Can you determine absolute motion?

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    Absolute Motion
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SUMMARY

The discussion centers on the concept of absolute motion and the implications of light propagation in a hypothetical apparatus consisting of two concentric spheres. Participants assert that an object cannot determine absolute motion, as all observers measure the speed of light (c) consistently, regardless of their relative motion. The Doppler effect is referenced to explain how light behaves when objects are in motion, emphasizing that the frequency changes, not the speed of light itself. Ultimately, the consensus is that absolute rest cannot be defined, aligning with the principles of relativity.

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  • #61
DaveC426913 said:
Yes. you have shown that, relative to two observers of your choice, they agree that two events have occurred simultaneously.

So what?

That is not absolute. As witnessed by a third observer, who comes in with an equally valid observation and says the events occurred separate in time. And he'd be right.

You still don't get 'absolute'. It does not mean that two observers of your choice agree. Or a hundred. Or a thousand.

You are correct so take out the "limited point of view" since they cannot be trusted. Toss something else into the mix. The Omnipotent Point of view. This view is not limited by space or time.

With this said this OPOV will be able to stop everything as if taking a 3d picture and can then traverse the environment (without time passing for any object).

To determine if Both light A and B flashed at the same time the OPOV analyses each frame of time taken.

This comes back to the difference between Actuality (absolute measurements) and Perception (how it is perceived by others).

In each time frame the OPOV goes to the exact location of Light A.

If light is present in that point in time then move to Light B.

If light exists at Point B then both lights are on at the same time.

He can then go back one unit of time (what ever that would be, second, microsecond, nanosecond ect) and where one moment of time both are off and the next moment in time they are perceived on (according to the OPOV as defined above) then this could be considered the the absolute sense that the lights flashed at the same point in time regardless of how they are perceived by a limited pov.
 
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  • #62
Physicist1231 said:
that setup was mainly for this quote here. not really defining absolute anything. He mentioned that things can only be perceived as simultanious ant at max one point at a time. I was simply showing otherwise.

You're battling trivialities while missing the bigger picture.
 
  • #63
Physicist1231 said:
You are correct so take out the "limited point of view" since they cannot be trusted. Toss something else into the mix. The Omnipotent Point of view.
No!

They can be trusted! They are perfectly correct!

There is no omnipotent point of view!

Argh!
 
  • #64
Physicist1231 said:
You are correct so take out the "limited point of view" since they cannot be trusted. Toss something else into the mix. The Omnipotent Point of view. This view is not limited by space or time.
No such thing as omnipotent PoV

With this said this OPOV will be able to stop everything as if taking a 3d picture and can then traverse the environment (without time passing for any object).
No such thing as an absolute snapshot.

To determine if Both light A and B flashed at the same time the OPOV analyses each frame of time taken.

This comes back to the difference between Actuality (absolute measurements) and Perception (how it is perceived by others).
No such thing as an actual measurement.

In each time frame the OPOV goes to the exact location of Light A.
No such thing.

If light is present in that point in time then move to Light B.

If light exists at Point B then both lights are on at the same time.

He can then go back one unit of time (what ever that would be, second, microsecond, nanosecond ect) and where one moment of time both are off and the next moment in time they are perceived on (according to the OPOV as defined above) then this could be considered the the absolute sense that the lights flashed at the same point in time regardless of how they are perceived by a limited pov.

Physicist1231, this is a complete lack of understanding of Einsteinian spacetime. You are using a classical Newtonian model, where space and time are absolute and unchanging backdrops against which all things can be measured.

The classical Newtonian model has been replaced with the Einsteinian model, which has been shown to be correct in what is arguably the most well-tested theory in the history of science.

The very fundamental principle of Einsteinian relativity is exactly this: simultaneity of events is relative to the observer's frame of reference. All other phenom fall out of this one.

Your arguiments are all based on an out-of-date model that has been shown to be false in literally uncountable experiments.
 
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  • #65
Honestly, I may catch some slack for this because relativity does not explicitly make this claim, but it is actually much easier to understand if you take it a step further in that not only can absolute motion not be measured, but it doesn't exist.
 
  • #66
Physicist1231 said:
He mentioned that things can only be perceived as simultanious ant at max one point at a time. I was simply showing otherwise.

