Re: Question about light and heat

[Jim Green <JMGreen@SISNA.COM>]

> I just really struggled with this one.  Depending on the definition, it can
> be either the thermal energy 'quantity' or the process in which the thermal
> energy is transferred.  You can "heat" something, or something can
> have "heat".  Because both are in general usage, I think it is important
> for students to be exposed to both and the difference between them.

Of course one can  use any word in a conversation anyway one wants - if one
is understood:

The problem with a skewed usage of the word "heat" is that hearers  think
they understand but they do not -- especially our students.

For most of  us the Q  in the  First Law is called "heat" -- but Q is not
"transferred" any more than W  is transferred.  W  is an  action _done_ on
a system  -- likewise Q is an action done on a system.  ie W is work done
such that dS=0 and Q is work done such that dS>0.  Assuming  that we want
the Second Law to remain valid.

The work done either by Q or W can  change the energy level of the system,
but neither is energy nor is energy transferred  in the normal sense of the
word.


Jim Green
mailto:JMGreen@sisna.com
http://users.sisna.com/jmgreen