Gravity is Time

[Eric 5]

Originally Posted by Eric 5

If physical matter really does contract, then physical forces are at work. A physical force would act on this matter to make it shorter, and a physical force would have to bring it back to its original shape

 

 

 

"really does" implies that there is a preferred reference frame, where one can measure an objective "truth" of the universe. And relativity tells us there isn't. It can't be a mundane physical force, because you will observe contraction or dilation of some other object if you are moving with respect to it (which cannot be distinguished from the situation of it moving with respect to you) — so there is no force acting on the object. It all boils down to the transformation between reference frames being nonlinear, and the physics working in all of those frames.

 

Do you think that physical objects physically contract during this phenomenon?

 

Length contraction means that different observers find lengths to be different. There is no "actual" length because you cannot define which observer is right. If you wish to argue otherwise, I suggest you provide proof. What you are doing right now is worming your way towards being banned.

 

All objects have a size and shape whether they are observed or not, agree?

 

Do you think that just by observing an object, that object will change length?

 

You say that length contraction means different observers find lenghts to be different. What makes the length of the object different for each observer?

 

I am interested in finding out more on this subject.

 

Thank You.

 

Eric 5

[swansont]

Originally Posted by Eric 5

If physical matter really does contract, then physical forces are at work. A physical force would act on this matter to make it shorter, and a physical force would have to bring it back to its original shape

 

 

 

 

 

Do you think that physical objects physically contract during this phenomenon?

 

 

 

All objects have a size and shape whether they are observed or not, agree?

 

Do you think that just by observing an object, that object will change length?

 

You say that length contraction means different observers find lenghts to be different. What makes the length of the object different for each observer?

 

I am interested in finding out more on this subject.

 

Thank You.

 

Eric 5

 

 

"Really does contract" implies a preferred frame, and that doesn't exist. Length is not an invariant quantity — it depends on the frame of reference you are in when doing the measurement. Any observer staying in one frame will not see anything change.

 

Observers in different frames won't agree on the measurement. The comparison of those measurements cannot be defined as "change"

[Slinkey]

Nothing wrong with being wrong, though, as long as you learn something.

 

As Timothy Leary said "I love the words 'I don't know' as I know I am about to learn something".

 

Water turning into ice can do work. There has to be a force, and it's the electrostatic force between the atoms.

 

I did think about that but didn't consider it a force in the same sense as Eric 5 meant it. ie. there is no force outside the ball compressing or decompressing it, but as you say, it can do work so therefore there must be a force to do that work. Bah!

 

The easiest way to understand the logic behind length contraction is with muon decay as it is well documented.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/muon.html

 

What you have to sort out in your mind first and foremost is the idea of reference frame as you seem to be having difficulty grasping it.

[Eric 5]

"Really does contract" implies a preferred frame, and that doesn't exist. Length is not an invariant quantity — it depends on the frame of reference you are in when doing the measurement. Any observer staying in one frame will not see anything change.

 

Observers in different frames won't agree on the measurement. The comparison of those measurements cannot be defined as "change"

 

If there are three observers in three different frames of reference observing the same physical object, they will observe that object being at a different length than the other frames of reference. That object is a physical thing. That object is at the effect of the laws of nature. If that object is going to change shape then there are physical forces at work.

 

So if three different observers in three different frames of reference observe the physical object at different lengths from the other frames of reference then are you going to say that the physical object is three different physical sizes at the same time?

 

 

Observers in different frames won't agree on the measurement. The comparison of those measurements cannot be defined as "change"

 

 

It does not matter if the observers disagree on the measurement. The object is the size that it is without any regard to what some observer thinks its size is. The object has a size before it is observed. Are you suggesting that objects are deciding what size to be by what frame of reference they are being observed from? Do you realize that by saying that objects are what size they are after being observed is saying that the objects physical size is effected by observation, and that object has to know what frame of reference that the observer is occupying in order to be the size that is appropriate to that frame of reference. In order to observe anything you have to receive light from that object. So, if the object is physically smaller when light was reflected off it, that object has to know in advance what size to be.

 

 

 

Or you could just say that the object APPEARS to be smaller, but in actuality it is not physically contracted.

 

So you see the question is; Does the object really contract or does it appear to contract. What do you think?

[swansont]

The object is the size that it is without any regard to what some observer thinks its size is.

 

That's the basic conceptual obstacle with which you keep colliding. There is no inherent length of an object — it is a function of your reference frame. What you are describing is called the "proper length" of the object — the length measured in its rest frame.

 

The thing is, if you want to do any useful physics, you have to use the contracted length and dilated time for a moving object. If you try and use the proper length and proper time, you get the wrong answer. If we assume that the laws of physics are the same in all frames, the contraction and dilation have to be real.

[Eric 5]

That's the basic conceptual obstacle with which you keep colliding. There is no inherent length of an object — it is a function of your reference frame. What you are describing is called the "proper length" of the object — the length measured in its rest frame.

 

 

Is this whole thing a concept and not a physical reality? You see if length contraction were a physical occurrence then you would have to state that I do not understand the physics behind this occurrence not the concept.

