Unit of time (second)(англ.). SI Brochure: The International System of Units (SI). BIPM. Дата обращения: 9 октября 2015. Архивировано 13 июня 2018 года.
In the late 1950s, the caesium standard was used to measure both the current mean length of the second of mean solar time (UT2) (9 192 631 830 cycles) and also the second of ephemeris time (ET) (9 192 631 770 ± 20 cycles), see L. Essen.Time Scales (англ.) // Metrologia[en]. — 1968. — Vol. 4, no. 4. — P. 161—165. — doi:10.1088/0026-1394/4/4/003. — Bibcode: 1968Metro...4..161E. Архивировано 14 декабря 2017 года.. As noted in page 162, the 9 192 631 770 figure was chosen for the SI second. L. Essen in the same 1968 article stated that this value «seemed reasonable in view of the variations in UT2».
In the late 1950s, the caesium standard was used to measure both the current mean length of the second of mean solar time (UT2) (9 192 631 830 cycles) and also the second of ephemeris time (ET) (9 192 631 770 ± 20 cycles), see L. Essen.Time Scales (англ.) // Metrologia[en]. — 1968. — Vol. 4, no. 4. — P. 161—165. — doi:10.1088/0026-1394/4/4/003. — Bibcode: 1968Metro...4..161E. Архивировано 14 декабря 2017 года.. As noted in page 162, the 9 192 631 770 figure was chosen for the SI second. L. Essen in the same 1968 article stated that this value «seemed reasonable in view of the variations in UT2».
W. Markowitz (1988). A. K. Babcock, G. A. Wilkins (ed.). The Earth's Rotation and Reference Frames for Geodesy and Geophysics. IAU Sumposia #128 (англ.). pp. 413—418. Bibcode:1988IAUS..128..413M.
In the late 1950s, the caesium standard was used to measure both the current mean length of the second of mean solar time (UT2) (9 192 631 830 cycles) and also the second of ephemeris time (ET) (9 192 631 770 ± 20 cycles), see L. Essen.Time Scales (англ.) // Metrologia[en]. — 1968. — Vol. 4, no. 4. — P. 161—165. — doi:10.1088/0026-1394/4/4/003. — Bibcode: 1968Metro...4..161E. Архивировано 14 декабря 2017 года.. As noted in page 162, the 9 192 631 770 figure was chosen for the SI second. L. Essen in the same 1968 article stated that this value «seemed reasonable in view of the variations in UT2».
Unit of time (second)(англ.). SI Brochure: The International System of Units (SI). BIPM. Дата обращения: 9 октября 2015. Архивировано 13 июня 2018 года.
In the late 1950s, the caesium standard was used to measure both the current mean length of the second of mean solar time (UT2) (9 192 631 830 cycles) and also the second of ephemeris time (ET) (9 192 631 770 ± 20 cycles), see L. Essen.Time Scales (англ.) // Metrologia[en]. — 1968. — Vol. 4, no. 4. — P. 161—165. — doi:10.1088/0026-1394/4/4/003. — Bibcode: 1968Metro...4..161E. Архивировано 14 декабря 2017 года.. As noted in page 162, the 9 192 631 770 figure was chosen for the SI second. L. Essen in the same 1968 article stated that this value «seemed reasonable in view of the variations in UT2».
In the late 1950s, the caesium standard was used to measure both the current mean length of the second of mean solar time (UT2) (9 192 631 830 cycles) and also the second of ephemeris time (ET) (9 192 631 770 ± 20 cycles), see L. Essen.Time Scales (англ.) // Metrologia[en]. — 1968. — Vol. 4, no. 4. — P. 161—165. — doi:10.1088/0026-1394/4/4/003. — Bibcode: 1968Metro...4..161E. Архивировано 14 декабря 2017 года.. As noted in page 162, the 9 192 631 770 figure was chosen for the SI second. L. Essen in the same 1968 article stated that this value «seemed reasonable in view of the variations in UT2».
