Download - 3 thermodynamics fall Energy 101 fall 2015
Thermo Quote
Let me quote Sir Arthur Stanley Eddington here:"The law that entropy always increase..(lots about it in Atkins book)..-the second law of thermodynamics - HOLDS, I think, the supreme position among the Laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations - then so much the worse for Maxwell's equations. If it is found to be contradicted by observers - well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics, I can give you no hope; there is nothing for it but to collapse in deepest humiliation".
Add arrow of timeWhy anything happens
Dyson Sphere
Gaia Hypothesis and Life on Mars - Lovelock
The space shuttle's power at takeoff is about 11,000,000,000 Watts, or 11 Giga Watts (GW), or 11,000,000,000 Joules of energy being converted from stored chemical energy to kinetic energy and thermal energy every second. Eleven Giga Watts is the same as 14.75 million horsepower, or 10,424,048 BTU's of chemical energy converting to kinetic energy second.
Vegetarians and Entropy• Note the substantial losses in net production as energy passes from one trophic level to the next. • The ratio of net production at one level to net production at the next higher level is called the conversion
efficiency. Here it varied from – 17% from producers to primary consumers (1478/8833) to – 4.5% from primary to secondary consumers (67/1478).
• From similar studies in other ecosystems, we can take 10% as the average conversion efficiency from producers to primary consumers. Animal husbandry often exceeds this 10% value. For example, broilers (young chickens) can gain half a pound of weight for every pound of food they eat. (Since the water content of the two is not the same, the conversion efficiency is somewhat less than the apparent 50%.) Nonetheless, the loss of energy as it passes from producers to primary consumers explains, for example, why it costs more to buy a pound of beefsteak than a pound of corn.
• Conversion efficiencies from primary consumers to secondary consumers (herbivores to carnivores) tend to be much lower, averaging about 1%.
• In this ecosystem, all the gross production of the producers (20,810) ultimately disappeared in respiration (14,198) and downstream export and decay (6612). So there was no storage of energy from one year to the next. This is typical of mature ecosystems, such as a mature forest.
• Some ecosystems do store energy, for example, The slow rate of decay in bogs causes peat to accumulate (the source of the world's coal)
• A young forest accumulates organic matter as the trees grow.
Trophic Levels
EnergyKcal/sq meter/yearSilver Springs
BiomassDry weight per sq meter, Silver Springs
Numbers(Acre of Bluegrass)Source: E. Odum, Fundamentals of Ecology
Energy, order, complexity• 1st Law of Thermodynamics
– Energy is neither created nor destroyed – it eternally flows in transformation from one form to another
• 2nd Law of Thermodynamics:– In every energy transformation, some usefulness is lost– Energy disperses from concentrated to diffuse– Energy is needed for regeneration and renewal
• Energy, regeneration, renewal, and deep sustainability– Life creates conditions conducive to life, restores order, creates negative entropy– 2nd law suggests this requires energy
• Primacy of Solar energy– Nature– Man
Gaia Hypothesis and Life on Mars - Lovelock
Lecture 2Thermodynamics and Sustainability
E-101 - Energy and Sustainability Professor Lonnie Gamble
Sustainable Living Department Maharishi University of Management
This presentation was prepared on solar powered computers
Energy, order, complexity• 1st Law of Thermodynamics
– Energy is neither created nor destroyed – it eternally flows in transformation from one form to another
• 2nd Law of Thermodynamics:– In every energy transformation, some usefulness is lost– Energy disperses from concentrated to diffuse– Energy is needed for regeneration and renewal
• Energy, regeneration, renewal, and deep sustainability– Life creates conditions conducive to life, restores order, creates negative entropy– 2nd law suggests this requires energy
• Primacy of Solar energy– Nature– Man
Thermodynamics
Infinity expressed within boundaries:How creation manifests
Why Anything Happens in Creation
How Intelligence Becomes Intelligent
Encyclopedia of human thermohttp://www.eoht.info/
A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists. Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. Yet I was asking something which is the scientific equivalent of: Have you read a work of Shakespeare's? C. P. Snow, 1959 Rede Lecture entitled "The Two Cultures and the Scientific Revolution".
A theory is the more impressive the greater the simplicity of its premises, the more different kinds of things it relates, and the more extended its area of applicability. Therefore the deep impression that classical thermodynamics made upon me. It is the only physical theory of universal content which I am convinced will never be overthrown, within the framework of applicability of its basic concepts. Albert Einstein (author)
Zeroth Law of Thermodynamics
When two systems are in thermal equilibrium with a third body (like a thermometer), they are also in thermal equilibrium with each other. Further, these bodies are all at the same temperature.
This law allows us to define temperature scales and thermometers. Two objects in thermal equilibrium with each other are taken to be the same temperature.
First law of thermodynamics
Energy is neither created nor destroyed: It is eternally transformed
2nd law Energy spontaneously tends to flow from being concentrated in one place to becoming diffused or dispersed and spread out.
All physical processes proceed in such a way that the availability of the energy involved decreases (Peet)
Unless you deliberately move heat by doing work on a system, heat will always flow from hot to cold
Second Law of Thermodynamics: Time’s ArrowQ: Who cares about the second law of thermodynamics?A: Anyone who wonders how the material world -- our world of energy and matter --works.
