Constancy of SOL from all objects

[Mordred]

Well unfortunate on the time frame terminology mistake itself. Doesn't change the fact that length contraction, time dilation occurs without observer by dimensions (ct,x,y,z).

 

 

We just went through this. There is no "real" to be had here. It implies one frame is "truth". There is no underlying reality to be had. if you measure the meter stick to be 0.8 meters, then that's how long it is, as measured in your frame. "How long is it, really?" is a nonsensical question; it has no answer.

cross posted with this accurate statement.

[Strange]

there cannot be 10 "real" different length contractions for a single object.

 

 

What do you mean by "real"?

 

 

Each observer measures a different length contraction, that's all.

and if you go next to the measured object and join the same frame, you will measure no contraction at all.

 

Exactly.

 

I'm not sure I understand what your problem is with all this.

[StringJunky]

 

 

What do you mean by "real"?

 

 

Exactly.

 

I'm not sure I understand what your problem is with all this.

I can only think he thinks there's only one reality.

Edited July 28, 2016 by StringJunky

[michel123456]

I can only think he thinks there's only one reality.

Yes.

 

Think of it this way:

you have 10 observers observing the same object, they see it contracted in 10 different ways.

Then one of the tens (say observer A) takes the object in its own frame and says, look guys, I was right, the object "truly" was contracted the way I calculated it.

But observer B could also do the same and shout : I was right!

Then comes observer C and takes the object in his C laboratory and say that the object contracted the way C calculated it

 

I don't know if you follow, but it gets insane. Much worse than Schrodinger's cat.

It is not possible for the object to get "truly" contracted billion times differently at the same time because there are billion observers, and all that billion contractions "truly" happen. The observer has absolutely no power upon the observed object.

 

However, it is possible for a single object in a specific state to be observed differently by different observers in different frames. In this case, It is a matter of observation and not a matter of things "truly happening".

 

The only single state of the object on which all observers will agree (I mean all observers will see the same thing) is the state that is observed from the frame of the object. In all other situations the object will be seen in different states (that Relativity tells us the relations), none of which is "true".

---------------------------------------------------------

Now, if an observer A in his A laboratory exerts forces upon an object O, of course he will observe that the result of his experiments comply with Relativity, because the lab is still in frame A. There is no ambiguity, it all happens as seen from A.

But if you could put lab A in a frame X, then observer X will observe object O differently. Which means that object O didn't "truly" contracted. It contracted only as seen from A.

It is not so complicated.

Edited July 29, 2016 by michel123456

[imatfaal]

...

It is not so complicated.

 

But it is wrong. As numerous people have been telling you. Just because you cannot conceptualize it does not mean that it is not true - this is the argument from incredulity; and in this case it is almost justified. Once you get your head around what Einstein was say it is pretty amazing, it goes against most of what we have been taught, and it is contrary to common sense - you clearly have knowledge of what SR entails but are rejecting it because it does not fit into your worldview.

 

How does the muon hit the earth's surface if it is all an observational artefact? - because they do.

 

The muon has a half life in the order of 2 microseconds and a speed of .98c

The distance they must travel from the point of creation in the atmosphere to the earth is c. 10km

The simple maths shows that about 3 in 10 million will make it.

The observation is that 500,000 out of 10 million will make it.

[michel123456]

 

But it is wrong. As numerous people have been telling you. Just because you cannot conceptualize it does not mean that it is not true - this is the argument from incredulity; and in this case it is almost justified. Once you get your head around what Einstein was say it is pretty amazing, it goes against most of what we have been taught, and it is contrary to common sense - you clearly have knowledge of what SR entails but are rejecting it because it does not fit into your worldview.

 

How does the muon hit the earth's surface if it is all an observational artefact? - because they do.

 

The muon has a half life in the order of 2 microseconds and a speed of .98c

The distance they must travel from the point of creation in the atmosphere to the earth is c. 10km

The simple maths shows that about 3 in 10 million will make it.

The observation is that 500,000 out of 10 million will make it.

That is my example of lab A.

Even you will recognize that the same event will not appear the same for an observer B in a different frame B traveling nearby the Earth. You have the Theory and the maths to calculate it.

[Strange]

That is my example of lab A.

Even you will recognize that the same event will not appear the same for an observer B in a different frame B traveling nearby the Earth. You have the Theory and the maths to calculate it.

 

But you seem to be assuming that one of those is "true" (i.e. what really happened) and the other is some sort of distorted view of reality. That is what is wrong with your analysis.

