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Vincent
21-06-2003, 22:19:51
I read a lot of books about time travels. I know the idea of time travel is interesting when you are interested in history, but it's lame if you want to know technical details. Plus I'm an idiot about the "time". But some points made me wonder.

I always thougt it would be cool to build a complicated "time machine" and invite some friends. You tell 'em: "This machine works. Come back tomorrow and I'll show you". The next day you say "Well: I was here yesterday, I'm here today, so I travelled in time! It works".

Obviously we travel in time. From that experience we know two (OK, a lot more) concepts:

1. Places are unique
2. "Semantic places"

The idea is
1. If I go to bed at 23:00 and sleep 12 hours, I wake up in my bed at 11:00. My bed is still my bed. This works, I tried it!
2. I can name a time and place and the place exists and you can be there. Example; CG meeting in Schweinfurt Hauptbahnhof on 13. August 2004, 14:00. This concept also works. It's good for making appointments and showing holiday pictures.

The corresponding concepts of time travels I found in movies and books in several variations are

A. H.G. Well's Time machine principle)
B. The Time Tunnel principle

A. means, you got a machine in a room. If you use it, you move forward and backward in time, but you stay in that room (the unique place).
B. means you can travel using a date and a place, like "Center of Stonehenge, 263 AD, April 16 15:00" (the semantic place)

I never found an explanation if it's really so simple. If you go to bed and sleep 12 hours - are you really in the same place? No, because it's day! So the earth has turned 180! And the earth has moved along it's path around the sun. And the solar system has moved.
Think about in a time machine on a train. If you move back 5 minutes - where will you be? Where the train was 5 minutes ago? Or will you be outside the train, the spot where the train was when you started the time travel? (In that case you got 5 minutes to push your time machine away from the railroad tracks) If you stay inside the train, what will happen if you travel back 200 years? The train did not exist then!

The problem with the semantic places is that it's hard to find out where these places are. The top of Mount Everest 2 Million years ago. The mountain did not exist like it exists now. If you use a "place" as a description, where will it be, especially in the future? What if erosion destoyed the mountain? What if you will materialize in a tree, building etc? It's the same problem like the unique place, but even more complex.
"My bed" in 3 years. Will it still exist? Where was it a year ago? The place (room) where it is now existed, but I don't know what it was like. And 200 years ago even the room did not exist.

So I think it's a good way to use the good olde Mark Twain method of "A Connecticut Yankee in King Arthur's Court": Undefined wonder ...

Funkodrom
22-06-2003, 09:35:55
Good points. Don't know what to say about it but I agree.

Dyl Ulenspiegel
22-06-2003, 09:50:24
"If you go to bed and sleep 12 hours - are you really in the same place? No, because it's day! So the earth has turned 180!"

Read Rosendorfer's "Briefe in die chinesische Vergangenheit"?

chagarra
22-06-2003, 14:37:50
Good theory.... But.

Unfortunately time does not exist.
What is generally considered as time, is history.

We exist in that quantum state fermi second,like a standing wave, between the future, which doesn't exist but may develop out of the aether, and the past, which has already occured and is already set in stone.

The only alternative is the multiple choice parallel universe theory, where all things are possible.

Sir Penguin
22-06-2003, 18:18:45
You think.

SP

chagarra
22-06-2003, 22:46:51
always....

Guy
23-06-2003, 13:16:30
Christ, Monday morning and the first thread I try to read here is this one.


I'm going back to bed, regardless of where or when it is.

Bob
23-06-2003, 13:19:32
What if you are orbiting planet work?

Guy
23-06-2003, 13:31:57
Escape velocity has been reached, now cruising towards the Apathy Nebula.

maroule
23-06-2003, 13:53:18
Originally posted by chagarra

The only alternative is the multiple choice parallel universe theory, where all things are possible.

we are already in such a parallel universe
in the normal universe, I'm a highly successful football player. I know it, I just know it.

Vincent
23-06-2003, 17:28:33
In the other universe "football" is a term for "anal sex".

Dyl Ulenspiegel
23-06-2003, 18:09:10
So they have "Why Maroule must be footballed!" threads?

