[MikeS]

Mattyh,
My sincere thanks, that's the only bit of encouragement I have received on this site.

Mattyh, one don't has to like it, but one do need to know the 'mainstream' definition, Einsteins own actually, first. As for needing the math? Oh yes, you will need to learn it, and as you do you also will need to redefine Einstein's definitions to fit this idea of 'variable light'.

Isn't it amazing how people try to turn things around.  My ideas are to the best of my knowledge completely in keeping with Relativity as expressed in my previous posts.  I assume the above is another missquote like the rest you mention. The same can not be said about about yor_on who while telling me I had got relativity wrong quite obviously did not understand gravitational time dilation himself.  Having said that I note from his latter posts that his attitude towards gravitationa time dilation is now falling more inline.

If you are interested in gravitational time dilation you may be interested in my articles on Time and Gravity in the New Theories section.  They do contain the maths but no replies.  You just can't win.

Thanks again

[MikeS]

I should have added by way of update.  I have e.mailed Nasa once and Jpl twice in the last seven weeks on the Pioneer anomalies and am still awaiting replies. 

If I were definitely wrong then I would have expected a reply by now.

[imatfaal]

Mike - please stop asserting in the Physics forum that your ideas are mainstream, they simply are not. 

I have explained here why your points about JPL not using any GR in their calcs are simply wrong.
http://www.thenakedscientists.com/forum/index.php?topic=38611.msg353958#msg353958

I will take the time to have a look at your thread in New Theories - but as you have already posted that
the maths to calculate the effect of GR time dilation on the above probe is beyond then there is no way that you can validly approximate your theories to mainstream views.  The complexities of GR are formidable and beyond all unless they are willing to dedicate time and effort to it.

Lastly please do not criticise another member of the forum or question their knowledge apart from within the context of a debate with that member and addressed to that member.

matthew

[mattyh]

I'd like to apologise for flaring things up, that was by no means my intention here. (Late night, a few beers, then a boat load of coffee).

On a final note I'd like to say, If everyone had the same views, used the same proven science and no one took that 'leap of faith', would science (hell, even the World) be better off? I don't think so, it needs people who think outside the box to move forward. Diversity is the key, much like in evolution.

Kind regards Matt

[imatfaal]

Think nothing of it Matt - if we didn't relish a little cut-n-thrust we wouldn't be here! 

I don't think there is a single scientist, amateur or professional, lay or academic, who would disagree with you; but science moves on with new ideas that are challenged, shown to be consistent with evidence, and build upon or overthrow the current thinking.  What science does not do is envisage an idea and insist it must be correct because it 'feels right' or it fits an internal logic; merely providing an alternative heuristic is no good whatsoever if the new underlying theory does not corectly explain and predict experimental results.  Many of the great ideas of science seem to be simple isolated logical plans backed up by easily understood thought experiments - however, they are in fact also founded upon amounts of data, maths, and interconnecting logic.  There will no doubt be another great leap forward in our understanding, which after the fact will seem simple, and which may be pilloried at first; but the vast majority of science is hard work and slow grind.

[yor_on]

Mike, I believe the way I look at light here as being the way Einstein looked at it too And that's just a simple truth.

[MikeS]

you_on

That's exactly the way I look at it.

If you look back through your posts you could not accept that there are 'pockets' of varying time which are necessary for time to be constant.

[MikeS]

you_on

That's exactly the way I look at it.

If you look back through your posts you could not accept that there are 'pockets' of varying time which are necessary for time to be constant.

Sorry, should read
If you look back through your posts you could not accept that there are 'pockets' of varying time which are necessary for the speed of light to be constant.

[yor_on]

Well, that is where we differ. As I said, you can possibly? See it that way. Although it would wreck havoc on the idea of light as a 'constant' and redefine what a constant should be seen as. It would make this universe a lot more complicated though. Going out from the light constant we have a simple way of explaining how 'frames of reference' will produce a time dilation as it comes naturally from that definition. Using your definition it becomes a definition of light not being a constant, more of the room time geometry as a whole being one, with each 'frame of reference' then representing a different island, and as you need to remember, all of them able to be created at a instant, depending on your acceleration. And as I said, neither Einstein nor me have this impression, at least as I understands it.

[MikeS]

Correct me if I am wrong but I have always maintained that the speed of light in a vacuum is a constant because the 'passage of time' is variable.  That is in full agreement with Einstein.

You have previously referred to this as 'pockets of time' and denied that they can exist.  Furthermore, you have said that both you and Einstein are on agreement on this.  You are not.  Pockets (your word) of varying passage of time do exist.  This is in full accord with what Einstein said.

[JP]

Correct me if I am wrong but I have always maintained that the speed of light in a vacuum is a constant because the 'passage of time' is variable.  That is in full agreement with Einstein.

Actually, what Einstein would have claimed is that the speed of light is locally constant in an inertial reference frame in vacuum.  Therefore, observers in different reference frames do not agree when they compare lengths and time intervals.

This is quite a bit different from your claims that "the speed of light in a vacuum is a constant because the 'passage of time' is variable."

