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Arbitrary units

Posted: Thu Sep 28, 2006 11:20 am
by viator
sandy_mcd wrote:[Since the speed of light is defined to be 299,792,458 meters per second, then even I can add 5 million more significant figures: just append 5 million zeroes.
A defined value is not accurate beyond the specified significant figures unless it is a natural integer. You can add all the zeros you want and it does not increase its real accuracy. The 888576587.631673... number will be accurate to what ever significant figures you wish to use.

I thought the Swiss Office of Metrology definition for the "metre" would suffice to explain that the only arbitrary unit now is the duration of the second. Once they defined the speed of light and then defined the meter relative to the speed of light the only original variable is the duration of the second.
sandy_mcd wrote:No, there are still two arbitrary choices. The speed of light is given in units of distance per time. The choice of these units is arbitrary.
The speed of light is now a defined value, and we don't even know why they did not identify the measured value, and the meter was then defined in relation to the speed of light value. I really wonder what value they used for a "distance" to come up with the 299792458 number, since the meter was defined after they came up with the defined numeric value for the SOL. Below is another persons statement on the speed of light definition issue.
Professor V. Stenger wrote:Now, perhaps someday it will turn out that defining distance this way was a bad move and some clock- independent operational definition of distance should be re-introduced. But, until then, without a redefinition of distance, any claim that c is variable is simply false.
http://www.colorado.edu/philosophy/vste ... iefs/c.pdf
sandy_mcd wrote:Note: not necessarily so on this forum where some may not feel that the speed of light is constant nor that some physical numbers (e.g. radioactive decay rate) are more fundamental than others (e.g. age of the earth).
That is the whole issue as to why there is a need for an near-absolute accurate reference value for the speed of light, it gives everybody a reference point for their measurements. I find it ludicrous that they can say that the speed of light is a constant in "free space" because the only place it has been measured is in a vacuum on the earth's surface. They do not know if permittivity/permeability is even constant everywhere within the influence of the Sun's heliosphere, it has never been measured. NASA has published some documents that make you wonder, but this is a separate topic.
sandy_mcd wrote:Why choose a hydrogen hyperfine transition and not some other number, such as the hydrogen Lamb shift (2p(1/2)-->2s(1/2) transition of 28 cm, or some other number? It is still an arbitrary choice of a distance.
I do not know why the length that represents the hydrogen hyperfine transition "wavelength" was chosen. If you can make the Lamb shift wavelength fit the equation set in the EuclideanUnits-TheBasics.pdf article, and the dimension set of 47.713 cm at an angle of 26.25400 degrees, let me know how.
sandy_mcd wrote:Other numbers such as e, the golden ratio, and the fine structure constant are also embedded in science, but that is no reason to throw them into the definition of a unit either.
Pure mathematical and other "dimensionless" numbers are not modified by Euclidean Electromagnetic Units (EEU). In the last paragraph of the Stenger article, he points out the pit-fall of using a fixed definition for the speed of light when "calculating" the value for the fine structure constant. He is basically saying, "you can't have it both ways".
sandy_mcd wrote:The proposed system is more complicated.
The proposed system is costly to implement as the units are quite different.
I do not see the complications, as it is to be used for scientific purposes only. The only people that really need to use it are those that would now be using Planck Units or one of the other so-called "Natural Units", everybody else can use SI. It would be easy to convert between the unit systems, but I see no need for that. Somebody working with statistics, designing a building, airliner, toaster, spacecraft, etc., should use SI units. The majority of the people in the world do not know about "other" measurement systems, and there is really no reason for them to know. Think of the number of people that are taught about Planck Units and how often they use them? During my formal collegiate days, I was taught a few things that would be used only a small number of individuals in my particular area of study, but you had to know them if you were going to go in that direction and if you want to communicate with them.

