ENGLISH

Splitting the second - the story of atomic time

By A Jones

Book information

Publisher
Taylor & Francis
Year
2000
ISBN
0750306408, 9780750306409, 9781420033496
LCC
QB107 .J66 2000
Open Library ID
OL21745328M
Language
english
Format
PDF
Filesize
2 MB (1681612 bytes)
Edition
1
Pages
202\202
Topic
Physics
Library
Kolxo3
Scanned
yes
Time added
2009-07-20 03:45:11

Description

Astronomers were historically the custodians of time, but the discovery that the period of Earth's rotation is not constant meant that they needed to reassess their basic units. On a separate path, physicists developed atomic clocks and held out the prospect of a timekeeping system rooted in physical constants.These two stories came together in 1955 when the unit of astronomical time, the ephemeris second, was calibrated in atomic terms. For some years the debate resumed about whether timekeeping was the responsibility of astronomy or physics. In the UK, both the National Physical Laboratory and the Royal Greenwich Observatory regarded themselves as official timekeepers.From 1972, the world formally adopted atomic time, but it now looks as though astronomy is making a comeback and millisecond pulsars are strong candidates to make better clocks...

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