In relativity, different "reference frames" refer to observers that are moving relative to each other. Two observers at different locations, and at rest with respect to each other, both observe the same two events to be simultaneous (or not), after correcting for signal-travel time from the events. Two observers that are moving with respect to each other, differ in their observation of the time interval between two events.

When we talk about a "reference frame" we are talking about the whole collection of possible observers that are stationary with respect to each other, and who are at rest in that reference frame.
 
  • #67
1MileCrash said:
Honestly, I may catch some slack for this because relativity does not explicitly make this claim, but it is actually much easier to understand if you take it a step further in that not only can absolute motion not be measured, but it doesn't exist.

Good point.

(But if one were going to catch anything, it would be not slack, it would be flak. They're kind of opposites. :wink:)

http://en.wikipedia.org/wiki/Flak_(disambiguation)"
 
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  • #68
Too early, they rhyme, close enough. :)
 
  • #69
Don't know if troll... or just very stubborn...
 
  • #70
jeppetrost said:
Don't know if troll... or just very stubborn...

No call for that.
 
  • #71
AFAIK Newton proposed absolute space (such as with his rotating bucket experiment) and it got hammered away a bit by Mach, but then Einstein came forth and basically said "space isn't absolute -- spacetime is." So in other words, the spacetime continuum is an "absolute" concept where you're trading off motion in time for motion in space. Acceleration and gravity, according to Einstein, are the same thing. Space and time fall out of sync in different inertial frames.
 
  • #72
DaveC426913 said:
Physicist1231, this is a complete lack of understanding of Einsteinian spacetime. You are using a classical Newtonian model, where space and time are absolute and unchanging backdrops against which all things can be measured.

The classical Newtonian model has been replaced with the Einsteinian model, which has been shown to be correct in what is arguably the most well-tested theory in the history of science.

The very fundamental principle of Einsteinian relativity is exactly this: simultaneity of events is relative to the observer's frame of reference. All other phenom fall out of this one.

Your arguiments are all based on an out-of-date model that has been shown to be false in literally uncountable experiments.

It is not really a lack of understanding of Einsteinian spacetime rather reviewing history as to why the classical Newtonian model has been replaced with the Einsteinian model.

Doing the research (really getting off topic though) you will find that the notion if time dilation was perceived where an object in motion at a high rate did not seem to tick the same time as it did on earth. This may have been with the satelites in space or perhaps rocket launches. We as the world saw a phenomonon and wanted to find out what was causing this. Galileo tried to do this with the Galilian transformation. This was using the Newtonian modle and the assumption that space and time have rigid values though they can be perceived differently. This proved to be inaccurate (in 3d space where it did work in a one dimensional space, the level of inaccuracy increased as speeds increased). About the same time the failure was noted the Lorentz Transformation came about with a completely new thought process of time and space being flexible. Einstein took this idea and ran with it to develop GR and SR. Thus completely abandoning the Newtonian physics.

This was a very dramatic and rapid change in the scientific thought process. So rapid in fact that no one looked back to see why the Galilean Transformation was incorrect while using Newtonian physics (which ALWAYS worked accuratelty for any previous experiment).

In short things can be explained using Newtonian Physics using a rigid strucutre of spacetime, its just that Galileo failed at that attempt and science ran in a different direction.

One of the largest supporting expiriments that is used to support the theories of SR and GR for time dilation is the Hafele–Keating expiriment. This has since been debunked by even Dr. Keating himself.

http://www.google.com/url?sa=t&source=web&cd=4&ved=0CCoQFjAD&url=http%3A%2F%2Fwww.shaping.ru%2Fcongress%2Fenglish%2Fspenser1%2Fspencer1.asp&ei=yl7JTbnALs3Lswao75CQAw&usg=AFQjCNHWdDddqaNxYeKn-egojeHvd64BRQ

http://www.google.com/url?sa=t&sour...75CQAw&usg=AFQjCNFC78HsYCpF2GNd_dvwtC0_IU0-fg

http://www.google.com/url?sa=t&source=web&cd=9&ved=0CFEQFjAI&url=http%3A%2F%2Fwww.phil-inst.hu%2F~szekely%2FPIRT_BP_2%2Fpapers%2FNAWROT_09_FT.doc&ei=yl7JTbnALs3Lswao75CQAw&usg=AFQjCNGuyJ40-VXlCoDs0uHomjbfDDSZJw

http://www.anti-relativity.com/hafelekeatingdebunk.htm

The raw data was not looked at by majority of the scientific community because of the attitude of "hey they did it and it worked!" rather than looking at the results as to why the original conclusion was that it worked.
 
