The Underlying Problem With Some Science Is Interpretation.

[xyz]

The outside observer sees the object fall in accordance with the acceleration caused by gravity, yes.  As the object gets faster, his assessment of the speed of the object begins to differ from the speed of the object as measured on the object.  d/t is changing because t is changing.

d/t of the falling object does not change, the speed of the falling object is a constant acceleration until the object reaches its maximum velocity. The object will always take the same amount of time to fall a set distance. Both the outside observer and the observer on the falling object will both agree in the speed of the object, the outside observer having priority in their view perspective compared to an internal observer.  My point is that a slower rate clock on the object does not slow down the speed of the fall. The object falls in the same amount of time every time which we have to agree on. 

This is what science has done  and the historical facts about time - Science took the second from the likes of a mechanical clock, they then used the Caesium atom rate to equal the second, then because their Caesium clock was not a constant time keeper, came up with time dilation.  Time dilation is of the imagination, the Earth's rotation , one day , not affected by any Caesium atom rate.   The Earths rotation the rudiment of measuring time relative to the suns motion.

 

Now do you understand?  I discoursed your information. 

[billvon]

d/t of the falling object does not change, the speed of the falling object is a constant acceleration until the object reaches its maximum velocity. The object will always take the same amount of time to fall a set distance. Both the outside observer and the observer on the falling object will both agree in the speed of the object, the outside observer having priority in their view perspective compared to an internal observer.  My point is that a slower rate clock on the object does not slow down the speed of the fall. The object falls in the same amount of time every time which we have to agree on. 

This is what science has done  and the historical facts about time - Science took the second from the likes of a mechanical clock, they then used the Caesium atom rate to equal the second, then because their Caesium clock was not a constant time keeper, came up with time dilation.  Time dilation is of the imagination, the Earth's rotation , one day , not affected by any Caesium atom rate.   The Earths rotation the rudiment of measuring time relative to the suns motion.

 

Now do you understand?  I discoursed your information. 

Wow, there's so much going on there with that I don't know where to start.  Let's go in order:

 

The first issue is that you have the examples wrong.

 

>d/t of the falling object does not change

Yes, it does.  It increases as it falls, by 9.8 meters per second every second.

 

>the speed of the falling object is a constant acceleration until the object reaches its maximum velocity.

No.  If it is falling in a perfect vacuum it never reaches a "maximum velocity" (until it hits the ground, of course.)  If it is falling in air - which is the only way the term "maximum velocity" makes sense - then it experiences a gradually decreasing acceleration.

 

>The object will always take the same amount of time to fall a set distance.

Given that you are talking about falling in air, then a great many things will influence the speed of its descent - its weight, its drag coefficient etc.

 

However, none of that has anything to do with relativity; it's basic Newtonian physics.

 

Let's switch back to the discussion on relativity.  For the purposes of this discussion we will assume falling in a perfect vacuum towards a gravitational point source.  With that in mind:

 

>Both the outside observer and the observer on the falling object will both agree in the speed of the object

 

No, they won't.  At first their observations will be almost identical.  As the object descends, two things will happen:

 

1) The object will get deeper into the gravitational field relative to the stationary observer.  This will cause time experienced on the object to pass more slowly AS OBSERVED BY THE STATIONARY OBSERVER.  It will stay the same AS OBSERVED BY THE OBJECT. 

 

2) The object will be going faster relative to the stationary observer.  This will cause time experienced on the object to pass more slowly AS OBSERVED BY THE STATIONARY OBSERVER.  It will stay the same AS OBSERVED BY THE OBJECT.

 

You don't need to believe me on the above.  Have you ever used a GPS receiver?  If so, then you have a device that corrects for that effect.  GPS depends on timing, and if (as you claim) people on the ground and the clocks on the satellite ran at the same speed (and thus would agree on d/t) then it would not need any correction.  However, in the real world, it does need correction.  That means clocks run slower on the satellites - and someone on the satellite measuring speed vs. someone on the ground measuring speed will not agree.

 

>My point is that a slower rate clock on the object does not slow down the speed of the fall.

 

Correct!  In fact, from the perspective of the object, the object falls FASTER than expected, since his clock is slowing down relative to the stationary frame.  (More distance in a longer "second.")

