A248508 Decimal expansion of K_J = 2 e/h (Josephson constant) in units of A s^2 kg^{-1} m^{-2} in the 2019 SI system of units.

4, 8, 3, 5, 9, 7, 8, 4, 8, 4, 1, 6, 9, 8, 3, 6, 3, 2, 4, 4, 7, 6, 5, 8, 2, 8, 5, 0, 5, 4, 5, 2, 8, 1, 3, 5, 3, 5, 3, 3, 5, 1, 1, 8, 6, 6, 0, 0, 4, 0, 1, 4, 4, 6, 0, 9, 6, 9, 7, 4, 9, 9, 2, 0, 3, 2, 0, 4, 1, 7, 9, 7, 8, 0, 6, 8, 0, 4, 0, 8, 2, 8, 0, 9, 1, 7, 4, 6, 0, 5, 5, 5, 4, 0, 9, 3, 0, 2, 4, 5

Offset

15,1

Comments

The value of K(J-90) is 483597.9 * 10^9 Hz V^-1 based on measurements in 1990. - Ralf Steiner, Jan 03 2019

The value of K(J) is 2 * e / h = 483597.848416... * 10^9 Hz V^-1 based on SI definitions (effective on May 20, 2019). - Ralf Steiner, Jan 03 2019

From Wolfdieter Lang, May 20 2019: (Start)

For the seven units of the 2019 SI system see A322415 with references.

Here only the Planck constant h = 6.62607015*10^{-34} J s, with J = kg m^2 s^(-2), and the elementary charge e = 1.602176634*10^{-19} C, with C = A s are used.

The 1990 definition of Volt with symbol V is K_{J-90} = (V s)^{-1}, where s^(-1) = Δν_{Cs}/9192631770. (End)

Links

Table of n, a(n) for n=15..114.

BIPM, On the revision of the International System of Units (SI), BIPM, Nov 13-16 2018.

NIST, Josephson constant

Wikipedia, Josephson effect

Formula

Equals 2 * A081823 / A003676.

Example

K_J = 2*e/h = 4.83597848416983632447658285054528135353351186600401446096974992032041797... * 10^14 A s^2/(kg m^2). - Wolfdieter Lang, May 20 2019

Mathematica

RealDigits[2*(1.602176634`100*10^(-19))/(6.62607015`100*10^(-34))][[1]]

Prog

(PARI) 21362355120000000000000/44173801 \\ Charles R Greathouse IV, Jul 16 2023

Crossrefs

Cf. A003676 (h), A081823 (e), A248507 (inverse).

Sequence in context: A234001 A248946 A232808 * A362530 A065191 A229988

Adjacent sequences: A248505 A248506 A248507 * A248509 A248510 A248511

Keyword

nonn,cons,easy

Author

Arkadiusz Wesolowski, Oct 07 2014

Extensions

Updated by Ralf Steiner, Jan 03 2019

Status

approved