 

An object exist physically right? An object has an atomic structure. That atomic structure is already in existence before that object is observed. There are objects existing right now that are unseen that exist and take up space and have a location. No two objects can occupy the same space at the same time. This means that an object has a certain size that prevents other object from occupying its space, so objects do have an influence on other objects in that all objects have an inherent area of occupation by that object. If these objects are never observed they still remain as a physical object with a specific size that influence other objects. So objects are a certain size regardless of if they are observed or not, Right?

 

We can see an object so it physically exists. Are you going to tell me that an object only exists because it is being observed? That is basically what you are saying, an object does not have a size until it is observed. Than the observer is responsible for the objects physical size.

 

Are you suggesting that all of the fossils that have a certain size did not gain that size until they were observed? There are objects that left impressions of what size they were without ever being observed. These objects had a physical size, so yes objects do have an inherent size.

 

You will have to believe that physical objects have zero size until they are observed. Where is the science behind the idea that mere reflection of light from an object can physically change the shape of an object to fit the frame of reference of the observer. You have to understand that you are putting the effect before the cause. The physical size of the object was undetermined until it was observed, and that observation of the object is the observation of the light reflected off that object. So in essence that object had to know in advance what size to be in accordance to your frame of reference, before the light that you see being reflected off that object reaches your eyes. The size of object is being effected by your frame of reference before you actually recieve the reflected light from that object. the object has to know in advance what size to be before the light that is going to be reflected off of it to your frame of reference. The object was the appropriate size to your frame of reference BEFORE the light that was reflected off of it to you. Do you really think that your observation of an object physically determines its size?

[Cap'n Refsmmat]

Is this whole thing a concept and not a physical reality?

No.

[Eric 5]

Originally Posted by Eric 5

Is this whole thing a concept and not a physical reality?

 

 

No.

 

Alright, so you believe that length contraction is a physical reality. Right?

 

After reading my post that you were answering, can you give some explaination on how objects will physically contract to fit the frame of reference of the observer?

 

After reading my whole post, the only comment that you can make is that you do not agree that length contraction is a concept. Is that the only point that you disagree with about my post? Can I assume that you only find a disagreement in the first sentence of my post and the rest you agree with.

 

You really did not say much. Did you read the whole post?

[iNow]

Eric,

 

You still appear to be approaching this issue as if "length" is somehow an inherent property of objects. It's not, as has been repeated several times in this over 80 post thread.

 

No matter how many times you continue asking the same question, the answer will remain the same.

[Eric 5]

Eric,

 

You still appear to be approaching this issue as if "length" is somehow an inherent property of objects. It's not, as has been repeated several times in this over 80 post thread.

 

No matter how many times you continue asking the same question, the answer will remain the same.

 

 

O.K. Lets get to the basics here. Do objects physically exist? I say yes.

 

If you say yes, then do these objects occupy a location in space? I say yes.

 

If you say yes, then can there be objects that exist in a location without ever being observed? I say yes.

 

What say you?

[Slinkey]

Eric 5, consider this question please:

 

Two trains are travelling towards a station from opposite directions.

 

Train A is moving at 0.8c. (these are exceptionally fast trains).

 

Train B is moving at 0.6c.

 

On the platform is a bench.

 

As train A passes the bench it measures the bench to be 6m. long.

 

As train B passes the bench it measures the bench to be 8m long.

 

 

How long is the bench?

[Klaynos]

A better question would be:

 

If you say yes, then do these objects occupy a location in space-time? I say yes.

[Slinkey]

 

Cough

[insane_alien]

the bench would be 10m in its own frame. but it doesn't make the other measurements wrong.

[Zephir]

Simply put: gravity = time.

Why we should consider this insight?

Which new testable predictions we can derive from the above claim?

[Slinkey]

Zephir,

It's not a claim. If you had bothered to actually read this thread you would already know that.

 

the bench would be 10m in its own frame. but it doesn't make the other measurements wrong.

 

Indeed. It doesn't make them wrong. This is precisely what we are trying to get across to Eric 5 - the length is dependent on the frame of reference.

[insane_alien]

oh sorry, i didn't see the bit where it was aimed at eric 5. whoopsee.

[Eric 5]

Eric 5, consider this question please:

 

Two trains are travelling towards a station from opposite directions.

 

Train A is moving at 0.8c. (these are exceptionally fast trains).

 

Train B is moving at 0.6c.

 

On the platform is a bench.

 

As train A passes the bench it measures the bench to be 6m. long.

 

As train B passes the bench it measures the bench to be 8m long.

 

 

How long is the bench?

 

 

 

How nice, a word problem.

 

If I was to believe that length is dependent on an observers frame of reference, then my answer to the question “How long is the bench” would be, the length of the bench depends on my frame of reference. Both measurements from both trains are right. But I do not believe that an objects length is dependent on the frame of reference of the observer, and since I think there is another possibility than the two choices that you gave me, I am going to have to complain that your question is a false dichotomy, your set of options are incomplete. (Ha. Ha). I am sorry, I had to say that. You have to admit that was a bit funny.

 

 

Anyway, I would really like to answer your question but since I do not see things your way in regards to this length contraction business, I will need a bit more info than you gave me. Here is what I would like established and on record.

