A Chapter by Chapter Summary/Notes.
Nicolas Carnot, J.P. Joule, Lord Kelvin, Rudolf Clausius and Ludwig Boltzmann all played a roll in the early understanding of heat and work. While not always correct their drive to understand nature of the things lead to the industrial revolution and the modern era.
The four laws of thermodynamics are, interestingly enough, created of out order, with the “2nd Law” first and “Zeroth Law” last.
- Zeroth Law of Thermodynamics – “Formulated by about 1931, it deals with the possibility of defining the temperature of things.”
- First Law of Thermodynamics – “Energy is conserved.”
- Second Law of Thermodynamics – “…recognizes that there is a fundamental dissymmetry in Nature: the rest of this book is focused on that dissymmetry, and so we shall say little of it here. All around us, though, are aspects of the dissymmetry: hot objects cool, but cool objects do not spontaneously become hot; a bouncing ball comes to rest, but a stationary ball does not spontaneously begin to bounce. Here is the feature of Nature that both Kelvin and Clausis disentangled from the conservation of energy: although the total quantity of energy must be conserved in any process (which is their revised of caloric), the distribution of that energy changes in an irreversible manner. The Second Law is concerned with the natural direction of change of the distribution of energy, something that is quite independent of its total quantity.”
- Third Law of Thermodynamics – “…deals with the properties of matter at very low temperatures. It states that we cannot bring matter to a temperature of absolute zero in a finite number of steps.”
- Revolutions of dissymmetry
- The identification of the dissymmetry
The wide spread mastery(by people of the natural dissymmetry priciples is a recent developement. While energy has been converted to work through fire it wasn’t till the developement of the steam engine that mastery of natural dissymetries really has taken root.
It is through an understanding of energy in a steam engine that one can begin to understand the nature of energy itself. An analysis of Carnot’s cycle.
The Signpost of Change
- The nature of heat and work
- The seeds of change
- Kelvin- “No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work”
- Clausius-“No process is possible in which the sole result is the transfer of energy from a cooler to hotter body.”
- Towards corruption
- Measuring the entropy
- The Dissipation of quality
- Ceilings to efficiency
- The end of the external
Heat and work are descriptions of methods and not things. Hover, many incorrectly thought of heat incorrectly as a “caloric” fluid. Now it is understood that heat and work are terms relating to the transfer of energy.
Kelvin and Clausisc had rival statements of the second law of thermodynamics.
According to Atkins these two statements “are really one”. They are equivalent statements of experience are just two faces of the 2nd Law.
The laws of thermodynamics suggest a need for a property of systems for deciding whether a particular state is accessible. This property has come to be know as entropy.
The 2nd law restated or sometimes know as the entropy princple “Natural processes are accompanied by and increase in the entropy of the universe”
Entropy is a measure of (heat supplied)/Temperature which isn’t necessarily intuitive. It easier to understand a liter of hot and cold water as having different temperatures when in fact they both have different entropies as well.
If one thinks of energy in terms of “high quality” and “low quality” then increased entropy is the process of transforming high quality into low quality energy. An example not given in the book would be the burning of gasoline. Burning gasoline would be converting the “high quality” chemical energy into “lower quality” and thus increasing the overall entropy of the universe.
Efficiency = 1 – (Tcold Sink/THot Source). This is the upper limit of the efficiency of an engine.
“We have seen that the Universe is rolling uphill in entropy, and this it is thriving off the corruption of the quality of energy. Yet all this is superficial. We have been standing outside the world events, but we have not yet discerned the deeper nature of change. Now is the time to descend into matter.”
Collapse Into Chaos
- Inside energy
- Modeling the Universe
- The directions of natural change
- Natural processes
Particles possess energy by either their position(potential energy) or motion (kinetic energy). The law of the conservation of energy tells us a particles energy will remain constant unless there is an externally applied force. The non uniformed incoherent motion of particles in an object is thermal motion.
The initial state of a Mark I universe modeling two blocks of metal in contact.
Some time after the initial state the energy has spread out in the “Universe” but still in greater concentrations in smaller block.
Finally a uniform distribution across the entire “Universe”.
Temperature is a measure of incoherent motion and can be written as: Temperature = A/log (Numberoff/Numberon),
Energy tends to disperse is the foundation of the Second Law. The dispersal of energy is not only spatial but of “coherence as well”
A natural process is one that comes with the dispersal of energy. Energy moves towards chaos and entropy is the measure of that chaos.
The Enumeration of Chaos
S= k log W
- Boltzmann’s Demon
- The Demon’s Cage
- Chaos, coherence, and corruption
- Carnot under the microscope
- Stirling’s engine
- Internal combustion
- Turbine power
- Towards coherence
Boltzmann’s Demon helps illustrate how many ways a can the inside of a system be arranged without an external oberserver being aware that rearrangements have occured.
