MadSci Network: Chemistry

Re: what is the fourth law of thermodynamics?

Date: Sun Nov 5 15:52:50 2000
Posted By: James Griepenburg, , Chemical consultant, Chemmet Services
Area of science: Chemistry
ID: 969969367.Ch

There are 4 generally accepted Laws of Thermodynamics usually referred to 
as the Zeroth, First, Second and Third Laws.  These Laws are based on long 
standing, careful, empirical work and are based on macroscopic amounts of 
matter.   They depend on bulk properties of matter mostly because 
individual atoms or particles cannot be defined precisely and cannot be 
returned to a previous state with any degree of accuracy.  However, the 
thermodynamic laws do follow exactly from kinetic theory, statistical 
mechanics and quantum mechanics, all of which take the individual 
particles into account.

Zeroth Law: This law is the foundation of temperature and temperature 
scales.  It states that if system A is in thermal equilibrium with system 
B and if system B is in thermal equilibrium with system C then system A is 
also in thermal equilibrium with system C.  How is the attainment of 
equilibrium determined?  By measuring properties and ascertaining that 
they are not changing with time, position, distance from the area of 
thermal contact etc.  It does not necessarily mean chemical equilibrium, 
just that no chemical reaction is occurring at a sufficient rate to be 
measurable.  For example: a stick of dynamite could well be in thermal 
equilibrium with the hole it is in until the fuse is lit or a battery 
could be in thermal equilibrium with the flashlight bulb until the switch 
is closed and could become so again after it runs down and the light dims 
Systems that are in thermal equilibrium with each other are at the same 
temperature and this temperature is not dependent on the composition of 
the systems in thermal equilibrium.  This law also is expressed in the 
development of temperature scales based on the concept of an ideal gas, 
the Second Law of Thermodynamics and from statistical mechanics and 
kinetic theory.   These temperature scales turn out to be the same and are 
independent of the material being measured [but do depend on the material 
or method used for the measurement hence the need for temperature 

The First Law was formulated about 1850 based on work by Joule and others 
demonstrating the equivalence of work and heat.   This law is the basis of 
the Law of Conservation of Total Energy.  First, it postulates that there 
exist STATE FUNCTIONS of a system that are dependent only on the initial 
and final states of a system and are independent of the path from state 1 
to state 2.  It also states that for a cyclic process where the initial 
and final states of a system are the same the change in these state 
functions is zero.  An example of such a function is the internal energy, 
U.   A change in the internal energy is defined as the heat gained by a 
system minus the work done by a system.  Heat and work are not state 
functions; they are path dependent.  For a completely isolated system the 
total energy is constant.  Also for a cyclic process where a system is 
returned to the initial conditions the change in the energy, or any other 
state function of the system, is zero.  The utility of this Law lies in 
enabling the calculation of energy changes from measurements of system 
properties in two different states.  The First Law enables the calculation 
of energy changes but doesn’t calculate total energies.

The Second Law of Thermodynamics:[Kelvin 1851, Clausius 1854]  The second 
law has many statements.  It basically states that that it is impossible 
to completely convert a quantity of heat into the equivalent amount of 
work without causing some other change in the system or the environment.  
In the operation of a heat engine between two different temperatures some 
heat is transferred to the lower temperature heat reservoir.  The ultimate 
result will be the attainment of equilibrium and the loss of the ability 
to do work.   Other views of the Second Law use the State Function of 
Entropy.  Entropy is a measurement of the randomness of a system.  The 
more random the system the higher the entropy.  Entropy can also be 
measured from the First Law.  For a process occurring at constant 
temperature[isothermal] such as boiling or freezing of water the entropy 
change is the heat loss or gain divided by the temperature in Kelvins.  
The Second Law states that any spontaneous process happens with an 
increase in the entropy of the system and its environment.  Other 
statements indicate that a system will eventually reach equilibrium, a 
condition of maximum entropy and minimum energy, in which the system can 
do no work.  For a system at equilibrium  the Gibbs Free Energy, a state 
function combining the internal energy and entropy state functions, equals 
zero and for a chemical system the chemical concentrations are those that 
satisfy the equilibrium constant.  The Second Law enables the predictions 
of the direction of a reaction or process from First and Third law 
measurements.  It defines the condition of equilibrium.  The Second law 
does not explicitly enable predictions of the rates of chemical reactions; 
it won’t tell you when that stick of dynamite will explode but will give a 
good representation of what will happen if it does.