[yor_on]

Yep that's true, I keep forgetting to add this 'inertial' definition. What that mean is just that light is defined as moving at 'c' anyway we measure it in a inertial frame as Earth. But the same will hold true for an accelerating frame too. He defined that one in SR 1905. He used this definition to define how two inertial 'frames of reference' could 'tick' at the same rate while still being defined as measuring all light at 'c'. Why i keep forgetting to add that one is that there are two effects of this definition. One is that all 'local time' will be the same, and that one must be true. That is, your own 'time' as measured by you will alway have the same duration and there will be no way for you to lengthen that time, except relative another frame of reference. The other is that 'c' will hold for accelerating frames too. There is no way I know of to measure light as other than propagating at 'c' in a vacuum.

When I think of the definition of 'inertial frames' I automatically connect it to 'time' as described above.
==

But you're not the only one having this idea of a variable time. I've seen the people using a train analogy with 'light clocks'¨ticking finding it to prove that 'time' is variable. That's wrong, room time is a variable, but only as compared between frames. If time was variable, why would there would be a synchronization when the 'twins' meet up? The mere idea that they will find a time dilation builds on their 'local time' being the same, as long as they share the approximate same 'frame of reference', as on Earth. So your (always) local time, combined with lights invariant speed in a vacuum defines the frames you measure.

[JP]

What that mean is just that light is defined as moving at 'c' anyway we measure it in a inertial frame as Earth. But the same will hold true for an accelerating frame too.

Actually, I do have a slight mistake in what I said above.  The speed of light is constant globally in inertial reference frames. 

It is constant locally in non-inertial reference frames. 

Geometrically, this amounts to the speed of light being constant if measured over flat regions of space-time.

If you're in curved space-time, you need to look at a very tiny chunk of it which appears to be flat (just like your backyard looks flat compared to the curvature of the earth), so you say it is locally flat--which means that locally the speed of light is constant.

[yor_on]

Yep but don't mess up my beautiful explanation here please.
We can discuss gravity as only able to be defined by 'point particles' too

There is no way you ever will measure light in a vacuum other than at 'c'. And all points might be called 'flat' But yeah, that definition is worthy of a thread of its own I think JP. Why did Einstein find it necessary to define it this way?

[MikeS]

Correct me if I am wrong but I have always maintained that the speed of light in a vacuum is a constant because the 'passage of time' is variable.  That is in full agreement with Einstein.

Actually, what Einstein would have claimed is that the speed of light is locally constant in an inertial reference frame in vacuum.  Therefore, observers in different reference frames do not agree when they compare lengths and time intervals.

This is quite a bit different from your claims that "the speed of light in a vacuum is a constant because the 'passage of time' is variable."

It's not different at all
E=mc2 says exactly that.  For the speed of light in a vacuum to remain a constant then either length or the'passage of time' have to be variable.  As we use the speed of light to define the length of a meter then 'time' itself is the variable.  In which case "the speed of light in a vacuum is a constant because the 'passage of time' is variable", is a perfectly reasonable statement.

[imatfaal]

Correct me if I am wrong but I have always maintained that the speed of light in a vacuum is a constant because the 'passage of time' is variable.  That is in full agreement with Einstein.

Actually, what Einstein would have claimed is that the speed of light is locally constant in an inertial reference frame in vacuum.  Therefore, observers in different reference frames do not agree when they compare lengths and time intervals.

This is quite a bit different from your claims that "the speed of light in a vacuum is a constant because the 'passage of time' is variable."

It's not different at all
E=mc2 says exactly that.  For the speed of light in a vacuum to remain a constant then either length or the'passage of time' have to be variable.  As we use the speed of light to define the length of a meter then 'time' itself is the variable.  In which case "the speed of light in a vacuum is a constant because the 'passage of time' is variable", is a perfectly reasonable statement.

Mike just because the metre is now set by reference to the speed of light does not mean that distance is a function of the speed of light.  Distance contracts AND time dilates - they do so that in a non-accelerating frame the speed of light will be measured as a constant.

Your continual use of misleading terminology is very confusing and will stop many taking anything you say seriously.  If you mean time dilation then use the term that people know.  If it is an entirely new (or with different equations) then also say so.  By the way the time dilation side of einstein's theory has been tested to amazing exactness - AND it requires a length contraction to maintain speed of light constancy.  If you are maintaining that no distance contraction occurs then you need to explain how light speed constancy remains when the time dilation is the sole effect and we know experimentally that time dilation follows the equations einstein used.

[MikeS]

Correct me if I am wrong but I have always maintained that the speed of light in a vacuum is a constant because the 'passage of time' is variable.  That is in full agreement with Einstein.

Actually, what Einstein would have claimed is that the speed of light is locally constant in an inertial reference frame in vacuum.  Therefore, observers in different reference frames do not agree when they compare lengths and time intervals.

This is quite a bit different from your claims that "the speed of light in a vacuum is a constant because the 'passage of time' is variable."

