Is this Relativity Falsified?

[ronians1]

Now, for relativity not to hold as you are claiming, one of these guys would have to have a way to determine that he is the one that is really moving and experiencing slow motion. If you can outline a method by which one would be able to detect time dilation, and therefore motion, in their own frame of reference, that would be the way to support your position. Even the most basic method of being able to tell that you are the one who is really moving in "slow motion" would suffice, with the caveat that you must be able to tell without changing your reference frame (that I'd, changing speed or direction).

 

There is a way to determine that the astronaught is the one who has experienced motion. The fact that he is x years younger when he returns to Earth. The difference in ages is proof of motion.

Edited August 10, 2012 by ronians1

[imatfaal]

There is a way to determine that the astronaught is the one who has experienced motion. The fact that he is x years younger when he returns to Earth. The difference in ages is proof of motion.

 

To bring him back to earth requires acceleration. Whilst there is a simple relative velocity the effect is mirrored - but to get the twins back together you got to do something to stop the distance between them increasing, that is the acceleration and then you get an age difference.

 

If you are going to contradict this idea again (other poster have said it in different ways) - please advise exactly how the twin in a space ship at .5 c heading towards Sirius gets back to his twin without accelerating AND how a twin (ie born at the same place) got to be in relative motion with his twin without one of them accelerating.

[Delta1212]

But how does this tie up with Biological systems? In the twin paradox the astronaught twin goes away and comes back years younger. This would present a huge problem for a biological system which metabolises according to its own biological time.

Here we have an independant system wihch relies on moment to moment function. Surely one cannot eliminate a huge wadge of time out of this function without physical compensation and that physical compensation would be slow motion.

Ah, it's because no chunk of time is being removed. The length of a "moment" is simply different.

 

Your body functions in the way it does, and at the rate it does, because it takes a certain amount of time to go through the complex chemical processes that keep you alive. Your bodies various functions need to stay in sync with each other and in sync with these processes or stuff starts to break.

 

When you have time dilation, everything takes longer but stays in sync. You may breathe half as often, but that's ok, because your heart is beating half as often and your cells are using up oxygen half as fast. Because everything in your body takes twice as long to accomplish the same thing, you effectively age half as quickly. And since your brain is also operating at half speed and everything around you is going half as fast, you can't tell the difference between that and normal speed.

 

From the perspective of Earth, you are in effect moving in slow motion. Now here's the rub, the astronaut looks back at Earth and sees everything there moving in slow motion in comparison to him! Who is correct? Well, since in the twin paradox, the astronaut returns to Earth younger, he was obviously moving in slow motion, not the Earth, correct?

 

 

Well, let's look at this from another perspective. The Earth is hurtling through space at a very high speed around the galactic center. If the astronaut blasts off in the opposite direction, you could say he is actually slowing down to a stop while the Earth continues flying along at close to light speed.

 

So the spaceship is now at rest watching Earth fly off at the speed of light. This spaceship doesn't have a twin on it, it has two triplets, with the third remaining on Earth. These two see the third triplet age slower than them. Now, one of the triplets decides to take the escape pod and return to Earth.

 

The triplet remaining on the spaceship sees him take off and speed off at a rate that is even faster than Earth is moving. After all, he had to catch up with Earth. This means the triplet on the escape pod is not only moving in slow motion to the twin on the spaceship, he is moving in slower motion than Earth. To the triplet on the spaceship, the triplet on Earth is younger than the triplet on the escape pod, but is now aging faster.

 

By the time the escape pod reaches Earth, the triplet on board will actually be younger than the triplet who remained on Earth.

 

From Earth's perspective, the two triplets took off, approached light speed, aged slower and then one returned younger than the triplet who stayed. From the spaceship's perspective, it slowed to a stop, Earth moved away at lightspeed, the people there aged slower, then one twin took off and aged even slower so that he'd be younger by the time he reached Earth.

 

There's really no way to determine which of these two perspectives is actually correct, so effectively we must treat both as equally true.

