jbn@wdl1.UUCP (08/23/85)
The names of the units of measure in Systeme Internationale (SI) are
determined by the International Standards Organization, headquartered in
Severes, France. The term ``hertz'', named after Dr. Heinrich Hertz, who
predicted from theoretical considerations that radio waves had to exist and
then demonstrated experimentally that they did, was adopted in the 1960s
to replace the previous English term ``cycles per second.'' The use of
terms unique to any one language is avoided in SI; thus units do not need
to be translated when translating documents, at least amongst the languages
written in Roman letters.
The electrical units of measure are all named after pioneers in the
electrical field. Where possible, the unit is named after the person who
discovered the phenomenon being mesaured. Thus, the ``ohm'', the unit of
electrical resistance, is named after George Simon Ohm, who discovered
resistance, the ``volt'' after Andresso Volta, who invented the battery,
the ``farad'', the unit of capacitance, after Michael Faraday, and the
``henry'', the unit of inductance, after Joseph Henry, who invented the
electromagnet. The ``watt'', the unit of power, is named after James
Watt, who, while not the original inventor of the steam engine, was the
first to make effective steam engines.
These are all metric units and are part of the metric system.
The prefixes ``tera'' (10**12), ``giga'' (10**9), ``mega'' (10**6),
``kilo'' (10**3), `milli'' (10**-3), ``micro'', (10**-6), ``nano''
(10**-9), ``pico'' (10**-12), and ``femto'' (10**-15) may be used with
any of the units given above. There are standard abbreviations for
all of these; consult any metric handbook for details.
I hope that this historical note may be of some value.
John Nagle