What is the Standard Definition of One Second in the Metric System?

[samieee]

hello
recently this question arose in my mind that how much time is called 1 second?.As 1 meter has an international standard of length which is a platinum-iridium standard bar measured at boiling point and situated in France.1 kg also standardly defined:

The kilogram (symbol: kg) is the base unit of mass in the International System of Units (SI, from the French Le Système International d’Unités), which is the modern standard governing the metric system. The kilogram is defined as being equal to the mass of the International Prototype Kilogram[1] (IPK), which is almost exactly equal to the mass of one liter of water.(from wikipedia)

.But how 1 second is idealized? what is the amount of 1 second? when clocks oscillate how they measure 1 second?

 

[ZapperZ]

hello
recently this question arose in my mind that how much time is called 1 second?.As 1 meter has an international standard of length which is a platinum-iridium standard bar measured at boiling point and situated in France.1 kg also standardly defined:.But how 1 second is idealized? what is the amount of 1 second? when clocks oscillate how they measure 1 second?

http://hyperphysics.phy-astr.gsu.edu/hbase/acloc.html

Zz.

 

[f95toli]

They you look up the wiki for the definition of the second?

If so you should have seen this

The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom

meaning that an atomic clock works by counting the frequency of a transition between two atomic energy levels.

 

[Dale]

As 1 meter has an international standard of length which is a platinum-iridium standard bar measured at boiling point and situated in France.

Actually, this is not how a meter is defined. Since 1983 the definition of the meter is:

The metre is the length of the path traveled by light in vacuum during a time interval of 1/299 792 458 of a second.

http://www.bipm.org/en/si/base_units/

 

[energiste]

To answer samieee's original concern, a normal watch (digital or standard) counts the oscillations of a quartz crystal (Which is normally 32,768 Hz). And atomic clocks as zapper pointed out count by measuring the radiation of caesium 133 atom.

 

[dacruick]

yes and to cover your next question. the milliliter is the amount of water enclosed by a 1 centimeter cubed box.

 

[Ranger Mike]

how much time is one second...about 6 months ifin you are talking about First Place checker flag and Second P...all that late night work, busted knuckles and blood sweat and tears..but ifin you are in P1 and holding off the herd..and win it...priceless..I been on the pit wall watching a 10 second lead drop to one second because we started out on rain tires only to have the sun pop out and the last place car cut thru the pack on slicks..and darn near win it...one second is a life time...