The Example of the Nasa Astronaut and his twin to illustrate Time Dilation is flawed

[DavidL]

As the illustration goes, a Nasa astronaut travels into space (lets say in 2021) at near light speed, resulting in his time frame slowing down. Many years later (lets say 50 years later, earth time) he returns to earth. Lets say the Astronaut's elapsed time is 30 years, due to time dilation.

According to the well known illustration, his twin brother would have aged 50 years while he has aged 30 years.

But, if the Astronaut's time has passed much slower than his brother's, would he not return to an earth that is in the Past, 2051, instead of 2071?

In other words, he would have traveled back in time by 20 years, and his brother would be at the same age as he is. He came back to the world as it is 30 years later, not 50 years later. If time dilation has resulted in time travel to the past for the Astronaut, it is impossible for him to ever meet his brother in the Future.

 

[Atlan0001]

The illustration was based on the observer always having the traveler under observation. Never, ever, losing sight of the traveler. Physicists have never understood the distortion of their own mapping of the territory.

A traveler traveling away from an observer but remaining under constant observation by the observer -- as the map maps -- would not really be under observation at all. A light born image of him would be under constant observation, not him in the flesh. This continuous light born observation would distort regarding time as lengthening distance lengthened the time it would take light to travel from the traveler to the observer. That is, itself, time stretching in progress.

The traveler, the real traveler and his clock, will gradually get ahead in space and time of the lagging observation of them by the observer. This means the traveler will appear to be slowing down in aging, and his clock will appear to be slowing down in clocking time, distance growing between ticks of the clock. The light born image under constant observation as to physics will be falling behind in time both the time of the real traveler and, at the same time, the time of the observer. It will also be falling behind, not only in time, but in spatial locality. The real traveler will be apparently traveling faster than the speed of light since he will be outrunning and gaining distance on his own image as far as the observer in the rest frame behind doing the observing -- of the light born image -- is concerned. The shift of the light from the growing expansion in distance between is redshift.

This is the true map of the territory.

When and if the traveler reverses course contraction in space and speed up in the movie images will begin and progress. The traveler will appear to be aging faster now, from slowing down in aging before, and the clock will appear to be clocking time faster, also from slowing in clocking time before. Now the image will appear to age faster than the observer rather than slower, the clock to clock faster than the observer's clock. And the shift of the light from the growing contraction in distance between is blueshift.

This is the true map of the territory.

The difference that grew between twins will have disappeared upon reunion, all other things than simple parting and travel being equal.

If time actually slowed down for the traveler and his clock for simply speeding away from the rest frame of the observer, can you imagine what his observation of the observer separating away from him would have been? It would in no way match one for one the reverse observation of him by the observer. Though space and time would be lengthening between them, and light taking longer to travel in each direction between them, all at the same rate, there would be no appearance, to the traveler, of slowing down in aging by the observer, or slowing down in clocking time by the observer's clock. He must see, observe, all of it, most especially the time dilation, happening only to himself and none of it happening to the observer, to Earth, or to the Sun of Earth so rapidly speeding away from him. He must have a sense that the speed of light itself is speeding up, one way only(!), in bringing to him the observer's light born image.

What he must really see is an Earth, and Earth bound observer, falling behind in space and time as fast as he is. He, too, must lose the reality of the observer, the real observer, and the real Earth, then appearing to travel faster than the speed of light, just as the observer will lose the reality of him to the same appearance of traveling faster than the speed of light, as both get ahead of the game of light lengthening and light itself appearing to slow down for lengthening as distances between increase.

But, again, this is based upon all other things, all other physics, being equal, including a constancy of gravs of acceleration being equal.

The above picture matches almost precisely what physicists talk as actually physically happening to travelers. There seems to be no recognition of the fact that there are two of everything, one in the light universe, and the other out front of it in the dark universe. Even the universe observed at 13 billion light years distant is behind the times of whatever is there now by 13 billion years. So the traveler being observed to be a distance of a tenth of a light second distant from any observer is one tenth of a second behind the times of the real traveler, and so is his relative clock a tenth of a second behind the times of the real clock. We are told a traveler can get behind in time, slow down in time, and simultaneously look it in arrived light, which means light would have traveled instantaneously across the distance.

