Time Travel anyone?

[willcowskitz]

1)How do you explain the infinite loop caused by going back in time 20 seconds and watching yourself get into the time machine in the first place? Before getting in you should already be there! Not only that, but there should be infinite copies of yourself appearing 20 seconds before each ‘copy’ of yourself gets in.

2) Matter and energy are interchangeable but energy (and therefore matter) cannot be created or destroyed, only changed from one form to another. So, where does the extra matter come from to create the copies of the time traveller?

The fundamental error that people make in this kind of thinking is the presumption that they are somehow unique as a gathering of carbon-based molecules and their interactions to create a single representer of certain form of life. Though we acknowledge that there were people alive before the births of ourselves, it is indeed difficult to imagine what will happen when we die. The theory (I'd rather call it a play on thoughts) of parallel universes says there already exist 'infinite' (probably a mere descriptive expression, rather than accurate) number of universes more or less similar to that of ours. Mass is not really a problem for the existence, it is only a problem for the comprehensive human mind that is used to calculate everything with the help of abstract concept of "energy". To bring in another example on how or when the parallel universes could "spread away from their originating 'line'" (I earlier mentioned this happens when a conscious choice is made), we could look at the particles and their interactions on a closer view: If there exist particles that are not dividable to smaller units, what happens when they confront each other, when they do no have shaped edges to them that could define the direction of the motion they would gain from the collision? I'm not sure, but does this have something to do with quantum physics?, its based on probabilities rather than definite measures. (I'm not a physicist, I pretty much lost my interest in that field of science in high school, so everyone is welcome to correct my misconceptions on that.)  -When this collision of undividable particles occur, their new directions of motion are either almost totally random, or they consume each other. In the former, on every collision of particles that we have infinite number already in the puny universe of ours, a new parallel universe is created, with the directions of those particles having ended up being different from that of ours (the future is just a row of parallel realities that we seamlessly switch between). Every one of us exists or doesn't in those other realities, and lives their lives just like we live ours. If I were to meet myself in the past or the future, it would be like meeting a doppelgänger, and probably very confusing to both of us, but that's it, the existence won't collapse. There is no conflict - the only origin of paradox is the human mind, so instead of blaming the universe for being self-contradictory, we could always look forward to updating our own understanding on it's mechanisms.

Inane technicalities or not, they cannot be brushed aside with fanciful abstract concepts of time travel. REAL physics put men on the moon and brought them back safely, abstract physics isn’t going to make time travel possible.

I'm not really personally in favour or against the possibility of time travel, I just like to play on thoughts. Even less am I a physicist; if I'd have to "title" myself, I'd probably call myself a metaphysicist or a philosopher. But as it is now, none of us really is even close to knowing the answers to these questions so we shouldn't take them too seriously.

[xvimbi]

There is no conflict - the only origin of paradox is the human mind, so instead of blaming the universe for being self-contradictory, we could always look forward to updating our own understanding on it's mechanisms.

You can't just claim that anything is possible and justify it by saying that the human mind is limited, and we just don't understand. That would be too easy.

Seems like people believe whatever they want, and if someone points out inaccuracies in the arguments it gets brushed aside as a "technicality". Speculation is nice, but it has to be somewhat grounded in reality.

[ahmedito]

Something similar happens in a Hitchhikers Guide to the Galaxy.... I read it a long time ago so I Dont remember, something about a sad poet and a company that wants him to endorse something.... anyone remember?

[willcowskitz]

You can't just claim that anything is possible and justify it by saying that the human mind is limited, and we just don't understand. That would be too easy.

True, but the idea of travelling in time comes from the human mind so it is only natural to come to face different paradoxes. However the first paradox doesn't render the concept of time travel impossible, it just needs to be "written away". On the other hand, if people have no imagination sufficient to fulfill the need for a more tangible theory, we can take a step backwards and say that the original concept itself is paradoxal. I didn't see it necessary to take the step just yet, so I thought I'd introduce the idea of parallel realities since nobody else brought it in.

[Daniel_piano]

Where, if I may ask, do you get this stuff? And you present it as if it was the most established piece of knowledge. Time a circle? There must be a discontiuity. An old universe can't just gradually turn into a young universe. Locally, time can go back and forth, but I have never heard of a circular timeline. Care to present any references?

Yes:

1) Huw Price: New Directions for the Physics of Time
2) Julian Barbour: The End of Time and The Next Revolution in Physics
3) John Brockman: The End of Time
4) Rupert Sheldrake: The Presence of the Past
5) Brian Greene: The Fabric of the Cosmos

[piano_learner]

True, but the idea of travelling in time comes from the human mind so it is only natural to come to face different paradoxes. However the first paradox doesn't render the concept of time travel impossible, it just needs to be "written away". On the other hand, if people have no imagination sufficient to fulfill the need for a more tangible theory, we can take a step backwards and say that the original concept itself is paradoxal. I didn't see it necessary to take the step just yet, so I thought I'd introduce the idea of parallel realities since nobody else brought it in.

Willcowskitz,

If you read back through this thread I did suggest that past/present/future coexist. I suppose that is a type of parallel reality?

