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Question about relativity as a means of time travel.


Dream_

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So, I've been thinking a little recently. I've had this idea in my head that I feel is probably wrong, but I'd like some insight into why it's wrong if that be the case. So let me explain...

 

I understand that objects moving at very high rates of speed experience time dilation. A clock aboard a spaceship moving at a high rate of speed will tick slower than one sitting stationary on earth. So, in theory, someone who boards a hypothetical spaceship could move at a very high rate of speed over an extended period of time and exit with less time being passed on his body than what has been experienced by the outside world. Thus being time travel. However, I've been doing some thinking, and have thought of a difference between the ticking of a clock and the aging of the human body.

 

The ticking of a clock is a scheduled event. It is predetermined to happen once every second. Thus, every second produces another tick of the second hand. The clock will tick slower for an outside observer because time is passing slower on the hypothetical ship, thus making these scheduled events more spaced out in the remote observers relative time.

 

However, aging seems to be sort of a dynamic process. Driven by cause and effect. It is reactionary to things that happen within one's body and no event is predetermined (at least it seems) to have a certain amount of time in between it and the next event. So would this mean that perhaps relativity would not slow down the aging of the body? Or am I looking at the idea of relativity in the wrong way? I'm sure it's the latter, but if anyone could offer an explanation, that would be great.

 

I realize a few extra problems and/or questions in regards to this. Obviously nothing would appear to be happening any slower than normal to the on-board observer. So his aging would appear to take place at the same rate as it would appear to him on earth. But if my original thought is correct, then his aging would seem to take place more rapidly since time on the craft is moving slower, at least I'd think.

 

I felt like I'd share my thought/confusion with you all. It seems I may just not be fully grasping the concept of time.


Apologies, just realized this probably should have went in the "Speculations" forum. Feel free to move it if you'd like.

Edited by Dream_
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It doesn't matter what process you use as a standard, everything is affected. Clocks are used because scientists can more easily see and measure the difference in the size of the gap between the ticks..

Edited by StringJunky
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If you leave Earth at relativistic speed go a long way and then return at relativistic speed when you land you will have aged just a little but everyone on Earth will have aged a lot. The exact amounts are dependent upon your velocity and how far you traveled (the time it took you, but that confuses things). A really fast ride could, therefor, serve as a one way time machine ... no way back however.

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This sort of situation is not usually considered as time travel.

 

Anyway, time dilation effects all clocks no matter how they work. This means that the human 'body clock' (i.e. the rate of chemical interactions etc) is also effected and so ageing is effected; as measure by some other observer we take to be stationary.

 

Note though that as far as the moving person is concerned they notice no change and time for them just ticks on as it ever did.

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The ticking of a clock is a scheduled event. It is predetermined to happen once every second. Thus, every second produces another tick of the second hand. The clock will tick slower for an outside observer because time is passing slower on the hypothetical ship, thus making these scheduled events more spaced out in the remote observers relative time.

 

Most clocks don't tick once a second — that's just the readout. The "tick" is some process that's governed by the rules of nature, which are the same rules that govern other forms of time passage, including aging. As ajb said, this affects clocks regardless of type, so it equally affects a grandfather clock ticking once a second, a quartz clock ticking tens of thousands of times a second, or an atomic clock ticking billions (or tens of trillions, for optical clocks) of times a second.

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However, aging seems to be sort of a dynamic process. Driven by cause and effect. It is reactionary to things that happen within one's body and no event is predetermined (at least it seems) to have a certain amount of time in between it and the next event. So would this mean that perhaps relativity would not slow down the aging of the body? Or am I looking at the idea of relativity in the wrong way? I'm sure it's the latter, but if anyone could offer an explanation, that would be great.

It seems you've accepted the answer, but if you want to convince yourself of it, try considering it in terms of two similar systems, such as two ships moving inertially relative to each other. For each ship, the other's clock ticks slower.