 

Edit to respond to your previous post: If the two triplets then left Earth and came back to the spaceship, the triplet on board would find them both arriving younger than him. So the ages on the spaceship would go, from oldest to youngest: Triplet on Spaceship, Triplet on Earth, Triplet on Escape Pod.

Edited August 10, 2012 by Delta1212

[ronians1]

Perhaps because you have not adequately defined what you mean by "slow motion".

 

There is no effect on the human body because the effect is on time itself, and everything in that frame is affected equally. In that frame you see no effect at all from moving at a constant velocity with respect to another frame.

 

You are saying that there is no effect on the human body.

 

Delta 1212 says:

 

When you have time dilation, everything takes longer but stays in sync. You may breathe half as often, but that's ok, because your heart is beating half as often and your cells are using up oxygen half as fast. Because everything in your body takes twice as long to accomplish the same thing, you effectively age half as quickly. And since your brain is also operating at half speed and everything around you is going half as fast, you can't tell the difference between that and normal speed.

 

I have heard differing views about this. Is the human body physically affected by time dialation or not? If it is not then the effect is on only time itself.

 

If the answer is yes then what happens when the speed is increased to near light speed and the astronaught is virtually fozen in time?

Does everything appear normal to him then?

 

This is a very important point for a lot of people. Thanks

Edited August 10, 2012 by ronians1

[ACG52]

Does everything appear normal to him then?

 

 

Yes. In his frame of reference, time moves normally. It's when it's compared to another frame of reference that we see time dilation.

[Delta1212]

I think the confusion is arising from the fact that when people are saying there is no effect on the human body, they mean that it does not change in operation in any way *except* that from the frame of someone who isn't moving at the same speed, it is operating more slowly.

 

This slowing has no *additional* impact on the body, which is what everyone is talking about when they say the body isn't affected.

 

If your heart beats 50 times a minute according to the clock next to you, when you speed up and it takes twice as long for a minute to pass, it'll take twice as long for your heart to beat 50 times. From your perspective, your heart is still beating 50 times per minute. From Earth's, your clock takes two minutes to register a minute and your heart takes two minutes to beat 50 times.

Edited August 10, 2012 by Delta1212

[ronians1]

I think the confusion is arising from the fact that when people are saying there is no effect on the human body, they mean that it does not change in operation in any way *except* that from the frame of someone who isn't moving at the same speed, it is operating more slowly.

 

This slowing has no *additional* impact on the body, which is what everyone is talking about when they say the body isn't affected.

 

If your heart beats 50 times a minute according to the clock next to you, when you speed up and it takes twice as long for a minute to pass, it'll take twice as long for your heart to beat 50 times. From your perspective, your heart is still beating 50 times per minute. From Earth's, your clock takes two minutes to register a minute and your heart takes two minutes to beat 50 times.

 

At last we are getting some consensus on the definition of the meaning of the word "slow motion" as used in this thread. Some agreement is being reached on the twin astronaught's perception of matters in the cabin of his spacecraft at nearly the speed of light and of his metabolism and indeed of his movement.

 

I have someone who is entrenched in the idea that everything is and appears absolutely normal for the astronaught during the flight and that time dialation is never experienced by oneself in the same FOR but something only something percieved by third parties when frames of refernce are switched.

 

However the common consensus seems to be that metabolism and indeed movement is restricted for the astronaught during this flight and that should he throw an object against the wall of the spacecraft during the flight, actuality dictates that the passage of the ball would be similar to that in a slowed-down movie.

 

The common consensus vis-a-vis to thae astronaught's perception of things seems to be, rather then percieving reality the astronaught

actually percieves that everything is normal even if he is travelling at the near speed of light and frozen in time. Although paralysed and probably dead, he still sees himself as functioning normally!

[swansont]

Although paralysed and probably dead, he still sees himself as functioning normally!

This is where you go off the rails. Why would he be paralyzed and probably dead?