 

>The object falls in the same amount of time every time which we have to agree on.

 

From the stationary observer - yes.  From the perspective of the object - no.

Edited November 30, 2016 by billvon

[xyz]

Wow, there's so much going on there with that I don't know where to start.  Let's go in order:

 

The first issue is that you have the examples wrong.

 

>d/t of the falling object does not change

Yes, it does.  It increases as it falls, by 9.8 meters per second every second.

 

>the speed of the falling object is a constant acceleration until the object reaches its maximum velocity.

No.  If it is falling in a perfect vacuum it never reaches a "maximum velocity" (until it hits the ground, of course.)  If it is falling in air - which is the only way the term "maximum velocity" makes sense - then it experiences a gradually decreasing acceleration.

 

>The object will always take the same amount of time to fall a set distance.

Given that you are talking about falling in air, then a great many things will influence the speed of its descent - its weight, its drag coefficient etc.

 

However, none of that has anything to do with relativity; it's basic Newtonian physics.

 

Let's switch back to the discussion on relativity.  For the purposes of this discussion we will assume falling in a perfect vacuum towards a gravitational point source.  With that in mind:

 

>Both the outside observer and the observer on the falling object will both agree in the speed of the object

 

No, they won't.  At first their observations will be almost identical.  As the object descends, two things will happen:

 

1) The object will get deeper into the gravitational field relative to the stationary observer.  This will cause time experienced on the object to pass more slowly AS OBSERVED BY THE STATIONARY OBSERVER.  It will stay the same AS OBSERVED BY THE OBJECT. 

 

2) The object will be going faster relative to the stationary observer.  This will cause time experienced on the object to pass more slowly AS OBSERVED BY THE STATIONARY OBSERVER.  It will stay the same AS OBSERVED BY THE OBJECT.

 

You don't need to believe me on the above.  Have you ever used a GPS receiver?  If so, then you have a device that corrects for that effect.  GPS depends on timing, and if (as you claim) people on the ground and the clocks on the satellite ran at the same speed (and thus would agree on d/t) then it would not need any correction.  However, in the real world, it does need correction.  That means clocks run slower on the satellites - and someone on the satellite measuring speed vs. someone on the ground measuring speed will not agree.

 

>My point is that a slower rate clock on the object does not slow down the speed of the fall.

 

Correct!  In fact, from the perspective of the object, the object falls FASTER than expected, since his clock is slowing down relative to the stationary frame.  (More distance in a longer "second.")

 

>The object falls in the same amount of time every time which we have to agree on.

 

From the stationary observer - yes.  From the perspective of the object - no.

OK, I ''see'' the problem here, you have read my post with ambiguity and replied to most of it with unrelated ''stuff'' to my intentions.  Perhaps a falling object is a bad scenario with so many factors that can affect the result. 

I know you do not understand because I am sure if you did , you would have to agree with me. 

To clarify something though,

 

''The first issue is that you have the examples wrong.''

 

>d/t of the falling object does not change

 

''Yes, it does.  It increases as it falls, by 9.8 meters per second every second.''

 

The ambiguity here is that it does not change, it increases as it falls yes, but the rate of fall does not change, meaning  ''It increases as it falls, by 9.8 meters per second every second'', 9.81m/s2   which is a G constant that does not change. 

 

 

I will reply a bit later with a better  more thoughtful scenario that shows the error in thinking about time dilation.

[exchemist]

OK, I ''see'' the problem here, you have read my post with ambiguity and replied to most of it with unrelated ''stuff'' to my intentions.  Perhaps a falling object is a bad scenario with so many factors that can affect the result. 

I know you do not understand because I am sure if you did , you would have to agree with me. 

To clarify something though,

 

''The first issue is that you have the examples wrong.''

 

>d/t of the falling object does not change

 

''Yes, it does.  It increases as it falls, by 9.8 meters per second every second.''

 

The ambiguity here is that it does not change, it increases as it falls yes, but the rate of fall does not change, meaning  ''It increases as it falls, by 9.8 meters per second every second'', 9.81m/s2   which is a G constant that does not change. 

 

 

I will reply a bit later with a better  more thoughtful scenario that shows the error in thinking about time dilation.

