Problematic thermodynamics: A new beginning?
Below is a post on thermodynamics. It’s from Kent Mayhew. I don’t necessarily agree or disagree with his views, but I do agree that new ideas on entropy are needed, please comment and let us know your thoughts.
When seriously learning thermodynamics we often start with the random walk, and from that we learn probabilities and how the interaction of matter and energy can be best summed up by probabilities. Few ever question this guise, all forgetting that probabilities give results, not reasons. Deal a deck of cards and the results of a pair, flush, full house etc all come into play, yet the reason remains the cards were dealt, and only the results are defined by probabilities.
To say that thermodynamics needs a rewrite because probabilities give results and not reasons is an ambiguous argument that would not alter anyone’s mindset. However with this in the back of our minds, let us reconsider some aspects of thermodynamics.
If one accepts that our atmosphere exerts a pressure then one must accept that the atmosphere consists of mass located in a gravitational field. Now consider an expanding system; in order to experience a volume increase, it must upwardly displace our atmosphere’s mass. And this constitutes work (W=PdV)!
Sure such an expansion may simply cause a region pressure increase but as an open system, once mechanical equilibrium is attained, the net result will the upward displacement of Earth’s atmosphere, which required isobaric work: W=PdV. Furthermore you cannot simply recover this work, hence it becomes “lost work”/”lost energy”. This is discussed in my paper titled “Second law and lost work” Physics Essays 2016
- This paper is also posted on my website: http://www.newthermodynamics.com/#!mypapers/c1qsm
Sadly, the 19th century scientific greats, i.e. Clausius, Maxwell, Kelvin etc, all failed to understand the above simple premise. Some may call this a minor oversight but the reality becomes that this is perhaps the biggest blunder ever endeared by the sciences. Just think of the consequences.
Clausius realized that something when multiplied by temperature (T) defined energy, and named that something entropy (S). Hence the basis of the following fundamental isothermal isobaric thermodynamic relation was realized:
TdS = dE+PdV (1)
Eqn (1) states that isothermal entropy change (TdS) equals the change in internal energy (dE) plus the isobaric volume change (PdV).
All who have studied thermodynamics have accepted the above relation (1) without any real consideration. Furthermore, we have all thought that the lost work (PdV) experienced by expanding systems can be best explained in terms of entropy change (dS). For example latent heat of vaporization (AKA enthalpy of vaporization) involves PdV, which is often discussed in terms of changes to the liquid molecule’s entropy/randomness. Engineers often describe this as “non-sensible” work.
It sounds so simple, until you ask what is entropy? Well it turns that entropy has different interpretations, all dependant upon it application. When Shannon asked Von Neumann what should I call my mathematical entity in his information theory, he was basically told: “You should call it entropy, for two reasons. In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, nobody knows what entropy really is, so in a debate you will always have the advantage.” Interestingly Shannon was going to call it information and perhaps that would have been a superior choice over entropy.
The point remains entropy lacks clarity and yet it forms the basis of the most used/pertinent differential equation in thermodynamics, that being eqn (1).
What does eqn (1) imply to most physicists. Consider that one accepts Boltzmann’s conceptualization that entropy signifies “the randomness of molecules in incessant motion” or Frank Lambert interpretation that entropy signifies ”the dispersal of a system’s energy”. Either way, the conceptualization of randomness/dispersal remains vague, and herein I am in agreement with the likes of Arieh Ben-Naim, in saying that such terminology is not particularly scientific.
However unlike everyone else I believe that the association of randomness to lost work is basically due to the fact that we studied expanding systems, saw that the systems became more random and then jumped to the erroneous conclusion that the lost work (PdV) is due to randomness increase within expanding systems, rather than due to the displacement of the surrounding atmosphere by such systems.
To some readers this may sound like a simple mistake but unfortunately this gross oversight now pervades every aspect of the sciences. It has allowed entropy to attain a demigod status (for lack of a better word). Entropy is used to explain so much, yet it remains a variable without any concise meaning. Entropy may be nothing more than a mathematical contrivance, as is discussed in my other 2016 paper published in Physics Essays titled “Entropy: An ill-conceived mathematical contrivance?”
Some might argue that we use mathematical contrivances all the time, and they would be right. Is this to say, so what if entropy is one? Come on folks. We must at least understand that if we are going to base a whole science upon a mathematical contrivance then it would be nice if that contrivance eventually had an all encompassing meaning that made sense. Some may argue that this eventuality may arise with further study. Perhaps but after over 150 yrs of use, we might now be better off examining the sanity of our past. Moreover the conceptualization that eqn (1) has anything to do with randomness makes no real sense.
