- What is a second?
- History of the second
- How long is a second?
- How long is a minute?
- How many hours and minutes are there in a year?
We explain what a second is in the measurement of time, how long it lasts and the history of its definition. Also, how long is a minute.
What is a second?
Second is called the base unit for the measurement of the weather of International System of Units (YES). This unit is also shared with the Cegesimal System of Units and the Technical System of Units.
It is represented by the letter s (without a period or capital letter, as it is not an abbreviation). The incorrect use of sec, sec or s. as abbreviations, none of which are formally accepted.
According to the International System, seconds can be divided into smaller units, such as the millisecond (ms) equivalent to 10-3 seconds; the microsecond (μs) equivalent to 10-6 seconds and the nanosecond (ns) equivalent to 10-9 seconds, just to name their three best-known submultiples.
There are also ascending multiples such as decaseconds (days) or hectoseconds (hs), but generally for these cases it is preferred to use units of weather older, like minutes.
History of the second
The ancient Romans were the first to divide the hours into minutes and seconds, which is why these words come from Latin. They divided each hour into 60 portions plus girls who called pars minute cousin or "first small part", from which the term was imposed minute.
In turn, they divided the minutes into 60 again, which were logically called pars minute secunda or “second small part”, which ended up being called “second”. Ultimately, the name of the second comes from the Latin sequire, "follow, continue".
To this should be added the Hebrew heritage in Western culture, whose fervor for the number twelve as a sacred number led them to divide the hours of the day in this way, from sunrise to sunset. Sun, a consideration that is still used today. Thus, each of the twelve hours has 60 minutes and these in turn 60 seconds, which means that in an hour there are 3600 seconds.
How long is a second?
The definition of what a second is comes from centuries past, and was subject to debate and inaccuracies until it was defined as eighty-six thousand four hundredth (1 / 86,400) of an average solar day between 1750 and 1890. This seemed to settle the subject with an acceptable margin of error.
However, in 1967 the need for even more exact measurements imposed a redefinition, no longer based on astronomical time but on atomic time. Thus, today we understand that a second has the duration of 9,192,631,770 oscillations of the radiation emitted by the isotope 133 of cesium (133Cs) at a temperature 0 degrees Kelvin (0 K).
How long is a minute?
According to the International System, a minute has the exact duration of 60 seconds, that is, according to atomic time, of 551,557,906,200 oscillations of the radiation of a atom cesium 133 at 0 degrees Kelvin.
How many hours and minutes are there in a year?
Extending the previously handled figures to a whole year of time, we will have that this represents 525,600 minutes, equivalent to 8760 hours. These figures correspond to a “typical” or average year, since not all years are exactly identical in size.