# Light Speed, Are We Talking Relativity?

Light speed relativity

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### #86 Mattzy

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Posted 14 June 2019 - 06:50 PM

I'll have a look at the link. I live in eternal hope. I was being quite serious about the subject of time. I understand the difficulties, but as yet, not the explanations.

I can perceive existence and change, but not any concept of anything but man made recording of history. That is why I think ralfcis is probably right about having to understand albebra. I wonder if Einstein really did explain relativity to a barmaid! (As he suggested) I doubt it. I'll try your link. Thanks.

I've just read through the link that you recommended on light clocks and rods by John D. Norton. It is by far the best explanation I've had. The two light clocks orientated and moving perpendicular to each other are an excellent frame of reference. The movement in parallel and the explanation of contraction is made clear to me. Also very interesting about the corner mirrors placed on the moon (I didn't know that).

As no mass can ever reach even near light speed then the scale of contraction is easier to accept and it does seem to be the only explanation - without mathematics.

I can also understand the ralfcis argument too. Because we are seemingly having to accept that everything slows and contracts simply because we have no other explanation. It is a big ask - as ralfcis says - for us to believe in physical contraction of material or space in order to keep photons moving at the same speed relative to an approaching mirror. It's difficult to conceive a connection that can enforce this effect. This connection must be spacetime? The elasticity of spacetime?

### #87 Mattzy

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Posted 14 June 2019 - 07:05 PM

Ralfcis is wrong. You do not need algebra to understand time! Nor even to understand relativity theory (which obviously involves time, but is not the same thing AS time).

You don't need any math at all to understand it! But, if you want some numbers, all you need is elementary geometry and very simple arithmetic -- as is demonstrated at the link I gave you.

If you sincerely are a beginner trying to learn about relativity, why are you talking to cranks like ralfics? It's the worst thing you can do. You can take a class, read an elementary text, or take advantage of the massive amount of info on relativity that can be found on the internet.

As I said, the link was very well worth reading for a beginner such as myself, but what of time? What if I were to say that there is no such thing as time? Do we have to have time as a reality? It is useful for comparison in the human mind to record the interval between events, but in reality we only have this fleeting instant of existence and the events of change. Does that idea conflict with the concept of spacetime?

### #88 exchemist

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Posted 15 June 2019 - 07:47 AM

As I said, the link was very well worth reading for a beginner such as myself, but what of time? What if I were to say that there is no such thing as time? Do we have to have time as a reality? It is useful for comparison in the human mind to record the interval between events, but in reality we only have this fleeting instant of existence and the events of change. Does that idea conflict with the concept of spacetime?

Without a concept of time, I don't see how you can have any concept of cause and effect and thus no way of making sense of experience.

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### #89 Dubbelosix

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Posted 15 June 2019 - 09:59 AM

I'll appease this ONE time and if you don't follow I won't be bothering again. Now, why do you think this statement is true? I am not saying it is wrong, I want to see if you can follow one step at a time.

Common now... you've continuously argued that no one has been listening to you, and don't play the ''I never read this post card.'' I will bring this up one more time or I am going to start complaining to moderation about the quality of posts which have been allowed to remain in this subforum.

If you can't answer this question, I think its about time you and your several other monikers stop this whole ''relativity is wrong,'' because I entertained it once and now you are not even answering my questions. You are, as I always said, wasting my time and others ... and even your own.

### #90 Mattzy

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Posted 15 June 2019 - 04:33 PM

Without a concept of time, I don't see how you can have any concept of cause and effect and thus no way of making sense of experience.

I'm glad that you said "concept" because I think that perhaps our intuitive concept of time is the human condition. We have a strong curiosity and unique desire to make sense of experience - as you say - but that may be producing a man made fallacy when it comes to believing in time itself (I am only thinking aloud here).

If there is a collision of two masses then that is that. There is nothing before or after that collision. If humans record the event they create a concept of time in their minds. Sluggo said that a time line is a history of positions - which I think is precisely right - that seems to me to be no more than human concept.

Our concept of time is a useful tool, like mathematics, but matter and energy don't use mathematics any more than they need time - they only continue to exist.

### #91 VictorMedvil

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Posted 15 June 2019 - 11:20 PM

I guess there is a difference between understanding time and getting the concept, you can get the concept of time with a clock but to truly understand time you must witness time at every aspect of the universe meaning you get the concept but do not truly understand time until you understand relativity meaning relativity takes account time in every location of the universe not just the locations that you are familiar with time's concept in. To truly understand all the quirkiness of time, Special and General Relativity are necessary along with a understanding of Quantum Mechanics in the way the time changes when matter is small in such that it ceases to be linear due to probabilities, but that is just the beginning. There are hundreds to thousands of time-spaces that people have created over the years that are accurate or models of reality each telling a story about the universe ever since Einstein made the first Unified Field Theory.