Q: Big deal? A: The biggest, most powerful, most general idea in all of science. Why paper, trees, coal, gas and all things like them burn (and why people "should" spontaneously catch fire in air), why sand and dry ice even in pure oxygen can't ever burn, why the sun will eventually cool down, why iron rusts (but not why it rusts faster nearer the ocean), why there are hurricanes or any weather at all on earth, what makes things break, why houses get torn apart in tornadoes or explosions, why everything living tends to die. That's for starters.
2nd law, entropy
In all energy transformations, some usefulness of the energy is lost. This loss in usefulness is called entropy.
Energy cannot be created or destroyed, but entropy can.
2nd law implications:
No 100% efficient energy transfer, no reversability
Carnot efficiency for thermal power systems
Entropy= lost ability to do work
See Peet
Heat and the 2nd law
Unless you deliberately move heat by doing work on a system, heat will always flow from hot to cold
2nd law implicationsActivation energy
The initial energy push (usually from heat), shown by the small energy "hill" in the diagram below, is the activation energy, Ea, that is necessary to overcome the bond-strength obstacle to the second law in most chemical reactions. Thus, this requirement for input of an initial energy, the energy of activation, hinders both desirable and undesirable reactions from occurring. An important idea is "Activation energies protect substances from change."
Main Point
4. Deep sustainability is about regeneration and renewal, which includes offsetting the effects of entropy and leaving opportunities for future generation. Learning to use solar energy for regeneration and renewal of human society is essential for sustainability. The group practice of TM offsets entropy in collective consciousness, supporting regeneration and renewal at the level of entire societies.
Gaia Hypothesis and Life on Mars - Lovelock
Earth Life Sun as an Entropy Machine
Show diagram of entropy of soalr energy as it flows thorugh the erathl;s system s
Hydrological cycle
Main Point
3. A source of high quality energy must be continually introduced into a system to offset the effects of entropy, to create order and structure. Solar energy provides this for earth. The regular experience of the silence of Being offsets the effects of entropy in the physiology and mind (Maharishi’s principle of the second element)
Example• In a coal power plant,
some of the heat from burning coal is converted to work using a steam-driven turbine
Steam Turbine Plus Generator
Inside the Steam Turbine
How A Generator Works
Wires
Moving Magnet
How Does It Get To Us?
60,000-600,000V 480-3000V 120 V
Heat to Mechanical Energy:Carnot efficiency limit
When the second law of thermodynamics states that not all the supplied heat in a heat engine can be used to do work, the Carnot efficiency sets the limiting value on the fraction of the heat which can be so used.
Efficiency = (THOT - TCOLD)/THOT x 100(Rankine temperature scale: T in absolute temperature - TRankine =TF+460)Note: It doesn’t matter what materials or fluids are used
Typical Tcold=60-100 Deg F
Typical Thot = 360 – 500 deg F
Carnot, maximum theoretical efficiency, and perpetual motion
Efficiency =(Tin-Tout)/Tin = 1-Tout/TinIn degrees Kelvin
Ex Tin=400 Tout=80, max efficiency = 37.2%
Coal train analogy
Example
• OTEC: Ocean Thermal Energy Conversion
• TH = 298 K
• TC = 278 K• Carnot efficiency
= (1-278/298)x100%= 6.7%
No perpetual motion machine
Main Point # 1
2. The second law: as energy is changes form, it loses usefulness. Energy flows from more concentrated forms to less concentrated forms. This gives a direction to change and has been called time’s arrow. Energy is not lost when energy is transformed, but entropy goes up and the energy can no longer do the same quality of work. It loses usefulness. In meditation, the mind spontaneously flows from more concrete to less concrete forms of the mantra until the mantra disappears and we are left with being. We just take the correct angle, and the process is automatic from there. Meditation offsets the effects of entropy on the mind and physiology.
Third Law of Thermodynamics
The entropy of a substance approaches zero as its temperature approaches absolute zero - at absolute zero, everything stops. In the unified field entropy is zero, order is perfect, and all activity ceases.
Thermodynamics restated
1. You Can’t Win - You can’t create energy
2. You Can’t Break Even - There is always some unrecoverable loss in energy transformatio
3. You Can’t Get Out of the Game - Processes stop at absolute zero
Energy Quality:Not all energy has the same usefulness
Match source to end use
More orderly forms of energy can do more forms of work
1 kw of electrical energy has ability to do more kinds of work than 1 kw of 70 degree heat
End
Examples
Energy to heat hot water
Electrical energy use in a home
Solar electric energy production
• "A theory is more impressive the greater is the simplicity of its premises, the more different are the things it relates, and the more extended its range of applicability. Therefore, the deep impression which classical thermodynamics made on me. It is the only physical theory of universal content which I am convinced, that within the framework of applicability of its basic concepts will never be overthrown."
• - Albert Einstein
Main Point #1
1. The first law: Energy is neither created nor destroyed but is eternally changing from one form to another. Being is the silent source of all creation, destruction, and maintenance.
Main Point
5. The Third Law: At absolute zero, entropy approaches zero, and everything stops. In the Unified field (the absolute) entropy is zero, order is perfect, and all activity ceases.