Segondra
Ny segondra (eva SI: s), hafohezina amin' ny hoe s. na seg. tsindraindray, dia anaran-tsingam-potaona ary izy no ampiasain' ny SI (système internationa) rehefa mandrefy ny fotoana. Azo refesina izy amin' ny famataranandro. Misy 60 segondra ny iray minitra ary misy 3 600 segondra ny iray ora.
Singam-potoanan' ny andro ny segondra. Ny segondra iray dia 1/86 400 andro (satria 1/24×60×60). Fa tamin' ny taonjato faha 19-20, ny fandinihana ara-kainkintana dia milaza fa mihalava ny salan' ny segondra, ary noho izany, tsy natao ho tsiahin' ny singam-potoana intsony ny fihodinan' ny Tany. Amin' ny famataranandro atômika, azo atao ny mamaritra ny segondra amin' ny alalan' ny fototoetran' ny natiora.
Mbola azo zaraina 60 ny iray segondra mba hahazoana ny atao hoe tiersa, ka ny iray tiersa dia iray ampahenimpolon' ny segondra. Indreto koa ny fizaràna hafa: milisegôndra, mikrôsegondra, nanôsegondra, pikôsegondra, femtôsegondra, ary atôsegondra.
Jereo koa
[hanova | hanova ny fango]Ventim-potoana
- Fotoana
- Ora
- Minitra
- Segondra
- Milisegôndra
- Mikrôsegondra
- Nanôsegondra
- Pikôsegondra
- Femtôsegondra
- Atôsegondra
Rohy ivelany
[hanova | hanova ny fango]Miteny anglisy
- National Physical Laboratory: Trapped ion optical frequency standards Archived Febroary 14, 2009 at the Wayback Machine
- High-accuracy strontium ion optical clock; National Physical Laboratory (2005)
- National Research Council of Canada: Optical frequency standard based on a single trapped ion Archived Martsa 14, 2008 at the Wayback Machine
- NIST: Definition of the second; notice the cesium atom must be in its ground state at 0 K
- Official BIPM definition of the second
- Seconds and leap seconds by the USNO Archived Jiona 11, 2012 at the Wayback Machine* The leap second: its history and possible future
- What is a Cesium atom clock? Archived Febroary 20, 2009 at the Wayback Machine
