Can Wormholes Enable Time Travel to the Past?

[sweetvirgogirl]

from my understanding of wormholes, you can use a wormhole to build a time machine to go back in past.

However, i think you can't go back in time before the time machine was built... right? or is there a way around?

 

[Vast]

However, i think you can't go back in time before the time machine was built... right? or is there a way around?

Well, there is a way around. If there was a naturally occurring wormhole in space, you could use that to go further back into the past. If what you mean is, a man made time machine forbids anyone going back further than when the time machine was created?

Of course all this is very speculative, but I’m not sure general relativity rules it out.

 

[sweetvirgogirl]

Well, there is a way around. If there was a naturally occurring wormhole in space, you could use that to go further back into the past. If what you mean is, a man made time machine forbids anyone going back further than when the time machine was created?
Of course all this is very speculative, but I’m not sure general relativity rules it out.

well ... even if there was a naturally occurring wormhole, i think you can go to future and come back ... I'm not sure how you can go farther back in time

could you show me a link that illustrates your point?
^I'm not tryina argue ... just trying to understand the basic concepts :)

 

[Vast]

well ... even if there was a naturally occurring wormhole, i think you can go to future and come back ... I'm not sure how you can go farther back in time

What I meant was, if there was a man made time machine created sometime in the year 2300, as you said, you couldn’t use that to go back in time to the year 2000, just say. But if you found a naturally occurring wormhole, which had existed for hundreds of millions of years in some local region of space, then you could use that to go further back in time than the year 2000.

could you show me a link that illustrates your point?
^I'm not tryina argue ... just trying to understand the basic concepts :)

I’ll see what I can find on the net, but I mainly read about this in books over the years. If you’re interested in doing a little reading on the subject yourself, I highly recommend https://www.amazon.com/gp/product/0393312763/?tag=pfamazon01-20 by Kip Thorne.

 

[sweetvirgogirl]

What I meant was, if there was a man made time machine created sometime in the year 2300, as you said, you couldn’t use that to go back in time to the year 2000, just say. But if you found a naturally occurring wormhole, which had existed for hundreds of millions of years in some local region of space, then you could use that to go further back in time than the year 2000.

I disagree ... based on what i know about wormholes ...

man i get confused easily... so whateva

 

[Vast]

I disagree ... based on what i know about wormholes ...
man i get confused easily... so whateva

Ok, we have two independent time machines, one man made, and the other a black hole or wormhole naturally existing in space somewhere nearby. The man made one is switched on sometime in the twenty third century, which means one could travel to the future and to the past, but not before the time in which it was switched on. The other black hole or wormhole located in space has existed for hundreds of millions of years, which means you can use that one to travel back in time. There is a problem though. With the naturally occurring wormhole, we would be unable to see where the other end would lead to; we would have no control over where we went.

There are some other means of achieving time travel into the past, such as faster than light travel. Stephen Hawking has a few in http://www.hawking.org.uk/lectures/warps.html"

 

[Vixus]

Wait, I want to know something. Does the time-machine move with the user or does the user 'step inside' and get transported to the time-machine in the future? In that case, say the user stepped inside in the year 2000 and wished to travel to the year 3000. What if the time machine was destroyed by accident or otherwise in the year 2500? It's also therefore impossible to go back in time as the machine never existed.

If the machine traveled with the user, then, I have no idea. It would have to be completely self-reliant energy-wise, etc.

How are wormholes created? Are they created spontaneously or gradually? If it was spontaneous the creation process is occurring in the future and past at the same time, depending on where either end of the wormhole is, right? From that moment on the wormhole's ends are fixed in time. So there isn't a limit in terms of when the wormhole was created. The wormhole 'creates' itself with one end already in the past/future.

Wormholes connect black-hole singularities, correct? I'm assuming they connect across time, rather than space:

http://bg.spheredev.net/wh.PNG

So was the wormhole created spontaneuosly when the black hole was created? Then there's no way you can travel further than when the black hole was created as that's the end of the wormhole.

I don't know much about this sort of thing. It's all very sci-fi at the moment.

How would one create a time machine anyway? :D

 

[russ_watters]

I'm just an engineer, but I always thought a wormhole simply allowed you to outrun your own light cone.

 

[Vast]

Wait, I want to know something. Does the time-machine move with the user or does the user 'step inside' and get transported to the time-machine in the future? In that case, say the user stepped inside in the year 2000 and wished to travel to the year 3000. What if the time machine was destroyed by accident or otherwise in the year 2500? It's also therefore impossible to go back in time as the machine never existed.
If the machine traveled with the user, then, I have no idea. It would have to be completely self-reliant energy-wise, etc.

