Jump to content
An Old School Catholic Message Board

Time travel


infinitelord1

Recommended Posts

[quote name='philothea' date='Jul 23 2005, 12:44 PM']Just a detail the fiction writers always seem to forget in their time travel...

The earth moves at over 65,000 mph.  It's never been in the same spot twice.

If you could move back in time, you'd wind up in open space.  Ooops.
[right][snapback]655896[/snapback][/right]
[/quote]
Not if the Borg's temporal vortex accounts for the spatial variance.

:biglol:

Link to comment
Share on other sites

argent_paladin

Time travel definitely is possible. In fact, I am doing it right now.
Forward, that is.
But that's pretty boring. Slightly less boring, but not opposed to any physics is traveling forward in time slower than normal by traveling at a high fraction of the speed of light. Thus if you traveled at .99C (99% of the speed of light) to the nearest star and back, you would have traveled only a few moments in the future but eight years would have elapsed on earth. So, it is definitely possible to time travel millions of years into the future. The down side is that you couldn't come back.
The second, even less boring, possibility is to travel back in time in the sense of being able to sense and experience the past but not directly interact with it or change it. This avoids the time paradoxes and doesn't seem to break any physical laws. It could take the form of a supercomputer and virtual reality based on sensors that could detect past events in some way.
But again, this is not what people think of as time travel. The real question is: Is it possible to travel back in time and change past events? Does it create paradoxes? What are the theological implications.
There are two theories of changing the past, negative and positive curve. The negative curve theory asserts that almost all changes in the past would be quickly eliminated and the present would look the same as it does now, which implies that there is something in the universe that "wants" to go a certain direction. Positive curve asserts that small changes grow larger and larger and the present would be unrecognizable, even if the smallest change is introduced into the past. Both are used in science fiction well.
I think the paradoxes are too large to get around. The easiest to understand is the famous "grandfather" paradox. Basically, can you travel back in time and kill your grandfather? If so, then you wouldn't be born. If you aren't born, you can't travel back in time. If you can't travel back in time, you can't kill your grandfather. Paradox.
One little theory that I like is that it is possible to invent a time machine but time conspires to prevent it every time because it would introduce impossible paradoxes into time. Thus, any universe that invents a time machine destroys itself. This, of course, involves the multiverse theory. So perhaps there are innumerable universes that invented time machines but they all died out.
As for theological implications, I think that the paradoxes highlight other paradoxes involving free will. The grandfather paradox seems to show that one couldn't freely will killing your grandfather.
If you want to read an interesting book on time travel with some theology, read Orson Scott Card's Pastwatch. The plot involves traveling back in time to change time to avoid the gencide of North American peoples. It sounds PC but is actually good. There is a great plot twist involving Columbus leading a new Crusade against the Muslims. It gives a good treatment of time travel and the paradoxes involved.

