world, he would see it in only one dimension (project from 2 to 1), and so it would look like this:
code:
-*********
He would see a continous line of... him! And that is what we would be if the universe is a 4 dimensional entity, instead of three dimensions with this odd time dimension thrown in as something completely seperate. A series of 4 dimensional static movements, but as 3D creatures we can only see our 3D selves, and thus we would see blobs of us scattered across the globe, following our travels and trials, each from meshed into the next in a continual path of life that spread itself through all 4 dimensions, and traveling back in time may confuse the image but would remain unrestricted acess in the 4 dimensional realm, causation becoming meaningless.
Which touches upon two things, one is that time travel, would probaby not be a jump, it would be continious. Just as you can get from point a to be without traveling through an infinite number of interlaying points (no matter how close a and b are), so you could probably not travel through time in jumps, but with a constant velocity.
And point 2, time is odd in that it may be a linear dimension of three dimensions, but it is the only one in which one point could never mistaken for another. In other words, time is the only dimension in which direction is evident. Which is very, very, very odd. It's the qeuivelant of saying, whenever you move to your left, your mass will decrease, and whenever you move to your right, it will increase. All the time, no matter what (reffering to increase in entropy here). How odd time is.
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