It is apparent from the above that you are unable to get clear the distinction between acceleration and velocity. If you can't do that, you have no business lecturing people on why relativity is wrong.

 

Also, 9.81m/sec², the acceleration due to gravity on the Earth's surface, is generally denoted by g, not G. G is the gravitational constant, 6.67 x 10⁻¹¹ m³/kg-sec². 

[xyz]

It is apparent from the above that you are unable to get clear the distinction between acceleration and velocity. If you can't do that, you have no business lecturing people on why relativity is wrong.

 

Also, 9.81m/sec², the acceleration due to gravity on the Earth's surface, is generally denoted by g, not G. G is the gravitational constant, 6.67 x 10⁻¹¹ m³/kg-sec². 

You are being awkward instead of trying to understand, I am not a scientist so do not expect me to be perfect but expect me to speak rather in generalised terms. 

 

I have took this from wiki - 

 

 

Kinematic time dilation

[edit]

According to special relativity, the rate of a clock is greatest according to an observer who is at rest with respect to the clock. In a frame of reference in which the clock is not at rest, the clock runs more slowly, as expressed by the Lorentz factor. This effect, called time dilation, has been confirmed in many tests of special relativity, such as the Ives–Stilwell experiment and time dilation of moving particles. Considering the Hafele–Keating experiment in a frame of reference at rest with respect to the center of the earth, a clock aboard the plane moving eastward, in the direction of the Earth's rotation, had a greater velocity (resulting in a relative time loss) than one that remained on the ground, while a clock aboard the plane moving westward, against the Earth's rotation, had a lower velocity than one on the ground.

Gravitational time dilation[edit]

Main article: Gravitational time dilation

General relativity predicts an additional effect, in which an increase in gravitational potential due to altitude speeds the clocks up. That is, clocks at higher altitude tick faster than clocks on Earth's surface. This effect has been confirmed in many tests of general relativity, such as the Pound–Rebka experiment and Gravity Probe A. In the Hafele–Keating experiment, there was a slight increase in gravitational potential due to altitude that tended to speed the clocks back up. Since the aircraft flew at roughly the same altitude in both directions, this effect was approximately the same for the two planes, but nevertheless it caused a difference in comparison to the clocks on the ground.''

 

The above is correct, however it is called a time dilation, the correct and accurate description would be a  clock dilation, the Caesium atom is  not related to time, the only connection and relationship with time the Caesium clock has, is the relationship we give it. 

 

 

Do you agree?

 

p.s the relationship we give it is subjective.

Edited November 30, 2016 by xyz

[billvon]

The above is correct, however it is called a time dilation, the correct and accurate description would be a  clock dilation, the Caesium atom is  not related to time, the only connection and relationship with time the Caesium clock has, is the relationship we give it. 

 

Do you agree?

No.  It is called time dilation because it is time dilation.  Clocks measure time, so they run faster or slower.  But that is not due to a defect in the clock.  The clocks are accurately measuring a slower or faster passage of time with respect to an observer in a different frame.

 

The kinematics of the cesium atom is, of course, related to time.  A cesium atom, when stimulated, will transition between its two hyperfine ground states 9,192,631,770 times a second, exactly.  It always does this.  If, due to relative speed differences, a different observer looks at it, they may see more or less than 9,192,631,770 transitions a second.  However, the cesium atom is doing exactly what it always does, which is transitioning 9,192,631,770 times a second.  That hasn't changed.  The definition of a second has changed - relative to the other observer.

[xyz]

No.  It is called time dilation because it is time dilation.  Clocks measure time, so they run faster or slower.  But that is not due to a defect in the clock.  The clocks are accurately measuring a slower or faster passage of time with respect to an observer in a different frame.

 

The kinematics of the cesium atom is, of course, related to time.  A cesium atom, when stimulated, will transition between its two hyperfine ground states 9,192,631,770 times a second, exactly.  It always does this.  If, due to relative speed differences, a different observer looks at it, they may see more or less than 9,192,631,770 transitions a second.  However, the cesium atom is doing exactly what it always does, which is transitioning 9,192,631,770 times a second.  That hasn't changed.  The definition of a second has changed - relative to the other observer.

You really are stuck in this world of subjective education aren't you?

