login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A082726 Continued fraction expansion of current estimate of the fine-structure constant alpha. 2
0, 137, 27, 1, 3, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The estimate is continually changing.

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

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.

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

LINKS

Table of n, a(n) for n=0..6.

NIST, fine-structure constant

NIST, inverse fine-structure constant

Wikipedia, Fine-structure constant.

FORMULA

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.

EXAMPLE

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.

CROSSREFS

Cf. A005600.

Sequence in context: A091510 A134885 A259680 * A189998 A138358 A138329

Adjacent sequences:  A082723 A082724 A082725 * A082727 A082728 A082729

KEYWORD

nonn,cofr,hard,more

AUTHOR

N. J. A. Sloane, May 21 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 15 22:28 EST 2019. Contains 320138 sequences. (Running on oeis4.)