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  • #73
Wait a second here are you trying to say that time dilation is a farce?
 
  • #74
Physicist1231 said:
We can make it more simple.

Light A is at -10ls,0,0
Light B is at 10ls,0,0
Observer is at 0,0,0

Light A and B emit light at the same time

Provided that the entire setup is motionless the observer will see the lights flash at the same time

Move the observer to 0,5ls,0 and he will observe the same thing just takes a fraction of a second longer to see them.

Move to 0,5ls,5000ls and he will still observe that both happened at the same time. just takes a lot longer to see it.
How does this conflict with jtbell's statement that events are only simultaneous in one frame? If those two observers are at rest in the coordinate system where you are giving the position coordinates, then they are normally said to share the "same frame", it doesn't matter if their positions are different. If the two observers have different velocities and just happen to be at those positions when the light strikes them, then as I already told you before, saying events are simultaneous in your frame is not the same as seeing the light from them simultaneously, in their own frame the activation of light A and B may not have happened at the same distance from their own position, in which case seeing the light from them simultaneously implies they did not occur simultaneously in their own frame.

Nevertheless jtbell's statement is slightly inaccurate if we are talking about a space with more than 1 dimension, in this case it is possible for two frames to judge the same pair of events to be simultaneous, but only if the spatial axis between the events is orthogonal to (at right angles to) the axis of motion between the two frames. For example if two events happen at x=0,y=0,t=0 and x=10,y=0,t=0 in my frame, and you are moving along my y-axis but you have zero velocity along the x-axis, then in your frame the events are still simultaneous.
 
  • #75
Physicist1231 said:
It is not really a lack of understanding of Einsteinian spacetime rather reviewing history as to why the classical Newtonian model has been replaced with the Einsteinian model.
Because it has been shown to be false. You made incorrect assertions. We showed them to be wrong. This should have been a very short thread.

Physicist1231 said:
Galileo tried to do this with the Galilian transformation. This was using the Newtonian modle and the assumption that space and time have rigid values though they can be perceived differently. This proved to be inaccurate (in 3d space where it did work in a one dimensional space, the level of inaccuracy increased as speeds increased). About the same time the failure was noted the Lorentz Transformation came about with a completely new thought process of time and space being flexible. Einstein took this idea and ran with it to develop GR and SR. Thus completely abandoning the Newtonian physics.

This was a very dramatic and rapid change in the scientific thought process. So rapid in fact that no one looked back to see why the Galilean Transformation was incorrect while using Newtonian physics (which ALWAYS worked accuratelty for any previous experiment).

In short things can be explained using Newtonian Physics using a rigid strucutre of spacetime, its just that Galileo failed at that attempt and science ran in a different direction.

So, you are championing classical Newtonian model with fixed background of space and time, or are you here to champion the Galilean Transform? If the former, every experiment in the last 80 years has refuted it. If the latter, why are you not using it to make your case here? Why are we still discussing events of simultaneity in classical Newtonian model with no modifications?

We have been taking your statements at face value. And at face value they are incorrect.

Seems kind of disingenuous to claim that you've been playing your cards close to your chest all along, stringing us along with all this talk of Newtonian classical space and time.

Are you conniving aforethought? Or are you backpedaling to save face? Got to be one of the two.

Perhaps it's time to close this thread and open a new one making your case for the resurgence of the Galilean Transform.
 
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  • #76
Physicist1231 said:
One of the largest supporting expiriments that is used to support the theories of SR and GR for time dilation is the Hafele–Keating expiriment. This has since been debunked by even Dr. Keating himself.