 

There is a similar discussion going on at the moment on another forum (the CosmoQuest forum, under the heading "Is Lorentz Contraction Real"). One of the points being made there is that all we can know about reality is what we measure - there is no other "reality". So if different observers measure different things, then that is reality.

 

And trying to ask questions about what "happens" to the ruler, just shows that our language (and concepts) are not appropriate because they developed based on things that are intuitive, where these effects are not apparent. Nothing happens to the ruler (or photon), we just have different views of reality.

Edited July 29, 2016 by Strange

[michel123456]

 

But you seem to be assuming that one of those is "true" (i.e. what really happened) and the other is some sort of distorted view of reality. That is what is wrong with your analysis.

 

There is a similar discussion going on at the moment on another forum (the CosmoQuest forum, under the heading "Is Lorentz Contraction Real"). One of the points being made there is that all we can know about reality is what we measure - there is no other "reality". So if different observers measure different things, then that is reality.

 

And trying to ask questions about what "happens" to the ruler, just shows that our language (and concepts) are not appropriate because they developed based on things that are intuitive, where these effects are not apparent. Nothing happens to the ruler (or photon), we just have different views of reality.

Yes. (for the bold part)

And there is one single reality. As you say, we just have a different view of ....what? of reality. Yes.

There are no many overlapping realities. It would be like accepting that events in space-time overlap.

 

The observer has absolutely no power to change the reality. The concept following which the observer dictates what is happening is bogus.

 

Except when he does dictate, in a lab.

 

AND when you get to realize that you may understand that you cannot use a theory that is fundamentally observational, you cannot use this Theory to describe a supposed absolute single event like the Big Bang. But that is another fight.

Edited July 29, 2016 by michel123456

[StringJunky]

 

One of the points being made there is that all we can know about reality is what we measure - there is no other "reality". So if different observers measure different things, then that is reality.

That's the conclusion I've come to reading about science: the measurement is the closest you can get to conceiving reality ontologically.

[Strange]

Yes.

And there is one single reality.

 

And how do we find out what that reality is?

 

The only access we have to reality is through our measurements. So how do you decide which of the many possible measurements is the "true" one? Is it that you are always right and everyone else is wrong?

[swansont]

 

The only single state of the object on which all observers will agree (I mean all observers will see the same thing) is the state that is observed from the frame of the object. In all other situations the object will be seen in different states (that Relativity tells us the relations), none of which is "true".

How do you analyze the interaction between something that is moving with respect to the thing it interacts with? They are in different frames, and most parameters are not invariant.

 

That points to the underlying issue that this is a physics problem, not one of philosophy. Saying that the "true" state of an object is what it is in its own frame is a convention (though what is the true state of the photon, which has no rest frame?) but there is no physics that says that one frame is preferred over any other; physics is supposed to work no matter which frame you choose.

[StringJunky]

And there is one single reality.

Imagine you are sitting on a rock in featureless space, with no external reference points, and in the distance you see me on a rock moving towards you.; I experience the same from my position. Am I moving towards you or are you moving towards me? Which/whose frame is the true reality? We can't both be stationary but we each feel stationary in our own frames. You should be able to see that there is no preferred frame and this includes time dilation.

Edited July 29, 2016 by StringJunky

[michel123456]

 

And how do we find out what that reality is?

 

The only access we have to reality is through our measurements. So how do you decide which of the many possible measurements is the "true" one? Is it that you are always right and everyone else is wrong?

You should ask yourself the question when you use this Theory to describe the single birth of this Universe and proclaime that it happened this way because we earthlings are seeing it this way and we are correct.

 

To me, reality is what it is in its own frame. It is not a convention, it corresponds to an origin point in a diagram. You put the origin at the intersection of all viewers, and the intersection is at the event of the observed object.

 

For C, which is observed the same in all frames, there is no issue of ambiguity, there is no need to be in the photon's frame. Anyways all observers agree, no matter the frame.

 

Imagine you are sitting on a rock in featureless space, with no external reference points, and in the distance you see me on a rock moving towards you.; I experience the same from my position. Am I moving towards you or are you moving towards me? Which/whose frame is the true reality? We can't both be stationary but we each feel stationary in our own frames. You should be able to see that there is no preferred frame and this includes time dilation.

 

Exactly. You will be time dilated for me, and I will be time dilated for you. We agree. But if you insert a 3rd observer that says I am more time dilated than you think I am, you will realize that it is just a matter of measurement. I cannot be time-dilated and double-time-dilated "truly" because someone decided to turn his telescope on me. That is nonsense.

