The Relativity of Simultaneity: A Fundamental Concept in Special Relativity

In summary, RoS is a consequence of time dilation, which is a feature of the Lorentz transform. It is not a separate stand-alone component of SR.
  • #316
mangaroosh said:
[..] If there is a universal present moment, then events which are simultaneous in the universal present, are simultaneous for all observers; that is, they are simultaneous in my present, and in your present, and we share the same present moment.

RoS is not compatible with that.
Well ... after many weeks of discussions and explanations, you keep on denying that observers can not know true simultaneity. However, we explained that that is a basic result of SR that is related to RoS which directly follows from the Lorentz transformations, as we also showed. So, take it or leave it!
 
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  • #317
mangaroosh said:
The question also remains as to whether RoS is a philosophical interpretation of clock synchronisation;
RoS is not a philosophical interpretation, but a consequence of what can actually be measured and applies equally to SR and LET.
mangaroosh said:
insofar as RoS refers to events which are simultaneous in one reference frame being non-simultnaeous in another, it is not compatible with the concept of presentism provided. If LET is compatible with that concept of presentism, then it suggests that RoS cannot be a necessary consequence of the LT, because RoS is not compatible with presentism.
Assuming that presentism is the notion of a absolute reference frame that defines a universal "now" (as embodied in Newtonian physics) then SR says IF there is a universal reference frame it cannot be detected and LET says there IS a universal reference frame, but it cannot be detected. Both theories acknowledge that the universal reference frame is undectable. Both SR and LET agree that by any measurements any observers with relative motion will disagree on the simultaneity of events. RoS is a consequence of the LT in both SR and LET. IF presentism is the concept of a universal "now" that can be measured, then presentism is incompatible with both LET and SR, but is compatible with Newtonian physics which has been shown to be wrong by experimental evidence.
mangaroosh said:
So, the question of presentism being a philsophical viewpoint does not resolve the issue, because RoS is arguably a philopsophical viewpoint also - regardless of the assertions to the contrary.
We cannot measure a universal "now" or conduct any experiments that can detect a universal absolute reference frame but we can measure RoS. Therefore presentism is philosophical (unmeasurable) and RoS is not philosophical, in that it can be measured.
mangaroosh said:
The question of whether or not presentism is compatible with, or incorporated into, LET would help to resolve the issue.
Presentism, in a form that can be measured, is not compatible with LET.
mangaroosh said:
Insofar as LET is based on Newtonian, or Galielan time and space, then it suggests that LET does not allow for events that are simultaneous in one reference frame to be non-simultaneous in another.
LET is not based on Newtonian or Galilean time and space. In Newtonian physics, time as measured by clocks and space as measured by rulers is absolute. LET on the other hand has time dilation and length contraction and so time measured by clocks and space measured by rulers is not absolute in LET.
mangaroosh said:
Is RoS compatible with Newtonian physics, and Galilean relativity?
No, it is not.
mangaroosh said:
It's been mentioned that LET is essentially based on the Newtonian concepts of time and space, and Galilean relativity. If that is correct, and RoS is not compatible with those, then it probably means that RoS is not compatible with LET, I would think.
That is not correct.
mangaroosh said:
It might be worth asking if Newtonian mechanics allowed for RoS, or did it incorporate the idea of a universally shared present moment?
Newtonian mechanics does not allow for RoS but it did have a universally shared present moment. Newtonian mechanics has been experimentally shown to be incorrect.
 
