Re: [Phys-l] Heat is a noun

[John Denker <jsd@av8n.com>]

On 02/10/2008 01:24 AM, carmelo@pacific.net.sg wrote:

> Romer claims that heat should not be used as a noun. While I agree  
> with the spirit of using the word heat correctly, I disagree that heat  
> is not a noun. 

There are several problems with trying to define heat.
Arguing about "noun" versus "verb" makes little if any
progress toward solving the problems.

> Heat is indeed a noun, but it is the name of a process,  
> not the name of what is transferred.

Not necessarily; see below.

> Although this has been discussed in Phys-L before, it seems that there  
> is still no agreement on whether “Heat is a process” or “Heat is a  
> noun”.

There are four or five different well-established technical definitions 
of heat.  Each of these makes a certain amount of sense in some
context or another, but none covers all the bases.
  http://www.av8n.com/physics/thermo-laws.htm#sec-heat

In addition there are quite a few metaphorical and nontechnical
uses of the word "heat" ... not to mention outright misconceptions
and misnomers.

> Hence, it could be better to write “Heat should be defined as a  
> process” or “Heat should be defined as a noun”. Actually, there are  
> also students who get very confused when they are taught that “Heat is  
> not a noun”.

None of that solves the problem.

===================

You may be wondering, how can something as important as heat be
so poorly defined?  Well, the question almost answers itself:
Loose and/or conflicting definitions of heat survive because the 
definition of heat is not very important.  As far as I can tell, 
whenever somebody thinks they need to quantify heat, they wind 
up quantifying entropy and/or energy instead.

There is a useful analogy to phlogiston.  For many, many years,
experts argued about the definition of phlogiston.  There were
inconsistencies everywhere.  Eventually they gave up and replaced
phlogiston by *two* concepts:  oxygen and energy.

Today we are in the same position with respect to heat.  There
are inconsistencies that will never be resolved.  The solution
is to give up on heat, and to replace it with *two* concepts:
energy and entropy.  Both energy and entropy are very strictly
and precisely defined.

If you want to continue using heat as a quaint, colorful, qualitative
term, that's OK.  On the other hand, arguments about the precise 
definition of heat are not worth the trouble.

For details on all this, see
  http://www.av8n.com/physics/thermo-laws.htm#sec-heat