 

If you consider this from the rest frame of either ship, an astronaut on the ship is at rest. If an astronaut was aging faster or slower than normal, while at rest in an inertial frame, there would have to be something special about that inertial frame (which experimental evidence doesn't support). If you accept that all inertial frames are equivalent (the first postulate of special relativity) then no process could tell the difference between one frame vs another, and all processes would occur at the same rate relative to a rest clock in any given inertial frame.

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  • 2 weeks later...

Relative travelers have relative length contractions. The factor defines relative time and relativity of simultaneity on distance. It is simpler than you think. You see length contraction of traveler frame by gamma factor and traveler sees length contraction of your frame by gamma factor.

gamma=1/(1-v2/c2)1/2

v is relative speed, it is the same for the two frames.

c is speed of light, it is constant for any frame

All clocks simultaneously have the same time in one frame on any distance.

But every observer in one frame on different distance of the length sees length contraction of traveler frame to co-located point of frame of traveler. Traveler sees the same relative to the observer frame.

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  • 1 month later...

Your interpretation of Relativity needs to be simplified. Time travel is not LITERAL it is figurative. In Steven Hawking's "Briefer History Of Time" he uses the analogy of a man bouncing a ping pong ball on a train to describe relativity. The man on the train bounces the ball, and from his point of relativity it bounces in the same spot twice. A man standing along the rails though would see the ball bounce in two different spots from his point of relativity. The realization of relativity, found by Einstein, was that both men were right! The ball had bounced in the same spot on the train, but the train was in two different spots as the time between bounces transpired. To fully understand this one must use what I like to call the "God View" where one can pause/FF/rewind time while zooming in and out to fully understand what transpired(like the view one has while running a simulation).

Relativity has confused many scientists who, encouraged by Steven Hawking, believe that time is curved and can be manipulated by speed. This is false. Relativity is the understanding that when you conduct an experiment your observations will be relative to the scale at which you observe! Zoom in and you may see a ball bouncing in the same spot, then zoom out and you realize that the trains speed changes the location of the spot as time moves forward, and the results of your experiment change. I predict that if one were to zoom in on the inner workings of a clock you would find that they are effected by gravity, so as you increase/decrease the gravitational pull on the clock the time between ticks will change effectively fooling humanity into believing they had just went forward/backward in time, like the guy on the train. Time is a measurable dimension that is constant and consistent.
Time Travel is commonly thought of in it's literal form such as a time machine, or relativity's twist on this using a space ship traveling faster than light. These are both fictitious. Time travel is not LITERALLY possible, however it is RELATIVELY possible! Have I got you confused yet? LOL! Relatively speaking when we look at a star 4 light years away(Proxima Centauri) we are seeing 4 years into it's past because it's light takes 4 years to reach our eyes. If we were flying in a space ship at the speed of light twords the star we would have witnessed 8 years of the stars history in 4 years, and thus we would have relatively "fast forwarded" in time. The God View however would be able to see the lights long journey to earth, watched the space shuttle travel twords the star and all things would happen in sequence without any disruption or "singularities".
Now we should have a common understanding of "Relativity's" meaning, so lets talk about realistic time travel. In order to bring this into the realm of universal understanding I am going to use our Galaxy as the point of the topic, however once grasped it makes one wonder about the implications once the whole body of the Universe is taken into account!

A Solar System is the area in which planets orbit a star. Our galaxy, the Milky Way, is filled with solar systems approximated by NASA to be some tens of billions. NASA places our solar system somewhere about halfway between our black hole and the outer rim of the galaxy. Taking into consideration the long term scale on which galactic events happen, one could imagine that just as our planet evolved so to must other, much older, planets have evolved. A solar system with conditions similar to ours, and nearer to the black hole, would have had the chance to produce life long before our planet was anything more than dust. Therefore, if the planet's lifeforms had discovered science, their lifeforms would most likely have escaped their planet before it's eventual doom and effectively became a space faring species! If we traveled twords this species space station and learned to communicate(given they are peaceful) we would have relatively traveled to the future, learning all kinds of technologies from these beings. Because our Galaxy is roughly 100,000 Light Years across(NASA) we can say that if we were observing this planet we would be seeing about 50,000 years into it's past, possibly before it was developed by life. If these lifeforms had learned to travel faster than light it seems likely they would send their scientist's to other planets similar to their's to observe the creation of life and the advancement of intelligence, possibly explaining UFO sightings across the globe! Also they would likely be searching for resources and possibly even a relocation home. Of coarse "History 2" experts claim to have found planets made entirely of diamonds, water, and even marijuana! This too would make sense if this civilization had invented a "Universal Assembler", nanobot technology that takes any raw material and reconfigure it's atoms to create any product you desire.