Thorne and Morris detail a scenario in which a wormhole is constructed, so that mouth A is placed in a spaceship and mouth B at the launch pad. The spaceship takes off and travels close to the speed of light for several light years and then comes back to Earth. In this scenario, the wormhole is converted into a time machine, so that stepping through the wormhole would provide faster than light travel which would also mean traveling into the past or future depending which side you were on.

How are wormholes created? Are they created spontaneously or gradually? If it was spontaneous the creation process is occurring in the future and past at the same time, depending on where either end of the wormhole is, right? From that moment on the wormhole's ends are fixed in time. So there isn't a limit in terms of when the wormhole was created. The wormhole 'creates' itself with one end already in the past/future.

I think the difficulty lies in keeping the wormhole open. Either it remains open for a very short amount of time, or the opening is so small that nothing can pass through. The rest I have no idea.

Wormholes connect black-hole singularities, correct? I'm assuming they connect across time, rather than space:

They should be able to connect both space and time.

So was the wormhole created spontaneuosly when the black hole was created? Then there's no way you can travel further than when the black hole was created as that's the end of the wormhole.

Not sure about this either, but for more information: http://en.wikipedia.org/wiki/Wormhole"

 

[Vast]

I'm just an engineer, but I always thought a wormhole simply allowed you to outrun your own light cone.

Wouldn’t that be in the case of traveling faster than light, not necessarily to do with wormholes?

 

[masudr]

I'm just an engineer, but I always thought a wormhole simply allowed you to outrun your own light cone.

Fear not, your humour isn't lost on everyone.

 

[pervect]

well ... even if there was a naturally occurring wormhole, i think you can go to future and come back ... I'm not sure how you can go farther back in time
could you show me a link that illustrates your point?
^I'm not tryina argue ... just trying to understand the basic concepts :)

Try reading John Cramer's alternate view columns online

http://www.npl.washington.edu/AV/altvw33.html

for the first article he wrote on wormholes,

http://www.npl.washington.edu/AV/

for the index. Cramer is a physicist, but the articles are written for a mass audience (the science fact column of analog) - so you've got reasonable quality, but not a lot of the detailed math (I assume that's a plus in your case?).

I may write a little more later, but right now I have to go.

 

[robousy]

I think the basic ideas can be summarized as follows.

1) To go BACK IN TIME:

you will need,

i) A stable wormhole
ii) One end of the wormhole to be moving at the speed of light - or very close to.

So, you enter the wormhole mouth at ANY time and emerge at the other end (that is traveling close to the speed of light) roughly at the same time the wormhole was constructed.

2) To go FORWARDS IN TIME:

This one is easy.

If you can achieve everything in 1) then it shouldn't be too hard to hire a ship that can travel very close to the speed of light.

Sit in the ship for a few minutes at top speed and when you come back to Earth say a thousand years would have passed. (for example)

 

[JesseM]

I think the basic ideas can be summarized as follows.
1) To go BACK IN TIME:
you will need,
i) A stable wormhole
ii) One end of the wormhole to be moving at the speed of light - or very close to.
So, you enter the wormhole mouth at ANY time and emerge at the other end (that is traveling close to the speed of light) roughly at the same time the wormhole was constructed.

The usual idea is that you take one mouth on a round trip at relativistic speeds, and then bring it to rest again relative to the other mouth. Just like in the twin paradox, the two mouths will have aged differently, so this will mean there's a constant time difference between them. That means one trip isn't going to automatically take you back to when the wormhole was created, regardless of when you enter; instead, if you enter one mouth you'll exit the other at some fixed amount of time before you entered (say, 1 hour earlier), and by circling back to the other mouth at this earlier time you can enter it and exit the other mouth at an even earlier time, so by making multiple trips you can eventually get back to the moment when the time difference was first created between the two mouths.

2) To go FORWARDS IN TIME:
This one is easy.
If you can achieve everything in 1) then it shouldn't be too hard to hire a ship that can travel very close to the speed of light.

But if you already have a wormhole with a time difference between the two mouths, then if traveling into mouth A and exiting mouth B takes you back in time x seconds, then traveling into mouth B and exiting mouth A takes you forwards in time x seconds. So again, by making multiple trips you can end up as far in the future as you want, provided the wormhole still exists in that time.

