The SI System

Basic Units of Measurement

All other units used by scientists are derived from these 7 units.

For example the unit of measure for angles is not degrees but radians which is based on length.

Different magnitudes were also needed to specify the exact value of these units. They were worked out as per the decimal system and given standard names. The current nomenclature is given below.

The SI is intended to be an evolving system; units and prefixes are created and unit definitions are modified through international agreement as the technology of measurement progresses and the precision of measurements improves. For example, the most recent derived unit, the katal, (an unit for measuring catalytic activity of enzymes) was defined in 1999.

We have to be careful about using the correct case (upper/lower) and they could mean different units.

As of now the SI has been adopted by all countries except the United States, Liberia and Myanmar. In US for some reason, milk is measured in gallons while soft drinks are measured in ml!

A recent addition to really large & really small numbers is googol & googolplex.

A googol is defined as one followed by one hundred zeros.

1 preceded by a googol zeros is a googolplex. If it’s difficult to comprehend how long that number would be, it’s because writing it out would result in a figure so large that if it were written down and published in a volume series of books, it would weigh more than the whole globe.

New Measurement Units Introduced in Recent Years

With the advancement of science & technology, the amount of data generated has increased astronomically. Hence need has arisen for inventing more measurement units.

By 2010, companies like Google which generate and use huge amounts of data started using terms like "hella bytes". Media also started using unsanctioned prefixes for data storage such as brontobytes and hellabytes.

Hence the International Bureau of Weights and Measures and the Decimal System had to invent and standardise units & their prefixes.

However metric prefixes needed to be shortened to just their first letter—and B and H were already taken, ruling out bronto and hella.

The only letters that were not used for other units or other symbols were R and Q and hence the units were called "Quetta % Ronna"

Some of these, along with the year in which they were introduced, are given below.