Giovanni Giorgi
Encyclopedia
Giovanni Giorgi was an Italian electrical engineer
who invented the Giorgi system of measurement, the precursor to the International System (SI
).
Giorgi was born in Lucca
and studied engineering at the Institute of Technology of Rome, he worked at Fornaci Giorgi in Ferentino
, then was the director of the Technology Office of Rome between 1906 and 1923. He also taught at the University of Rome
between 1913 and 1939.
Toward the end of the 19th century, after James Clerk Maxwell
's discoveries, it was clear that electric measurements could not be explained in terms of the three fundamental units of length, mass and time. Therefore, in 1901, Giorgi proposed to the AEI (Associazione Elettrotecnica Italiana) a new system that had as fundamental units the metre, the kilogram, the second
and a fourth unit to be chosen from the units of electrotechnology.
In 1935 this was adopted by the IEC
as the Giorgi system, also known as MKSΩ, because the fourth fundamental unit was that of electrical resistance
, the ohm. In 1960, at the 11th General Conference of Weights and Measures, the SI
(International System) was adopted, which was based on seven fundamental units: metre, kilogram, second
, ampere
, kelvin
, mole
and candela
.
Giorgi died in Castiglioncello
, Livorno
at the age of 79.
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
who invented the Giorgi system of measurement, the precursor to the International System (SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
).
Giorgi was born in Lucca
Lucca
Lucca is a city and comune in Tuscany, central Italy, situated on the river Serchio in a fertile plainnear the Tyrrhenian Sea. It is the capital city of the Province of Lucca...
and studied engineering at the Institute of Technology of Rome, he worked at Fornaci Giorgi in Ferentino
Ferentino
Ferentino is a town and comune in Italy, in the province of Frosinone, Lazio, 65 km southeast of Rome.It is situated on a hill 400 m above sea-level, in the Monti Ernici area.-History:...
, then was the director of the Technology Office of Rome between 1906 and 1923. He also taught at the University of Rome
University of Rome La Sapienza
The Sapienza University of Rome, officially Sapienza – Università di Roma, formerly known as Università degli studi di Roma "La Sapienza", is a coeducational, autonomous state university in Rome, Italy...
between 1913 and 1939.
Toward the end of the 19th century, after James Clerk Maxwell
James Clerk Maxwell
James Clerk Maxwell of Glenlair was a Scottish physicist and mathematician. His most prominent achievement was formulating classical electromagnetic theory. This united all previously unrelated observations, experiments and equations of electricity, magnetism and optics into a consistent theory...
's discoveries, it was clear that electric measurements could not be explained in terms of the three fundamental units of length, mass and time. Therefore, in 1901, Giorgi proposed to the AEI (Associazione Elettrotecnica Italiana) a new system that had as fundamental units the metre, the kilogram, the second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
and a fourth unit to be chosen from the units of electrotechnology.
In 1935 this was adopted by the IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...
as the Giorgi system, also known as MKSΩ, because the fourth fundamental unit was that of electrical resistance
Electrical resistance
The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...
, the ohm. In 1960, at the 11th General Conference of Weights and Measures, the SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
(International System) was adopted, which was based on seven fundamental units: metre, kilogram, second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
, ampere
Ampere
The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
, kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
, mole
Mole (unit)
The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12 , the isotope of carbon with atomic weight 12. This corresponds to a value...
and candela
Candela
The candela is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function . A common candle emits light with a luminous intensity of roughly one candela...
.
Giorgi died in Castiglioncello
Castiglioncello
Castiglioncello is a frazione of the comune of Rosignano Marittimo, in the province of Livorno, Tuscany, Italy. It stands on a promontory reaching out into the Tyrrhenian Sea, surrounded by pinewoods and hills that fall right down to the sea forming cliffs, little inlets, coves and sandy...
, Livorno
Livorno
Livorno , traditionally Leghorn , is a port city on the Tyrrhenian Sea on the western edge of Tuscany, Italy. It is the capital of the Province of Livorno, having a population of approximately 160,000 residents in 2009.- History :...
at the age of 79.