%I #52 Jun 08 2023 17:47:54

%S 6,7,7,7,2,6,5,3,1,2,3,1,2,0,6,7,6,1,0,6,1,7,2,7,0,2,3,4,6,5,8,4,3,5,

%T 5,3,9,4,4,6,4,5,5,7,0,6,2,4,2,3,2,3,9,8,0,4,2,6,6,2,2,4,5,0,7,0,9,9,

%U 8,6,1,7,6,7,8,8

%N Decimal expansion of h * Δν_{Cs} / c^2 in units of kg in the 2019 SI system of units.

%C The seven defining constants of the SI system (May 20 2019) are (see the BIPM link):

%C Δν_{Cs} = Δν(133Cs)_{hfs} = 9192631770 s^(-1)

%C c = 299792458 m/s

%C h = 6.62607015*10^{-34} J s [kg m^2 s^(-1)]

%C e = 1.602176634*10^{-19} C [A s]

%C k = 1.380649*10^{-23} J/K [kg m^2 s^(-2) K^(-1)]

%C N_A = 6.02214076*10{23} mol^(-1)

%C K_{cd} = 683 lm/W [cd sr s^3 kg^(-1) m^(-2)]

%C In brackets are the units given in s, m, kg, A, K, and cd*sr. The symbol sr stands for steradian (or sterad).

%C K_{cd} is the luminous efficacy of monochromatic radiation of frequency 540*10^12 Hz, with Hz = 1/s.

%C The given combination of three constants defines the kg from the Planck constant h after s and m have been expressed in terms of Delta nu_{Cs} and c.

%H BIPM, <a href="https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1">On the revision of the International System of Units (SI)</a>, Nov 13-16 2018.

%H Max Planck, <a href="https://doi.org/10.1002/andp.19003060105">Ueber irreversible Strahlungsvorgänge</a>, Ann. Physik 1 (1900) 69-122. See paragraph 26. Natürliche Maasseinheiten. pp. 120-122; <a href="https://www.semanticscholar.org/paper/Ueber-irreversible-Strahlungsvorg%C3%A4nge-Planck/cfb44a5b59c30c19c7ba0e560d5eb0c898255982">alternative link</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/2019_redefinition_of_SI_base_units">2019 redefinition of SI base units</a>

%F Equals 0.677726531231206761061727023465843553944645570624232398042662245... * 10^{-40} kg.

%Y Cf. A230458 (Δν_{Cs}), A003678 (c) A003676 (h), A081823 (e), A070063 (k), A248510 (R_K), A248508 (K_{J}), A322579 (m), A322580 (kg), A324031 (A), A324032 (K), A324033 (lm), A324034 (J).

%K nonn,cons,easy

%O -40,1

%A _Wolfdieter Lang_, Feb 11 2019