Those (commericial interests) that have forced SI on the world took no thought of the costs to implement. EEU is not being forced upon the world, they are for those involved in identifying the fundamental characteristics of our physical universe, and anybody else that wants an "accurate" reference value, to a significant number, for the speed of light.
sandy_mcd wrote:And this is back to Hamming's and Wigner's points: it is amazing that so much of nature is invariant to many influences (a ball drops just the same no matter who lets it fall) and formulae are invariant to the choice of units.
True, but the numeric results will be different, and that can make a significant difference. If you pull up my first reference again, I have updated it to add a perspective section. Originally, I extracted the 888576587.631673... number starting with just the dimension and the angle. Initially, I used a spreadsheet process to iterate the results and I did not know that the ultimate value for the speed of light would have the same numeric value as the hyperfine transition emission frequency when expressed using the units that "emerged" when the angle was 45 degrees. I was impressed.

I believe the mathematical term for this is "convergence". Those that seek to identify a "Unified Theory" expect everything will "converge" and this concept is addressed using a variety of terms, the "theory of convergence" and the "theory of everything" being two.

If you choose your units arbitrarily you will miss the convergence which physicists intuitively expect to find.

Re: Arbitrary units

Posted: Fri Sep 29, 2006 6:30 pm
by sandy_mcd
viator wrote:A defined value is not accurate beyond the specified significant figures unless it is a natural integer. You can add all the zeros you want and it does not increase its real accuracy.
There is a difference between a measured value and a defined value. The speed of light is defined to be 299 792 458 m/s and that is what it is, there are no other non-zero digits. Since the value of c is a definition, it is by definition accurate and precise to as many significant figures as one cares to print zeroes. Example: suppose I am charged a 10.5% fee to convert currencies. The fee on $10.00 would be 10.5% or $1.05. The fee on $1 000 000 000.00 would be 10.5% or $105 000 000.00. The 10.5% is a definition and is thus 10.5000000...% to as many zeroes as one desires; it is not 10.500004267939%.
viator wrote:I thought the Swiss Office of Metrology definition for the "metre" would suffice to explain that the only arbitrary unit now is the duration of the second. Once they defined the speed of light and then defined the meter relative to the speed of light the only original variable is the duration of the second.
True.
viator wrote:I really wonder what value they used for a "distance" to come up with the 299792458 number, since the meter was defined after they came up with the defined numeric value for the SOL.
They used the accepted value of the meter at that time. This meant no discontinuity in reference units, as the H hyperfine standard would engender.
http://www.bipm.org/jsp/en/ViewCGPMResolution.jsp?CGPM=17&RES=1 wrote:# that the present definition does not allow a sufficiently precise realization of the metre for all requirements,
# that progress made in the stabilization of lasers allows radiations to be obtained that are more reproducible and easier to use than the standard radiation emitted by a krypton 86 lamp,
# that progress made in the measurement of the frequency and wavelength of these radiations has resulted in concordant determinations of the speed of light whose accuracy is limited principally by the realization of the present definition of the metre,
# that wavelengths determined from frequency measurements and a given value for the speed of light have a reproducibility superior to that which can be obtained by comparison with the wavelength of the standard radiation of krypton 86,
# that there is an advantage, notably for astronomy and geodesy, in maintaining unchanged the value of the speed of light recommended in 1975 by the 15th CGPM in its Resolution 2 (c = 299 792 458 m/s),
# that a new definition of the metre has been envisaged in various forms all of which have the effect of giving the speed of light an exact value, equal to the recommended value, and that this introduces no appreciable discontinuity into the unit of length, taking into account the relative uncertainty of 4 ´ 10—9 of the best realizations of the present definition of the metre,
# that these various forms, making reference either to the path travelled by light in a specified time interval or to the wavelength of a radiation of measured or specified frequency, have been the object of consultations and deep discussions, have been recognized as being equivalent and that a consensus has emerged in favour of the first form,
viator wrote:I do not see the complications, as it is to be used for scientific purposes only. The only people that really need to use it are those that would now be using Planck Units or one of the other so-called "Natural Units", everybody else can use SI. ... EEU is not being forced upon the world, they are for those involved in identifying the fundamental characteristics of our physical universe, and anybody else that wants an "accurate" reference value, to a significant number, for the speed of light.
So you don't mean all scientists, just some subset working on fundamental values. Where do astronomers fit in? Some would use the new system, some wouldn't. It sounds awfully confusing to me.
viator wrote:True, but the numeric results will be different, and that can make a significant difference. If you pull up my first reference again, I have updated it to add a perspective section. Originally, I extracted the 888576587.631673... number starting with just the dimension and the angle. Initially, I used a spreadsheet process to iterate the results and I did not know that the ultimate value for the speed of light would have the same numeric value as the hyperfine transition emission frequency when expressed using the units that "emerged" when the angle was 45 degrees. I was impressed.