http://www.google.com/url?sa=t&source=web&cd=4&ved=0CCoQFjAD&url=http%3A%2F%2Fwww.shaping.ru%2Fcongress%2Fenglish%2Fspenser1%2Fspencer1.asp&ei=yl7JTbnALs3Lswao75CQAw&usg=AFQjCNHWdDddqaNxYeKn-egojeHvd64BRQ

http://www.google.com/url?sa=t&sour...75CQAw&usg=AFQjCNFC78HsYCpF2GNd_dvwtC0_IU0-fg

http://www.google.com/url?sa=t&source=web&cd=9&ved=0CFEQFjAI&url=http%3A%2F%2Fwww.phil-inst.hu%2F~szekely%2FPIRT_BP_2%2Fpapers%2FNAWROT_09_FT.doc&ei=yl7JTbnALs3Lswao75CQAw&usg=AFQjCNGuyJ40-VXlCoDs0uHomjbfDDSZJw

http://www.anti-relativity.com/hafelekeatingdebunk.htm
I don't think any of these papers has been published in a peer-reviewed mainstream source, you can find all sorts of crackpot claims if you look around at random websites, including authors who apparently misunderstand the techniques used to get final values from the raw data, see the note in blue here. In any case the Hafele-Keating experiment has been repeated at later times with more accurate clocks and the results continue to confirm the predictions of relativity, see for example http://www.npl.co.uk/upload/pdf/metromnia_issue18.pdf where they found:
On return to NPL the traveling clock was predicted to have gained 39.8 ns, including
an additional geometric factor. This compared remarkably well with a measured gain of 39.0 ns. We estimated the uncertainty due to clock instabilities and noise to be around ±2 ns.
 
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  • #77
SeventhSigma said:
Wait a second here are you trying to say that time dilation is a farce?

Not completely. People percieve time differently but this does not mean that Time in an absolute sense is flexible. Just able to be perceived differently. Again the difference between Actuallity and Perception.
 
  • #78
Physicist1231 said:
Not completely. People percieve time differently but this does not mean that Time in an absolute sense is flexible. Just able to be perceived differently. Again the difference between Actuallity and Perception.

But relativity is all about coming to conclusions *after all observations have been made*. Besides, perception is all we have to define our reality, so evidence has to be taken very seriously. And the evidence, to date, points to relativity as being more consistent than the Newtonian sense where "absolute space" is concerned.
 
  • #79
Physicist1231 said:
Not completely. People percieve time differently but this does not mean that Time in an absolute sense is flexible. Just able to be perceived differently. Again the difference between Actuallity and Perception.
In relativity you are free to believe in the "actuality" of absolute space and time (though most people who accept relativity probably see no need for such an idea, as 1MileCrash suggested), as long as you accept that there would be no experimental way to determine the truth about things like absolute velocity and absolute simultaneity. If you think there would be, then you must reject some aspect of relativity, but you're going to have a very hard time constructing a theory that rejects some part of relativity but is consistent with so much experimental evidence that seems to support it.
 
  • #80
DaveC426913 said:
Perhaps it's time to close this thread and open a new one making your case for the resurgence of the Galilean Transform.

Tried that and got shot down and the thread was deleted... so I am asking individual questions to gain a better understanding.
 
  • #81
SeventhSigma said:
But relativity is all about coming to conclusions *after all observations have been made*. Besides, perception is all we have to define our reality, so evidence has to be taken very seriously. And the evidence, to date, points to relativity as being more consistent than the Newtonian sense where "absolute space" is concerned.

So if no one perceives an event did it actually happen? If we only base reality on what we as a group or individuals percieve then we will wind up with holes of unexplained things.

Classic example. If a tree falls in the woods and no one hears it, did it make a noise?
 
  • #82
JesseM said:
In relativity you are free to believe in the "actuality" of absolute space and time (though most people who accept relativity probably see no need for such an idea, as 1MileCrash suggested), as long as you accept that there would be no experimental way to determine the truth about things like absolute velocity and absolute simultaneity. If you think there would be, then you must reject some aspect of relativity, but you're going to have a very hard time constructing a theory that rejects some part of relativity but is consistent with so much experimental evidence that seems to support it.

so what you are saying is that i have a chance?
 
  • #83
Physicist1231 said:
Tried that and got shot down and the thread was deleted... so I am asking individual questions to gain a better understanding.
But your premises are all wrong.

You postulate an omniscient viewpoint where none exists.

You have an arbitrary number of observers at arbitrary locations. They observe some events and disagree on when they occurred.

Start from there.


Physicist1231 said:
So if no one perceives an event did it actually happen? If we only base reality on what we as a group or individuals percieve then we will wind up with holes of unexplained things.

Classic example. If a tree falls in the woods and no one hears it, did it make a noise?
Let's not get philosophical.