 

[sweetvirgogirl]

Try reading John Cramer's alternate view columns online
http://www.npl.washington.edu/AV/altvw33.html
for the first article he wrote on wormholes,
http://www.npl.washington.edu/AV/
for the index. Cramer is a physicist, but the articles are written for a mass audience (the science fact column of analog) - so you've got reasonable quality, but not a lot of the detailed math (I assume that's a plus in your case?).
I may write a little more later, but right now I have to go.

no ... lol ... I'm a nerd like that

 

[robousy]

The usual idea is that you take one mouth on a round trip at relativistic speeds, and then bring it to rest again relative to the other mouth. Just like in the twin paradox, the two mouths will have aged differently, so this will mean there's a constant time difference between them. That means one trip isn't going to automatically take you back to when the wormhole was created, regardless of when you enter; instead, if you enter one mouth you'll exit the other at some fixed amount of time before you entered (say, 1 hour earlier), and by circling back to the other mouth at this earlier time you can enter it and exit the other mouth at an even earlier time, so by making multiple trips you can eventually get back to the moment when the time difference was first created between the two mouths. But if you already have a wormhole with a time difference between the two mouths, then if traveling into mouth A and exiting mouth B takes you back in time x seconds, then traveling into mouth B and exiting mouth A takes you forwards in time x seconds. So again, by making multiple trips you can end up as far in the future as you want, provided the wormhole still exists in that time.

...fair enough.

 

[pervect]

A quick note on how wormholes are created: clasically, you do not create wormholes unless you already have a time machine.

(I believe this is mentioned in Thorne's book)
https://www.amazon.com/gp/product/0393312763/?tag=pfamazon01-20

I can't find the exact reference unless I find my copy of the book :-)

However, some theories have wormholes being spontaneously created on very small scales (the 'quantum foam' model), and it has been suggested that one of these wormholes could be "captured" and "tamed" by a sufficiently advanced civilization (i.e. not us).

Once you have a wormhole, it can be turned into a time machine as described by Jesse, simply by accelerating one end of the wormhole to relativistic velocities.

Many physicists including Hawking believe that the wormhole might "self-destruct" when it is turned into a time machine, due to quantum vacuum fluctuations building up towards infinity in the throat of the wormhole, at the instant it becomes a time machine. Do a google for "Chronlogy protection conjecture".

http://scienceworld.wolfram.com/physics/ChronologyProtectionConjecture.html

is good as far as it goes, but it doesn't go very far. This is also covered in Thorne's book (the one that I can't find the copy of).

 

[-Job-]

Doesn't time travel go against preservation of matter/energy? If someone disappears into the past then there'll less matter around. Does anything come out of the past to make up for this?
On the other hand, if we consider the 4D universe with time as the 4th dimension, then matter/energy are distributed throughout the 4 dimensions and if some body at x1, y1, z1, t1 jumps to x1, y1, z1, t2 then from a 4D perspective the universe still has the same amount of matter/energy, it just has been relocated.

 

[sweetvirgogirl]

Doesn't time travel go against preservation of matter/energy? If someone disappears into the past then there'll less matter around. Does anything come out of the past to make up for this?
On the other hand, if we consider the 4D universe with time as the 4th dimension, then matter/energy are distributed throughout the 4 dimensions and if some body at x1, y1, z1, t1 jumps to x1, y1, z1, t2 then from a 4D perspective the universe still has the same amount of matter/energy, it just has been relocated.

man... can i include whatever you wrote above in my paper on time travel?

 

[-Job-]

Sure, no problem, I'm quoted all the time.

 

[pervect]

http://www.npl.washington.edu/AV/altvw69.html

If a positive electric charge Q passes through a wormhole mouth, the electric lines of force radiating away from the charge must thread through the aperture of the wormhole. The net result is that the entrance wormhole mouth has lines of force radiating away from it, and the exit wormhole mouth has lines of force radiating toward it. In effect, the entrance mouth has now been given a positive electric charge Q, and the exit mouth acquires a corresponding negative charge -Q. Similarly, if a mass M passes through a wormhole mouth, the entrance mouth has its mass increased by M, and the exit mouth has its mass reduced by an amount -M.

So conservation of energy isn't a problem - the wormhole exit mouth loses an amount of mass equal to the mass of the object traveling through.

(This assumes that the wormhole mouth is in a flat space-time, so that the mass can be defined, the usual assumption in GR).

 

[-Job-]

Can we send a wormwhole mouth through a wormhole?

 

[pervect]

Can we send a wormwhole mouth through a wormhole?

An interesting question, don't know the answer.

 

[linhtm]

I am using geometry algebral to make the frame of time and i think by this way we can make a machine

 

[Wizardsblade]

Can we send a wormwhole mouth through a wormhole?

(Intuition here. no math to back up.)
I can not see a reason why we could not send a wormhole mouth through a wormhole, but you will only be changing one side of the anomaly. I.e. you would stretch the wormhole, make the time traveled back or forward shorter or longer.

 

[linhtm]

(Intuition here. no math to back up.)
I can not see a reason why we could not send a wormhole mouth through a wormhole, but you will only be changing one side of the anomaly. I.e. you would stretch the wormhole, make the time traveled back or forward shorter or longer.

I think if we can ,that is not nesecssary ,why do you want to do like that ?