BigGameHunter
23-06-2003, 23:17:28
I don't think time travel is possible. If it were, somebody would have colossally fucked everything up by now, somehow, and I mean WAY more fucked up than it is now.
You wouldn't have rich people, you'd have some God-Emperor type and we'd all be enslaved and castrated or something.
Now, it may be invented in the future, in which case we may be currently dodging a bullet, and suddenly *pfft! zap! bloop!* everthing will change and it will be Mad Max or Soylent Green of a giant amusement park world all of a sudden, but since it isn't, and since I refuse to believe this mundane and rather trite existence is the product of someone's god-like power, I doubt it has/will happen. Actually, will (might) I guess is a ot more of a possibility than has.
Read or watch "The Lathe of Heaven" by Ursula K. Le Guin. Similar paradox trotted out, only it's a guy whose dreams come true instead of time travel.
And if it does happen, I think it will happen in more of an Altered States genetic memory fashion than any kind of dipsy-doodle lounge chair with light bulbs attached that transports you somewhere.

Qweeg
24-06-2003, 11:30:05
I think future history is as set in stone as past history, it's just that there is no way for us to percieve it accurately, all we can do is make predictions based on current trajectories. I think human conciousness only exists in one direction, following a causual path through existance, however that does mean that what we are not capable of being concious of (5 hours/billion-years in the future, or 5 billion light years in that direction at this very instant) does not exist right now.

King_Ghidra
24-06-2003, 12:55:06
So everything is pre-ordained? Perhaps, but only in the sense that 'well the sun is composed of x amount of gas and is using it up at x rate so will burn out in x years'.

I don't think i'm pre-ordained to do 'x thing in x years', but i can say with a reasonable degree of confidence that i will be working late tonight, for instance.

But do those things (the sun going out, me staying late at work) exist now? No. And after they have happened will they exist? No.

Qweeg's argument seems to imply that just because something can't be seen/experienced/measured/whatever now, doesn't mean it doesn't exist. Hmm...same argument for the existence of ghosts, aliens and elvis...

Qweeg
24-06-2003, 14:34:12
Not at all, it's like living in a flat universe, by definition creatures in a flat universe will be unable to concieve of a three-dimensional universe, and therefore would naturaly respond to the idea that their incomplete one-dimensional existense is part of a three dimensional whole with words like 'Pah!', 'Proposterous!' and 'What Nonesense!'

To put it another way, everything that is going to happen has already begun. Therefore the history of everything that is going to happen already exists, and nothing exists unless it has a history (stuff don't just appear from out of the blue). The history of your decision to wear whatever you will wear on the seventh wednesday of next year already exists, (so long as you're still dressing yourself by then) even though nobody currently knows what the last few months of that history will consist of.

You're just not giving the 'medium of existence' itself credit for the fact that it 'knows' all the things we can't. We're human beings, just because there are things we could never know about, don't mean they don't exist right now, including the future. You appear to be saying for instance, that the dark side of the moon didn't exist untill someone went and looked at it, thus creating the dark side of the moon there and then.

As for goblins and elves, what I'm saying has nothing to do with proving that kind of thing, and I find your assertion kind of solipsistic.

Qweeg
24-06-2003, 14:39:37
so nyur :p

Qweeg
24-06-2003, 14:51:41
Vincent, if you travel back in time, that means the whole universe goes back to how it was... including you sitting in the train where it was on the tracks.... but that would also mean your neurons and synapses would be exactly how they were, so you wouldn't even know/'remember' that you went back in time? I could have travelled back in time just now, and not even know! *twilight zone music twilight zone music ...*

BigGameHunter
24-06-2003, 14:57:04
You would if you were in a Time Bubble!

