# How much time is needed for the time travel?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Eagle9, Oct 16, 2014.

1. ### Eagle9Registered Senior Member

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Of course, I know that time travel is still a science fiction, but I have heard that General Relativity allows this to happen, for example by means of wormholes:

http://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes

And:

http://en.wikipedia.org/wiki/Wormhole#Time_travel

Now I want to know- how much time is needed for the time travel?

Now it is 2014 year, and let’s assume that I have got the time machine and want to go to years 1914 and see the beginning of the First world war, so I travel back in time by 100 years. I want to know:

1) How much time is needed for the time travel by 100 years? The same 100 years? So, do I really need to spend 100 years from my life to see year 1914? But I (and nobody else in world!) will not be able to donate 100 years for this purpose.

But maybe during time travel the time passes much faster? In other words to cover 100 year timespan I will have to spend much less, for example 1 year only?

2) How much time will be passed for those people who attend my departure in 1914? Let’s assume that I intend to return to the very same date where I departed from (let it be 1-st of July of 2014). It means that for those people zero amount of time will be passed between my departure and return, right? For them it will be my instant voyage.

3) The time for time traveller during the time travel will pass forward in future or backwards in past? In other words, I will become younger or older during visiting year 1914? But if I become younger, then one problem arises: let’s assume that I departed to the year of 2004 WHERE I HAVE ALREADY BEEN/LIVED, it PROBABLY means that I should/cannot know that I came from 2014 (because I knew that I wanted to travel in time in 2014 and I did not think about it in 2004 when I was younger).

4) An “ordinary” time is affected by Special and General Relativity-time is slowed down at high speeds and near high masses. What can we say about “extraordinary” time which is passing during time travel?

3. ### krash661[MK6] transitioning scifi to realityValued Senior Member

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when traveling from one time line to another with a wormhole,time stops within the wormhole(no time existing)
it's simultaneous for the traveler.
time flows at what is considered an overall normal time flow for individuals in the initial time line and the resulting timeline.
it also flows normal again for the traveler when entered the resulting time line.
it's only the travelers time flow that's effected during the traveling.

the question for me is,
is the traveler in a physical state while within a wormhole.

5. ### SpaceFan0101Registered Member

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It's very complicated to answer the question because there are many ways to do time travel like going around a black hole or going through a wormhole and etc. Besides, we are not going to have time travel for a very LONG time.

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8. ### StryderKeeper of "good" ideas.Valued Senior Member

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The problem with Time Travel is the Law of Conservation of Energy. We'd assume that our universe as standard is an isolated "conserved" system. If a "traveller" was to pop into existence from some magic door, DeLorean or beanstalk then they would be increasing the energy within one time period while removing it from another (both instances would break that Conservation law)

It would generate some rather uneasy concerns in regards to Entropy.

Imagine if you created a 100 year project where you have a straight pin sent back to the present from 100 years in the future.

The rule would be simple, every time a pin is sent back, you'd use it to trigger a paradox by changing the time for it's arrival to one second later.

The outcome would be that 3,155,759,999 parallel universes would have sent a pin back after 100 years, however the weight of each universe will potentially be different depending on whether a pin was received or not. While a single pin weighs approximately 25 mg's (This could be incorrect but that's the figure being used here.) the weight of the universe that follows the projects rule (and has a pin for every second over that 100 years) would increase by 78.9 Tonnes.

The point here is to emphasise that if it was possible and it was misused either by accident or on purpose, such a system could cause catastrophic effects. (consider swapping the pin for something heavier.)

You'll likely have some assume that this is similar to how a Blackhole's are made, personally I wouldn't suggest so.

As for wormholes, they are great as pseudoscience to back scifi but I wouldn't suggest the nature of them for practical purposes. ( I wouldn't assume a "wormhole" to exist where there is an instance of Non-Locality)

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Interesting to say the least.
http://math.ucr.edu/home/baez/physics/Relativity/GR/time_travel.html

What little I do know is that, [1] GR allows closed time-like curves:
from Kip Thorne's "Black Holes and Time Warps" and [2] GR does not have global conservation laws. This is discussed in Misner, Thorne, and Wheeler, Gravitation, p. 457.

