Comparison of Special Relativity with a Galilean "preferred frame" theory

My goal on the forum is to have constructive discussions that increase my knowledge and understanding of science. I find letting other's know I am open to consider their views, by using wording that conveys that sentiment, helps in achieving that goal.

I do have your point of view on this; however I am open to consider sound arguments to the contrary. I find even if I remain confident my understanding is correct, objectively considering sound arguments will often increase and strengthen my understanding of an issue.

Maxila

 

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Wow, you sound exactly like me a few years ago. I admire your attempt at mature, intellectual discussion and I hope your conviction is stronger than mine on this forum...

 

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...only in the minds of crackpots, only in the minds of crackpots. It is refreshing to see you two agreeing again.
Luckily, the people at NIST know better.

Nothing to do with the basic subject at hand, thanks for the laughs.

 

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Both the second and the meter were defined prior to the current standard they are based on. The meter and second have not changed significantly as the the current standards of measurement were adopted. (Transitions rates of electrons in cesium atoms for seconds and the distance light travels in a second for the meter.)

Changing the standard of measurement or definition was driven by the understanding that the length of a day changes over time (the length of a day was the original basis for the definition of a second..) and that the distance from the equator to the pole (a distance from which the meter was initially derived), is not uniform.

If the second were truly defined on the electron transition rate of a cesium 133 atom, it would seem a somewhat more rounded number would have been chosen, rather than the duration of 9,192,631,770... And if the meter were really based on the distance that light travels in one second why was its length not adjusted to reflect the distance light travels in 1/300,000,000 of a second instead of 1/299,792,458 of a second?

We use cesium atoms and light to define seconds and the meter today, not because they are what we derived those measurements from, but because they are more dependably accurate over time. (at least so long as our current understanding of the physics involved with both QM and relativity remain intact.)

 

There is no "if", it IS.

Since there is no "If", the rest of your sentence is irrelevant. If pink unicorns were flying around, you , RJ and Farsight would be busy running around to catch them.

Again, there is no "if", it just IS. The answer is that because c was DEFINED to be 299,792,458 . Period.

 

From Wiki,

Between 1000 (when al-Biruni used seconds) and 1960 the second was defined as 1/86,400 of a mean solar day (that definition still applies in some astronomical and legal contexts).[3][4] Between 1960 and 1967, it was defined in terms of the period of the Earth's orbit around the Sun in 1900,[5] but it is now defined more precisely in atomic terms. Seconds may be measured using mechanical, electric or atomic clocks.​

​

The metre (meter in American English), symbol m, is the fundamental unit of length in the International System of Units (SI).[1] Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole (at sea level), its definition has been periodically refined to reflect growing knowledge of metrology. Since 1983, it has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second."[2]​

Neither originated with cesium atoms or how far light travels in some fraction of a second.

Really Tach!

 

Tach: OnlyMe is on your side and you're being belligerent to him because you're missing his point.

OnlyMe: That being said, your point is not valid because ALL measurement standards of temporal and spatial dimensions ultimately rely on the value of c (yes, even solar days and the length of the peasant's forearm).

 

It's a relatively simple matter. Circa 1980, the precision at which we could measure the speed of light in vacuum exceeded our ability to measure physical lengths with precision. The change in the definition of the meter means that the same experiment which used to measure the speed of light with precision now measures lengths in terms of post-1983 meters with precision. Likewise an experiment which used to compare the speed of light in different directions now compares the length of meters in different directions. But experiments which test Lorentz invariance still test Lorentz invariance, so it is not a fundamental problem with the experimental basis of special relativity.

Indeed, quite a lot of theoretical development of models of potential Lorentz violation are done in a choice of units where \(c = 1\). Just because c is defined as a constant by choice of units doesn't impair the search for violations of special relativity.

http://relativity.livingreviews.org/Articles/lrr-2005-5/

 

I think the takeaway from this is that IF all forms of dimensional measurement ultimately rely on a particular single variable then Lorentz invariance is inevitable. The former necessitates the latter. We are all arguing the same thing from different sides.