 

1. Is the bench a physical object?

2. Does the bench occupy a location in space?

3. Did this bench have a length before the trains passed it? If so how long was it?

 

From what I have seen and learned about the world around me I would have to think that the bench is a physical thing, occupies a location in space and since it is a physical object it has a size despite the fact that it is being observed or not, so I would say the bench has a length before the trains passed. If you do not think this is a correct line of logic, please tell me what you think. I would be curious to hear your reasoning.

 

I would also like to say that just because I disagree with the idea that length or size of an object is all dependent on what frame of reference that the object is being observed from does not mean that I think that you are wrong and I am right. I would really like to understand your point of view on this whole idea. The questions that I asked in the above section of this post are the questions that I ask myself when thinking about the trains passing a bench and getting different measurements. I am just showing you where I am coming from on this topic so that you do not think that I am just trying to disagree with you just for the fun of it. I would truly like to see things from your point of view on this. I just do not see how a physical object is subject to a change in length just by the pure observation from a different frame of reference.

 

If your answers to the above questions are different than the way I see things than please explain your line of reasoning. I would like to hear it. This goes for anyone who agrees that the physical length of an object is dependent on an observers frame of reference.

 

Thank You.

 

Eric 5

[swansont]

The "point of view" is very straightforward. It stems from the postulate that the speed of light is constant in all inertial frames. Length contraction is a direct consequence.

[Klaynos]

The "point of view" is very straightforward. It stems from the postulate that the speed of light is constant in all inertial frames.

 

Which itself is a result of electrodynamics, and Maxwell's equations.

[Eric 5]

The "point of view" is very straightforward. It stems from the postulate that the speed of light is constant in all inertial frames. Length contraction is a direct consequence.

 

 

 

So is the bench at the train station a physical object?

 

Does the bench occupy a location in space?

 

Did the bench have a length before the trains passed? If so how long was it?

 

From your above statement it sounds like objects appear to contract, but do not physically contract, is that what you are saying? If not, then by responding to the above questions you could clear things up on how the "point of view" is very straightforward.

 

Thank You.

 

Eric 5

[swansont]

So is the bench at the train station a physical object?

 

Does the bench occupy a location in space?

 

Did the bench have a length before the trains passed? If so how long was it?

 

From your above statement it sounds like objects appear to contract, but do not physically contract, is that what you are saying? If not, then by responding to the above questions you could clear things up on how the "point of view" is very straightforward.

 

Thank You.

 

Eric 5

 

The length of the bench depends on what frame you are in. It does not have an intrinsic length that can be absolutely determined. The best you can do is define its proper length.

[Slinkey]

So is the bench at the train station a physical object?

 

Yes.

 

Does the bench occupy a location in space?

 

Depending on your frame of reference there can be disagreement about how much space it occupies.

 

Did the bench have a length before the trains passed? If so how long was it?

 

It is different for anyone in non-mutual reference frames.

 

I notice you didn't answer the questions I gave you with the bench example. One person measures it as 8m and the other as 6m. So how long is the bench, Eric?

 

From your above statement it sounds like objects appear to contract, but do not physically contract, is that what you are saying? If not, then by responding to the above questions you could clear things up on how the "point of view" is very straightforward.

 

If an object changes shape then we try to discern why it changes shape. We don't exclaim "it didn't really change shape though".

 

Thank You.

 

You're welcome.

 

In my hand I have an object. How long is it, Eric?

 

You don't know? Then how can we know if anything has any dimensions unless we look at it in some way? Your question "Does the bench have a length when no one is looking?" is an insensible question as it assumes we can know something before we know it.

 

We only know the length of the bench from measuring it and, has been relayed to you countless times, the length depends on your frame of reference.

 

As Swanson told you: the "best" you can do is find its proper length. ie. the length you measure it to be when you are in the same reference frame as the bench.

 

In the example I gave the proper length of the bench is 10m, but for the two moving observers the length is not 10m and is dependent on their motion relative to the bench.

[Eric 5]

The length of the bench depends on what frame you are in. It does not have an intrinsic length that can be absolutely determined. The best you can do is define its proper length.

 

We are talking of length contraction here, so the length of the bench has to contract from a prior length. The bench has a length before it contracts. What is the length of the bench before any observer from any frame of reference measures it? The bench contracted from an initial length, a length that was present before it was observed.

[iNow]

We are talking of length contraction here, so the length of the bench has to contract from a prior length.

Only relative to an external observer. Length is not an inherent property, as has been REPEATEDLY pointed out to you.

 

The bench has a length before it contracts.

Again, length is not an inherent property of the bench, but a measurement relative to the reference frame of the observer.

 

Once you wrap your head around the fact that there is no absolute reference frame much of your confusion will be ameliorated.

 

 

What is the length of the bench before any observer from any frame of reference measures it?

Well, since length is dependent on reference frame, I suggest that your question is meaningless (trying to describe length without using a frame of reference).

 

 

The bench contracted from an initial length, a length that was present before it was observed.

 

Relative to whom?

 

 

I know it's not intuitive, but it's still true. People here will try to help you resolve your confusion, but you have to put the same effort in return.