 

You are saying that there is no effect on the human body.

 

I have heard differing views about this. Is the human body physically affected by time dialation or not? If it is not then the effect is on only time itself.

 

If the answer is yes then what happens when the speed is increased to near light speed and the astronaught is virtually fozen in time?

Does everything appear normal to him then?

 

This is a very important point for a lot of people. Thanks

I said there's no effect on the human body because of the way you are describing the situation. There is no extra detrimental (or advantageous) effect. "Frozen in time" is only a description for someone observing from another frame, but the time dilation of special relativity is reciprocal, so the observer would be "frozen in time" from the rocket's frame.

[ronians1]

This is where you go off the rails. Why would he be paralyzed and probably dead?

 

 

I said there's no effect on the human body because of the way you are describing the situation. There is no extra detrimental (or advantageous) effect. "Frozen in time" is only a description for someone observing from another frame, but the time dilation of special relativity is reciprocal, so the observer would be "frozen in time" from the rocket's frame.

 

I think I've got it now. Please correctme if I am wrong:

 

In terms of actuality, if I travel at the near speed of light I would feel absolutely nothing is out of the ordinary. The state of being frozen in time never actually happens. One just appears frozen in time to observers from another frame of reference.

[ronians1]

I think the confusion is arising from the fact that when people are saying there is no effect on the human body, they mean that it does not change in operation in any way *except* that from the frame of someone who isn't moving at the same speed, it is operating more slowly.

 

This slowing has no *additional* impact on the body, which is what everyone is talking about when they say the body isn't affected.

 

If your heart beats 50 times a minute according to the clock next to you, when you speed up and it takes twice as long for a minute to pass, it'll take twice as long for your heart to beat 50 times. From your perspective, your heart is still beating 50 times per minute. From Earth's, your clock takes two minutes to register a minute and your heart takes two minutes to beat 50 times.

 

Thus we are back to slow motion again for a biological system. It seems to me that the only way to deal with counterintuitive issues is to keep them separate from reality and separate them by saying this is theory and this is reality. Intuition has taken thousands of years to evolve through natural selection and one just can't just cast it aside because of a theory formulated over just a lifetime, effective as it may be.

 

To the layman, the only credible explanation for a twin coming back to Earth younger than is brother through having aged less is slow motion- anything else would represent the metaphysical.

[ACG52]

Intuition has taken thousands of years to evolve through natural selection and one just can't just cast it aside because of a theory formulated over just a lifetime, effective as it may be.

 

 

Intuition was formed by evolving in a low-energy, slow moving universe. Thus intuition is not suited to judging a or understanding a high-energy, relativistic universe.

 

To the layman, the only credible explanation for a twin coming back to Earth younger than is brother through having aged less is slow motion- anything else would represent the metaphysical.

 

Most laymen don't understand the physics of the universe. The test of an explanation is not if it's credible to someone knowing nothing of the subject, it's is the explanation correct.

[Greg H.]

I think I've got it now. Please correctme if I am wrong:

 

In terms of actuality, if I travel at the near speed of light I would feel absolutely nothing is out of the ordinary. The state of being frozen in time never actually happens. One just appears frozen in time to observers from another frame of reference.

 

This is the correct interpretation.

[MigL]

You make me want to bang my head against the wall !!!

 

Time is not universal, it 'flows/passes/moves' at different rates depending on the situation. At near light speed your subjective time is unchanged, if you time your heartbeat with the clock on the wall of your spaceship it will be your normal heartrate. YOU ARE NOT IN SUSPENDED ANIMATION OR SLOW MOTION !

An observer on the earth looking at you with a telescope would see you and the clock on the wall move at a much slower rate. This does not mean that he is at rest, for all you know the earth could be moving past the spaceship at near light speed, since there is no universal frame of reference. As a matter of fact if you have a telescope in your spaceship and you look back at the observer, you will see his motions and his wall clock run much slower.