 

Please try to listen and clear your mind from subjective thoughts.  For one last time, the Caesium atom/clock is not time, it is a clock. A clock doe's not affect time.   

 

A tape measure measures distance, a set of scales measures weight, a clock measures what exactly?  time is NOT a physical quantity it is arbitrary based originally on the Earths rotation. 

 

Time does not change by a malfunctioning clock . 

 

Try to listen please. 

 

A car makes a journey at a constant 100 mph on the speedometer for exactly 1 hour, how far has the car travelled in 1 hour?

 

 

(please just answer this and ''play along'' and I will show you )

Edited November 30, 2016 by xyz

[xyz]

I and you know the answer is 100 mile. 

 

A car makes a journey at a constant 100 mph on the speedometer for exactly 1 hour, attached to the car is a Caesium clock that is ''ticking'' at half the rate of ''the normal rate of time'',  how far has the car travelled in 1 hour?

Edited November 30, 2016 by xyz

[xyz]

Now if time was really slowing down for the car, it would travel 200 mile at 100 mph for 1 hour.   However that is not the case, it travels 100 mile as before. The speedometer not telling no lies , using a constant speed to measure ''time'' and distance. 

Edited November 30, 2016 by xyz

[billvon]

Please try to listen and clear your mind from subjective thoughts.  For one last time, the Caesium atom/clock is not time, it is a clock. A clock doe's not affect time.   

 

A tape measure measures distance, a set of scales measures weight, a clock measures what exactly?  time is NOT a physical quantity it is arbitrary based originally on the Earths rotation. 

 

Time does not change by a malfunctioning clock .

You are making the classic mistake - assuming that relativistic time compression "makes clocks malfunction."  The clocks are working right here on the Earth.  The clocks are working right on GPS satellites.  They are accurately measuring the passage of time.  They do not agree.

 

>A car makes a journey at a constant 100 mph on the speedometer for exactly 1 hour, attached to the car is a Caesium clock that is ''ticking'' at half the

>rate of ''the normal rate of time'',  how far has the car travelled in 1 hour?

 

If the cesium clock is working correctly, then to an outside observer the car has traveled 100 miles, to an inside observer the car has traveled 200 miles.  However, at those speeds the relativistic time dilation is infinitesimal, so that would not happen.

 

If the cesium clock (and/or the speedometer) is broken, then no accurate determination can be made.  And at 100 miles an hour, the only way that the two could disagree to any degree is for one or the other to be broken.

 

=================

 

Let's take a more meaningful case.

 

Your "car" is moving at 200,000 km per second.  An outside observer sees the car moving 200,000 kilometers in 1 second, by noting that it takes 1 second to go between two objects 200,000 kilometers apart.

 

Inside the "car" the (accurate) speedometer is reading 260,000 km per second.  (It is covering the same distance, but what the driver sees is different - because his time is dilating.) In 1 second he sees his car drive past the first object, then the second object, then travel an additional 60,000 km.  So he concludes that his speedometer is accurate.

Edited November 30, 2016 by billvon

[exchemist]

You are being awkward instead of trying to understand, I am not a scientist so do not expect me to be perfect but expect me to speak rather in generalised terms. 

 

I have took this from wiki - 

 

 

[edit]

According to special relativity, the rate of a clock is greatest according to an observer who is at rest with respect to the clock. In a frame of reference in which the clock is not at rest, the clock runs more slowly, as expressed by the Lorentz factor. This effect, called time dilation, has been confirmed in many tests of special relativity, such as the Ives–Stilwell experiment and time dilation of moving particles. Considering the Hafele–Keating experiment in a frame of reference at rest with respect to the center of the earth, a clock aboard the plane moving eastward, in the direction of the Earth's rotation, had a greater velocity (resulting in a relative time loss) than one that remained on the ground, while a clock aboard the plane moving westward, against the Earth's rotation, had a lower velocity than one on the ground.

Gravitational time dilation[edit]

Main article: Gravitational time dilation

General relativity predicts an additional effect, in which an increase in gravitational potential due to altitude speeds the clocks up. That is, clocks at higher altitude tick faster than clocks on Earth's surface. This effect has been confirmed in many tests of general relativity, such as the Pound–Rebka experiment and Gravity Probe A. In the Hafele–Keating experiment, there was a slight increase in gravitational potential due to altitude that tended to speed the clocks back up. Since the aircraft flew at roughly the same altitude in both directions, this effect was approximately the same for the two planes, but nevertheless it caused a difference in comparison to the clocks on the ground.''