In this practical case you have observers. They observe. We need to explain what they observe.
 
  • #84
Physicist1231 said:
so what you are saying is that i have a chance?
Only if by "chance" you mean that it's logically possible to have a theory where almost all phenomena behave as relativity predicts but with some rare and so-far unobserved exceptions that might established a preferred frame (something like a Lorentz ether theory where nearly all phenomena length-contract and time-dilate when moving relative to the preferred frame, but there are a few exceptions). But you don't have a chance if you want to disprove relativity just by thought-experiments and theoretical arguments, it is provably self-consistent mathematically, the only way to show it is flawed would be to go out and do some new experiment no one has ever tried and find clear-cut observations of a phenomena that doesn't obey Lorentz-symmetric laws.
 
  • #85
DaveC426913 said:
But your premises are all wrong.

You postulate an omniscient viewpoint where none exists.

You have an arbitrary number of observers at arbitrary locations. They observe some events and disagree on when they occurred.

Start from there.



Let's not get philosophical.

In this practical case you have observers. They observe. We need to explain what they observe.

You say that none exists. Do you say that becase we have never discovered one? Thousands of years ago if I said that atoms existed I might get the same reaction.
 
  • #86
DaveC426913 said:
So, you are championing classical Newtonian model with fixed background of space and time, or are you here to champion the Galilean Transform?

Actually I would support the Newtonian model but not really the Galilean transform. Galileo had the right idea but the formula was incomplete.
 
  • #87
Physicist1231 said:
You say that none exists. Do you say that becase we have never discovered one? Thousands of years ago if I said that atoms existed I might get the same reaction.

Correct. Thousands of years ago we did not have the scientific method. We've advanced a little since then.

Consequently, in this day and age we try not to explain the universe by resorting to the existence of God and his Omniscient viewpoint.

You'll not make a lot of progress here on PF singing that tune.
 
  • #88
DaveC426913 said:
Correct. Thousands of years ago we did not have the scientific method. We've advanced a little since then.

Consequently, in this day and age we try not to explain the universe by resorting to the existence of God and his Omniscient viewpoint.

You'll not make a lot of progress here on PF singing that tune.

LOL I was not trying to bring The Almightly into this. I could... but won't in this case. I was simply using the Omnipotent POV to express it is not limited to Space and time.

But part of theories is to find out the implications of what you are saying.

If we were (and don't shoot me for saying) to use Newtonian Physics in calculating things like time Dilation then we would not be removing Relativity. Merely, redefining it. Is it completely impossible that NONE of GR and SR is wrong?
 
  • #89
Physicist1231 said:
LOL I was not trying to bring The Almightly into this. I could... but won't in this case. I was simply using the Omnipotent POV to express it is not limited to Space and time.
How can you have the latter without the former? That's a rhetorical question. The latter implies the existence of the former. We do not ascribe to the existence of the former.

An omnipotent PoV is beyond science. You cannot invoke it as a valid argument.


Physicist1231 said:
If we were (and don't shoot me for saying) to use Newtonian Physics in calculating things like time Dilation then we would not be removing Relativity. Merely, redefining it. Is it completely impossible that NONE of GR and SR is wrong?
Why don't you start with the results of the experiments? We have ample evidence of time dilation; Einsteinain SR and GR explain it very well. The Newtonian model does not.

Why are you trying to fix what ain't broke? What is the impetous driving your desire to find another answer when we have an answer?
 
  • #90
Physicist1231 said:
Thousands of years ago if I said that atoms existed I might get the same reaction.
Thousands of years ago the ancient Greek philosophers postulated atoms, that is where the word came from. But that is not the point. The point is that there is no experimental evidence in favor of an absolute reference frame. This means that it is not necessary in order to explain experimental results and, if it exists, it does not significantly impact any experimental data obtained to date.

Physicist1231 said:
I was simply using the Omnipotent POV
The word is "omniscient" meaning all-knowing, not "omnipotent" meaning all-powerful.

Physicist1231 said:
If we were (and don't shoot me for saying) to use Newtonian Physics in calculating things like time Dilation
Nonsense. Time dilation is not part of Newtonian physics.

Re your OP. There is no way to detect absolute motion. Your proposed device would not register any inertial motion effects. You should learn the Lorentz transform and do the derivation yourself. It will be very instructive for you.
 

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