Edited by VictorMedvil, 15 June 2019 - 11:28 PM.

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### #92 Amplituhedron

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Posted 16 June 2019 - 08:27 AM

Common now... you've continuously argued that no one has been listening to you, and don't play the ''I never read this post card.'' I will bring this up one more time or I am going to start complaining to moderation about the quality of posts which have been allowed to remain in this subforum.

If you can't answer this question, I think its about time you and your several other monikers stop this whole ''relativity is wrong,'' because I entertained it once and now you are not even answering my questions. You are, as I always said, wasting my time and others ... and even your own.

Are you actually addressing this to me?? I ALREADY ANSWERED this!  And ... I have continuously argued that no one has been listening to me?? Dude, are you on drugs? Also, here is a news flash: No one owes you an answer to ANY of your posts.

### #93 Dubbelosix

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Posted 16 June 2019 - 09:11 AM

Are you actually addressing this to me?? I ALREADY ANSWERED this!  And ... I have continuously argued that no one has been listening to me?? Dude, are you on drugs? Also, here is a news flash: No one owes you an answer to ANY of your posts.

I'm addressing everyone, and anyone, or just the one person, that these anti-relativity posts will have to stop if you will not intend to not listen - had an interesting conversation with the moderator, from now I will simply be flagging posts if you will not listen or you are intentionally creating word salad posts for attention. Keep this in mind.

### #94 Dubbelosix

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Posted 16 June 2019 - 09:12 AM

Yes they do, when they constantly say ''but how can you disprove my theory when you won't address it?''

You can't have it both ways I am afraid.

### #95 sluggo

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Posted 16 June 2019 - 11:54 AM

Mattzy;

I joined Physforum (closed now) about 2006 to occupy my mind. Why were these people debating a theory 100 yrs old, with well established experimental evidence, (after more research)? After participation in  other forums, and learning the theory SR, my conclusion, those disagreeing with it, don't understand it.

Of course 'time' is primary element of SR. Here is the results of my research.

What is time?

The operational definition of assigning a time to an event as mentioned by A. Einstein in his 1905 paper is essentially what it is, and how it's been done since humans appeared.

It is a correspondence convention, i.e., assigning events of interest to standard clock events, a measure and ordering of activity, with 'time' always increasing/accumulating.

It is an accounting scheme developed out of practical necessity, for human activities like agriculture, business, travel, science, etc. The unit of measure for time initially referred to relative positions of astronomical objects, stars, sun, and moon, which implies earth rotations and earth orbits. The year equates to the periodic motion of the earth relative to the sun, the month, the moon relative to the earth, and the day, the earth rotation relative to the stars. All units of time are by definition, involving spatial motion or distance. The clock further divides the day into smaller units of measure. The reference in the 1905 paper of the watch hand to a position on the watch face involves nothing more than counting hand cycles (hand motion of specific distances representing subdivisions of a day). Current scientific research requires clocks that generate smaller and more precise periods than those of the past. The second is defined as n wave lengths of a specific frequency of light. Note "n wave lengths" is a distance, but labeled as "time".

If we use a light based clock to time the speed of an object along a known distance x, what are we actually doing?

We are comparing the simultaneous motion of an object to the motion of light for a duration (number of ticks). The result is a ratio x/s = vt/ct = v/c or speed. It should be obvious that the ticks serve to correlate the positions of the object with the positions of the light signal, for simultaneous comparisons. If you use Minkowski space-time diagrams the vertical scale is not 'time', but ct, light path distance, i.e. they plot speed. This allows a simple comparison of equivalent entities, without consideration of the nature of those entities.

In summation: A clock provides a beat or rhythm via a periodic process, to coordinate and measure events.

quotes by the author of SR

From 'The Meaning of Relativity', Albert Einstein, 1956:

page 1.

"The experiences of an individual appear to us arranged in a series of events; in this series the single events which we remember appear to be ordered according to the criteria of "earlier" and "later", which cannot be analyzed further. There exists, therefore, for the individual, an I-time, or subjective time."

page 31.

"The non-divisibility of the four-dimensional continuum of events does not at all, however, involve the equivalence of the space coordinates with the time coordinate."

page 32.

"Finally, with Minkowski, we introduce in place of the real time co-ordinate l=ct, the imaginary time co-ordinate..."

Edited by sluggo, 16 June 2019 - 11:58 AM.

