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Re: [Phys-l] operational definition on heat

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From: [mailto:phys-l-] On Behalf Of
Sent: Saturday, September 12, 2009 7:09 PM
Subject: Re: [Phys-l] operational definition on heat

Quoting Bernard Cleyet <>:
I thought we decided not to use that word except as a verb.

Thanks for all the responses. The usage of the word "heat" may not be
agreed by all physicists. For example, John Denker may not agree.

Interestingly, In one engineering text, the operational definition of
heat is defined via Born-Caratheodory form of the First Law of
Thermodynamics. Then one paper in the context of Chemistry, proposed
qualitative and quantitative definitions on heat. The quantitative
definition on heat can be defined, for example, with the use of

In a recent PhD Thesis on the role of language in learning physics,
the operational definition of heat is considered to be the energy
transferred between objects because of a temperature difference, and
heat is preferred to be a process. This seems inconsistent to me. If
heat is a process instead of a noun, how can it be measured? Besides,
this common textbook definition does not involve any explicit
operational procedure. How could it be categorised as operational
definition? At least, the chemists mention calorimentry.

Most texts do agree that heat is to be reserved for energy in motion or the
transfer of energy due to a temperature difference. But then the authors
often proceed to use it in sentences which imply that heat is a "thing"
rather than being the accounting of a transaction. I know of one text where
virtually all sections headings treated it as a noun, thus contradicting the
given definition. Try reading your text to see how it treats heat. You may
be surprised.

Then of course you have terms like specific heat. The problem here is that
heat naturally looks like a noun, and students have been using it that way
for a long time. So rather than trying to beat the students into using it
the "correct" way, why not use other language and avoid the term until they
have learned the concepts, then introduce the term as a specific physics
term for the already learned concepts.

But as I pointed out it is a textbook problem because the students see the
word heat in the book and then interpret it differently, even when they have
been told how to interpret it. But since most students hardly crack open
the book, using other language and then much later introducing the word heat
as the usual word for the process should not pose difficulties.

The calorimetry definition may tend to reinforce the student idea that the
object has gained heat, thus making it a noun. But this is only bad if they
have to read or interact with sources that treat it only as a transaction.

John M. Clement
Houston, TX