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Posted

Lets say we witness the twin paradox in real life without any knowledge of relativity. On Earth we see the astronaught twin climb out of his spacecraft considerably younger than his brother and both the clock on the ground and the one in the spaceship show different times.

 

With no knowledge of relativity at all - how does one explain what has happened to a group of laymen onlookers?

 

The only explanation I can think of is that (1) the astronaught has spent his time in space in slow motion

 

(2) the difference in clock times is due to time and reality slowing down on the spaceship.

 

This is fact and reality surely - something that overrides everything else for the layman! Any other answer would seem like magic to them.

 

Once this fact is established then one can go into the realms of relativity theory

 

Will anyone agree that from a FOR from the spaceship (1) The astronaught has spent his time in space in slow motion and (2) the difference in clock times is due

to time and reality slowing down on the spaceship?

 

Human brains have been educated to accept certain things without question and to think a certain way- in the box so to speak. What is needed is a willingness to think out of the box.

Posted

What is needed is a willingness to think out of the box.

 

This isn't thinking out of the box, it's an artificial constraint on a problem. Yes, to someone with no knowledge of relativity, it might seem like magic. That's substantially the same as Clarke's third law. How on earth do you think it somehow falsifies relativity? Ignorance of the law is not the same as falsification of it.

Posted

Will anyone agree that from a FOR from the spaceship (1) The astronaught has spent his time in space in slow motion

Most definitely not.

Posted

This isn't thinking out of the box, it's an artificial constraint on a problem. Yes, to someone with no knowledge of relativity, it might seem like magic. That's substantially the same as Clarke's third law. How on earth do you think it somehow falsifies relativity? Ignorance of the law is not the same as falsification of it.

 

Does not relativity predict that everything should be and appear normal in the FOR of the spacecraft during near-light speed and if it isn't then relativity would be falsified?

 

Most definitely not.

 

In reality how did he spend his time in space? If you say he spent his time normally, how would you describe normally ?

Posted (edited)

Your whole premise makes very little sense.

The builders of this spaceship have technology which permits relativistic speeds, yet have no knowledge of relativity ???

 

And stop confusing special and general relativity. Special relativity involves uniform motion. Accelerated motion as is the case with the twin paradox, is more the realm of General relativity. Acceleration is basically equivalent to a gravitational field.So how would you explain to laymen the time difference ( very slight, I admit ) between someone who lives at sea level and someone who lives at 10000ft, assuming their 'watches' are initially synchronized ???

Edited by MigL
Posted (edited)

Your whole premise makes very little sense.

The builders of this spaceship have technology which permits relativistic speeds, yet have no knowledge of relativity ???

 

And stop confusing special and general relativity. Special relativity involves uniform motion. Accelerated motion as is the case with the twin paradox, is more the realm of General relativity. Acceleration is basically equivalent to a gravitational field.

 

Can we stay as simple as possible and omit acceleration?

How do you explain to laymen onlookers how one twin aged less than the other other than that he spent his time in space in slow motion?

How do you explain to the onlooker the diffrerence in time shown by the two clocks other than that time slowed down thus forcing the astronaught to go into slow motion (if thats possible). How does a biological system survive slow motion?

How does relativity theory deal with these very real issues?

Edited by ronians1
Posted (edited)
How do you explain to laymen onlookers how one twin aged less than the other other than that he spent his time in space in slow motion?

 

You start by introducing the laymen to the theory of relativity, with particular respect to relative time dilation.

 

How does relativity theory deal with these very real issues?

 

Quite well.

 

The only explanation I can think of ...

 

Your ignorance does not falsify the theory.

Edited by ACG52
Posted

Quite well.

 

 

 

Your ignorance does not falsify the theory.

 

 

The absence of the reconciliation of Quantum Theory with the Theory of Relativity I feel warrants attempts at falsification

from all and sundry irrespective.

Posted

Does not relativity predict that everything should be and appear normal in the FOR of the spacecraft during near-light speed and if it isn't then relativity would be falsified?

 

Everything is normal in the spacecraft's FOR.

 

How do you explain to laymen onlookers how one twin aged less than the other other than that he spent his time in space in slow motion?

That's a matter of pedagogy, not of the validity of the theory.

 

How do you explain to the onlooker the diffrerence in time shown by the two clocks other than that time slowed down thus forcing the astronaught to go into slow motion (if thats possible). How does a biological system survive slow motion?

How does relativity theory deal with these very real issues?

 

There is no slow motion. Straw-man arguments are not real issues.

 

The absence of the reconciliation of Quantum Theory with the Theory of Relativity I feel warrants attempts at falsification

from all and sundry irrespective.

Special relativity is incorporated into QM. It's general relativity that has issues.

Posted

The absence of the reconciliation of Quantum Theory with the Theory of Relativity I feel warrants attempts at falsification

from all and sundry irrespective.

 

As pointed out it is GR and QM that have compatibility issue. The Merger of SR and GM has actually produced the most predicatively accurate theory to date.