It's not different at all
E=mc2 says exactly that.  For the speed of light in a vacuum to remain a constant then either length or the'passage of time' have to be variable.  As we use the speed of light to define the length of a meter then 'time' itself is the variable.  In which case "the speed of light in a vacuum is a constant because the 'passage of time' is variable", is a perfectly reasonable statement.

(1)Mike just because the metre is now set by reference to the speed of light does not mean that distance is a function of the speed of light.  (2)Distance contracts AND time dilates - they do so that in a non-accelerating frame the speed of light will be measured as a constant.

(3)Your continual use of misleading terminology is very confusing and will stop many taking anything you say seriously.  If you mean time dilation then use the term that people know.  If it is an entirely new (or with different equations) then also say so.  By the way the time dilation side of einstein's theory has been tested to amazing exactness - (4)AND it requires a length contraction to maintain speed of light constancy.  If you are maintaining that no distance contraction occurs then you need to explain how light speed constancy remains when the time dilation is the sole effect and we know experimentally that time dilation follows the equations einstein used.

(1) The speed of light (meaning speed of light in vacuum), usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time. 
http://en.wikipedia.org/wiki/Speed_of_light
 It seems to me that distance is precisely defined as a function of the speed of light (and vice-versa).

(2) I thought the speed of light(in a vacuum)was constant in any inertial frame.

(3)Your continual use of misleading terminology is very confusing and will stop many taking anything you say seriously. 
‘Passage of time’  Einstein, sometimes used the word passage.  'Passage of time', I believe is self descriptive and would be understood by everyone.  Time dilation only refers to time slowing down not speeding up so is imprecise as a term to explain time being variable.  The problem is the inadequacies of language, as we have already established dt/dt makes little sense.

(4)AND it requires a length contraction to maintain speed of light constancy.  If you are maintaining that no distance contraction occurs then you need to explain how light speed constancy remains when the time dilation is the sole effect and we know experimentally that time dilation follows the equations einstein used.
As I understand it, distance contraction only applies to objects traveling at relativistic speed.  Gravitational time dilation is not accompanied by an associated length contraction.  Therefore, length contraction is not required to maintain speed of light constancy.

Speed is distance divided by time.  As long as the arbitrary units defining length and time remain the same (299,792,458 metres per second) the speed of light will remain a constant.  However, the ‘length’ of a second and a meter can both change within that constraint.

[imatfaal]

No - a metre is defined in terms of the speed of light - there is a difference.  we have found that many measurements can be linked - ie they can be independently measured to a high degree of accuracy AND they can be calculated from other measurements taken from completely different experiments.  to make life easy we set constants in one and only one way - and that means that some measurements are done in terms of other things.  velocity is a function of distance - but the speed of light is so central to out physics that when it comes to measurement we use the speed of light to define the standard metre rule.

On your point on contraction - if you say distance contraction doesn't happen you must explain how relative velocity contraction/dolation works, not just find a circumstance in which it doesnt apply.

[JP]

No - a metre is defined in terms of the speed of light - there is a difference.  we have found that many measurements can be linked - ie they can be independently measured to a high degree of accuracy AND they can be calculated from other measurements taken from completely different experiments.  to make life easy we set constants in one and only one way - and that means that some measurements are done in terms of other things.  velocity is a function of distance - but the speed of light is so central to out physics that when it comes to measurement we use the speed of light to define the standard metre rule.

Yes.  This is an important point.  The meter wasn't always defined in terms of the speed of light.  It was defined in terms of the size of the earth at one point.  The speed of light was experimentally found to be constant under this old definition.  As a result of this experimental evidence, the meter was redefined since the speed of light was apparently a universal constant.

[MikeS]

quote from imatfaal
Mike just because the metre is now set by reference to the speed of light does not mean that distance is a function of the speed of light.

quote from MikeS
 The speed of light (meaning speed of light in vacuum), usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time. 
http://en.wikipedia.org/wiki/Speed_of_light
 It seems to me that distance is precisely defined as a function of the speed of light (and vice-versa).

quote from imatfaal
No - a metre is defined in terms of the speed of light - there is a difference. 

In your first quote above you say that distance isn't a function of the speed of light. 
In your second quote above you say that distance is a function of the speed of light.
They can't both be correct.

quote imatfaal
By the way the time dilation side of einstein's theory has been tested to amazing exactness - AND it requires a length contraction to maintain speed of light constancy.
I was merely pointing out that in general relativity, gravitational time dilation does not require a length contraction.  Therefore, length contraction cannot be a pre-requisite for the speed of light to be constant.  I am not proposing anything new.   

quote from imatfaal
velocity is a function of distance - but the speed of light is so central to out physics that when it comes to measurement we use the speed of light to define the standard metre rule.

Velocity is a function of distance and time.  As we use the speed of light to define the 'length' of the meter and length (distance) is a function of speed then it's a circular argument.  So when I said that "It seems to me that distance is precisely defined as a function of the speed of light (and vice-versa)." was reasonable.  To measure velocity (speed) we have to use distance but distance is defined from speed which means its a circular argument.