Exploring the Paradox of Time Dilation: Who Experiences Slower Time?

In summary, the conversation discusses the concept of time dilation and its implications in special relativity. It is explained that the amount of accumulated time on a clock depends on its speed, and that two clocks in motion relative to each other will appear to run slower to the other observer. The "twin paradox" is also mentioned, where one twin ages less due to acceleration and a non-inertial frame of reference. The conversation concludes by stating that the amount of accumulated time on a clock depends on its speed and distance traveled.
  • #106


DaleSpam said:
If object A is at rest relative to object B and is therefore absolutely moving then what is object A's absolute speed?
Absolute movement of any parfticluar thing can’t be measured because there is no absolute stationary to measure it against. A thing is always stationary relative to itself but a single thing alone can’t be used to measure it’s own movement. The only movement that can be measured therefore is relative movement. That relative movement exists proves that movements exists. That nothing can be absolutely stationary establishes that all things move in an absolute or universal sense.
 
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  • #107


p764rds said:
Relativity is a consequence of the speed of light not being infinite. If it were infinite, then
there would be only one reference frame and Lorentz invariance would rule.
But in quantum entangled state correlations, 'things' can move at infinite speed. There is only one reference frame then. But the 'things' are quantum state information and not particels/mass etc.
Sorry but none of that makes any sense to me.
 
  • #108


swerdna said:
Yes you CAN be REALLY stationary RELATIVE to something else but this is ONLY a RELATIVE stationary and NOT an ABSOLUTE stationary. In other words, RELATIVE stationary isn’t REALLY stationary in an ABSOLUTE or universal sense. Given that there is ABSOLUTELY no evidence that a thing can ever be ABSOLUTELY stationary then (by default if nothing else) it must be concluded that everything is REALLY always moving in an ABSOLUTE sense (IMHO).

Don’t forget - “Written in layman-speak“
Can't you see that if "absolutely stationary" makes no sense, then "absolutely moving" makes no sense either?

Consider an analogy. Someone on Earth might say "the Moon is above the Earth". An astronaut on the Moon might say "the Earth is above the Moon". Which one is above the other depends on which direction you decide is "up". I hope you will agree, therefore, that the Moon is not absolutely above the Earth. But it doesn't follow that the Moon is absolutely below the Earth.

It is a simple matter of linguistic logic

NOT (absolutely stationary) ≠ absolutely (NOT stationary)​
 
  • #109


DrGreg said:
Can't you see that if "absolutely stationary" makes no sense, then "absolutely moving" makes no sense either?

Consider an analogy. Someone on Earth might say "the Moon is above the Earth". An astronaut on the Moon might say "the Earth is above the Moon". Which one is above the other depends on which direction you decide is "up". I hope you will agree, therefore, that the Moon is not absolutely above the Earth. But it doesn't follow that the Moon is absolutely below the Earth.

It is a simple matter of linguistic logic

NOT (absolutely stationary) ≠ absolutely (NOT stationary)​
The opposite of nonsense is sense. The opposite of absolute stationary is absolute moving . If absolute stationary is “nonsense” then absolute moving is “sense”. If a thing isn’t stationary it’s moving there is no third alternative. That absolute stationary makes no sense establishes that absolutely moving makes sense as it‘s the only thing left.

The relationship between the Earth and the Moon is completely relative. In an absolute or universal sense nothing is ever up, down, faster, slower, etc.
 
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  • #110


swerdna said:
... The opposite of absolute stationary is absolute moving. ...

It is a logical fallacy to take the refutation of a certain claim as the affirmation of an opposite claim. It's a false dichotomy.

If you want "opposite", then take the opposite of "absolute"; not of "stationary". You really really want to use the word "absolute" here for some reason, and so you set up two absolute alternatives. Neither one is correct.

The real situation is that the state of being stationary or in motion is not absolute at all. There is no absolute. Not for being stationary, not for being in motion. Whether an object is in motion or stationary is relative.

Cheers -- sylas
 
  • #111


sylas said:
It is a logical fallacy to take the refutation of a certain claim as the affirmation of an opposite claim. It's a false dichotomy.

If you want "opposite", then take the opposite of "absolute"; not of "stationary". You really really want to use the word "absolute" here for some reason, and so you set up two absolute alternatives. Neither one is correct.

The real situation is that the state of being stationary or in motion is not absolute at all. There is no absolute. Not for being stationary, not for being in motion. Whether an object is in motion or stationary is relative.