King_Ghidra
24-06-2003, 15:15:23
i've heard the 2d/3d universe argument before - it wasn't convincing then, it isn't convincing now - the experience of someone inhabiting a theoretical 2d universe might sound great as a metaphor, but as an argument for scientific fact it's worthless (unless you know of any 2d universes we can use as examples)

no i am not making the argument that something does not exist until you can see it, i am making the argument that something does not exist simply because you can imagine it - there has to be a combination of imagination and measurable reality (to take the dark side of the moon as an example, anyone who knew that the moon was a sphere could reasonably assume (through induction) that there was a dark side of the moon and phtographing it is a nice way of confirming it)

in the case of your theory of the future and the past existing 'now', you have theory (imagination) which cannot ever be substantiated or (conveniently) disproved.

i raise the ghosts and aliens issue because it is the same logic:

'if you can't prove aliens don't exist then they do'

to that i say habeas corpus

Dyl Ulenspiegel
24-06-2003, 15:16:43
$-) $-) $-)

Funkodrom
24-06-2003, 15:46:17
The 2d creature being unaware of the third dimension which they travel through and us as humans being three dimensional creatures who can't comprehend the fourth dimension (time) which we travel through. Is a very common scientific metaphor which I think works because all it's telling you is that when you start thinking about "time" you have to forget everything you instinctively know and understand about it.

In other words, we can comprehend going forwards and backwards in time but we don't have any frame of reference, or even terminology for going up and down in time or sideways in time.

Also what we consider moving forward and backwards in time is only really valid for a given observer. For someone somewhere else in a different situation it's meaningless. The only reason we have this simplistic view is that for humans the differences between what different observers on this planet can see are undetectable.

King_Ghidra
24-06-2003, 16:39:19
Originally posted by Funkodrom
In other words, we can comprehend going forwards and backwards in time but we don't have any frame of reference, or even terminology for going up and down in time or sideways in time.

isn't there a good reason for that, i.e. it ain't possible?

BigGameHunter
24-06-2003, 16:47:42
So our travel through time is not a point on a line so much as it is a surfer on a wave.

DaShi
24-06-2003, 17:20:13
1. Vincent, when you wake up it is a different bed. Beds don't travel through time. The bed you wake up in may look very much like your bed but older looking. There's a different you too.

2. BGH, someone did travel back in time. That's why everything is so fucked up now.

BigGameHunter
24-06-2003, 20:00:13
I don't buy it...someone with that power would be akin to Hugh Hefner or someth--hey!

Funkodrom
25-06-2003, 08:58:16
Originally posted by King_Ghidra
isn't there a good reason for that, i.e. it ain't possible?

I think it is possible but the words up/down/sideways are irrelevant.

Let's stick with the 2D 3D thing because I think it helps, helps me explain anyway...

Imagine one of those 2d maze puzzles you get in puzzle books. You have to trace your way through the maze to the middle. We've got our ubiquitous 2D creature, put him on the maze and get him to find the middle. No problem.

Then we put the same map on a dome. Our 2D creature happily solves the maze as before thinking it's an identical maze. But we from the outside can see that his height has changed in the mean time.

OK, now imagine a person standing on the earth. Time is moving for them just as it always has. Suddenly the person disappears and randomly reappears on a rock which is shooting through the solar system at close to the speed of light. In their perception they keep moving through time just as they always did. To an observer back on the earth though, time appears to be running slower for the guy on the rock. Conversely to the guy on the rock time also seems to be running slower back on earth.

Maybe that is a move 'sideways' in time. Perhaps if we could properly see in 4 dimensions it would be as obvious what has happened there as it's obvious to us that the 2D creature has moved vertically when solving the maze on the dome.

Right, so that's special relativity. General relativity tells us that time also moves differently when you are accelerating. If your speed is the "sideways" motion of time maybe your acceleration is the "up down" motion. But those terms don't have any real meaning.

That's a very over simplistic overview anyway.

chagarra
25-06-2003, 10:15:01
Where are our metaphysics guru's when you need them.

Special relativity simply states that our rate of "the recording" of history, commonly known as time, changes with our relation relative to the limit of movement variation in this universe, otherwise known as "C".
If we could reach that limit, the obvious logical conclusion would be that we would no longer be in this universe.

Since we already have a very complex movement relative to the earth, relative to the sun, relative to the ........... universe.
Could somebody please stop the world, I want to get off.

Qweeg
25-06-2003, 11:29:16
Ghidra, okay lets use some imagination, imagine if you will a sentient tree.