Link to comment
Share on other sites

Don John of Austria

[quote name='argent_paladin' date='Jul 23 2005, 04:02 PM']Time travel definitely is possible. In fact, I am doing it right now.
Forward, that is.
But that's pretty boring. Slightly less boring, but not opposed to any physics is traveling forward in time slower than normal by traveling at a high fraction of the speed of light. Thus if you traveled at .99C (99% of the speed of light) to the nearest star and back, you would have traveled only a few moments in the future but eight years would have elapsed on earth. So, it is definitely possible to time travel millions of years into the future. The down side is that you couldn't come back.
The second, even less boring, possibility is to travel back in time in the sense of being able to sense and experience the past but not directly interact with it or change it. This avoids the time paradoxes and doesn't seem to break any physical laws. It could take the form of a supercomputer and virtual reality based on sensors that could detect past events in some way. 
But again, this is not what people think of as time travel. The real question is: Is it possible to travel back in time and change past events? Does it create paradoxes? What are the theological implications.
There are two theories of changing the past, negative and positive curve. The negative curve theory asserts that almost all changes in the past would be quickly eliminated and the present would look the same as it does now, which implies that there is something in the universe that "wants" to go a certain direction. Positive curve asserts that small changes grow larger and larger and the present would be unrecognizable, even if the smallest change is introduced into the past. Both are used in science fiction well.
I think the paradoxes are too large to get around. The easiest to understand is the famous "grandfather" paradox. Basically, can you travel back in time and kill your grandfather? If so, then you wouldn't be born. If you aren't born, you can't travel back in time. If you can't travel back in time, you can't kill your grandfather. Paradox.
One little theory that I like is that it is possible to invent a time machine but time conspires to prevent it every time because it would introduce impossible paradoxes into time. Thus, any universe that invents a time machine destroys itself. This, of course, involves the multiverse theory. So perhaps there are innumerable universes that invented time machines but they all died out.
As for theological implications, I think that the paradoxes highlight other paradoxes involving free will. The grandfather paradox seems to show that one couldn't freely will killing your grandfather.
If you want to read an interesting book on time travel with some theology, read Orson Scott Card's Pastwatch. The plot involves traveling back in time to change time to avoid the gencide of North American peoples. It sounds PC but is actually good. There is a great plot twist involving Columbus leading a new Crusade against the Muslims. It gives a good treatment of time travel and the paradoxes involved.
[right][snapback]655977[/snapback][/right]
[/quote]



Well the Grandfather paradox isn't much of one if time is really understood, there cannot be time paradoxs because if you go back in time it is not a second event but you have simply displaced yourself temporally into anothor moment in time. If you go back in time you cannot kill your grandfather because of course you didn't kill your grandfather. Likewise you couldn't kill hitler or stalin or stop Cortez because of course you didn't or thats what would have happened. It really isn't that complicated, it just is more rigid than people like to see it. The Past is immutable becaue it is the past and it happened and is still happening.

Link to comment
Share on other sites

JMJ
7/23 - St. Apollinaris of Ravenna

If time is the measurement of change, then it doesn't seem to make much sense to think of travelling backwards in time. Wouldn't that just be more change? If so, isn't time moving foward (because measuring something backwards doesn't make much sense to me)?

Of course, I'm speaking of time as a philosopher, not as a scientist.

Link to comment
Share on other sites

Don John of Austria

[quote name='Pio Nono' date='Jul 23 2005, 04:26 PM']JMJ
7/23 - St. Apollinaris of Ravenna

If time is the measurement of change, then it doesn't seem to make much sense to think of travelling backwards in time.  Wouldn't that just be more change?  If so, isn't time moving foward (because measuring something backwards doesn't make much sense to me)?

Of course, I'm speaking of time as a philosopher, not as a scientist.
[right][snapback]656003[/snapback][/right]
[/quote]


But time isn't a measurement of change persay, there is no reason from a physics prespective that time cannot run backwards, there is even the possiility ( but evidece doesn't point this way) that time IS runningg backwards.

Link to comment
Share on other sites

JMJ
7/23 - St. Apollinaris of Ravenna
[quote name='Don John of Austria' date='Jul 23 2005, 04:40 PM']But time isn't a measurement of change persay, there is no reason from a physics prespective that time cannot run backwards, there is even the possiility ( but evidece doesn't point this way) that time IS runningg backwards.
[right][snapback]656011[/snapback][/right]
[/quote]
I was joking, but if you're going to take me seriously and try to answer me, then answer one thing at a time. If time isn't a measurement of change, then what is it? Second, what part of that definition allows time to run backwards?

Link to comment
Share on other sites

Laudate_Dominum

[quote name='Don John of Austria' date='Jul 23 2005, 04:40 PM']But time isn't a measurement of change persay, there is no reason from a physics prespective that time cannot run backwards, there is even the possiility ( but evidece doesn't point this way) that time IS runningg backwards.
[right][snapback]656011[/snapback][/right]
[/quote]
That's not what all the physicists at the convention thing were saying. It was years ago but I remember them objected to the presenters theory with numerous reasons why time travel is not possible.

But you're speaking of something else really. I believe the thing you're describing involved the quantum level. Maybe something like Feynmen diagrams or something? I admit I'm behind the times. Too busy for physics anymore.