If you made it through this with your brain in one piece, bravo! You now understand the universe through God's eyes and see the possibility of other intelligent lifeforms! Even if we all agree we are the only life in this Galaxy, only a prideful man could claim we are the only life in the Universe! Assuming the Big Bang theory's single starting point, travelling closer to the center of the universe would almost certainly end with the discovery of other space-faring species, billions of years older than humanity. Thank You for reading, I hope all our ambitions of understanding this universe may be fulfilled! -James Weninger


I feel as though I must add that Steven Hawking's teachings on time are throwing off science entrepreneurs with his theories. One must understand that he see's things the way he does because he has a SPECIFIC goal to his research, to discover time travel. If I wanted to become the size of an atom bad enough I could create a delusional world where this was possible too, but that doesn't mean that it will ever actually work. He is looking at the universe relatively while I am looking at it from "God View" and that is how I have come to these conclusions. Although I must refrain from defaming him too much as my "White Hole/Black Hole Cycle Theory" is based on his discovery of Hawking Radiation! -James Weninger

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Moderator Note

 

Anon_ghost

 

Do not answer questions in the mainstream fora with your own speculative and unproven ideas. You already have a thread on this topic (which I have just moved to Speculations) do not bring it up anywhere apart from in that thread

 

It is considered spamming to place multiple copies of the same post in different threads. Please try to avoid this

 

Report this post if you feel it is unfair.

 

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ok I understand the "posting in multiple threads" thing but I originally wrote this to help this young mans understanding. So what you are saying by moving all my posts to speculation is that I am wrong, correct? PROVE IT!!! I'd love to see you try! Explain how you are going to bend time to LITERALLY travel back and forth in time...back to the question originally asked, if you want the answer go to speculation/trash that's where the moderators send the real answers...

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!

Moderator Note

 

Moderator Note

I should have been explicit

 

"Report this post if you feel it is unfair" was a way of saying

 

"Please do not respond to this moderation note within the thread as this further derails a topic aread taken off course by the offending post - if you think this is unfair please report this post to bring it to staff attention"

 

From now on please do not respond to moderation notes.

 

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Explain how you are going to bend time to LITERALLY travel back and forth in time...back to the question originally asked, if you want the answer go to speculation/trash that's where the moderators send the real answers...

Google Closed-Timelike-Curves.

 

Classical general relativity seems to allow such strange curves.

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  • 2 weeks later...

Perhapts a poetic perspective could help bring some understanding.

Plank length is stretched as the proton pendilum swings in the clock of a hydrogen atom speeding away from my perspective standing still.

Perhaps not.

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This thread is still alive? Honestly this was more or less a shower thought that I figured I'd post for feedback from people more informed on the topic. Thanks to everyone for your contribution.

Edited by Dream_
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If you consider this from the rest frame of either ship, an astronaut on the ship is at rest. If an astronaut was aging faster or slower than normal, while at rest in an inertial frame, there would have to be something special about that inertial frame (which experimental evidence doesn't support). If you accept that all inertial frames are equivalent (the first postulate of special relativity) then no process could tell the difference between one frame vs another, and all processes would occur at the same rate relative to a rest clock in any given inertial frame.

 

But there are such processes: redshift or blueshift.

If somebody travels at speed close to speed of light, he/she just needs to analyze microwave background radiation.

If it's relativistic Doppler shifted, such person should be able to detect it.

Edited by Sensei
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