Lets not think about how a tree came to be sentient in the first place, lets just say that it grew up where it grew, spends its entire life stuck to the same patch of earth from seedling to big fuck-off sequoia.

As far as this sentient tree is concerned, the universe is tree shaped, all energy comes from the vast leaves-shaped surface at the top end, all water and nutrients magicaly appear from the vast roots-shaped surfaces at the bottom end, and that's the universe according to this sentient tree.

As far as the tree is concerned nothing exists at all outside the shape of its own inner surface, no other space exists, there is nothing outside of its own reality.
The tree can't say how the water/nutrients/energy appears in its reality, it is impossible for tree to say, because in fact (so the tree believes) water/nutrients/energy doesn't exist until it's appeared in the trees tree-shaped universe, by definition.

Effectively the tree IS the universe, and anything outside of the tree-shaped universe is pure wild speculation and completely outside of existance. And if the tree decided to believe that there is existense beyond itself afterall, then yes, the sentient tree may as well believe in sprites and fairies too.

So applying my unreasonable and overly-Qweegy tree metaphor to us, we humans are stuck in time, we can only be aware of ourselves sequentialy (one moment following the other) we're not omni-present, we aren't able to be concious of every fact in our lives that will ever be, sometimes we can see things that happen to be pointed right in front of us long before they happen because they are neat and linear and reasonably uniterruptable (like the suns burn-rate) but most things that will happen in the future blindside us, we won't see them coming (even though the fact they are coming exists) because we couldn't possibly know every fact reflective of their existense.

We might not see an asteroid that will eventually collide with Earth coming because the rock is so far out, and will have its path of travel bent around a few gravity wells first, but if we knew all the infinate facts involved (that its there, what speed its going, it's mass, it's direction, all the gravitational influences along the way, it's tumble or spin, its topography and constitution) if we knew all these things we'd know it's eventual collision is unavoidable, mathematically certain.

So I spose all I'm saying is I think that the univere is essentially determinist, and a deterministic universe is a complete structure that exists entirely, regardless of your location or awarenesss within it.

I don't buy that Schroedinger's cat nonsense, if you know enough facts, the universe is not uncertain, and the whole consistent structure of all fate would emerge from those facts Complete, like infinity summed up.
Summing infinity is of course imposssible, which is why we can never actually know all the facts even though those facts and 'fate' do exist beyond our ability to know them.

So it is you sir, who has the fuzzy la-d-da thuroughly unsientific ideas about the future, and not I. So there.

:bounce: :lol: :cry: :sleep:

Funkodrom
25-06-2003, 11:41:15
Schroedinger's cat.

Take your asteroid. A space probe takes a still picture of an asteroid. It looks big and it's quite close to the earth.

Everyone's worried and wants to know if it will hit the Earth or not. We can't possibly tell though. We know where it is because we have this still picture of it but we have no idea which direction it's moving in or how fast, we don't even know how massive it is, although we can guess it.

You're argument is that if you know enough facts then it's not uncertain, which is fine, except that for quantum events you can't always 'observe' all the variables at the same time. In some cases there is no possibility of observing all the variables at the same time because it's not physically possible.

Qweeg
25-06-2003, 11:51:22
I know, like I said we're only human, and I read something about you can know where a sub-atomic particle is, or you can know what direction it is going, but not both at once. I just don't believe the reality of what is and what will be is entirely determined by what human beings can know or do. Why do people keep coming out with these entirely human-centric notions about how reality is real, I don't get that at at all.

I'm almost tempted to start talking in terms of what 'god' knows... which is deeply contrary to my beliefs... but I'm starting to see how a god concept could be useful in discussing these things. Euwgh!

Funkodrom
25-06-2003, 12:09:02
You're right that we can't rule out the idea that there are things that are 'real' but outside human experience, or even outside our (current) ability to observe. We discover new stuff all the time.

Humans come out with human-centric notions because they are human.

