A082726 - OEIS

%I #15 Sep 13 2017 03:10:05

%S 0,137,27,1,3,1,1

%N Continued fraction expansion of current estimate of the fine-structure constant alpha.

%C The estimate is continually changing.

%C The term a(7) is today known to be in between 15 and 17, but most likely equal to 16.

%C The value refers to the zero-energy limit of the coupling constant. At higher energies the value increases; e.g. at the energy 90 GeV of the Z-boson, it is about 1/128.

%C a(7) is believed to be 17 or 18 according to the revised 2014 CODATA value. - _Charles R Greathouse IV_, Sep 13 2017

%H NIST, <a href="https://physics.nist.gov/cgi-bin/cuu/Value?alph|search_for=fine+structure">fine-structure constant</a>

%H NIST, <a href="https://physics.nist.gov/cgi-bin/cuu/Value?alphinv|search_for=fine+structure">inverse fine-structure constant</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Fine-structure_constant">Fine-structure constant</a>.

%F alpha = e^2*c*mu/2h, where e ~ 1.602e-19 is the elementary charge, c = 299792458 m/s the speed of light, mu = pi*4e-7 H/m the vacuum permeability, and h ~ 6.626e-34 Planck's constant.

%e CODATA 2014: alpha = 0.007 297 352 5664(17) = 1 / 137.035 999 139(31), where values in parentheses indicate uncertainty in the preceding 2 digits.

%Y Cf. A005600.

%K nonn,cofr,hard,more

%O 0,2

%A _N. J. A. Sloane_, May 21 2003