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### #96 sluggo

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Posted 16 June 2019 - 12:00 PM

Mattzy;

The perception connection:

Subjective time requires memory, which allows a comparison of a current state to a previous state for any changes, which lends itself to an interpretation of 'time' flowing. Patients with brain damage to specific areas involved in maintaining a personal chronology, lose their ability to estimate elapsed time, short or long term. Consider the fact that people waking from a comatose state, have no memory of how much elapsed time, whether hrs, days, or even years.

If you are in a cave with no light and no clock, how do you know how much 'time' has elapsed? You rely on your memory and sensory input.

Since you can't see any of your surroundings, you rely on your biological perception concluding you are still self aware, breathing, pulse, etc. This requires energy, so there is (must be) energy , if there is awareness.

The mind supplies the perception of continuity of events just as it supplies the perception of motion for viewing a sequence of still images, movies and electronic screens.

Any uniform periodic event serves as a clock to meter 'time' just as a stick with uniform marks serves to measure distance. Time like distance is an intangible relation that is malleable in the process of motion.

Like the planetary orbits, the lunar sphere, lines, points, etc., these things only exist in the mind. They are real as mental constructs, but there is nothing corresponding to them in the physical world outside the mind.

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### #97 exchemist

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Posted 16 June 2019 - 12:53 PM

I'm glad that you said "concept" because I think that perhaps our intuitive concept of time is the human condition. We have a strong curiosity and unique desire to make sense of experience - as you say - but that may be producing a man made fallacy when it comes to believing in time itself (I am only thinking aloud here).

If there is a collision of two masses then that is that. There is nothing before or after that collision. If humans record the event they create a concept of time in their minds. Sluggo said that a time line is a history of positions - which I think is precisely right - that seems to me to be no more than human concept.

Our concept of time is a useful tool, like mathematics, but matter and energy don't use mathematics any more than they need time - they only continue to exist.

Well, it's a line of argument I suppose but, to take one example, assuming you think wave phenomena are real, how could they exist without time?

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### #98 Mattzy

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Posted 17 June 2019 - 12:28 AM

Well, it's a line of argument I suppose but, to take one example, assuming you think wave phenomena are real, how could they exist without time?

Please don't think of what I said as anything more than a question. I'm glad I asked it because - as you can see - the responses are educational for me. If it wasn't for relativity I would probably be happy to say that time is only a human concept. But there IS relativity.

Sluggo's second post gives some support to what I was thinking, but the other two posts suggest that time has to exist if SR is fact. I am in no position to refute SR as I am only just beginning to understand it. Knowing what spacetime is will be a hurdle.

### #99 Dubbelosix

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Posted 17 June 2019 - 01:11 AM

Yes, for a while I did entertain the idea myself that maybe time did not exist, primarily through the work of Barbour, however, since then I am more convinced than ever  it probably exists, to the point I have explored rigorous arguments that quantum mechanics has been misunderstanding time, in various ways - the most crucial one is that it doesn't tend to treat it as an operator outside the unitary operator, which is trivial.

### #100 Mattzy

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Posted 17 June 2019 - 01:47 AM

Mattzy;

I joined Physforum (closed now) about 2006 to occupy my mind. Why were these people debating a theory 100 yrs old, with well established experimental evidence, (after more research)? After participation in  other forums, and learning the theory SR, my conclusion, those disagreeing with it, don't understand it.

Of course 'time' is primary element of SR. Here is the results of my research.

What is time?

The operational definition of assigning a time to an event as mentioned by A. Einstein in his 1905 paper is essentially what it is, and how it's been done since humans appeared.

It is a correspondence convention, i.e., assigning events of interest to standard clock events, a measure and ordering of activity, with 'time' always increasing/accumulating.

It is an accounting scheme developed out of practical necessity, for human activities like agriculture, business, travel, science, etc. The unit of measure for time initially referred to relative positions of astronomical objects, stars, sun, and moon, which implies earth rotations and earth orbits. The year equates to the periodic motion of the earth relative to the sun, the month, the moon relative to the earth, and the day, the earth rotation relative to the stars. All units of time are by definition, involving spatial motion or distance. The clock further divides the day into smaller units of measure. The reference in the 1905 paper of the watch hand to a position on the watch face involves nothing more than counting hand cycles (hand motion of specific distances representing subdivisions of a day). Current scientific research requires clocks that generate smaller and more precise periods than those of the past. The second is defined as n wave lengths of a specific frequency of light. Note "n wave lengths" is a distance, but labeled as "time".

If we use a light based clock to time the speed of an object along a known distance x, what are we actually doing?