Cheers -- sylas
Seems to be turning into a semantic debate. I’m happy to use the term “universal” rather than “absolute” if that’s more acceptable.

If things didn’t move relative to other things then everything would be universally stationary. The reality is however that things do move relative to other things and that means there is nothing that is universally stationary. Everything is always moving relative to something else universally.

There can be relative movement and relative stationary but there can’t be universal stationary. There is always movement universally regardless that some things are relatively stationary.
 
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  • #112


swerdna said:
Seems to be turning into a semantic debate. I’m happy to use the term “universal” rather than “absolute” if that’s more acceptable.

I'll stick with the word "relative". Motion is only meaningful relative to something else.

... Everything is always moving relative to something else universally.

You are much better just to leave out the word "universally". It leads you into inconsistency.

Your first sentence makes good sense if you leave off that redundant word.
Everything is always moving relative to something else.

The reason you should omit that additional word is because EXACTLY THE SAME THING holds for being stationary.
Everything is always stationary relative to something else.

There can be relative movement and relative stationary but there can’t be universal stationary. ...

There's your inconsistency. The only sense in which there is "universal motion" applies just as well to say "universal stationary". Just like everything is always moving relative to something else, so too everything is always stationary relative to something else.
 
  • #113


sylas said:
The real situation is that the state of being stationary or in motion is not absolute at all. There is no absolute. Not for being stationary, not for being in motion. Whether an object is in motion or stationary is relative.

sylas said:
I'll stick with the word "relative". Motion is only meaningful relative to something else.



You are much better just to leave out the word "universally". It leads you into inconsistency.

Your first sentence makes good sense if you leave off that redundant word.
Everything is always moving relative to something else.

The reason you should omit that additional word is because EXACTLY THE SAME THING holds for being stationary.
Everything is always stationary relative to something else.



There's your inconsistency. The only sense in which there is "universal motion" applies just as well to say "universal stationary". Just like everything is always moving relative to something else, so too everything is always stationary relative to something else.
What about acceleration? There’s nothing relative about acceleration.

As diazona said in post #37 - “something can be assumed to be moving in an absolute sense, if it is accelerating”. You seemed to agree with him/her at the time.
 
  • #114


swerdna said:
What about acceleration? There’s nothing relative about acceleration.

Whether you are in motion or stationary is relative.
Whether you are accelerating or inertial is absolute.

This is not hard.

I got to ask, what is the point here? Are you just trying to twist things into contradictions, or are you seriously still not understanding basic relativity?

The measurement of acceleration as a number is still relative to an observer; but you can define a "proper" acceleration as being the acceleration of an object as measured in the inertial frame where it is (instantaneously) with a velocity of zero. That still leaves the direction of acceleration as relative, but it does give an unambiguous absolute magnitude for "proper acceleration".
 
  • #115


sylas said:
Whether you are in motion or stationary is relative.
Whether you are accelerating or inertial is absolute.

This is not hard.

I got to ask, what is the point here? Are you just trying to twist things into contradictions, or are you seriously still not understanding basic relativity?

The measurement of acceleration as a number is still relative to an observer; but you can define a "proper" acceleration as being the acceleration of an object as measured in the inertial frame where it is (instantaneously) with a velocity of zero. That still leaves the direction of acceleration as relative, but it does give an unambiguous absolute magnitude for "proper acceleration".
It’s not so much a difficulty of understanding basic Relativity. It’s a difficulty in accepting the validity of one of the basic building blocks that Relativity is founded on. If I could accept that the building block was valid I don’t see that I would have much difficulty in accepting basic Relativity. It’s more to do with accepting than understanding. Although I guess it’s more than likely that my lack of acceptance is a result of my lack of understanding. I’m not trying to be clever or difficult. I’m trying find out what the truth is.

When you are accelerating you are absolutely in motion (no relativeness required).
When you are inertial you are not absolutely stationary.
 
  • #116


swerdna said:
When you are accelerating you are absolutely in motion (no relativeness required).
When you are inertial you are not absolutely stationary.

Are you aware that this is true in Newtonian physics, not just special relativity?

Also, are you aware that the statements mean:
1. When you are accelerating you are absolutely in motion (no relativeness required). = When you are accelerating relative to a particular inertial frame, you are accelerating relative to all inertial frames.
2. When you are inertial you are not absolutely stationary. = When you are stationary relative to a particular inertial frame, you are not stationary relative to all inertial frames.
 
