Sigfrido Leschiutta 2005 Metrologia 42 S10 doi:10.1088/0026-1394/42/3/S03
The definition of the 'atomic' second
Sigfrido Leschiutta
Show affiliationsWhen the reference of a unit is changed, the task remains of expressing the new definition in the terms of the previous one. In two centuries, for instance, the definition of the metre was changed six times. Around 1955, the definitions of the second as the SI unit of time were changed from astronomical ones, based on the rotation (or revolution) of the Earth, to a definition stemming from a quantum phenomenon. The expression of the new atomic second in terms of the previous definitions required a number of actions and measurements. The aim of this paper is to review these actions, some of which, fifty years later, are being forgotten for a lack of adequate documentation.
- PACS
- Subjects
- Dates
-
Issue 3 (June 2005)
Received 25 April 2005
Published 7 June 2005
-
The definition of the 'atomic' second
Sigfrido Leschiutta 2005 Metrologia 42 S10
-
A brief history of astronomy: 1905–2005
Paula Martin 2005 Phys. Educ. 40 245
-
Solitons/instantons in d-dimensional
gauged 
Skyrme models
Y Brihaye and D H Tchrakian 1998 Nonlinearity 11 891
-
X-ray absorption fine structure of bromide ions attracted by cationic surfactants at the heptane-water interface
Hajime Tanida et al 2009 J. Phys.: Conf. Ser. 190 012061
-
Phonon Hall effect in four-terminal nano-junctions
Lifa Zhang et al 2009 New J. Phys. 11 113038
-
Compression of Intense Laser Pulse through Filamentation in an Argon-Filled Cell
Liu Jun et al 2006 Chinese Phys. Lett. 23 374
-
Astrophysical applications of Fabry-Perot multiple beam interferometry by Fabry, his colleagues and followers
G Courtes 1986 J. Opt. 17 29
-
Multiple-bandwidth photoacoustic tomography
Geng Ku et al 2004 Phys. Med. Biol. 49 1329
-
Single and multiple scattering XAFS Debye-Waller factors for crystalline materials using periodic Density Functional Theory
N Dimakis et al 2009 J. Phys.: Conf. Ser. 190 012011
-
A biomagnetic assessment of colonic electrical activity in pigs
T Cordova-Fraga et al 2007 Physiol. Meas. 28 41
Users also read
What's this?- Towards an optimal weighting scheme for TAI computation
- Fifty years of atomic time-keeping: 1955 to 2005
- Fifty years of commercial caesium clocks
Related review articles
What's this?- Gravimetric methods for the preparation of standard gas mixtures
- Laser frequency standards at the P N Lebedev Physical Institute
- Bandwidth characteristics and comparisons of surface texture measuring instruments