 

To recap, there is no universal time and there is no universal space ( frame of reference ). We can speak of time and space at low speeds because of years of 'intuition' or 'common sense' ( ie the error is negligible ), but at relativistic speeds we can only speak of space-time because we have no 'intuition'or 'common sense' experience ( and the error is extremely large ) at those speeds.

 

Incidentally time dilation occurrs in gravitational potential wells also. Time goes by slower for you at sea level on the earth than it would for someone who has scaled the peak of Mt. Everest, because you are deeper in the potential well ( very slight but measurable ). Does that mean you are in slow motion ???

Edited August 12, 2012 by MigL

[DimaMazin]

 

 

Incidentally time dilation occurrs in gravitational potential wells also. Time goes by slower for you at sea level on the earth than it would for someone who has scaled the peak of Mt. Everest, because you are deeper in the potential well ( very slight but measurable ). Does that mean you are in slow motion ???

Yes,slowed time creates slowed motion.

[MigL]

Again ( more head banging ), your time at sea level is slowed compared to a person at higher elevation.

 

So. are you, at sea level, in slow motion RIGHT NOW ????

[ronians1]

Again ( more head banging ), your time at sea level is slowed compared to a person at higher elevation.

 

So. are you, at sea level, in slow motion RIGHT NOW ????

 

Of course you are, only it is so minimal that you don't notice it.

[DimaMazin]

Theoretically we can see that fast traveler is measuring speed of perpendicular light to his motion.Then the relativity is a whole idiocy.

[ronians1]

WhatI I need is confirmation from experts that in terms of reality here on Earth (we are not talking relativity theory in this respect) time slows down as we speed up. I have been told by this by physicists elsewhere. I just need confirmation from members of this forum.

[swansont]

WhatI I need is confirmation from experts that in terms of reality here on Earth (we are not talking relativity theory in this respect) time slows down as we speed up. I have been told by this by physicists elsewhere. I just need confirmation from members of this forum.

 

You're not going to get contradiction of that here. Yes, time slows down as you speed up in inertial reference frames. As confirmed by the Hafele-Keating experiment.

[ronians1]

You're not going to get contradiction of that here. Yes, time slows down as you speed up in inertial reference frames. As confirmed by the Hafele-Keating experiment.

 

Thanks. So if it were possible for a train say to travel at the near speed of light on Earth its occupants

would actually and physically be virtually frozen in time.

 

Why, when I try to explain this, why am I shouted down?

[MigL]

Because you don't seem to understand that the relativistic train and its occupants are in a different inertial frame than the rest of the earth and its inhabitants. And while the rest of the earth sees the train and its occupants almost frozen in time, the train's occupants would not notice any such effect, everything would happen as normal to them. From their frame it is the rest of the earth and its inhabitants that are virtually frozen in time

[swansont]

Thanks. So if it were possible for a train say to travel at the near speed of light on Earth its occupants

would actually and physically be virtually frozen in time.

 

Why, when I try to explain this, why am I shouted down?

Because relativity demands you cite which frame of reference is being used to make the observation. A train, at this very moment, is traveling near the speed of light with respect to a great many reference frames, and yet we would not describe them as being frozen in time. Also because you then go on to state that the occupants would be killed by doing this. It points to a misunderstanding.

[Delta1212]

It might help conceptually to think of velocity not as a property that objects have but a sort of location or space that they occupy. Every velocity space has its own timeline, and the further you get from your own velocity space, the slower time will appear to move and the less in sync the timelines are. When you accelerate, you aren't gaining or losing speed so much as shifting to an adjacent velocity space with its own timeline.

 

The "real" timeline will always be the one you are currently occupying. So if you see a train go by at close to the speed of light, you will really see the people on board moving in slow motion. In your timeline, they are moving in slow motion.

 

The train is in a different velocity space, however, with its own timeline. The people on the train see you moving in slow motion, and in that timeline, you really are moving in slow motion.

