🚀 go-pugleaf

On Feb 24, 4:43 am, Pentcho Valev <pva...@yahoo.com> wrote:
> What is the probability that Mr. X looks like Mr. Y? Clearly the prior
> (Mr. X and Mr. Y are identified but there is no additional information
> concerning them) probability is virtually zero. This means that for
> the argument:
>
> Premise: Mr. X and Mr. Y are identical twins.
> Conclusion: Mr. X looks like Mr. Y.
>
> the combination "false premise, true conclusion" is virtually
> impossible.
>
> Consider an oversimplified version of the Carnot theorem:
>
> Premise: Heat is an indestructible substance (cannot be converted into
> work in the heat engine).
     The second law of thermodynamics implies that entropy is an
indestructible substance.
    The word heat, as used in science articles, can mean one of four
mutually exclusive things.
1) A quantity of entropy.
2) The quantity of energy being carried by a quantity of entropy.
3) Entropy density.
4) The density of energy carried by entropy.
       The choice of meaning is context sensitive. However, for most
situations the difference isn't important. However, sometime is is
very important and causes confusion.
      Thus when we define enthalpy as the "heat of reaction," we are
talking about heat in the sense of #3. When we say that the heat can
only flow from high temperature to low temperature, we are talking
about #1. When we say that heat is the randomized kinetic energy of
molecules, we are using #2.
    An adiabatic process is sometimes defined as a process in a
chamber that is closed to the transfer of heat. In reality, this
chamber is actually closed to the transfer of entropy. The energy held
by the entropy can leave the chamber in the form of work. I remember
being confused by this point.
    When Carnot used the word "caloric," he was usually referring to
what we now call entropy. Sometimes he slips and refers to the energy
that the caloric carries. When the second law is quoted nowadays, the
word "heat" usually refers to the entropy.
   Science teachers often define heat  as a form of "energy". They are
of course referring to the energy carried by the entropy, not the
entropy.