A Demon’s Cage is the Dynamic equilibrium that the demon trapped in.
“However energy is dispersed, by spreading from one platform to another, or by the platforms themselves spreading and mingling with other platforms, or by simple loss of coherence within a sample, it corresponds to the increase of entropy. That is the power of the Boltzmann equation: it enumerates corruption in all its forms.”
The Potency of Chaos
A Carnot Engine is a simple heat engine that consists of a piston, hot source, cold source and gas contained within a cylinder. It is an abstract design.
The Stirling engine has recently come of age, for it can be pollution-free, self-contained and quiet.
An Internal combustion engine is an efficient design for putting heat to work.
The turbine engine is idealized in the Brayton Cycle.
“so long as a process is occurring in which more chaos is generated than is being destroyed, then the balance of the energy may be withdrawn as coherent motion. We have seen that natural change arises as the Universe slips into, and is trapped in, states of ever-increasing probability. But we ave also seen-and this is the crucial point-that the state of greater probability, the state of more chaos, can allow greater coherence locally, so long as greater dissipation has occurred elsewhere.”
Transformation of Chaos
- Chemical transformations
- Iron burning
- Cooling as heating
- The rate of dispersal
- Chaos of order
Atoms group together and split apart which releases energy. More structured(lower entropy) product can come from (higher entropy) reactants if compensating chaos is created elsewhere.
Iron buring or what is more commonly refered to as rusting is an example of a chemical reaction.
Chemical cooling may correspond the counter intuitive inflow of heat. This possible because reactions disperse energy not lower it.
There is a difference between the rate of spontaneous change and its direction. Spontaneous means natural. Choas determines a system’s destination as well the rate at which it reaches it’s destination.
Chaos can lead to order.
Powers of Temperature
- Normal life
- Catching cold
- The first power down
- The second power down
- Lower powers down
- Powers hotter
- Hotter than infinity
- Toward life
Powers of ten refers to ascending and descending through temperature by powers of 10. So decending would be 300, 30, 3 and so on. The Normal life temperature is around 300k.
“A refrigerator is an engine that is driven in reverse. So long as work is done, heat may be transported from a cold source to a hot sink”
Going from 300k to 30k(the first power down) all chemical and activities have ceased. The atoms in molecules still have a wobble, but they don’t have enough energy to change their partners.
3k the second power down from “normal life” is the temperature of space.
At .03k “Now even physics is beginning to stop in the almost perfect quiet of the interiors of solids, where the movement of atoms is no more than an occasional rustle.”
When tempuratures reach 3,000 all but a few materials will melt away. Individual atoms roam free no longer constrained by the holds of lower tempuratures.
A isolated system can be in a state of negative temperature if “more of its atoms are ON than OFF.” A system with negative temperature technically possesses more energy than any positive tempurature through semantics it is hotter than infinity.
All that is covered in
- The 2nd Law
has been building toward the power of chaos and its ability to “achieve that most unnatural of ends, life itself.
- The emergence of intricate form
- Free energy
- The unnatural reactions of life
- The electrochemistry of life
The unatural can come from the natural. A drop of oil in a glass of water is an example. Because it doesn’t disolve but keeps it shape it actually decreases the entropy of the water it sits in.
“A scattering of disconnected amino-acid molecules has a much higher entropy than when they are pinned together into a geometrically chaotic but still specific sequence. Does a Director have to direct this stage of the emergence of living things, or can this essential primary step also emerge as a consequence of chaos?”
Free energy is the energy availible for work. Free energy = (Total energy) – Temperature x (Entropy change).
“That high quality emerges initially from the Sun, whose temperature is so high that its energy is stored with very low entropy. Energy of very excellent quality rains down on us daily, and is captured at its peak by photosynthesis. It then begins its progress through plants, and continues through animals.”
Mitochondria can be compared to electrochemical cells.
Patterns of Chaos
- Dissipative structures
- The emergence of complexity
- The apotheosis of the steam engine.
Structure signifies coherenent regiments of particles while lack of coherence signifies lack of structure. Coherence and structure are synonymous. This can apply to liquids, gases and even time.
Dissipative structures arrive as a result of dispersal. The structures are a result of the flow of energy and “return to dust” when energy ceases flowing through them. A biological system is and example of a disapative structure.
“…individual processes, each one of which may increase entropy or enhance the chaos of the Universe, can give rise to structures of great complexity.”
“Yet, when we look around and see beauty, when we look within and experience consciousness, and when we participate in the delights of life, we know in our hearts that the heart of the Universe is richer by far. But that is sentiment, and is not what we should know in our minds. Science and the steam engine have a greater nobility. Togerther they reveal the awesome grandeur of the simplicity of complexity.”