 

This means that you won't agree on the order in which some things happen, but that's ok because you can only intersect once. You'll both agree on what was happening in each others timelines at the exact moment that the train passes you, but you won't agree on the order or duration of events before or after. The reason this works without fundamentally breaking things like causality is that you can't pass each other a second time to compare notes without one or both of you shifting into a new velocity space in order to turn around and head back in the other direction.

 

Once you move to a new velocity space, the timeline for that velocity becomes the real one. If the train comes around and goes past you again, it will have to shift through a velocity space with a timeline that will prevent the disagreement on the order of events that it has with you from breaking causality (i.e. Prevent it from reaching you before something happens for you that already happened for it or vice versa).

 

If the train slows to a stop next to you, it will wind accept your timeline and the people on board, having been moving in slow motion, will find that they have aged less than the rest of the world.

 

If, on the other hand, you were to jump on another train, catch up to the other one and board it, you would be moving into their velocity space, accepting their timeline, and find that you had actually aged less than all the people on the train because you were the one moving in slow motion.

 

The reason people are having a hard time when you ask what really, physically happened is because what really physically happens may really, physically not be the same thing from one timeline to the next.

 

This is hard to grasp and not intuitive because we evolved and have spent our entire lives in one single timeline, or at least a very small subset of timelines that were so close together the difference is effectively imperceptible to anyone that isn't trying extremely hard to measure it. There was never any need to understand how things worked when dealing with multiple, parallel timelines and so that can be much harder to internalize, almost like trying to imagine what life what be like if we could move around in four spacial dimensions instead of three.

 

As a note, I used the term velocity space in order to evoke a certain conceptual understanding, but that is actually what a reference frame is. It's not a completely perfect analogy, but I'm hoping it might help you internalize what is actually going on, even if it seems a little surreal to think of overlapping alternate timelines based on speed.

 

Just to extend it a bit, in this way units of speed like mph are actually units of distance between timelines. If something is moving 10mph faster than you, it would be equally accurate to say that your timelines are 10mph apart. It just happens that this is ridiculously close and you need to get as "far apart" as a significant fraction of the speed of light before the timelines are really noticeably out of sync.

[ronians1]

It might help conceptually to think of velocity not as a property that objects have but a sort of location or space that they occupy. Every velocity space has its own timeline, and the further you get from your own velocity space, the slower time will appear to move and the less in sync the timelines are. When you accelerate, you aren't gaining or losing speed so much as shifting to an adjacent velocity space with its own timeline.

 

The "real" timeline will always be the one you are currently occupying. So if you see a train go by at close to the speed of light, you will really see the people on board moving in slow motion. In your timeline, they are moving in slow motion.

 

The train is in a different velocity space, however, with its own timeline. The people on the train see you moving in slow motion, and in that timeline, you really are moving in slow motion.

 

Thank you for your most erudite reply! I note that in reality I will see the people on board moving in slow motion and that in the timeline of the train, I in reality am moving in slow motion. This is a huge point and an issue that has caused a great deal of agrument.

 

Please correct me where I am wrong:

 

When we take into consideration that time dialation is applicable to every move we make on Earth it becomes obvious that dialation does not just apply to other parties in other reference frames as proposed by some who follow science but applies to all movement in the Universe, it's just that that on Earth the speeds concerned are so small it is physically imperceptible - but at near light speeds the slow motion is considerable, patently obvious and actually happens. This is where the disagreement lies. .

 

Since time dialation is inherent in the Universe, there must be a velocity/time differential in all movement. If there is a velocity/time differential in every frame of reference that is not inertial how can all frames of reference be comprable/relative?

When in reality a ball thrown in the air moves more slowly in one frame of reference compared to another depending on the speed of travel, how can the laws of physics be the same in all reference frames?

Edited August 13, 2012 by ronians1

[Delta1212]

I'm having a little trouble following what you're trying to say. I sort of see the point you're making, but not well enough to address it well. Could you try rephrasing your point or giving a more detailed example of where you see the problem so I can fully understand the issue?