Edited July 29, 2016 by michel123456

[imatfaal]

You should ask yourself the question when you use this Theory to describe the single birth of this Universe and proclaime that it happened this way because we earthlings are seeing it this way and we are correct.

 

To me, reality is what it is in its own frame. It is not a convention, it corresponds to an origin point in a diagram. You put the origin at the intersection of all viewers, and the intersection is at the event of the observed object.

 

For C, which is observed the same in all frames, there is no issue of ambiguity, there is no need to be in the photon's frame. Anyways all observers agree, no matter the frame.

 

 

"To me, reality is what it is in its own frame. It is not a convention, it corresponds to an origin point in a diagram. You put the origin at the intersection of all viewers, and the intersection is at the event of the observed object."

 

From the frame of the muon the Burj al Khalifa is 160m high - I will give you a 200 metre rope and you can try abseiling down it. It is 160m and it is 820m. Length is dependent on relative velocity - the longest you will measure is in the objects rest-frame; there is no datum concrete reality and observational artefact - there is a firm mathematical relationship

 

"For C, which is observed the same in all frames, there is no issue of ambiguity, there is no need to be in the photon's frame. Anyways all observers agree, no matter the frame."

 

inertial observers - those in accelerated frames will not

[Strange]

Exactly. You will be time dilated for me, and I will be time dilated for you. We agree. But if you insert a 3rd observer that says I am more time dilated than you think I am, you will realize that it is just a matter of measurement. I cannot be time-dilated and double-time-dilated "truly" because someone decided to turn his telescope on me. That is nonsense.

 

Why is three different results any different than two?

[michel123456]

 

Why is three different results any different than two?

When you state that the 3 results are "truly happening" at the same time then there is a problem.

If you don't understand it then you may have an issue concerning the relationship between your neurons.

 

 

"To me, reality is what it is in its own frame. It is not a convention, it corresponds to an origin point in a diagram. You put the origin at the intersection of all viewers, and the intersection is at the event of the observed object."

 

From the frame of the muon the Burj al Khalifa is 160m high - I will give you a 200 metre rope and you can try abseiling down it. It is 160m and it is 820m. Length is dependent on relative velocity - the longest you will measure is in the objects rest-frame; there is no datum concrete reality and observational artefact - there is a firm mathematical relationship

 

"For C, which is observed the same in all frames, there is no issue of ambiguity, there is no need to be in the photon's frame. Anyways all observers agree, no matter the frame."

 

inertial observers - those in accelerated frames will not

It is absurd. It is wrong.

You believe that the observer dictates what the height of the Burj al Khalifa is. Is that it?

You believe that the tower has multiple heights at the same time because there are multiple observers? It is not science, it is Harry Potter.

[Strange]

When you state that the 3 results are "truly happening" at the same time then there is a problem.

 

But it is OK for two different things to be "truly happening" at the same time?

[michel123456]

 

But it is OK for two different things to be "truly happening" at the same time?

No, no.

It is ok to appear happening. It is OK to appear an infinity of times differently.

But there are no rock "truly" time dilated in different ways at the same time.

[Markus Hanke]

You believe that the tower has multiple heights at the same time because there are multiple observers? It is not science, it is Harry Potter.

 

 

If you place a donut on a table and get 10 different people to look at the donut from different places and angles, they will all see it in different ways; some see it to be bigger than others, some might argue it does not have a hole at all ( if they look at it only sideways e.g. ), some mightn't see it at all ( if they are under the table e.g. ). Nonetheless, they are all talking about the same donut, just from different points of view. The same is true in relativity - events are real and physical, but the labels ( i.e. coordinates ) we give them are not, they are as arbitrary as the name we give to a street on a map. When an observer talks about the "height" of an object such as the building, then this is merely a quantity formed from a specific set of coordinates - since the coordinates are arbitrary, then so is a measure such as height. Different observers may arrive at different numbers for this measurement.

 

However, here's the thing - while coordinates themselves are arbitrary, the relationship between coordinate system is not. It turns out that to go from one observer to another, you just perform a rotation ( and/or boost ) in spacetime, in the same manner as you go from one donut observer to another by rotating the point of view. That is just what Lorentz transformations are - hyperbolic rotations in spacetime. Crucially, rotations and boosts leave the length of 4-vectors invariant, so we can arrive at a description of objects that everyone agrees on by considering not isolated measurements of space and time, but rather separations in spacetime. For example, instead of talking about the height of a building, we could consider the separation of the top of the building from a point at the bottom of the building in terms of a spacetime interval, either a time-like one or a light-like one, and we will then find that all observers agree on this. This does not, however, constitute a frame of reference, since the choice of coordinates is arbitrary for this - the separation in spacetime will be same no matter what labels we choose to give to individual events.