 

The above is correct, however it is called a time dilation, the correct and accurate description would be a  clock dilation, the Caesium atom is  not related to time, the only connection and relationship with time the Caesium clock has, is the relationship we give it. 

 

 

Do you agree?

 

p.s the relationship we give it is subjective.

Sorry, I haven't the patience. Billvon is doing a great job and I'll leave it to him.

[A-wal]

quite clearly you underestimate me in your arrogance sir.

I managed to overestimate you. I thought you would at lest be able to understand this simple sentence: A model without time dilation and length contraction is incompatible with a constant speed of light.

 

If you don't even understand that then you're in no position to refute it. How can you hope to against something that you don't even understand?

[xyz]

You are making the classic mistake - assuming that relativistic time compression "makes clocks malfunction."  The clocks are working right here on the Earth.  The clocks are working right on GPS satellites.  They are accurately measuring the passage of time.  They do not agree.

 

>A car makes a journey at a constant 100 mph on the speedometer for exactly 1 hour, attached to the car is a Caesium clock that is ''ticking'' at half the

>rate of ''the normal rate of time'',  how far has the car travelled in 1 hour?

 

If the cesium clock is working correctly, then to an outside observer the car has traveled 100 miles, to an inside observer the car has traveled 200 miles.  However, at those speeds the relativistic time dilation is infinitesimal, so that would not happen.

 

If the cesium clock (and/or the speedometer) is broken, then no accurate determination can be made.  And at 100 miles an hour, the only way that the two could disagree to any degree is for one or the other to be broken.

 

=================

 

Let's take a more meaningful case.

 

Your "car" is moving at 200,000 km per second.  An outside observer sees the car moving 200,000 kilometers in 1 second, by noting that it takes 1 second to go between two objects 200,000 kilometers apart.

 

Inside the "car" the (accurate) speedometer is reading 260,000 km per second.  (It is covering the same distance, but what the driver sees is different - because his time is dilating.) In 1 second he sees his car drive past the first object, then the second object, then travel an additional 60,000 km.  So he concludes that his speedometer is accurate.

Ok, this is where you are going wrong, -

 

''If the cesium clock is working correctly, then to an outside observer the car has traveled 100 miles, to an inside observer the car has traveled 200 miles.  However, at those speeds the relativistic time dilation is infinitesimal, so that would not happen''.

 

 

Yes the dilation at those speeds is infinitesimal, however you have it wrong, the inside observer also observes 100 mile because of the use of the speedometer.  Consider the outer observer has set the ratio of the speedometer , the internal observer, observes the same ratio of the speedometer, the rotation of the wheels relative to the speedometer is mechanical.   100 mph on the speedometer is 100 mph to any observer. 

 

I will look at your relativistic of light in a bit. 

[billvon]

Yes the dilation at those speeds is infinitesimal, however you have it wrong, the inside observer also observes 100 mile because of the use of the speedometer.  Consider the outer observer has set the ratio of the speedometer , the internal observer, observes the same ratio of the speedometer, the rotation of the wheels relative to the speedometer is mechanical.   100 mph on the speedometer is 100 mph to any observer. 

 

I will look at your relativistic of light in a bit. 

Again - in reality, there is effectively no time dilation at 100mph.  So it's meaningless to talk about.  Both instruments agree.

 

When the vehicles are going much faster, then the speedometer will show that the car is going faster than the outside observer thinks it is.  The internal speedometer (based on wheel rotation per unit time, or any other metric you want to use) will not match the external "speedometer" (based on how long it takes the vehicle to move between two points in a unit of time.)  This is not because the internal speedometer or external meauring device is broken or malfunctioning.  Even if everything works perfectly, they will measure different speeds.

 

And once again, you can see this happening in the real world in GPS satellites.  So no matter how much you believe yourself to be right, reality disagrees.

[xyz]

Again - in reality, there is effectively no time dilation at 100mph.  So it's meaningless to talk about.  Both instruments agree.

