Preface Page 1: Introduction (to preface page 2) (Problematic Thermo)
Imagine if you will that the Earth's atmosphere has weight? Weight being mass in a gravitational field. Then one might assume that
the lifting of the Earth's atmosphere by an expanding system requires work. This raises the question: Where in traditional
thermodynamics is this work clearly described?
If you answer "I do not know", then you possess the accepted understanding!
Think about it, nowhere in traditional thermodynamics is the work required to lift our atmosphere by an expanding system clearly described!
Those well
versed in the science, may or may not realize that the following accepted isothermal entropy change (TdS) relation describes
both the change to system's internal energy (dE) and work done (PdV) by an isothermally expanding system (closed or otherwise):
TdS=dE+ PdV (1) Blog about expanding systems
For most a first impression of eqn (1) is that it describes what is happening within the expanding system. I.e. TdS is that system’s isothermal entropy change, while dE is the system’s internal energy change and PdV is work done but where? If the work is done within the expanding system, then how can that be? Specifically the system’s internal energy change accounts for all the system’s microscopic energy changes which when summed is dE. So if PdV is a result of the system's energy change then it cannot be part of the system, because if it was then it have to be part of dE!
Accordingly, PdV must be work done externally to the system and that more often than not, this means that the work is done onto the surrounding atmosphere. You may now exclaim that the work required to lift our atmosphere is defined by W=PdV and you would be right.(Reference my 2015 paper "Second law and Lost Work" in Peer reviewed Journal Physics Essays). Hence equation (1) receives clarity by rewritting it as follows:
(TdS)system = dEsystem + (PdV)atmosphere (2) see blog on parameters if need be
The clarity given in eqn (2) is not traditionally expressed in thermodynamics i.e. eqn (1). Specifically, PdV is not always clearly defined as work done onto the surrounding atmosphere. And this allows us to wrongly think that PdV maybe part of the expanding system's energy, which fits because the so-called entropy change (dS) is within that system. Moreover, since PdV is irreversible work done by the system onto its surroundings hence that work is no longer energy that is associated with the expanding system i.e. lost work.
It is interesting that traditional thermodynamics too often wrongly considers work as being reversible (see Illusionary Reversible Work) when describing the work done by isothermally expanding systems in terms of the expanding system's paramerters Also see Parameters.
The strangeness surrounding the expanding system's isothermal entropy change (TdS) does not stop here. Consider the 20th century understanding of entropy, i.e. "the randomness of molecules in incessant motion". Herein, energy is associated with randomness i.e. the more random an expanding system appears, then the more energy was lost by that system. Again such tradiational assertions provides no clarity as to where this lost energy goes. Moreover, the entropy change is within the system while the lost work onto the the surrounding atmosphere, is exterior to that expanding system. Note: Second law of thermodynamics is based upon TdS>0 for isolated systems, hence is problematic.
There will be those amongst us who rightfully
realize that although not clearly written, PdV is the work done onto the surrounding atmosphere See Surroundings. But they
seemingly do not fully appreciate what this means. If the lost work represents energy that is given into the surrounding atmosphere,
then this is energy that cannot be retrieved i.e. it is irreversible! Think about it, you give energy into the atmosphere,
which ultimately results in an infinitesimally small (not measureable) rise in its potential energy and/or temperature within the
atmosphere. Now ask: How are you supposed to retrieve that energy because the expanding system and atmosphere are still
isothermal and isobaric? In order a system to readily extract energy from its neighbor then in general there needs to be a significant
temperature difference between the two systems. Similarly, in order for a system to do work onto another system there needs to
be a pressure difference.
The above is lost work by the expanding system, as was first described in this author's 2015 paper (Journal: Physics Essays) titled "Lost Work and the Second Law". Moreover, since the second law was conceived in order to explain why devices like the steam engine were inefficient i.e. why processes tend to be irreversible i.e. why perpetual motion machines do not exist, then our new understanding concerning lost work provides insight into irreversibility without the need of the second law i.e it actually renders the second law into a false postulate!
Furthermore, if PdV is work done onto the atmosphere then you cannot do Gibb's "differential shuffle" where
d(E+PV) and/or d(TS) are then traditionally added
to or taken away from each side of equation (1). The reason being that there is again no clarity as to whether you are talking
about the system, or its surroundings. Not to mention the absurdity of trying to add them together as is tradiationally done
i.e. eqn (1). Understand: d(E+PV) only makes sense when dE is the system's energy change and PdV is the work done onto the atmosphere.
see parameters
Obviously in equation
1) PdV traditionally lacked clarity. Perhaps this in part explains why entropy (S) is a parameter without clarity. Clarity remains
essential to any science. Yet we and our forefathers have allowed a science to have laws that supposedly govern our universe to be
based upon concepts that lack clarity. Governance without clarity, sounds more like politics than constructive science.
This
website, combined with my papers and books will demonstrate that traditional thermodynamics requires a rethink. This author likes
to believe that this all provides a starting point for this to happen. For those in the sciences I ask that you take this
as an opportunity rather than view it as some sort if indignity.
1) Entropy generation has relevance: Our reality is that perhaps it does not. I apologize but one cannot
determine this until someone explains just what entropy is! Fact is entropy has little to do about the randomness of a system’s molecules
in incessant motion!
2) Expanding system’s entropy increase is lost work due to an increase in that system’s randomness. The reality
is: Lost work by expanding systems is the energy/work lost in displacing our atmosphere’s mass against gravity. See Lost Work