 

Even then, GR has been found to be highly accurate at the macro scale, So any theory that "replaces" it would not only have to resolve the issues it has with QM at the sub-atomic scale, but also retain the predictions it makes at the macro scale. IOW, relativity will not be thrown out in its entirety.

Posted

A fundamental postulate of relatvity is that the laws of physics are the same in all rest frames. This is why text books state that everything is normal in all rest frames - if not relativity is falsified. Time dialation is real for a body in motion as evidenced by the Hafel-keating experiment.

 

Time dialation in the rest frame of the spaceship travelling at the near speed of light results in the spaceship clock actually running slow and biological systems actually running in slow motion. If the spaceship was not travelling at the near speed of light but at say only at mach 1, everything on board would appear normal to the naked eye but in actuality be running very slightly slower than normal. All experiments concrning this matter have been performed at insignificant speeds compared to that of light. As a consequence the laws of physics appear the same in all rest frames.

 

It would only be when travelling at extreme speeds approaching to that of light that the fact that the laws of physics are not the same in all rest frames becomes apparent. Time and matter actually run slow in the FOR of the spaceship travelling at a near light speed when time and matter actually run normally in the FOR of Earth.

Posted

In reality how did he spend his time in space? If you say he spent his time normally, how would you describe normally ?

I would describe 'normally' as the way you experience time right now. No different. You are at this moment travelling through space at near light speed from the FOR of something else. Do you feel as if you are moving in slow motion?

Posted

It would only be when travelling at extreme speeds approaching to that of light that the fact that the laws of physics are not the same in all rest frames becomes apparent. Time and matter actually run slow in the FOR of the spaceship travelling at a near light speed when time and matter actually run normally in the FOR of Earth.

 

Nah. The laws of physics are the same in any uniformly moving reference frame. Say you are in a rocket going at a constant speed of 99.9 percent the speed of light relative to me.

 

From your point of view, you and your rocket are at rest and I am moving by you in the opposite direction at 99.9 percent the speed of light.

 

But from my point of view, I am at rest and it is you who are moving.

 

Since in your reference frame, you are at rest, time for you goes by "normally." You see no effects of motion on the rate of passage of your time. But you see me going at 99.9 the speed of light. So from your point of view, my time is running much slower. (By a factor of 0.045X.)

 

What do I see? I see myself at rest, my time running normally, and your time running much slower by the same factor.

 

Whose point of view is correct? They both are. Time is relative.

Posted (edited)

Nah. The laws of physics are the same in any uniformly moving reference frame. Say you are in a rocket going at a constant speed of 99.9 percent the speed of light relative to me.

 

From your point of view, you and your rocket are at rest and I am moving by you in the opposite direction at 99.9 percent the speed of light.

 

But from my point of view, I am at rest and it is you who are moving.

 

Since in your reference frame, you are at rest, time for you goes by "normally." You see no effects of motion on the rate of passage of your time. But you see me going at 99.9 the speed of light. So from your point of view, my time is running much slower. (By a factor of 0.045X.)

 

What do I see? I see myself at rest, my time running normally, and your time running much slower by the same factor.

 

Whose point of view is correct? They both are. Time is relative.

 

Biological time can't be relative. One can't treat biological systems as if they were inanimate objects surely? Biological systems would have to function in slow motion if clocks tick slower. There is no ther way around for biology. Metabolism is a straight arrow which can only ensure the survival of an organism by working between certain margins.

 

Biology cant just function to a point of view. For a biological system to survive something else must give and that something could be the FOR or Time itself. Biological time is not relative.

Edited by ronians1
Posted

You don't seem to grasp the implications of time dilation. Time runs slower in a moving frame relative to the stationary frame as measured from the stationary frame. For the moving frame, less time passes, as measured from the stationary frame. But as measured in the moving frame, time is running normally. There is no 'slow motion'.

Posted

You don't seem to grasp the implications of time dilation. Time runs slower in a moving frame relative to the stationary frame as measured from the stationary frame. For the moving frame, less time passes, as measured from the stationary frame. But as measured in the moving frame, time is running normally. There is no 'slow motion'.

 

There's a contradiction here. You say : Time runs slower in a moving frame- in other words - slower when moving = slow motion

 

You say: For the moving frame, less time passes - in other words- slower when moving = slow motion

 

You say: But as measured in the moving frame, time is running normally: In the moving frame a second may still take a second but each second takes longer to pass like a light clock whose beam has to travel further. If each second takes longer to pass in the moving frame slow motion will ensue in that moving frame. Things look normal at insignificant speeds.

Posted

There's a contradiction here. You say : Time runs slower in a moving frame- in other words - slower when moving = slow motion

 

That's not a contradiction, it's a misunderstanding

The two sides of this

" slower when moving = slow motion"

are not actually equal.

 

If I watch a "slow motion" video of a hummingbird , it doesn't make the real bird slow down.

The speeds of video and the bird are not actually related.

 

So time can run slower in a moving frame without any problems (and experiments show that it actually does).

Posted (edited)

That's not a contradiction, it's a misunderstanding

The two sides of this

" slower when moving = slow motion"

are not actually equal.