 

That's the modern consensus value for the speed of light. The key word is 'invariant' when measured in local coordinate and local proper frames. Somebody said something about Einstein subsumed SR to GR. This is an important part of the theory of relativity. This is what it means: Special Relativity is the 'special case' for a General theory of gravity where the effects of gravity can be ignored: IE the effects are so small as to not have any relevant bearing on empirical measurements. A local segment, of the natural path, where the spacetime is essentially flat. Over the weak field, like our solar system, this segment is very large. In the strong field, black holes, neutron stars, etc., it's much smaller. For example a Laboratory frame such as the LHC doesn't need to account for any gravitational effects during experiments. A local experiment where very small gravitational effects needs to be accounted for is the GPS. That's because the signals travels .333564 meter per nanosecond. This means, for the most part, the mathematics of SR is used for doing the physics in the local coordinate and local proper frames. This is where measurements of the local coordinate speed of light are invariant:

dr/dt=1.

The remote coordinate speed of light is not invariant because it's not a local measurement but instead a global measurement that takes into account the effects of gravity over the entire path. Spacetime curvature over the entire path. This can be observed in measurements associated with the Shapiro delay. The delay being the extra time associated with lights path through curved spacetime as compared to the time the light would take if it's path was over flat spacetime. Measurements of the local coordinate speed of light over segments of flat spacetime are invariant. Measurements of the remote coordinate speed of light are frame dependent.

 

Excellent discussion

 

Take away whatever nonsense you feel comfortable with.

 

[the answer fully explained]

I can only show you the logic, brucep, I can't make you accept it.

 

No, he's not, he's simply writing a different kind of nonsense than you and Farsight. What is true is that you and Farsight write the same kind of nonsense.

 

You're batting .000 against me, Tach. Don't you notice a pattern? I ask a question; you announce the answer; I question your answer; you call me a crackpot; you are proven wrong. The funny thing is that my questions are sincere while your pronouncements of the truth are false. I stumble upon the truth through curiosity, logic and an open mind while you reside in a closed and often incorrect world of misconceptions.

 

He's batting a 1.000 compared to you. You don't even have a bat. Let's leave the discussion on the technical aspect associated with the measurement of the speed of light to folks who know how to do it. That doesn't include you.

 

I'm not really concerned with whether you understand what I'm saying or not, brucep. I explained things and it's clear that you shut your mind off just as well as Tach does when it comes to reading facts that don't support your world view. I guess in that respect you make a mediocre scientist but a fine cheerleader, so why don't you go over to the side lines and let the actual players hash this out.

 

You are confusing science with baseball, no wonder you can't get anything right.

One can never prove a crackpot wrong, so I never claimed that I proved you wrong because I know it isn't possible.

I suggest you and Farsight write a letter to NIST and explain to them that they've been wrong since 1983.
I'm not holding my breath that they'll manage to explain your misconceptions to you two.

 

You say all measurements made in the local proper frame are circular because they rely on the speed of light. That's clueless. Show me the logic about this

All measurements made in the local proper frame where the measurement is made are invariant. Pick a stick and use a piece of string to measure the stick in your living room. Take the stick and the string to your neighbors living room and measure it again. Take the stick and string to every living room in the universe and measure it again and again....... Guess what the measurement will always be the same. The measurement made in the local proper frame is an invariant. Now go back to your big living room at the LHC and use the string to measure the stick again. Call it 1 meter. Use that meter stick to measure the speed of light. Use that meter stick to measure the local coordinate speed of light in all the local proper frames you measured the stick in. Guess what the measurements made in the local proper frames you visited will be the same. So start by using your neighborhood as the initial test area. Let us know when you find a local proper frame where the speed of light is a requirement for measuring the stick with the string. From there logic would suggest that any refinements [changes] made to the stick while in the local proper frame where the measurement is made have no bearing on the invariance of the new measurement.
You told me awhile back that you have a good understanding of GR. I'm telling you your belief is delusional. You have to study this stuff, understand the derivations, to understand the theory. All the rest is bs.

 

You confuse the significance between frequency and propagation velocity. Counting transitions in a resonating time standard is a frequency measurement. So your conclusion does not follow.