 

As such, there really is no problem at all - observers disagree only because they consider quantities that are based on arbitrary coordinate choices; if they operate with separations in spacetime however, then different observers just means having different perspectives on the same thing. There is only one reality, which is given by invariants such as the metric and various geometric tensors on your spacetime, and everyone agrees on those. So there really is no issue here, just an unfortunate choice of formulation. Go away from coordinate-dependent measurements, and everything becomes very easy and intuitive. And since there is only one reality, it makes no sense to talk about anything being "absolute" or "universal". There's just spacetime and the events in it.

Edited July 29, 2016 by Markus Hanke

[swansont]

 

To me, reality is what it is in its own frame. It is not a convention,

 

 

 

"To me" is subjective, not objective. How can it be anything other than convention?

[michel123456]

 

 

If you place a donut on a table and get 10 different people to look at the donut from different places and angles, they will all see it in different ways; some see it to be bigger than others, some might argue it does not have a hole at all ( if they look at it only sideways e.g. ), some mightn't see it at all ( if they are under the table e.g. ). Nonetheless, they are all talking about the same donut, just from different points of view. The same is true in relativity - events are real and physical, but the labels ( i.e. coordinates ) we give them are not, they are as arbitrary as the name we give to a street on a map. When an observer talks about the "height" of an object such as the building, then this is merely a quantity formed from a specific set of coordinates - since the coordinates are arbitrary, then so is a measure such as height. Different observers may arrive at different numbers for this measurement.

 

However, here's the thing - while coordinates themselves are arbitrary, the relationship between coordinate system is not. It turns out that to go from one observer to another, you just perform a rotation ( and/or boost ) in spacetime, in the same manner as you go from one donut observer to another by rotating the point of view. That is just what Lorentz transformations are - hyperbolic rotations in spacetime. Crucially, rotations and boosts leave the length of 4-vectors invariant, so we can arrive at a description of objects that everyone agrees on by considering not isolated measurements of space and time, but rather separations in spacetime. For example, instead of talking about the height of a building, we could consider the separation of the top of the building from a point at the bottom of the building in terms of a spacetime interval, either a time-like one or a light-like one, and we will then find that all observers agree on this. This does not, however, constitute a frame of reference, since the choice of coordinates is arbitrary for this - the separation in spacetime will be same no matter what labels we choose to give to individual events.

 

As such, there really is no problem at all - observers disagree only because they consider quantities that are based on arbitrary coordinate choices; if they operate with separations in spacetime however, then different observers just means having different perspectives on the same thing. There is only one reality, which is given by invariants such as the metric and various geometric tensors on your spacetime, and everyone agrees on those. So there really is no issue here, just an unfortunate choice of formulation. Go away from coordinate-dependent measurements, and everything becomes very easy and intuitive. And since there is only one reality, it makes no sense to talk about anything being "absolute" or "universal". There's just spacetime and the events in it.

I have no problem with anything you wrote above.

BUT tell me, when observer B that sees no hole in the donut will extend his arm and take the donut at hand, will he get a better information or not? Will he see the hole in the donut or not? Will the donut "truly" lack a hole?

That is the question.

[swansont]

 

Exactly. You will be time dilated for me, and I will be time dilated for you. We agree. But if you insert a 3rd observer that says I am more time dilated than you think I am, you will realize that it is just a matter of measurement. I cannot be time-dilated and double-time-dilated "truly" because someone decided to turn his telescope on me. That is nonsense.

 

Yes, it is nonsense, as we've been saying. There is no "truly" involved whatsoever.

[michel123456]

Because some people here firmly believe that the donut will have no hole. If I understand clearly.

 

Yes, it is nonsense, as we've been saying. There is no "truly" involved whatsoever.

Then why do some people here believe that time dilation and length contraction "truly" happen?

[Strange]

But there are no rock "truly" time dilated in different ways at the same time.

That is not what you said before:

 

Exactly. You will be time dilated for me, and I will be time dilated for you.

 

So your clock runs at two different speeds (the one you see and the one I see).

 

It seems your view of reality is rather inconsistent.

[michel123456]

That is not what you said before:

 

 

So your clock runs at two different speeds (the one you see and the one I see).

 

It seems your view of reality is rather inconsistent.

I don't care about the one YOU see. Exactly as I don't care about what the billions of other humans see at my wrist.

My clock does not change speed because an E.T. passed by the Earth and looked at it.

Edited July 29, 2016 by michel123456