|
| |
|
|
|
|
|
|
|
|
|
second |
|
| |
|
1
Symbols. The SI unit of time. Its definition as 1/31 556 925.9747 of the tropical year 1900 (now known as the ephemeris second) was replaced in 1968 by a new definition as 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the {TAG(tag=>sup)}133{TAG}Cs nuclide.
2
Symbol â€. A unit of angle equal to one-sixtieth of a minute (which is, in turn, one-sixtieth of a degree) so 3600" = 1°. One second of arc is a very small angular separation in everyday terms: two objects separated by 4 mm subtend an angle about 1" at an observer 1 km away. However, in observational astronomy the second becomes a significant unit. |
|
|
|
|
Bookmark this page:
|
|
|
|
<< former term |
|
next term >> |
|
|
|
|
|
| |
|
|
| Other Terms : excited state | protease | dispersive power
|
| |
|
Home |
Add new article |
Your List |
Tools |
Become an Editor |
Tell a Friend |
Links |
Awards |
Testimonials |
Press |
News |
About
| Imprint |
|
Copyright ©2009 Globalscience24. All rights reserved. Terms of Use | Privacy Policy | Contact Us
|