10. ### EnmosRegistered Senior Member

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If no time exists in the wormhole, you spend zero seconds there, or, rather, no time at all.
So you are never in the wormhole. It's a meaningless question.

Last edited: Oct 18, 2014

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I don't see how time could not exist in a wormhole......Incredibly dilated of course, but it must exist...What is a wormhole? A deformed piece of spacetime.
If one were to cross the EH of a BH, they would reach the Singularity in a very small but finite amount of time.
I would say the same situation applies with a wormhole.

12. ### cosmictravelerBe kind to yourself always.Valued Senior Member

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Yes, a Sipuncula .

13. ### river

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but is the traveler physically connected to all other parts of his body in a Earth type of connection ?

14. ### Eagle9Registered Senior Member

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Does the time travel (more precisely travel into past) inside the wormholes allow to chanhe anything in past? I do not mean to kill travelers’ parents, this would lead to well-known paradox (we will discuss it later, I have got some question about it). I mean this: imagine that I departed to the past and I observe some historic event. My body’s temperature will be higher that the temperature of the air there (unless I am in hot desert) and my body will emit heat and I will raise both temperature and entropy there right? It means that I will definitely affect the past even in case if I do not want to do it intentionally.

What do you think about it?

krash661

Well, this is great if I do not have to sacrifice my time/life for time travel

In other words, you want to know if the traveler’s body will keep its structure or not? By the way, are any tidal forces inside wormhole?

SpaceFan0101

You mentioned many ways but wrote only two of them, could you please tell me about other ones?

Boris2

Thanks

By the way, do the laws of Physics work within wormhole?

Enmos

So, how much time is spent during time travel in wormhole?

Stryder

Interesting what you wrote, I need to think about it.

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You could ask how much time would it take to reach a BH Singularity, once you crossed the EH. The best answer I could give is a very small but finite amount of time.
I reason the same process would apply to a wormhole.
The time maybe able to be calculated mathematically[not by me

] so I'll hand you over the our mathematicians.

16. ### krash661[MK6] transitioning scifi to realityValued Senior Member

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as i understand it, they are three separate systems.
[1]past,[2]wormhole,[3]future.
the traveler 's energy or such is shared at simultaneous moments during it's departure from one system to the other.
your energy or temp will effect the future system as a new born does.
your arrival does not change the future system much to even measure when it comes to your temp and energy.
upon arrival, there will be a energy fluctuation and a signature. but the system will use that almost instantly to create balance.
so for a brief moment, there will be a temp and energy change.

that's one of the problems with time travel, one will more than likely never be able to return to the initial time line they departed from.
especially traveling from future to past, then going from that past back to the future.
it's very difficult.

yes, it's physical state.
IMO, everything points to transferring from physical state to nonphysical, but that's just my opinion.
and also,
no as far as i understand it, gravity is not effecting anything .
this is where it becomes difficult.
supposedly gravity continues as it does on the timelines, they stay balanced.

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Theoretically time travel into the past, would be inherently more difficult then future time travel due to obvious possible paradoxes.
But a couple of speculative explanations that may apply to circumvent such paradoxes may be possible..
[1] Any attempt to kill a grandparent would fail for any number of reasons.
[2] Any travel into the past would create a new timeline.
That and a few more here......

18. ### river

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2) would it though ?

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Worth noting that first and foremost, wormholes are a means of

Time travel into the past more difficult???
Sure it is. Future time travel is theoretically possible and within the laws of physics and GR.
Time travel into the past, requires FTL travel. I see a problem there.

20. ### river

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Its not so much about FTL , but about gathering all the information of the past

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It's about achieving time travel into the past first, before any Information can be gathered...obviously.

22. ### river

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Hmmm.... and just where is this moment where no information is gathered ?