I can accept the idea of a Multiverse(?) (many Universes existing together) because there is absolutely no reason to accept that our 'Big Bang' was the only one. This is 'tangible' theory and also stretches the imagination. It's what I call plausible science even though nobody can provide evidence of it. Time travel, to me, will always be implausible science, regardless of how poetically it is described.

[willcowskitz]

piano_learner:

I'm sorry for not having read through all the posts in detail; the reason for this was that the conversation seemed directionless to me at that point and it looked like everyone was arguing whether 2 is 1+1 or 2x1 (that is oversimplified but the setting is same, let's not get stuck in this), so I jumped over the arguing and tried to start stomping the side of the forest for a new path. So I wasn't aware that the possibility of parallelly had already been considered.

In my vision of multiple realities with differences varying from subtle nyances to radical, the Big Bang could still present the very beginning of all, it'd be the seed for the tree. What is really interesting about the concept of parallel realities, is how it forces us to think outside ourselves; If I was to go back in time, it is easy to conclude the difficult-to-approach situation that I would never be able to return to that *exact* reality, because I would be altering the original reality by leaving it, leaving changes behind me, and I would alter the past, creating more radical variations of the future by the visit. If so, I would probably navigate with my time machine to the "closest match" out of the realities in that specific moment in time that would be my time of arrival, and it would most probably consist of slightly different people than those that I left behind, without [the reality] being too much different from ours - all the necessary history would be to far extent in it's major details identical with my original reality, and that would fulfill whatever needs there were for my trip back in time, since the motives and relationships and the rest of the physical world would match well enough - they'd recognize me and I'd recognize them, which again reminds me that people's social behaviour is not that much more special from that of wolves', its just covered with lots of cream and cherries to make it look more fancy and complicated. Just another collasion of playfully created thoughts.

As for the term "plausible", I wouldn't have it as the category for the concept of time travel for myself either, yet it is fun to play on the thought of it.

[Skeptopotamus]

This is stupid.  Unless you have a degree in physics, don't reply here please.  It clutters up an already dumb conversation with even more crap.  I don't think anybody here has written anything remotely intelligent; they are just trying to show off big words they know.  Go take some classes, then you can talk.

You can't travel back in time to do something, because then it would have already been done in your real time and you wouldn't have traveled back in time to do it in the first place.


And Beethoven was deaf.

[piano_learner]

This is stupid.  Unless you have a degree in physics, don't reply here please.  It clutters up an already dumb conversation with even more crap.  I don't think anybody here has written anything remotely intelligent; they are just trying to show off big words they know.  Go take some classes, then you can talk.

You can't travel back in time to do something, because then it would have already been done in your real time and you wouldn't have traveled back in time to do it in the first place.

And Beethoven was deaf.

Skeptopotamus ,

1) Science should be for everybody, not only the people with a degree in Physics.

2) Did you ask anyone here if they had a degree in Physics?

3) Do you have a degree in Physics?

[xvimbi]

Skeptopotamus ,

1) Science should be for everybody, not only the people with a degree in Physics.

2) Did you ask anyone here if they had a degree in Physics?

3) Do you have a degree in Physics?

Yeah, right! Incompetence should not stop people to discuss important issues. What would we do with all those politicians?

[willcowskitz]

Incompetence should not stop people to discuss important issues. What would we do with all those politicians?

 

[earthward]

If you had a time machine,, and you traveled back in time to visit the composer Beethoven and took with you a CD of his Fifth Symphony.  Beethoven listens to it and writes the music down, then later his score is used to record your CD.  Where does the music come from?


-as

you're adorable! 

[sergei r]

    Here's a theory, combining Willcowskitz's parallel realities theory, and whoever it was that suggested past, present and future were coexistant -

    Maybe there is no "leading edge" as was discussed in the beginning of this thread. Maybe time already exists and has already happened infinitely forward since the Big Bang. Why doesn't time travel influence this? Rather than a parallel reality being created when a time paradox occurs, an infinite number of realities already exist infinitely forward from the Big Bang, when time started. These realities are an infinite number of possibilities of every possible way life could go, of what could happen. So the past, present and future all coexist in the form of possibilities which are, in turn, a set of parallel realities. When one travels between different times this will inevitably cause a change of some sort, however small due to the time travel chaos theory of one event leading to another and changes therefore becoming greater and greater the further down the chain. However, the event of one travelling into a different time, be it future or past, and causing a change in that reality has already been accounted for in one possibility. So whatever change a person has caused in a reality by travelling into a different time may be extremely dramatic but it will only happen in that possibility. When the person returns to their own reality, the possibility of the person travelling into time and coming back has also been covered in one possibility, and that is where that person will arrive upon their return. As for the reality which has been changed, there also exists an infinite number of realities in which it has not been changed, and all of these realities coexist. So in short, there is no time paradox because every possible reality, all the way back to the Big Bang and infinitely forward, already exists.
    Applying this theory to the original question, the music came from Beethoven because there does exist a number of possibilities in which Beethoven wrote the music. By taking a CD from the future and bringing it back to Beethoven for him to write down the music, you have not erased the possibility in which he did actually think up the music himself. Any possibility in which someone had gone back into the past and done this would be based upon a possibility in which Beethoven did compose the music. Even though he may not have in one possibility, he will have in another and that would be where the music came from.

    By the way, for those saying this situation would not be possible, remember that Beethoven was not born deaf.