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  • #117


atyy said:
Are you aware that this is true in Newtonian physics, not just special relativity?

Also, are you aware that the statements mean:
1. When you are accelerating you are absolutely in motion (no relativeness required). = When you are accelerating relative to a particular inertial frame, you are accelerating relative to all inertial frames.
2. When you are inertial you are not absolutely stationary. = When you are stationary relative to a particular inertial frame, you are not stationary relative to all inertial frames.
Yes, but I don’t understand the point of your question. Care to explain it?
 
  • #118


swerdna said:
Yes, but I don’t understand the point of your question. Care to explain it?

So those are the 2 statements you can't accept?
 
  • #119


atyy said:
Are you aware that this is true in Newtonian physics, not just special relativity?

Also, are you aware that the statements mean:
1. When you are accelerating you are absolutely in motion (no relativeness required). = When you are accelerating relative to a particular inertial frame, you are accelerating relative to all inertial frames.
Yes.
atyy said:
2. When you are inertial you are not absolutely stationary. = When you are stationary relative to a particular inertial frame, you are not stationary relative to all inertial frames.
Yes. You can only ever be stationary to one particular inertial frame at at time because all inertial frames always move relatrive to all other inerttial frames. This was covered and agreed earlier in the thread.
 
  • #120


atyy said:
So those are the 2 statements you can't accept?
No. I fully accept both statements. I made them. I don't accept sylas’s claim that - “Whether you are in motion or stationary is relative”.
 
  • #121


swerdna said:
No. I fully accept both statements. I made them. I don't accept sylas’s claim that - “Whether you are in motion or stationary is relative”.

Oh, I see. I believe sylas's claim is simply the traditional short hand for those two statements.
 
  • #122


atyy said:
Oh, I see. I believe sylas's claim is simply the traditional short hand for those two statements.
Doesn't make it any less wrong.
 
  • #123


swerdna said:
Doesn't make it any less wrong.

:confused: I thought you accepted the 2 statements? Or are you saying that it is not acceptable short hand for the 2 statements?
 
  • #124


atyy said:
:confused: I thought you accepted the 2 statements? Or are you saying that it is not acceptable short hand for the 2 statements?
What are you drinking? Doesn’t make Sylas’s statement - “Whether you are in motion or stationary is relative” any less wrong. Nothing to do with the statements I made. Sylas made that statement before I made mine.
 
  • #125


swerdna said:
What are you drinking? Doesn’t make Sylas’s statement - “Whether you are in motion or stationary is relative” any less wrong. Nothing to do with the statements I made. Sylas made his/her statement before I made mine.

Well, if sylas's statements have the same meaning as statements you consider correct, how can you consider them wrong?
 
  • #126


atyy said:
Well, if sylas's statements have the same meaning as statements you consider correct, how can you consider them wrong?
“Whether you are in motion or stationary is relative” (sylas) and “When you are accelerating you are absolutely in motion (no relativeness required)” (me) are NOT the “same meaning“. Please read at least some of the thread before commenting on it.
 
  • #127


swerdna said:
“Whether you are in motion or stationary is relative” (sylas) and “When you are accelerating you are absolutely in motion (no relativeness required)” (me) are NOT the “same meaning“. Please read at least some of the thread before commenting on it.

So you disagree with the traditional shorthand, which is fair enough. That means you have no problem with special relativity?
 
  • #128


atyy said:
So you disagree with the traditional shorthand, which is fair enough. That means you have no problem with special relativity?
How can sylas’s statement be a shorthand response to my statement when his statement was made first Is he psychic?

Whatever it is that you are drinking I think you really have had more than enough.
 
  • #129


Stationary can only exist in a relative sense and not an absolute sense.

Motion can exist in a relative sense and also in an absolute sense in the form of acceleration.
 
  • #130


swerdna said:
Stationary can only exist in a relative sense and not an absolute sense.

Motion can exist in a relative sense and also in an absolute sense in the form of acceleration.

Sure, that's understandable short hand for the 2 statements. So you accept special relativity?
 
  • #131


atyy said:
Sure, that's understandable short hand for the 2 statements. So you accept special relativity?
You’re just pulling my leg aren’t you. Very funny.
 
  • #132


swerdna said:
You’re just pulling my leg aren’t you. Very funny.

