![]() |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
![]()
"Uncle Al" wrote in message
... Dieter Britz ,in ... There used to be, at least, an October issue of some physics journal (Physics Today?) in which there was an update on the values of some physical constants. Which journal was that please, and is it still doing that October issue? I am trying to find out how the Avogrado constant can be measured to about 8-9 decimal plces, when it surely must involve weighing some sample of matter. Dieter Britz, Kemisk Institut, Aarhus Universitet, Danmark. [Al] Current accepted value 6.0221415(10) x 10^23/mol, http://physics.nist.gov./cgi-bin/cuu...s.x=78&All+val ues.y=18 1998 CODATA, 6.02214199(47) x 10^23/mol However, folks doing exceptionally accurate x-ray diffraction on silicon (to replace the Pt-Ir kilogram artifact) get a different value, ............... Becker, P. et al. "Determination of the Avogadro constant via the silicon route," Metrologia 40 271-287 (2003) 6.0221353 x 10^23/mol PTB Standards Laboratory in Braunschweig, Germany thus gives number which is way the Hell different. http://www.ptb.de/en/index.html Uncle Al [hanson] There seem to be more to Avogadro's constant, N_A, then is normally portrayed about it in literature. These, N_A's unspoken traits, may be one of the causes giving the problems that make it difficult to nail down a very accurate numerical result for N_A. It may have to do with the fact that all fundamental, physical constants are ultimately compared to and expressed in/by the (completely arbitrated/chosen/selected) metric system units, AND... complicating that fact is that N_A is tied to other fundamental physical constants such as h, c, and G, & so it is difficult to say which is the most fundamental one. h & c have been measured to great accuracy, but Newton's G is still problematic when it comes to the accuracy of its numerical value. There are a few old (1930?) relations/equations that may illuminate this accuracy-dependcency problem, such as: One mole of Planck time equals the atomic time unit: tau / t_pl = a^(-1) * (N_A*pi*sqrt3) or one mole of Planck length equals the H-Bohr radius or the classical electron radius: r_H / l_pl = a^(0) * (N_A*pi*sqrt3) r_e / l_pl = a ^(2) * (N_A*pi*sqrt3) or that one mole of electron masses equals the Planck mass m_pl / m_e = a^(1) * (N_A*pi*sqrt3) So, since all Planck units are combos of hbar, c & G, one can see that there are, for instance, the following relationsships between N_A and Newton's G, when re-expressing the above equations by straight forward means and substituting the Planck units, *_pl, with hbar, c, & G, as: G * N_A^2 = [1/3] * [ hbar * c] / [pi* a* m_e]^2 = const or equivalently: G * N_A^2 = [2/(3pi)] * [c^3] * [r_H^2 / h] = const or there are others like, G * N_A^2 = f(tau, etc) = f(Lyman freq, etc) = const These 2 lines loosely state or can be interpreted as to say that the product of the gravitational mass attraction at the gigantic mole-squared size level has something to do with or is equivalent to expressing some gravitational event/state or phenomena seen quantized (hbar) at the atomic level caused by EM effects. It may be akin to something like k*N_A = R(gas) or e*N_A = F where N_A couples the atomic domain of heat or electricity to/with the everyday cgs/MKS mole sized experience in the respective fields. Similarly, this G* N_A^2 product may be applicable/useful to estimate gravitational effects on other then the levels/magnitudes/domains where G is currently measured or tested at. From/with these two equations we can concoct a further story, a theory, for the accuracy issue at hand. 1) I leave it to the aficionado to make the numerical error analysis with the right side (atomic realm) of these 2 equations. 2) the result of (1) gives the projected possible min. uncertainty or max. accuracy spread of the product of G * N_A^2. 3) Being deep in the atomic domain here, where uncertainty is the order of the day (according to heuristic paradigm) we may have a demonstration and example of the HUP, manifesting itself here in the uncertainty of either G or N_A values. If so, then only the unwieldy product of G * N_A^2 may be of or may have a "fixed +/-" determinable numerical size/value, but either one of each one, the N_A or G values alone, may only be knowable in its accuracy at the expense of the accuracy of the other one. ... Classic HUP gig??..... However, since this product of G * N_A^2 is having the size of ~ 10^40 cm^3/(gr*s^2*mol^2), I won't loose too much sleep over it....unless some clever ****, or a dumb one by luck, discovers a new amplification mechanism thru which this product affects visibly/phenomenologically our macroworld and shows up measurably in the games that are playing out in astronomy, astrophysics or cosmology............will see! it would be rad!....... ahahahaha...... ahahahahanson ref: 11-avogadro-3 |
Thread Tools | |
Display Modes | |
|
|