  • #318
mangaroosh said:
I wasn't sure of the answer, as to what the experimental consequences of presentism are,
Well, once you have clarified the question then we can work on answering it.

mangaroosh said:
I think it would have experimental consequences, similar in nature to the Principle of Relativity; I probably risk an infraction by stating what they are though, as I suspect it might be classified as a personal theory. I would probably need express permission to do so.
If it has experimental consequences then the only reason it would be a taboo topic is if those predictions were contrary to existing observations, in which case presentism is already falsified.

mangaroosh said:
Is RoS compatible with Newtonian physics, and Galilean relativity?
No, the Galilean transform does not have RoS.

mangaroosh said:
If there is a universal present moment, then events which are simultaneous in the universal present, are simultaneous for all observers; that is, they are simultaneous in my present, and in your present, and we share the same present moment.
Prove it. Simultaneity is well defined, as are the transformations between reference frames. If your concept of the universal present works as you say then you should be able to start with one reference frame and two events which are simultaneous in the universal present, show that those events are simultaneous for some observer, transform to another observer moving at an arbitrary velocity relative to the first, and prove that they are simultaneous for that observer also.
 
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<h2>What is the theory of relativity?</h2><p>The theory of relativity is a fundamental concept in physics that explains how the laws of physics are the same for all observers in uniform motion. It is divided into two parts: special relativity, which deals with objects moving at constant speeds, and general relativity, which deals with objects in accelerated motion or in the presence of gravity.</p><h2>What is the relativity of simultaneity?</h2><p>The relativity of simultaneity is a concept in special relativity that states that the perception of simultaneity (two events happening at the same time) is relative to the observer's frame of reference. In other words, two events that appear simultaneous to one observer may not appear simultaneous to another observer in a different frame of reference.</p><h2>How does the relativity of simultaneity affect the measurement of time?</h2><p>The relativity of simultaneity has a significant impact on the measurement of time. In special relativity, time is not absolute and is relative to the observer's frame of reference. This means that two observers moving at different speeds may measure different amounts of time for the same event. This effect becomes more pronounced as the speed of the observers approaches the speed of light.</p><h2>What is the thought experiment used to explain the relativity of simultaneity?</h2><p>The most famous thought experiment used to explain the relativity of simultaneity is the "train and platform" scenario. In this experiment, two observers on a moving train and on a stationary platform observe a lightning strike at the same time. However, due to the relativity of simultaneity, the observers will perceive the lightning strike at different times.</p><h2>What are some real-world applications of the relativity of simultaneity?</h2><p>The relativity of simultaneity has many real-world applications, particularly in the fields of physics and engineering. For example, it is essential to consider the relativity of simultaneity when synchronizing clocks in GPS satellites to ensure accurate navigation. It also plays a crucial role in understanding the behavior of particles in particle accelerators and the effects of time dilation in space travel.</p>

What is the theory of relativity?

The theory of relativity is a fundamental concept in physics that explains how the laws of physics are the same for all observers in uniform motion. It is divided into two parts: special relativity, which deals with objects moving at constant speeds, and general relativity, which deals with objects in accelerated motion or in the presence of gravity.

What is the relativity of simultaneity?

The relativity of simultaneity is a concept in special relativity that states that the perception of simultaneity (two events happening at the same time) is relative to the observer's frame of reference. In other words, two events that appear simultaneous to one observer may not appear simultaneous to another observer in a different frame of reference.

How does the relativity of simultaneity affect the measurement of time?

The relativity of simultaneity has a significant impact on the measurement of time. In special relativity, time is not absolute and is relative to the observer's frame of reference. This means that two observers moving at different speeds may measure different amounts of time for the same event. This effect becomes more pronounced as the speed of the observers approaches the speed of light.

What is the thought experiment used to explain the relativity of simultaneity?

The most famous thought experiment used to explain the relativity of simultaneity is the "train and platform" scenario. In this experiment, two observers on a moving train and on a stationary platform observe a lightning strike at the same time. However, due to the relativity of simultaneity, the observers will perceive the lightning strike at different times.

What are some real-world applications of the relativity of simultaneity?

The relativity of simultaneity has many real-world applications, particularly in the fields of physics and engineering. For example, it is essential to consider the relativity of simultaneity when synchronizing clocks in GPS satellites to ensure accurate navigation. It also plays a crucial role in understanding the behavior of particles in particle accelerators and the effects of time dilation in space travel.

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