Of course I said "whatever is there now," meaning 13 billion times 6 trillion miles from Earth and the observer, and someone will up and say nothing is there "now." Was there 13 billion years ago, yes. Nothing there "now." You know.... the business of there being one and one only universe, one and one only traveler, the relative universe and traveler in the math.

 

[Helio]

As the illustration goes, a Nasa astronaut travels into space (lets say in 2021) at near light speed, resulting in his time frame slowing down. Many years later (lets say 50 years later, earth time) he returns to earth. Lets say the Astronaut's elapsed time is 30 years, due to time dilation.

According to the well known illustration, his twin brother would have aged 50 years while he has aged 30 years.

But, if the Astronaut's time has passed much slower than his brother's, would he not return to an earth that is in the Past, 2051, instead of 2071?

No because the rate of time is different for the traveler vs. those on Earth. Since his Earth-bound brother aged 50 years, the Earth and everything within its "inertial frame" would also age 50 years. The traveler would have never experienced anything but 30 years of tick-tocks for everything moving with the spaceship.

A near light-speed ship has its own inertial frame that allows time within that frame to pass at a different rate than any other frame that isn't moving relative to it at the same speed.

Another way to model the round trip is to not adjust the tick rate of the spaceship's clock but compress the distance (length contraction). It is just as valid (mathematically, at least) to reduce the distance for the travelers. Thus traveling at the same speed but over less distance will allow the travelers to make the trip in 30 years vs. 50 years.

There has been no experiment that has falsified either time dilation (due to relative speeds) nor length contraction for SR (Special Relativity). [Interestingly, you can't apply both; one must chose which one in making the calculation.]

In other words, he would have traveled back in time by 20 years, and his brother would be at the same age as he is. He came back to the world as it is 30 years later, not 50 years later.

If time dilation has resulted in time travel to the past for the Astronaut, it is impossible for him to ever meet his brother in the Future.

To restore them to meet with having the same age, simply let the other twin also do a round trip.

[I hope I'm not answering a homework question.]

 

[Atlan0001]

Helio,
You may refuse this view, but you are really dealing in the geometry of space-time with your above posting. What I mean is, the geometrical difference between line of curvature and straight line. Now I want to throw out the geometry view of things and can't. It goes as far as the folding of space like folding a towel into many folds and having a wormhole down the middle skipping all the folds. Further into geometry, 3-d it would be a Menger Sponge: 2-d a Sierpinski Carpet. In any case a massive difference between following the curvature of the fold, a longer line between two points and shorter life (so to speak), and getting into the straighter line of less to no curvature, a shorter line between the same two points and longer life (so to speak).

The above, of course, totally ignores the quantum view, also the view of string theory, of a shorter distance between two points in the straight line view, and no time difference. Or, rather a different view of the way both space and time works. We count the shifts of the light, red and blue, as pointing to a warping of both space and time to contraction and / or expansion.

But we are not on the same page as to the dimensions... or are we? You don't marry the blue and red into one picture of both applying simultaneously as blue forward and red rearward, at least not classically (if you get my meaning). Changing the picture dimensionally, you compensate, classically, by having the red and blue follow each other one-dimensionally in-line, the one-dimensional view of cycling one to the other in play instead of my view of both at work in exactly the same -- I have to say it -- more numbers of dimensions (greater dimensional) scenario. Eventually, and I guess inevitably, we arrive at the same final result, as long as you cycle red and blue, by two different progressions to the same final result. You the classical taken one step further from the red only to following up with the blue, and me by way of the multi-dimensional, marrying the blue and red into the same warp picture to simultaneously work together instead of one following the other in-line one-dimensionally.

I suppose I should be satisfied that the resulting destiny works out both ways, in both dimensionalities, magnificently. Grrrr!

I've learned something concerning a dynamic geometry and differing dimensionalities working to a same end, by thoughtfully sitting for a patient reading of what you wrote, for once! I feel I've lucked into a view even more comfortably dynamic, and more relaxing as far the tension and antagonism I've held against the one-dimensionality of the classical is concerned, than the one I had already held. I hope these things remain to mind for me as they are at this moment.