We are comparing the simultaneous motion of an object to the motion of light for a duration (number of ticks). The result is a ratio x/s = vt/ct = v/c or speed. It should be obvious that the ticks serve to correlate the positions of the object with the positions of the light signal, for simultaneous comparisons. If you use Minkowski space-time diagrams the vertical scale is not 'time', but ct, light path distance, i.e. they plot speed. This allows a simple comparison of equivalent entities, without consideration of the nature of those entities.

In summation: A clock provides a beat or rhythm via a periodic process, to coordinate and measure events.

"The experiences of an individual appear to us arranged in a series of events; in this series the single events which we remember appear to be ordered according to the criteria of "earlier" and "later", which cannot be analyzed further. There exists, therefore, for the individual, an I-time, or subjective time."

This is (above) is what I was thinking about.

"The non-divisibility of the four-dimensional continuum of events does not at all, however, involve the equivalence of the space coordinates with the time coordinate."

"Finally, with Minkowski, we introduce in place of the real time co-ordinate l=ct, the imaginary time co-ordinate..."

These two (above) are (it seems) what I am going to have to understand.

Thanks again sluggo.

Thanks for the work on my behalf sluggo. Firstly, I don't understand much about relativity, consequently I wouldn't dream of dismissing it - I'm in no position to. I am however proud to say  that I just came up with what you have given on the operational definition of time and aboutt clocks. After a few hours of thinking about it I reasoned that clocks give us a countable frequency that facilitate human comparative mathematics by recording numerical values for historic intervals between events. So when we do a clocked experiment we are only analysing a record of what happened in the past.

But I am none the wiser about spacetime and what time really is, because the above description is a man made concept - as you describe so well in your second post. Einstein said that "time is what clocks measure" I think he was saying that the spacetime continuum is something else to conceive, other than operational time - which is just a very small locality within it. Yes?

Spacetime seems to be something real. It is described as a fabric and depicted as a flat sheet which can be distorted by gravity. So I started reading about the Lorentz transformations and actually made some progress, but we have x,y,z and t. That is why I wanted to be clear about what t really is.

"The experiences of an individual appear to us arranged in a series of events; in this series the single events which we remember appear to be ordered according to the criteria of "earlier" and "later", which cannot be analyzed further. There exists, therefore, for the individual, an I-time, or subjective time."

The above is more or less what I was thinking about, but I have been suggesting that "earlier" is only recorded history and "later" does not exist. There can be no time between them, therefore operational time does not truly exist.

"The non-divisibility of the four-dimensional continuum of events does not at all, however, involve the equivalence of the space coordinates with the time coordinate."

"Finally, with Minkowski, we introduce in place of the real time co-ordinate l=ct, the imaginary time co-ordinate..."

These two quotes (above) are what I have to study.

Thanks again sluggo.

### #101 Mattzy

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Posted 17 June 2019 - 02:04 AM

I guess there is a difference between understanding time and getting the concept, you can get the concept of time with a clock but to truly understand time you must witness time at every aspect of the universe meaning you get the concept but do not truly understand time until you understand relativity meaning relativity takes account time in every location of the universe not just the locations that you are familiar with time's concept in. To truly understand all the quirkiness of time, Special and General Relativity are necessary along with a understanding of Quantum Mechanics in the way the time changes when matter is small in such that it ceases to be linear due to probabilities, but that is just the beginning. There are hundreds to thousands of time-spaces that people have created over the years that are accurate or models of reality each telling a story about the universe ever since Einstein made the first Unified Field Theory.

Well for now Victor I will have to work from acceptance at a basic level and aim for understanding later on. Thanks for the pointers.

### #102 Dubbelosix

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Posted 17 June 2019 - 02:51 AM

I think Einstein is using some old terminology when he says:

"The non-divisibility of the four-dimensional continuum of events does not at all, however, involve the equivalence of the space coordinates with the time coordinate."

Because I am not entirely sure what he means - today we say space and time only differ such that time is an imaginary leg of Pythagorean triangle - time is actually a dimension of space, otherwise curvature in three dimensional space would not manifest. Further, just because something is ''imaginary'' does not mean that it doesn't exist, this is just a mathematical expression. And no one would dare argue that time equals space, because that is not how we understand the metric which is

$s^2 = x^2 + y^2 + z^2 - (ct)^2 = x^2 + y^2 + z^2 + (ict)^2$

But I suppose Einstein must have been taking the idea that time didn't exist seriously, since he was famously quoting that past, present and future exist simultaneously. In a way, the past worldline does become affected in the present through an observation, as shown through Wheelers delayed choice experiment. But that doesn't mean that the past exists ''now'' unless we have to give up a notion of what we mean about past, present and future (ie. all that exists is a present moment). This is probably why he entertained the so-called block interpretation of time.