Giovanni Giorgi (November 27, 1871 – August 19, 1950) was an Italian

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

and

electrical engineer Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

who proposed the ''Giorgi system'' of measurement, the precursor to the

International System of Units The International System of Units, internationally known by the abbreviation SI (from French ), is the modern form of the metric system and the world's most widely used system of measurement. It is the only system of measurement with official s ...

(SI).

Early life

Giovanni Giorgi was born in Lucca on November 27, 1871.

Career

Giorgi studied

engineering Engineering is the practice of using natural science, mathematics, and the engineering design process to Problem solving#Engineering, solve problems within technology, increase efficiency and productivity, and improve Systems engineering, s ...

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 1905 and 1924. He also taught at the University of Rome between 1913 and 1939. During

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

he moved to Ferentino. He was an Invited Speaker of the ICM in 1924 in Toronto, in 1928 in Bologna, and in 1932 in Zurich.

Personal life

He was engaged to Laura Pisati, his former master's student who became the first woman invited to deliver a lecture at the fourth

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the IMU Abacus Medal (known before ...

(ICM), but she died in 1908 shortly before both her talk and their intended wedding.

Death

Giorgi died on August 19, 1950, in Castiglioncello, Livorno at the age of 78.

The ''Giorgi system''

Toward the end of the 19th century, after

James Clerk Maxwell James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish physicist and mathematician who was responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism an ...

's discoveries, it was clear that electric measurements could not be explained in terms of the three base units of length, mass and time, and that some irrational coefficients appeared in the equations without any logical physical reason. In 1901, Giorgi proposed to the (AEI) that the MKS system (which used the

metre The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of ...

, kilogram and second as its base units) should be extended with a fourth unit to be chosen from the units of

electromagnetism In physics, electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interacti ...

, solving also the presence of the irrational coefficients. In 1935 this was adopted by the

International Electrotechnical Commission The International Electrotechnical Commission (IEC; ) is an international standards organization that prepares and publishes international standards for all electrical, electronics, electronic and related technologies. IEC standards cover a va ...

(IEC) as the ''M.K.S. System of Giorgi'' without specifying which electromagnetic unit would be the fourth base unit. In 1946 the International Committee for Weights and Measures (CIPM) approved a proposal to use the ampere as that unit in a four-dimensional system, the MKSA system. The ''Giorgi system'' was thus the precursor of the

(SI) adopted in 1960, which was based on six base units: metre, kilogram, second, ampere, kelvin, and candela. The mole was added as a seventh base unit in 1971.

Works

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Notes

References

# # {{DEFAULTSORT:Giorgi, Giovanni 1871 births 1950 deaths Italian electrical engineers 20th-century Italian physicists Metrologists nl:Giovanni Giorgi