An example of the First and Second Laws in operation is the energy the 
Earth receives from the Sun and subsequently reradiates to outer space.  
Since the temperature of the Earth remains constant [we are ignoring 
global warming, biomass storage, and fossil fuel use for now] the First 
law tells us that the overall change in the internal energy of the Earth 
is zero.   Yet the Earth has used the Sunlight to grow biomass, power the 
winds and tides, maintain a reasonable temperature etc.   The Second Law 
explains it.  The energy from the Sun [black body temperature ~ 6000K, 
visible light range] consists of a smaller number of photons which have 
high average energy and low entropy; the energy emitted by the Earth 
[black body temperature ~350K, infrared range]   consists of a much larger 
number of photons with a much lower average energy and high entropy.  The 
total energy remains constant but the entropy increases. The increase in 
entropy is what drives the entire Earth.  If the Earth were irradiated 
with sufficient 350K light only, keeping the energy of the Earth constant, 
the processes that sunlight drives couldn’t happen and an equilibrium 
would be attained and things would be very different.

The Third Law was stated by Nernst in 1905 that the limit of the entropy 
change for all reactions approaches zero as the temperature approaches 
absolute zero [0K].  Max Planck extended this in 1913 and stated the Third 
Law  “The entropy of each pure element or substance in perfect crystalline 
form is zero at absolute zero.”  Both views have withstood experimental 
testing.  The second approach has given some interesting insight into 
materials that do not approach zero entropy near absolute zero.  Two 
examples are nitrous oxide NNO and water HOH, each of which has a 
statistical arrangement of molecules in its crystal; the crystals show an 
entropy of mixing.  The utility of the Third Law is that is gives a means 
of calculating equilibrium constants directly from thermodynamic 
measurements on the reactants and products of a reaction.

Both the Third and the Second Law imply that absolute zero can only be 
approached as a limit.  This also has been true according to experiment.

The fourth law does not yet seem to have made its way into the textbooks, 
however, I have been using older texts. We have located some comments on 
the internet, some of which make some sense.  The fourth law seems to have 
resulted from attempts to relate the 0-3rd Laws to more complex non-
thermodynamic systems.  It appears to need much refinement, consolidation 
or experimental quantification before it reaches the status of the 
others.  The following are links or articles that purport to explain the 
4th law.

This link discusses entropy and the 1st Law
phys16f.htm  This is a long winded brief that 
relates the Laws to what is happening in the world.  It requires much 
critical thought.
The following gives a fourth law which makes sense but is not quantified.
Sat, 6 Apr 1996 07:34:30 -0800 (PST) 
Michael Moore (
There has been some desire expressed on this list to minimize further 
discussion of entropy, which is surprising since Nicolas Georgescu-Roegen 
proposed so ably that entropy is a fundamental economic value which is 
not limited to mechanical engineers doing heat transfer equations.
I have three comments on the subject. First, I've come to express Sadi 
Carnot's Second Law and G-R's Fourth Law as follows:
The Second Law of Thermodynamics: 
in every transfer of energy, some energy will become unavailable for 
future use, 
thus some energy is wasted. 
The Fourth Law of Thermodynamics: 
in every contact of matter with matter, some matter will become 
unavailable for future use, 
thus some matter is wasted.
"Some" is not to imply "minute". Yet the waste of energy is always 
measureable, while the waste of matter is not. Just to reemphasize, 
waste means an irrevocable transfer, which is beyond recycling.
My formulation can put in perspective the US government's encouragement 
to increase entropy (waste) by giving allowances in the tax code for 
depreciation and depletion. We would have a substantially different 
environmental situation if these allowances were removed. For all the 
complaint's by business toward waste in government, I've not heard any 
derision of this encouragement of waste in business. 
Come to think of it, perhaps we need to reverse the practice by taxing 
depreciation and depletion, such as consumer goods whose half life is the 
trip home. 
My second comment about entropy concerns "closed system". The usual 
formulation about entropy reminds us that in a "closed system" all events 
tend toward an equilibrium. The comment was that the universe is a 
closed system, which I agree. However, our practical reality is the 
planet earth, which is not a closed system. It receives substantial 
daily energy from the sun in the form of heat and light. I expect it 
loses daily energy to "space".[comment  it does, vide supra]
Thus, thirdly, the entropy factor of our economic formula is small when 
the economy is deliberately living within the daily budget of the sun's 
energy. And carefully minimizing waste.
The entropy factor is large when the economy exceeds the daily budget by 
living on yesterday's savings. (Ours is not the first expression of life 
to create ghost towns.) We only increase our peril when we ignore the 
entropy factor, we magnify our peril when we discount the entropy factor.
G-R points out that all of life converts low entropy to high entropy. 
Thus our economic task, following the lead of mechanical engineers, is to 
minimize high entropy of energy and matter which is waste.
Michael Moore
Poulsbo, Washington, USA

