Quantity of electricity
Encyclopedia
In physics
the term quantity of electricity
refers to the quantity of electric charge
. It is designated by the letter Q and in the SI
system is measured in derived
units called Coulombs.
adjective electricus, originally meaning 'of amber
', was first used to refer to amber's attractive properties by William Gilbert in his 1600 text De Magnete
. The term came from the classical Latin electrum, amber, from the Greek ἤλεκτρον (elektron), amber. The origin of the Greek word is unknown, but there is speculation that it might have come from a Phoenician word elēkrŏn, meaning 'shining light'. The letter Q was used for electric charge instead of the letter E because the letter was already used to represent the electron.
to describe materials like amber that attracted other objects. The first usage of the English word electricity is ascribed to Sir Thomas Browne in his 1646 work, Pseudodoxia Epidemica
:
In this context, an "Electrick" or "Electrick body" was a non-conductor, or an object capable of attracting "light bodies" (like bits of paper
) when excited by friction
; a piece of amber is "an Electrick", while a piece of iron is not. "Electricity", then, was simply the property of behaving like an electric, in the same way that "elasticity
" is the property of behaving like an elastic
. ("Electric" continued to be used as a noun until at least 1913.)
It was not until later that the definition shifted to refer to the cause of the attraction instead of the property of being attractive.
Charge, in the electrical sense, was first used in 1767.
The term quantity of electricity was once common in scientific publications. It appears frequently in the writings of Franklin
, Faraday
, Maxwell
, Millikan
, and J. J. Thomson
, and was even occasionally used by Einstein
.
However, over the last hundred years the term "electricity
" has been used by electric utility companies and the general public in a non-scientific way. Today the vast majority of publications no longer refer to electricity as meaning electric charge. Instead they speak of electricity as electromagnetic energy. The definition has drifted even further, and many authors now use the word "electricity" to mean electric current (ampere
s), energy flow (watt
s), electrical potential (volt
s), or electric force. Others refer to any electrical phenomena as kinds of electricity.
These multiple definitions are probably the reason that Quantity of Electricity has fallen into disfavor among scientists. Physics textbooks no longer define Quantity of Electricity or Flow of Electricity. Quantity of electricity is now regarded as an archaic usage, and it has slowly been replaced by the terms charge of electricity, then quantity of electric charge
, and today simply charge. Since the term electricity has increasingly become corrupted by contradictions and unscientific definitions, today's experts instead use the term charge to remove any possible confusion.
Another problem arises because the population of physicists abandoned the term "electricity" without much public discussion and perhaps without much awareness on the part of their community. By silently altering the meaning of common and heavily-used terms, the scientific community caused an immense confusion on the part of the public. Whereas in the past the question "What is electricity?" was more or less easily answered, today the question itself has become meaningless. Is electricity a form of energy? Is electricity the same as electric charge? Is electricity nothing but a class of phenomena? Should we measure the quantity of electricity in Coulombs, or should we instead use amperes, joules, or watts, or even volts? Physics texts and reference books supply no solid answer, since physicists have gradually abandoned electricity as a scientific term.
And yet Quantity of Electricity still persists in its original definition in many major contemporary references. For example, in the modern SI
units of physics, the SI definition of Coulomb
is given as both the unit quantity of electric charge and also the unit quantity of electricity. Encyclopædia Britannica
defines the Coulomb as the unit quantity of electricity. The Merriam-Webster dictionary, in definition 1a, defines electricity as charge. And until the late 1980s, the glossary in the CRC Handbook of Chemistry and Physics
used the term "quantity of electricity" in place of "electric charge" in most of its definitions. Chemistry students will be familiar with Faraday's discovery that a unit quantity of electricity, when passed through an electrolysis cell, liberates a certain number of atoms of metal or gas. Under these definitions, electricity is not a form of energy.
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
the term quantity of electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
refers to the quantity of electric charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
. It is designated by the letter Q and in 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...
system is measured in derived
SI derived unit
The International System of Units specifies a set of seven base units from which all other units of measurement are formed, by products of the powers of base units. These other units are called SI derived units, for example, the SI derived unit of area is square metre , and of density is...
units called Coulombs.
Pre-English origins
The New LatinNew Latin
The term New Latin, or Neo-Latin, is used to describe the Latin language used in original works created between c. 1500 and c. 1900. Among other uses, Latin during this period was employed in scholarly and scientific publications...
adjective electricus, originally meaning 'of amber
Amber
Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...
', was first used to refer to amber's attractive properties by William Gilbert in his 1600 text De Magnete
De Magnete
De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure is a scientific work published in 1600 by the English physician and scientist William Gilbert and his partner Aaron Dowling...
. The term came from the classical Latin electrum, amber, from the Greek ἤλεκτρον (elektron), amber. The origin of the Greek word is unknown, but there is speculation that it might have come from a Phoenician word elēkrŏn, meaning 'shining light'. The letter Q was used for electric charge instead of the letter E because the letter was already used to represent the electron.
Entry into English
The word electric was first used by Francis BaconFrancis Bacon
Francis Bacon, 1st Viscount St Albans, KC was an English philosopher, statesman, scientist, lawyer, jurist, author and pioneer of the scientific method. He served both as Attorney General and Lord Chancellor of England...
to describe materials like amber that attracted other objects. The first usage of the English word electricity is ascribed to Sir Thomas Browne in his 1646 work, Pseudodoxia Epidemica
Pseudodoxia Epidemica
Pseudodoxia Epidemica or Enquries into very many received tenets and commonly presumed truths, also known simply as Pseudodoxia Epidemica or Vulgar Errors, is a work by Thomas Browne refuting the common errors and superstitions of his age. It first appeared in 1646 and went through five subsequent...