 

When the vehicles are going much faster, then the speedometer will show that the car is going faster than the outside observer thinks it is.  The internal speedometer (based on wheel rotation per unit time, or any other metric you want to use) will not match the external "speedometer" (based on how long it takes the vehicle to move between two points in a unit of time.)  This is not because the internal speedometer or external meauring device is broken or malfunctioning.  Even if everything works perfectly, they will measure different speeds.

 

And once again, you can see this happening in the real world in GPS satellites.  So no matter how much you believe yourself to be right, reality disagrees.

How peculiar , the speedometer shows 100mph, at no stage is the car travelling half the speed or twice the speed. Like the title says , it is about the correct interpretation, I do not believe specifying the Caesium clock rate to be time itself to be the correct interpretation of the facts of reality. I am pretty sure the correct interpretation would be a relative timing dilation, not a time dilation of actual time which has no physicality.

[OceanBreeze]

How peculiar , the speedometer shows 100mph, at no stage is the car travelling half the speed or twice the speed. Like the title says , it is about the correct interpretation, I do not believe specifying the Caesium clock rate to be time itself to be the correct interpretation of the facts of reality. I am pretty sure the correct interpretation would be a relative timing dilation, not a time dilation of actual time which has no physicality.

 

Notice that 100 mph is a ratio: 100 miles / 1 Hour

 

If I stay with your example of the clock in the moving car ticking at half speed (which of course is ridiculous at this very slow velocity, but nevertheless) then the distance will also be halved, keeping the ratio exactly the same.

 

In other words, time dilation does not happen independently of length contraction.

So, for the observer in the car, the car would travel 50 miles in ½ hour and the velocity is 100 mph. The relative velocity of the car is the same for two different observers; one in the car and the other at rest.

 

The observers agree on the velocity, but not on the time and the distance travelled.

I do understand if you are reluctant to accept this. You are not alone!! Most people struggle with SR and GR , but its predictions have been well tested and verified time and time again (no pun intended) and that means it is a good theory.

 

Furthermore, many people simply pretend they understand relativity when they really only have a superficial understanding of what it says. For a more thorough understanding one has to understand the mathematics of vector and tensor calculus and even then, it can be frustratingly difficult to grasp.

 

Personally, I think I do understand it, but sometimes I wonder if it isn’t all a load of hogwash.

;) 

 

As for “what is time” there are some philosophical arguments that time itself does not exist; only the measurement of time exists.

 

I think the accepted definition is: “Time is change” If clocks are slowing down due to time dilation, then the rate of change of everything is slowing also, not just for the clock.

[A-wal]

Furthermore, many people simply pretend they understand relativity when they really only have a superficial understanding of what it says. For a more thorough understanding one has to understand the mathematics of vector and tensor calculus and even then, it can be frustratingly difficult to grasp.

Nonsense! The only maths you need to understand is this:

 

A is moving at 10 mph relative to the road. B is in front of A and is moving at 20 mph relative to the road. C moves past A at 20 mph. What speed does B observe C overtaking them?

 

Answer: 10 mph. That's the only maths you need to grasp. Now just scale it up:

 

A is moving at a quarter of the speed of light relative to the road. B is in front of A and is moving at half the speed of light relative to the road relative to the road. C moves past A at c (the speed of light). What speed does B observe C overtaking them?

 

Answer: c, the speed of light. In the first example the only way to get C to move past A and B at the same velocity is through length contraction and time dilation. If B is time dilated from A's perspective so that B is moving through time at half their own rate then B would observe C moving past them twice as fast as A observes C moving past B but B would observe C moving past them at the same speed that A observed C moving past them.

 

Similarly, If B is length contracted from A's perspective so that B is moving through space at half their own rate then B would observe C moving past them twice as fast as A observes C moving past B but B would observe C moving past them at the same speed that A observed C moving past them.

 

Then you just have to get the square root of what the TD or LC would need to be on their own because velocity is distance over time so the effect of TD and LC are multiplied together. Because they're equal it should just be a case of what the square root of one of them on its own would need to be. I don't see why the SR equations are so complex. Surely that's a really cack handed way of doing it?

Edited December 4, 2016 by A-wal