Solar second
The Solar Second , Sun minute and sunshine hours are historical measures of time, before the introduction of the Ephemeris in 1960, the usual second were, minutes and hours.
These time measures were based on an assumed mean sunny day and divided this day into 24 hours with 60 minutes of 60 seconds each. Thus the unit of time was ultimately traced back to the very constant rotation speed of the earth. However, with advancing science and technology, this time limit could no longer suffice. So it was replaced in 1960 by the Ephemeris Period. For a more detailed overview of the reasons for replacing these units, see Ephemeris Second .
Individual proof
- ↑ Textbook of Navigation - Germany. Marine Office. ISBN 3-954-27126-5