:
In this context, an "Electrick" or "Electrick body" was a non-conductor, or an object capable of attracting "light bodies" (like bits of paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
) when excited by friction
Triboelectric effect
The triboelectric effect is a type of contact electrification in which certain materials become electrically charged after they come into contact with another different material and are then separated...
; a piece of amber is "an Electrick", while a piece of iron is not. "Electricity", then, was simply the property of behaving like an electric, in the same way that "elasticity
Elasticity (physics)
In physics, elasticity is the physical property of a material that returns to its original shape after the stress that made it deform or distort is removed. The relative amount of deformation is called the strain....
" is the property of behaving like an elastic
Elastomer
An elastomer is a polymer with the property of viscoelasticity , generally having notably low Young's modulus and high yield strain compared with other materials. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, although the latter is preferred...
. ("Electric" continued to be used as a noun until at least 1913.)
It was not until later that the definition shifted to refer to the cause of the attraction instead of the property of being attractive.
Charge, in the electrical sense, was first used in 1767.
The term quantity of electricity was once common in scientific publications. It appears frequently in the writings of Franklin
Benjamin Franklin
Dr. Benjamin Franklin was one of the Founding Fathers of the United States. A noted polymath, Franklin was a leading author, printer, political theorist, politician, postmaster, scientist, musician, inventor, satirist, civic activist, statesman, and diplomat...
, Faraday
Michael Faraday
Michael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....
, 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...
, Millikan
Robert Millikan
Robert A. Millikan was an American experimental physicist, and Nobel laureate in physics for his measurement of the charge on the electron and for his work on the photoelectric effect. He served as president of Caltech from 1921 to 1945...
, and J. J. Thomson
J. J. Thomson
Sir Joseph John "J. J." Thomson, OM, FRS was a British physicist and Nobel laureate. He is credited for the discovery of the electron and of isotopes, and the invention of the mass spectrometer...
, and was even occasionally used by Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
.
However, over the last hundred years the term "electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
" has been used by electric utility companies and the general public in a non-scientific way. Today the vast majority of publications no longer refer to electricity as meaning electric charge. Instead they speak of electricity as electromagnetic energy. The definition has drifted even further, and many authors now use the word "electricity" to mean electric current (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...
s), energy flow (watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s), electrical potential (volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
s), or electric force. Others refer to any electrical phenomena as kinds of electricity.
These multiple definitions are probably the reason that Quantity of Electricity has fallen into disfavor among scientists. Physics textbooks no longer define Quantity of Electricity or Flow of Electricity. Quantity of electricity is now regarded as an archaic usage, and it has slowly been replaced by the terms charge of electricity, then quantity of electric charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
, and today simply charge. Since the term electricity has increasingly become corrupted by contradictions and unscientific definitions, today's experts instead use the term charge to remove any possible confusion.
Conceptual problems
Despite their similarities, substituting the word "charge" for "electricity" presents new problems. Older scientific papers still exist, and their authors constantly discuss quantities of electricity and flows of electricity (meaning charge and current respectively.) Those historical authors know that their readers understand just one definition: the term electricity means charge and nothing else. Modern students who read physics papers from periods prior to 1930 (approx.) should make a continuous effort to remain aware of this issue. If historical physicists discuss quantities of "electricity" implying "electric charge," yet the modern reader assumes they're speaking of electrical energy, the writings of those physicists will be quite difficult to understand.Another problem arises because the population of physicists abandoned the term "electricity" without much public discussion and perhaps without much awareness on the part of their community. By silently altering the meaning of common and heavily-used terms, the scientific community caused an immense confusion on the part of the public. Whereas in the past the question "What is electricity?" was more or less easily answered, today the question itself has become meaningless. Is electricity a form of energy? Is electricity the same as electric charge? Is electricity nothing but a class of phenomena? Should we measure the quantity of electricity in Coulombs, or should we instead use amperes, joules, or watts, or even volts? Physics texts and reference books supply no solid answer, since physicists have gradually abandoned electricity as a scientific term.
And yet Quantity of Electricity still persists in its original definition in many major contemporary references. For example, in the modern 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...
units of physics, the SI definition of Coulomb
is given as both the unit quantity of electric charge and also the unit quantity of electricity. Encyclopædia Britannica
Encyclopædia Britannica
The Encyclopædia Britannica , published by Encyclopædia Britannica, Inc., is a general knowledge English-language encyclopaedia that is available in print, as a DVD, and on the Internet. It is written and continuously updated by about 100 full-time editors and more than 4,000 expert...
defines the Coulomb as the unit quantity of electricity. The Merriam-Webster dictionary, in definition 1a, defines electricity as charge. And until the late 1980s, the glossary in the CRC Handbook of Chemistry and Physics
CRC Press
The CRC Press, LLC is a publishing group which specializes in producing technical books. While many of their books relate to engineering, science and mathematics, their scope also includes books on business, forensics and information technology...
used the term "quantity of electricity" in place of "electric charge" in most of its definitions. Chemistry students will be familiar with Faraday's discovery that a unit quantity of electricity, when passed through an electrolysis cell, liberates a certain number of atoms of metal or gas. Under these definitions, electricity is not a form of energy.