Historical burdens on physics 56 The current and its article

<strong>Historical</strong> <strong>burdens</strong> on physics
56 The current and its article
Subject:
The following formulations, in which the word “current” appears without an
article, are taken from physics text books and from the internet: “Conventional
current assumes that current flows out of the positive terminal of a
power supply.” “When a potential difference is applied to a resistive element,
current flows according to Ohm’s Law…” “The flow of water through a
system of pipes can be used to understand the flow of current through an
electric circuit.”
Deficiencies:
By an electric current we understand in physics the flow of electric charge
through a conductive medium. Thus the term electric current describes a
phenomenon.
Possibly the reader may not have noted anything objectionable in the foregoing
citations. But let us remember a rule of grammar: No article is used
before uncount nouns when talking about them generally. Among the uncount
nouns are all substances:
“The ring is made of gold”, “Water flows downhill”, “Hydrogen reacts with
oxigen forming water”, “Hot air rises”, “I need money because I want to buy
wine”.
In all of our initial citations the noun “current” is used without an article. If by
current we really mean a phenomenon, then we have to use it with an article.
We must talk about the electric current in the same way as we talk
about a water current or a stream of people or a money flow, i.e. always
with an article.
If, as in our initial citations I drop the article, then the meaning of the statements
clearly is: I am talking about a kind of stuff, like wine, gold or money.
Particularly interesting is the expression “current flow”, which is often found
even in the scientific literature. Compare with “water flow” which means
flowing water. So current flow would mean flowing current. The current
seems to be something that can, but must not flow. Again we see, that the
word current is used for a substance-like entity. It is easy to identify what is
meant by current (without an article): the electric charge. The citations become
correct when replacing the word current by electric charge.
Origin:
Probably simply the unmindful dealing of experts with the language. Their
concern is not to preserve and cultivate the language.
Disposal:
1. When teaching physics, use the word current only to denote a phenomenon
and thus use it only with an article. One may comply to the habit of the
experts by allowing the use of the word current or electric current as a

name for the quantity I, i.e. the electric current intensity. But if we do so we
should tell to our students explicitly, that we use the same word with two
different meanings: as a name of a phenomenon and as a name of a physical
quantity.
When we discuss anything that is flowing, tell to the student from the beginning
what it is that flows: water, electric charge, energy… Never say that
current is flowing.
Friedrich Herrmann, Karlsruhe Institute of Technology