Qweeg
25-06-2003, 13:25:09
I assure you Funko, I'm human too, and I'm not the first person to not believe that the world ceases to exist whenever I close my eyes. Thinking time doesn't exist when you can't see it (like the future) is the same as thinking a space doesn't exist when you're not there, that's all. Should'a said it like that from the get go.

Funkodrom
25-06-2003, 13:31:13
Yep. That makes sense.

I understood the whole "the roots of what's going to happen in the future have already happened" thing anyway. If we could know everything about everything we'd 'know' the future. It seems that the universe has built in uncertainty that means that things aren't predetermined though. We might be able to make good predictions about small scale things over short time periods but the more complicated system we are looking at and the longer time period it's over the less likely we are going to be able to make a good prediction.

Qweeg
25-06-2003, 13:57:52
True. :beer:

King_Ghidra
25-06-2003, 14:07:15
Originally posted by Qweeg
I assure you Funko, I'm human too, and I'm not the first person to not believe that the world ceases to exist whenever I close my eyes. Thinking time doesn't exist when you can't see it (like the future) is the same as thinking a space doesn't exist when you're not there, that's all. Should'a said it like that from the get go.

This is the bit i don't agree with. There's a big difference between saying 'world war ii happened in the past' and saying 'world war ii exists in the past'

by the definition of existence that i subscribe to, something which has happened, or which might happen, does not exist in the sense that i exist as i type this post

thus, to return to the top of the thread, you can't travel to one of these past or future times, simply because they do not have the physical existence that i do at the present

Funkodrom
25-06-2003, 14:21:07
Hmmmm... interesting. I don't think that can be true because time is not an absolute value. The concept of "now" isn't something that's the same for everything in the universe.

One of the first things they had to beat out of us in the relativity course was the concept of simultaneous events. You might think that two things both happen "now" but to an observer in a different frame of reference they might appear to happen at different times.

What you need to try and forget is any concept of a timeline that goes forward and is the same for everything in the universe, and the concept of "now" or "the present". The only thing that's relevant to is you.

Qweeg
25-06-2003, 15:01:45
[shit stir]Time is a byproduct of animal awarness processing.[/shit stir]

BigGameHunter
25-06-2003, 15:10:46
Time war!!!!

Qweeg
25-06-2003, 15:17:19
Originally posted by King_Ghidra
This is the bit i don't agree with. There's a big difference between saying 'world war ii happened in the past' and saying 'world war ii exists in the past'

by the definition of existence that i subscribe to, something which has happened, or which might happen, does not exist in the sense that i exist as i type this post

thus, to return to the top of the thread, you can't travel to one of these past or future times, simply because they do not have the physical existence that i do at the present

So how do you explain fossils and world war 2 artifacts huh, aye, eh, tuff guy, I spoze you think they all just... magically appeared from a non existant nowhere or something eh? aye? is that what you think? Or I know, you think 'god' put them in the ground to wind us up.

Pah!:)

Guy
25-06-2003, 15:31:22
Originally posted by Funkodrom
I don't think that can be true because time is not an absolute value. The concept of "now" isn't something that's the same for everything in the universe...What you need to try and forget is any concept of a timeline that goes forward and is the same for everything in the universe, and the concept of "now" or "the present". The only thing that's relevant to is you.



To me, the fact that time is not an absolute and is experienced differently for every object in the universe only makes the possibility of "time travel" more probable. It would seem to be a matter of being able to change what kind of observer you are, though that's obviously very simplistic.

I also agree with Qweeg's view that the future history of the universe is pretty well determined already, the only uncertainty is in our understanding and perception of it.

DaShi
25-06-2003, 15:32:58
If you don't know what the future is, how can you change it?

King_Ghidra
25-06-2003, 15:47:23
There's a big difference between observing something and it existing in the sense of it having a tangible existence.

We acknowledge that we can see the light of stars which don't actually exist any more.

Now, you want to tell me that the star does exist if i can see it? No, only the visual effect of the star exists. The body which produced it does not exist. And it desn't matter what your frame of reference is or whatever the fuck you believe, if you want to go and visit that star, you're out of luck, it ain't there.

Noisy
25-06-2003, 15:52:09
Originally posted by Funkodrom
Yep. That makes sense.