 

If I watch a "slow motion" video of a hummingbird , it doesn't make the real bird slow down.

The speeds of video and the bird are not actually related.

 

So time can run slower in a moving frame without any problems (and experiments show that it actually does).

 

Are you then saying biological systems function to a point of view in actuality?

Edited by ronians1
Posted
Are you then saying biological systems function to a point of view?

 

Relativity is saying that time itself runs at different rates, depending on the relative motion of frames of reference.

Posted (edited)

Are you then saying biological systems function to a point of view in actuality?

 

Here's an example. Muons are a heavier form of electrons. They are unstable particles and only exist for a small fraction of a second before transforming into lighter particles. When they are made to go at speeds near the speed of light, e.g. in particle accelerators, they last much longer than they do when at rest. What gives these muons a longer life (as seen in the laboratory reference frame)? Time dilation. This increase in lifetime matches predictions of special relativity.

 

So here we have evidence for a subatomic particle and the relativitity of time. Since biological systems are made up of subatomic particles, this implies biological systems in uniform motion also experience slower aging as seen from a frame at rest.

 

Muon time dilation has also been verified in our atmoshpere. See link: http://home.fnal.gov...ght_page18.html

Edited by IM Egdall
Posted

First of all, there is no such thing as a rest frame. All uniformly ( ie non accelerating ) moving frames can be considered as if at rest.

 

Second, all motion is relative ( hence the name relativity ). If one frame is moving relative to another, observers in each ftame will see the other frame's time slow down, and even stop if it were possible to have a relative speed between frames equal to c. You can call it suspended animation or what ever you want, but the time dilation is only visible to the observer in the other frame. In your own frame everything happens as normal to the observer.

 

If you don't want me to complicate matters with acceleration, then don't bring up the twin paradox. If one twin leaves earth, he has to accelerate to relativistic speed, then decelerate, turn around ( angular acceleration ), accelerate back to relativistic seped and then decelerate once reaching earth. It is only then that he can compare ages with his twin who stayed behind and find the age discrepancy. Until that point things have proceeded as normal for both twins.

So you tell me, how do you disregard acceleration ??

Posted

Biological time can't be relative. One can't treat biological systems as if they were inanimate objects surely? Biological systems would have to function in slow motion if clocks tick slower. There is no ther way around for biology. Metabolism is a straight arrow which can only ensure the survival of an organism by working between certain margins.

 

Biology cant just function to a point of view. For a biological system to survive something else must give and that something could be the FOR or Time itself. Biological time is not relative.

 

You can't just assert this.

 

Let's say the normal pulse rate of a human is 72. This person is in a spaceship moving at 0.866c, so that gamma = 2, and makes a twin-paradox trip. In the spaceship frame, the person sees themselves as having a pulse of 72. But from their frame, the duration of any trip will be half as long as what an observer at rest measures (in both distance and time). There is no slow-motion. There is a disagreement of duration and length.

 

The observer will see the person as having a pulse of 36, because the clocks in the two frames disagree.

Posted

First of all, there is no such thing as a rest frame. All uniformly ( ie non accelerating ) moving frames can be considered as if at rest.

 

Second, all motion is relative ( hence the name relativity ). If one frame is moving relative to another, observers in each ftame will see the other frame's time slow down, and even stop if it were possible to have a relative speed between frames equal to c. You can call it suspended animation or what ever you want, but the time dilation is only visible to the observer in the other frame. In your own frame everything happens as normal to the observer.

 

Before I reply to the others let's get this straight:

 

If I got into a spaceship and circumnavigated the Earth indefinitely at the near speed of light, the hands of the spaceship clock would run slow(Hafele-Keating experiment but quicker). Would I or would I not be virtually frozen in time? If not why not? The hands of the clock on the wall of the spaceship would be. Why shouldn't my hands be frozen in time? Are you saying thet biological systems "are not" affected by time dialation?

Posted

From inside the spaceship you would notice nothing different. You would see the hands of the clock as moving normally. Only from a different frame of reference would you see time dilation.

Posted (edited)

Before I reply to the others let's get this straight:

 

If I got into a spaceship and circumnavigated the Earth indefinitely at the near speed of light, the hands of the spaceship clock would run slow(Hafele-Keating experiment but quicker). Would I or would I not be virtually frozen in time? If not why not? The hands of the clock on the wall of the spaceship would be. Why shouldn't my hands be frozen in time? Are you saying thet biological systems "are not" affected by time dialation?

 

 

In your example, if you were on that spaceship cicumnavigating the Earth, the hands on the spaceship clock would be running normally as you see it. From your perspective on the spaceship, you are at rest and the Earth is moving. From your point of view, you are not virtually frozen in time.

 

But we on Earth see your spaceship clock running much slower than our Earth clocks and, as Swansont pointed out, your heart beating much slower. To us on the Earth, you appear to be virtually frozen in time.

 

You on the spaceship measure the hands on the spaceship clock running at a different rate than we measure from here on Earth. As strange as this sounds and as hard as it might be to accept it, this is what relativity is telling us.

Edited by IM Egdall

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