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Paradox-free time travel is theoretically possible

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Re: Paradox-free time travel is theoretically possible

#61

Post by thaumasiotes »

deviation wrote: post #50

I'm so agnostic concerning the concept of time itself at the end of the day. I feel that we're so busy struggling to find a way to make time travel work, that we forget that time itself isn't a mechanism of the universe, and that it's just a word we use to describe some sort of effect or bi-product that we're observing. Here's a can of worms... Compare the concept of time travel to something like 'smell travel'. Is i…

> Compare the concept of time travel to something like 'smell travel'. Is it really that different?

What do you mean by moving from one smell to another smell?

Time is a kind of position; smell isn't.

Re: Paradox-free time travel is theoretically possible

#62

Post by offtop5 »

Time travel stories always seem to be centered around what if fantasy.

I think one of the movie adaptations of the time machine has the protagonist trying to save his wife.

I would like to explore what would happen if one went years into the future to party ? Would certain time periods become tourist traps

Re: Paradox-free time travel is theoretically possible

#63

Post by avereveard »

offtop5 wrote: post #62

Time travel stories always seem to be centered around what if fantasy. I think one of the movie adaptations of the time machine has the protagonist trying to save his wife. I would like to explore what would happen if one went years into the future to party ? Would certain time periods become tourist traps

You need to chart the future first, for even in moderately advanced countries you risk showing up during a riot or other agitations that could get you arrested and stranded, especially as our surveillance capabilities expand it will be hard to evade detection.

And, if we assume we live in a one timeline hypothesis, all that work is still at risk from other time travelers altering a midpoint between now and where you mapped.

Re: Paradox-free time travel is theoretically possible

#65

Post by [deleted] »

MetaWhirledPeas wrote: post #3

> Researchers ran the numbers and determined that even if you made a change in the past, the timeline would essentially self-correct, ensuring that whatever happened to send you back in time would still happen. I'm sure these researchers are pretty smart, but nothing in this article goes beyond the level of a grade-school debate. Maybe there's something enlightening in the paper. But if there was, you'd think it woul…

[deleted]

Re: Paradox-free time travel is theoretically possible

#66

Post by Daniel_sk »

drdeca wrote: post #54
deviation wrote: post #50

I'm so agnostic concerning the concept of time itself at the end of the day. I feel that we're so busy struggling to find a way to make time travel work, that we forget that time itself isn't a mechanism of the universe, and that it's just a word we use to describe some sort of effect or bi-product that we're observing. Here's a can of worms... Compare the concept of time travel to something like 'smell travel'. Is i…

So do you think that special relativity is misleading, or, if not, how do you reconcile this point with special relativity?

I think you partly misunderstood his comment. Basically instead of time we can look at it as a change of states, just a linear process. There is no time. If you place something on a table (in a perfect environment with no decay) you can't tell how much time it sat there. It could have sat there for 1 hour or 1 million years. It just didn't move and no one tracked the "time". Time is just a concept in our minds to track changes in space (or state of space). Special relativity I think doesn't contradict this. It just says that the "speed" of the state changes (e.g. you go from A to B) is relative. But this speed can't go negative. There is no trace of previous events where you could go back to.

Re: Paradox-free time travel is theoretically possible

#67

Post by Daniel_sk »

drdeca wrote: post #55
8bitsrule wrote: post #48

I've never seen the past or future. Only physical things still or moving, combining with other things or not ... What we call 'the past' is a mental picture of where physical things used to be positioned and their condition. But everything in 'that now' has changed. Just as when we 'travel' in physical space, when we get 'back home' it has changed. If I were to 'time travel' I'd be gone from now. But everyone else wo…

How do you reconcile this idea with special relativity?

By the speed of how these things move, interact or change state relative to each other.

Re: Paradox-free time travel is theoretically possible

#68

Post by littlestymaar »

The time-travel paradox arises only if you presuppose the existence of free will: if we don't, and just consider human beings as physical objects acting deterministically, then there can be no paradox: the time traveler will simply do what was already had been done in his past.

Re: Paradox-free time travel is theoretically possible

#69

Post by at_a_remove »

mpalmer wrote: post #27
paxys wrote: post #16

Earlier quoted context omitted.

Exactly. The article mentions the grandfather paradox, but doesn't really address it at all. Can't "self correct" shooting your past self in the head.

Think what they're getting at is that it won't happen that way. Gun will jam, you die of a brain aneurysm. We don't exist in a universe where impossible things happen, so we can't bring them about. But yes, the article doesn't really sink its teeth into it.

The thing about this "self-correction" is that nobody, but nobody has a mechanism to explain this force. Not how it works or worse yet, how it will know how to self-correct. What particular force decides that the friction on some surface will briefly rise and cause the gun to jam? How does it know to do that?

In all of the paradox-forbidding time travel scenarios, nobody has ever mentioned anything deeper than "Well, uh, reality just won't let that happen." If I right now posit that each time travel scenario spawns an intelligent angel whose sole job it is to dash about a closed timelike curve invisibly nudging away paradoxes through minuscule miracles of improbability, that's quite literally more than you'll see written about in these situations.

Re: Paradox-free time travel is theoretically possible

#70

Post by npmisdown »

drdeca wrote: post #55
8bitsrule wrote: post #48

I've never seen the past or future. Only physical things still or moving, combining with other things or not ... What we call 'the past' is a mental picture of where physical things used to be positioned and their condition. But everything in 'that now' has changed. Just as when we 'travel' in physical space, when we get 'back home' it has changed. If I were to 'time travel' I'd be gone from now. But everyone else wo…

How do you reconcile this idea with special relativity?

Every single oscillating particle needs to travel more absolute distance when speed increases, so it will oscillate with lower frequency for the external observer, thus causing time dilation.
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