I understood the whole "the roots of what's going to happen in the future have already happened" thing anyway. If we could know everything about everything we'd 'know' the future. It seems that the universe has built in uncertainty that means that things aren't predetermined though. We might be able to make good predictions about small scale things over short time periods but the more complicated system we are looking at and the longer time period it's over the less likely we are going to be able to make a good prediction. I disagree (and so I also disagree with Qweeg, who said "True" :p ). However, this may be just because you started of talking about "... small scale things over short time periods ..." and then contrasted those with "... more complicated system[s] ..." over long time periods. When you look at large scale considerations over long periods, we should be able to make good predictions (once we have the technology and ideas to test our predictions), because we should be able to make statements about whether the Universe is open or closed, and about the action of entropy (disorder increases). At the smallest scale (and over the shortest periods), quantum indeterminancy rules the roost (currently), and as the scale/time period increases our predictive capability gets more accurate (e.g. Newtonian gravity predictions - although my argument falls down with the three-body problem :D ).

Hah! Suck on that!

Funkodrom
25-06-2003, 16:09:02
Originally posted by King_Ghidra
Now, you want to tell me that the star does exist if i can see it? No, only the visual effect of the star exists. The body which produced it does not exist. And it desn't matter what your frame of reference is or whatever the fuck you believe, if you want to go and visit that star, you're out of luck, it ain't there.

The star might or might not exist but everything that was part of that star still exists in some form. Also the fact you can see it proves that it existed in the past, you can't really be sure whether it exists now or not, you can guess based on how you think stars work but you can't be sure. The only ways are to either travel to it (slower than the speed of light, you can't just instantly go and look) or wait for the light from 'now' to reach you.

If anything you can't be sure that anything in 'the present' exists, the only thing you can be sure is that things in the past exist because that's all your senses can tell you about.

Looking outside I can tell that 8 minutes ago the sun existed. Does it exist now? Probably but there is absolutely no way of telling other than waiting 8 minutes to find out. (travelling towards it would cut the time down some).

If I was the right distance away from Earth with a big enough telescope I could watch WWII going on now (or listen to it on the radio) just as I can look at the screen and see counterglow 'now'. I'm seeing the past with both those things. The picture from my screen is just a much more recent past than WWII. I don't see that one is any more or less real than the other.

I can't tell if anything has a tangible existence *now* I have to wait until the information from those things gets to me.

I guess we need to have some kind of definition of 'tangible existence'.

Funkodrom
25-06-2003, 16:15:44
Originally posted by Noisy
Hah! Suck on that!

You are right. I was just too lazy to talk about them too.

Qweeg
25-06-2003, 17:12:31
And I only said True because I was trying to disengage from the conversation, it makes me compulsively say more stuff.

DaShi
25-06-2003, 19:46:06
Blah, blah. Einstien and Newton were completely wrong. Gravity is caused by invisible demons. Big ones push planets and stars around, while small ones grab your ankles and hold you to the ground. Dark matter will prove this theory.

Guy
25-06-2003, 20:34:52
I don't know why we're even arguing about it. Time travel is obviously possible because these guys are posting from the future! Look! They're like five hours ahead of us!

BigGameHunter
25-06-2003, 21:41:34
Oooh! Who won the Mariner's game and what are the Powerball numbers?

Bob
26-06-2003, 08:27:30
I got no idea what you are talking about

Qweeg
26-06-2003, 10:40:06
Originally posted by DaShi
Blah, blah. Einstien and Newton were completely wrong. Gravity is caused by invisible demons. Big ones push planets and stars around, while small ones grab your ankles and hold you to the ground. Dark matter will prove this theory.


YOU FOOL DaShi:eek:

You're not supposed to come out and just tell them the truth! I was doing so well blabbing on about gravity and time and all the other things we at the Society of Obscurization have invented over the many years to red-herring the world and protect the population from the many disturbing truths of our giant turni- er... universe, and here you come and just plain say it like it really is!

Now I will have to kill them all, I hope you are happy now.

Bob
26-06-2003, 11:09:24
Now this makes sense!