Okay your attitude may be who cares because the science as it stands, can explain so much. My point becomes that we should care that our science complicates the simple. Moreover we should man up and accept the punishment, that being a shot to all of our prides for being fool hearty. Everyone with a science degree has made the mistake of accepting entropy’s association with randomness, and the implications to its accomplice, the second law, all without realizing that it is all a complication of the simple.
The second law should be limited to isolated systems as is stated in its definition. The mere fact that all useful systems here on Earth are expanding systems surrounded by our atmosphere, means that no useful systems here on Earth are isolated. In other words, all useful expanding system must upwardly displace our atmosphere! Therefore, such systems experience lost work (lost into surrounding atmosphere’s potential increase). Hence no useful system is isolated therefore the second law of thermodynamics does not apply. This is discussed in my papers previously described herein.
A referee did not want my paper “Second law and lost work” to be published. Although he thought I was right, he could not allow 150 yrs of indoctrination to be taken down by such a simple argument. Luckily saner minds prevailed.
If the above is not enough, now consider Boltzmann’s constant (k). Is it really a universal constant? The fact is; no it is not a universal constant. Rather it is a variable that depends upon the mass of our atmosphere and our gravitational field. Since our gravitational field is constant and our atmosphere’s mass is relatively constant then when we measure/calculate Boltzmman’s constant, it seems like a constant to us here on Earth.
We can take this a step further and realize that Boltzmann’s constant is what enables Boltzmann’s great eloquent math, commonly known as statistical thermodynamics, to work. If we were on another planet with a different atmosphere in a different gravitational field, then we could use the same basic statistical thermodynamics to explain what we see so long as we used a new so-called constant. In my way of thinking Boltzmann’;s constant (k) basically describes the ability of a system to do work here on Earth, as a function of its temperature.
No wonder the likes of Plank and Mach did not endear themselves to Boltzmann’s probability based world. Sure we could explain lost work (PdV) in terms of Boltzmann’s statistics but that is only because Boltzmann designed his constant (k) so that it equated to lost work (PdV) here on Earth. If you think about it this is classic circular logic, at its finest.
I like to think that Plank and Mach preferred more concrete ideologies based on rational. To bad that they did not think in terms of the upward displacement of Earth’s atmosphere because then they may have closed the door to randomness and the domination of all those associated probabilities. Do not get me wrong, there is nothing wrong with learning about probabilities, it is just that one must remember that for the most part they give results, not reasons.
The consequences go further than randomness vs work required to upwardly displace our atmosphere by expanding systems. Just consider cosmology:
- Does entropy even apply to things like the big bang? Assuming Hubble was right?
- CBR: Does entropy increases in radiation actually happen? Actually I have another explanation for CBR but that’s for another day!
- What about those so called black hole paradoxes?: Okay some claim to have solved it but whether they be right or wrong, would have the paradox even have existed?
The questions become numerous.
We could equally argue that entropy and the second law do not belong in biology, or any of the sciences. Okay entropy can remain as a mathematical contrivance until we further our understanding, which might actually happen once we simplify thermodynamics. Subjects like physical chemistry will need an extensive overhaul, but this should be viewed as an opportunity to finally apply some constructive logic, rather than remain an awkward subject wherein differentials are randomly moved about until some sort of seemingly acceptable result arises.
Speaking of awkward uses of differentials, now consider what we do with our equation (1). Certainly (1)[ TdS=dE+PdV] can be considered as the isothermal, isobaric version of:
$d(TS) = dE + d(PV)$ (2)
Another non-sensible aspect of thermodynamics is the fact that we generally starts of with (1) and then subtract versions of (2) from it to get the other differentials utilized in thermodynamics. Where else in mathematics do we start of with a part [eqn (1)] and then subtract the whole [eqn (2)] to get the other parts. Logic dictates that we should start off with a whole [eqn (2)] and then start determining its parts such as eqn (1). Sadly logic in thermodynamics is long lost. And then there is the 150 yrs of indoctrination.
There are those who rightfully believe that relativity needs to be challenged. Perhaps you will see that thermodynamics is in more need of revision. Not because it carries as much glamour as challenging Einstein’s thought. Rather because it is taught at the high school level and above. Imagine your children learning that our atmosphere has mass and that its upward displacement requires work rather than being daunted by the mystical entropy and its awkward association with randomness. This sort of logic may pervade their minds enabling some of them to then grow up and apply their newly found logic to all realms of the sciences, including relativity. Who knows maybe it will force any indignant physicist to actually open their minds to constructive criticism.
Herein I have just scratched the surface and could type for hours but will stop as I am wondering if there is any interest in further discussion by the good folk of Natural Philosophy. Thank you for your time.
Sincerely Kent Mayhew
P.S. There are some mistakes in my first edition of my book that have been changed and a new edition should be out in the new year if all goes to plan. Even so the mistakes remain minor when compared to the mistakes in thermodynamics that we all have accepted at some point in our lives.