Sunday, May 22, 2011

The Holocaust History Project: Pamphlet on David Irving

The Holocaust History Project Blog of The Holocaust History Project has announced an updated pamphlet on Holocaust denier David Irving.
The British court found that Irving's
misrepresentation of history was
"deliberate in the sense that he was motivated by a
desire borne of his own ideological beliefs to
present Hitler in a favourable light."

Friday, May 20, 2011

Free Energy

This post is part of a series,Nonsense and the Second Law of Thermodynamics. The previous post is entitled Entropy as Religious, Spiritual or Self-Help Metaphor.

You cannot get something for nothing, and the term "free energy" does not mean energy that has no cost.  Rather it refers to energy that is available to do something useful.  The use of the word "free" is in the sense of "liberated."  Free energy is energy that can be liberated to do something useful.



We know that the second law places limitations on how much energy can be used to do useful work.  In most situations, some of the energy must be dissipated as heat that cannot be used to do something useful.  The portion of the energy that can do something useful is the free energy.

At constant volume, the free energy is the Helmholtz Free Energy, given the variable A.

Saturday, May 7, 2011

Enthalpy

This post continues a tangent  from my series on the second law of thermodynamics.  It discusses another quantity in thermodynamics, but it is necessary before I can get to the next post in the series, which is on free energy.

This post discusses the term enthalpy.


At constant pressure the change in enthalpy is the heat transferred to a system.

      ΔH = q  at constant pressure.

Heat is not a state function, but enthalpy is.