So which part of special relativity don't you accept?
 
  • #133


atyy said:
So which part of special relativity don't you accept?
If you are actually interested read the thread.
 
  • #134


swerdna said:
If you are actually interested read the thread.

Which post? I can only tell you think you disagree with special relativity. I can't tell that you disagree with special relativity.
 
  • #135


swerdna said:
Written in layman-speak . . .

An inertial frame is defined by non-accelerating things that don’t move relative to each other.

Sure. Better: an inertial frame is defined as a frame in which the laws of physics look "pretty", eg. in which Maxwell's equations have their "standard" form. The reason this is better is that you have used "non-accelerating" without specifying whether it is non-accelerating relative to an inertial or a non-inertial frame. Your statement is true if "non-accelerating" is defined relative to an inertial frame. But then you would have used "inertial frame" in the definition of "inertial frame".

swerdna said:
No inertial frame can be stationary relative to any other inertial frame. It follows therefore that all inertial fames move relative to all other inertial frames.

Yes.

swerdna said:
There is absolutely no evidence that anything can ever be absolutely stationary. It follows therefore that no inertial frame can be absolutely stationary.

Yes, provided "absolutely" means "relative to all inertial frames".

swerdna said:
In other words inertial frames are always relatively and absolutely in motion.

Anything wrong with any of this?

This is wrong, if "absolutely" means "relative to all inertial frames", since each inertial frame is not in motion relative to itself, so it is not in motion relative to all inertial frames.
 
  • #136


Is the term “a thing is stationary relative to itself” really valid? Relative is one thing compared to another thing. For a thing to be relative to itself wouldn't it have to have multiple existence? How can a thing be relative to itself? A thing is itself. Stationary only exists as a relative situation so how can it be attributed to a situation that isn’t relative? A thing is in motion when it’s accelerating but acceleration isn’t a relative situation. I know I’ve used this term many times myself, but on reflection I thinks it’s nothing more than a nonsense
 
  • #137


swerdna said:
Is the term “a thing is stationary relative to itself” really valid? Relative is one thing compared to another thing. For a thing to be relative to itself wouldn't it have to have multiple existence? How can a thing be relative to itself? A thing is itself. Stationary only exists as a relative situation so how can it be attributed to a situation that isn’t relative? A thing is in motion when it’s accelerating but acceleration isn’t a relative situation. I know I’ve used this term many times myself, but on reflection I thinks it’s nothing more than a nonsense

I think it's ok.

But suppose it's not, that would still not make an inertial frame in motion relative to itself, so an inertial frame would not be in motion relative to all inertial frames, so it would not be in "absolute" motion, where "absolute" means "relative to all inertial frames".

Also, "acceleration is not relative" or "acceleration is absolute" is the traditional short hand for "acceleration is the same relative to all inertial frames".
 
  • #138


If I designed a 3D space (a big one) in a computer, then would relativity apply there to the objects I placed in it?
I was trying to work it out in my mind the other night, but got confused. Let's say I designed in a velocity of light (information) too. Probably no takers.. it was just a thought.
 
  • #139


swerdna said:
Is the term “a thing is stationary relative to itself” really valid? Relative is one thing compared to another thing. For a thing to be relative to itself wouldn't it have to have multiple existence? How can a thing be relative to itself? A thing is itself. Stationary only exists as a relative situation so how can it be attributed to a situation that isn’t relative? A thing is in motion when it’s accelerating but acceleration isn’t a relative situation. I know I’ve used this term many times myself, but on reflection I thinks it’s nothing more than a nonsense

BTW, I can't resist - have you heard of the man and his Ba? I think he tells his Ba not to leave him. Naively I understand a man's Ba to be himself, so the man is telling himself not to leave himself - how can that be? :confused: :smile:
 
  • #140


p764rds said:
If I designed a 3D space (a big one) in a computer, then would relativity apply there to the objects I placed in it?
I was trying to work it out in my mind the other night, but got confused. Let's say I designed in a velocity of light (information) too. Probably no takers.. it was just a thought.
What, you mean like a simulation? Not necessarily... the appeal of simulating things on the computer is that you can program in any physical laws you want. You could make your virtual world follow the laws of relativity if you want, or you could make it follow the laws of nonrelativistic mechanics (but then you'd run into trouble with Maxwell's equations, if EM fields existed in your virtual world).
 

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