A uniform time measure now kept by atomic clocks. Ephemeris Time (ET) was used in the Astronomical Almanac from 1960-1983, but was replaced by barycentric dynamical time when the IAU 1976 System of Astronomical Constants was implemented in the Astronomical Almanac in 1984.
|
揭示大自然的规律
| |||||||||||||||||||||||||||||||||
| >> << | |||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||
 |
回复Comments
{commenttime}{commentauthor}
{CommentUrl}
{commentcontent}