I believe the mathematical term for this is "convergence". Those that seek to identify a "Unified Theory" expect everything will "converge" and this concept is addressed using a variety of terms, the "theory of convergence" and the "theory of everything" being two.

If you choose your units arbitrarily you will miss the convergence which physicists intuitively expect to find.
I still don't understand the whole triangle setup. [I don't understand the triangle offense either.]
Could you give an example of how different numerical values would have a significant difference on anything?
Also, there are a number of mathematical meanings of convergence http://en.wikipedia.org/wiki/Convergence; I am not sure how any of them apply to a general theory of everything.

Re: Arbitrary units

Posted: Fri Sep 29, 2006 11:14 pm
by viator
sandy_mcd wrote:There is a difference between a measured value and a defined value. The speed of light is defined to be 299 792 458 m/s and that is what it is, there are no other non-zero digits. Since the value of c is a definition, it is by definition accurate and precise to as many significant figures as one cares to print zeroes.
I think we need to defer to metrologists that work with the science of accuracy and precision whether adding zeros to a defined value increases its accuracy.
# that there is an advantage, notably for astronomy and geodesy, in maintaining unchanged the value of the speed of light recommended in 1975 by the 15th CGPM in its Resolution 2 (c = 299 792 458 m/s),
It appears that they completely ignored the newly measured value, whatever it was, to mollify the astronomers and geodesists. I understand the problem with the geodesists, it can screw up all the benchmarks.
sandy_mcd wrote:So you don't mean all scientists, just some subset working on fundamental values. Where do astronomers fit in? Some would use the new system, some wouldn't. It sounds awfully confusing to me.
You already mentioned scientists of various types pick and choose whatever system of units they deem suitable for their areas of endeavor.
http://en.wikipedia.org/wiki/Natural_units
Euclidean Electromagnetic Units simply gives them another option. Let them decide if it suitable for their area of study. It is doesn't have to be forced on anybody.
sandy_mcd wrote:Could you give an example of how different numerical values would have a significant difference on anything?
I have given some thought to that but it would require that all the SI derived values that use time, distance and the speed of light to be recalculated. Then applying these recalculated values, they would be used to recalculate all the physical science constants that use those values, and then examine the "new" relationships. It would be a formidable task. As I stated earlier, I am not a mathematician or a physicist and it would required someone with those qualities, good computer skills, and knowledge of the available "mathematics" programs to programmatically examine the results.

Viator

Posted: Sat Oct 07, 2006 12:23 am
by David Blacklock
>>Correct me if I am wrong, but I am unaware of any mathematical formula that was created before some event(s) observation<<

I think many entities in physics, especially in quantum mechanics, quantum chromodynamics, quantum electrodynamics, and particle physics were first speculated to exist because of mathematical predictions. Many of the newer particles in the Standard Model have been found this way in various elaborate atom-smashing devices. Cosmology is full of mathematical predictions that have sparked searches and subsequent discoveries.

Of course, everything in string theory is a mathematical construct/prediction. This "theory" is the weakest example of a theory in science because it has as yet no testable aspects. When the CERN lab in Europe opens its new LHC (Large Hadron Collider), I have heard there might be some testing that could rule string theory in or out.