I hope you can see what I see of the larger, bigger, more dimensional and fleshed out pictures blown up from the geometry of the these lines curved, curving, and more or less straight. Not to forget either, expansionist progression up / out to the 2-d (as in the Sierpinski Carpet).... and on up / out to the 3-d (as in the Menger Sponge)....

 

[Atlan0001]

Sheesh. I'm not thinking! Geometry! Accelerating expansion?!?!

". . . . larger, bigger, more dimensional and fleshed out pictures blown up from the geometry of these lines curved, curving, and more or less straight. Not to forget either, expansionist progression up / out" (here I interrupt) 0-d point (as in "Universe's 0-point") up / out to the dynamism of the 1-d "line" geometry pursued above, and now back to: "up / out to the 2-d (as in the Sierpinski Carpet).... and on up / out to the 3-d (as in the Menger Sponge)...."

Geometry! Accelerating expansion?!?!
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"From a drop of water a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other. So all life is a great chain, the nature of which is known whenever we are shown a single link of it." -- Sherlock Holmes: A Study In Scarlet, by Arthur Canon Doyle.

"The man who removes a mountain begins by carrying away small stones." Old Chinese Proverb.
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It's a Multiverse Universe.

 

[DavidL]

No because the rate of time is different for the traveler vs. those on Earth. Since his Earth-bound brother aged 50 years, the Earth and everything within its "inertial frame" would also age 50 years. The traveler would have never experienced anything but 30 years of tick-tocks for everything moving with the spaceship.

A near light-speed ship has its own inertial frame that allows time within that frame to pass at a different rate than any other frame that isn't moving relative to it at the same speed.

Another way to model the round trip is to not adjust the tick rate of the spaceship's clock but compress the distance (length contraction). It is just as valid (mathematically, at least) to reduce the distance for the travelers. Thus traveling at the same speed but over less distance will allow the travelers to make the trip in 30 years vs. 50 years.

There has been no experiment that has falsified either time dilation (due to relative speeds) nor length contraction for SR (Special Relativity). [Interestingly, you can't apply both; one must chose which one in making the calculation.]

In other words, he would have traveled back in time by 20 years, and his brother would be at the same age as he is. He came back to the world as it is 30 years later, not 50 years later.

To restore them to meet with having the same age, simply let the other twin also do a round trip.

[I hope I'm not answering a homework question.]

Don't worry. This is not a homework question. I am just someone interested enough to buy a telescope. Had been interested since my school days. >50 Years Ago!

 

[Atlan0001]

Helio, above in post #3 is dead wrong, and so have I been in certain portions of posts and statements I have made in the past. And so have all the genius pro physicists I could name, among the mediocre. The statement was, "There is no such thing as faster than light travel! It is only an illusion stemming from the elasticity of space-time and, therefore, a capability to warp space-time."

The seemingly powered accelerating expansion of the universe itself will appear to back me up, offer proof of what I say. So does the "Big Vacuum (C^2)," as I call it. All continuously powered acceleration in open systemic universe (including that of "ship travelers" of the open systemic universe(s) at large) has ever been, is, and will ever be "faster than the speed of light!"

Physicists have tried to call it "warping" spacetime, or "wormholing" space-time, or anything but travel faster than the speed of light, but the simplest realization is that there is such a thing to the Multiverse Universe (U), to the universes (u), as "faster than the speed of light," including the very good probability of universe travelers, in the open system, doing it at will and all the time while under constant powered flight (continuous acceleration flight).

What Helio sees and talks about above concerning actual travelers being actually time stretched, among others always doing the same, is actually the light stretched travelers observed by observers in the light!, not in their distant unobservable reality! Regardless of what too many people think and believe to be the case, "reality" and "relativity" are not one and the same thing. One day it, reality and relativity being one and the same thing, will be generally realized to have been a very foolish notion in the first place.

 

[Atlan0001]

Oops! By "dead wrong" above in post #7 above, I mean the convolution always attached, and not just by Helio by a long shot, to thinking regarding the subject. It can be as simple, as I've pointed out, as that "faster than the speed of light" does exist (though only to the "open / opening system") and is a common physic in and to the Multiverse Universe (though once again for emphasis, only to the "open / opening system").