Link to comment
Share on other sites

Of course time-travel's possible! I know this guy in Florida who builds time-machines. He can sell you one for nice and cheap!

Link to comment
Share on other sites

argent_paladin

When the discussion turned to reverse time arrows I also immediately thought of Feynman diagrams. One theory of time indeed is that we are merely projecting our idea of time, that it is an interpretation and that forward causality is no more correct than a reverse view of time. But that is academic.
Back to the grandfather paradox. You have confirmed it. Essentially the grandfather paradox shows that you CANNOT change the past, as you pointed out. And if you cannot change the past, then you cannot go back in time in any substantial sense. Therefore the grandfather paradox shows that timetravel is impossible. That is why they call it a paradox, because it is impossible. If some situation results in a paradox, then you deduce that the situation is impossible.
And your last statement "the past is still happening" is a bit obscure for me. Care to elaborate how that differs from the way the present is still happening? Or how we cannot change something that is happening?
I don't think you are being imaginative enough, Don. Saying that you can't change the past because it has already happened is obvious. Saying how it differs from space is the question. One can move things in space as much as one wants. It doesn't suffice to say that you can't move an object because the object is there. Nor does it suffice to say that you can't change the past because it is already past. That begs the question and is like saying that you can't change the past because you can't change the past. Yes, but why? Why can't you reverse time's arrow? What makes time unidirectional but not any other dimension?

Link to comment
Share on other sites

Laudate_Dominum

I kind of recall seeing an argument for time being unidirectional that involved the second law of thermodynamics, but that was over 10 years ago so I don't think I could present the points and do them justice.
I also remember that I didn't quite buy it. The author seemed to assume too much about the second law which doesn't have to necessarily be true. Sort of like, if you assume x, y and z time must be unidirectional, but I'm only going to demonstrate z and y, you still have to just assume x. But since no one ever questions x it seems convincing. I question x.

hehe

Link to comment
Share on other sites

[quote name='Laudate_Dominum' date='Jul 24 2005, 06:05 AM']I kind of recall seeing an argument for time being unidirectional that involved the second law of thermodynamics, but that was over 10 years ago so I don't think I could present the points and do them justice.
I also remember that I didn't quite buy it. The author seemed to assume too much about the second law which doesn't have to necessarily be true. Sort of like, if you assume x, y and z  time must be unidirectional, but I'm only going to demonstrate z and y, you still have to just assume x. But since no one ever questions x it seems convincing. I question x.

hehe
[right][snapback]656659[/snapback][/right]
[/quote]
Laudate_Dominum,

The answer is to all the questions surrounding time travel can be found by studying Borg science; after all, they have discovered how to create a temporal vortex by emitting chronometric particles.

:biglol:

Link to comment
Share on other sites

Laudate_Dominum

[quote name='Apotheoun' date='Jul 24 2005, 08:12 AM']Laudate_Dominum,

The answer is to all the questions surrounding time travel can be found by studying Borg science; after all, they have discovered how to create a temporal vortex by emitting chronometric particles.

:biglol:
[right][snapback]656665[/snapback][/right]
[/quote]
I just need to build a time machine and go forward in time a couple centuries, retrieve the borg technology, and travel back to our own time.. Hmm.. I feel like I'm missing something here..

Link to comment
Share on other sites

[quote name='Laudate_Dominum' date='Jul 24 2005, 07:19 AM']I just need to build a time machine and go forward in time a couple centuries, retrieve the borg technology, and travel back to our own time.. Hmm.. I feel like I'm missing something here..
[right][snapback]656728[/snapback][/right]
[/quote]
Actually, the Borg Collective has existed for more than 2,000 years, and so the Borg of our time may already have that technology.

Link to comment
Share on other sites

Laudate_Dominum

[quote name='Apotheoun' date='Jul 24 2005, 09:30 AM']Actually, the Borg Collective has existed for more than 2,000 years, and so the Borg of our time may already have that technology.
[right][snapback]656745[/snapback][/right]
[/quote]
Cool. I just need to develop a warp drive real quick.. that's plausible. :)

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...