This one ??  I do not understand what they are trying to prove.
Self-organization: The fourth law of thermodynamics?
Charles Curtin and Drew Kerkhoff
Ecological Complexity Seminar: Fall 1996
Department of Biology
University of New Mexico

1. Criteria for evaluating theoretical constructs 
2. Energy dissipation vs. Maximum power 
3. Related and required readings 

Criteria for evaluating theoretical constructs
The following criteria for evaluating a new theoretical construct in 
ecology are suggested by O'Neill et al. (1986): 
1. The theory must be internally consistent. 
2. The theory must not be adopted simply because of success in other 
3. The theory must agree with known properties of ecosystems. 
4. The theory must be capable of producing new and testable hypotheses. 
We present these criteria as a basis for the evaluation of "complexity 
theory" as we have come to understand it over the course of our 
discussions and as a starting point for the further self-organization of 
this seminar. It may be fairly stated that self-organization lies at the 
basis of complexity as we have come to interpret it. It is the self-
organized order of Benard cells that renders the system complex. Below the 
critical temperature the system exhibits only uniform conduction. The 
system becomes more interesting when self-organization occurs, and self-
organization requires that a system be away from thermodynamic 
equilibrium. Morowitz (1992) provides an intuitive explanation. 
Indeed, there is a statement, sometimes called the fourth law of 
thermodynamics, which states that the flow of energy from a source to a 
sink through an intermediate system orders that system. Here the word 
order must be taken as increased complexity. 
Per Bak (1994) extends this notion of the fourth law, suggesting "that 
slowly driven systems ... naturally self-organize into a critical state." 
This implies that in nonequilibrium systems, criticality and complexity 
may be the rule rather than the exception (Bak 1994). O'Neill et al. 
(1986) anticipate Bak's conclusion with their proposal that the 
hierarchical structure of ecosystems is a consequence of the fourth law 
driving the evolution of increasingly complex nonequilibrium systems from 
the prebiotic, molecular level to the level of the ecosystem. O'Neill et 
al. (1986) present the above criteria as a challenge to their notion of 
hierarchical structure in ecosystems, but perhaps they can be even more 
usefully applied to the construct that underlies the proposed origin of 
such structure, the self-organization of nonequilibrium systems, 
the "fourth law" of thermodynamics. 
O'Neill, R.V., D.L. DeAngelis, J.B. Waide, and T.F.H. Allen. 1986. 
Hierarchical structure as the consequence of evolution in open, 
dissipative systems. in (same authors) A Hierarchical Concept of 
Ecosystems. Princeton University Press, USA. 

The thermodynamic Laws are explained at varying levels of 
understandability in many physical chemistry texts.  I recommend Robert A. 
Alberty  Physical Chemistry , Wiley  and recommend reading several perhaps 
starting with the College Outline Series.

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