Thursday, November 15, 2007

Was Carnot misunderstood?

Was Carnot misunderstood?

Nicolas Léonard Sadi Carnot (June 1, 1796 - August 24, 1832), “perhaps the greatest genius in the department of physical science at least that this century has produced" (19th), considered the father of the thermodynamics wrote the "Reflexions sur La Puissance Motrice du Feu"” with true philosophical caution, he avoids committing himself to this hypothesis; though he makes it the foundation of his attempt to discover how work is produced from heat." “The "two grand things" which Carnot originated and introduced were his idea of a "cycle" and the notion of its "reversibility,"” the foundation of “dynamical theory of heat”

His understanding of Robert Boyle, Jacques Charles and Joseph Louis Gay-Lussac theory of gases probably guided Carnot to explain the working of the steam engines based on their previous studies. On the other hand, the pioneers of the steam engine, concerned with steam consumption, used the lesser steam possible in the cylinder, added to the limited knowledge of fluids ( vapour alcohol is proposed by Carnot) led Carnot to primarily consider the expansion in the cylinder in his proposition for the operation of heat engines.
Carnot theories modernized, and in my personal opinion not totally interpreted, by Émile Clapeyron, guide Baron Kelvin, and Rudolf Clausius to lay the grounds for entropy and Second Law.
Rudolf Diesel mentioned Carnot as the mentor of his engine, and the combustion engine is explained in detail in his work.
Carnot, a great genius, referred in his work, what we call today cogeneration, proposed the recover of the condensation heat and introduced the concept of maximum power.
If Carnot had lived long, I believe that the ideal heat engine would be designed differently.
From a translation of Dr. Robert H. Thurston:

“Perhaps in low temperatures steam may be more convenient. We might conceive even the possibility of making the same heat act successively upon air and vapor of water. It would be only necessary that the air should have, after its use, an elevated temperature, and instead of throwing it out immediately into the atmosphere, to make it envelop a steam-boiler, as if it issued directly from a furnace”

“This kind of loss is found in all steam-engines. In fact, the water destined to feed the boiler is always cooler than the water which it already contains. There occurs between them a useless re-establishment of equilibrium of caloric. We are easily convinced, a posteriori, that this re-establishment of equilibrium causes a loss of motive power if we reflect that it would have been possible to previously heat the feed-water by using it as condensing-water in a small accessory engine, when the steam drawn from the large boiler might have been used, and where the condensation might be produced at a temperature intermediate between that of the boiler and that of the principal condenser. The power produced by the small engine would have cost no loss of heat, since all that which had been used would have returned into the boiler with the water of condensation”

“Since every re-establishment of equilibrium in the caloric may be the cause of the production of motive power, every re-establishment of equilibrium which shall be accomplished without production of this power should be considered as an actual loss. Now, very little reflection would show that all change of temperature which is not due to a change of volume of the bodies can be only a useless re-establishment of equilibrium in the caloric.* The necessary condition of the maximum is, then, that in the bodies employed to realize the motive power of heat there should not occur any change of temperature which may not be due to a change of volume. Reciprocally, every time that this condition is fulfilled the maximum will be attained. This principle should never be lost sight of in the construction of heat-engines; it is its fundamental basis. If it cannot be strictly observed, it should at least be departed from as little as possible.”

“It is easy to see the advantages possessed by high-pressure machines over those of lower pressure. This superiority lies essentially in the power of utilizing a greater fall of caloric. The steam produced under a higher pressure is found also at a higher temperature, and as, further, the temperature of condensation remains always about the same, it is evident that the fall of caloric is more considerable. But to obtain from high-pressure engines really advantageous results, it is necessary that the fall of caloric should be most profitably utilized. It is not enough that the steam be produced at a high temperature: it is also necessary that by the expansion of its volume its temperature should become sufficiently low. A good steam-engine, therefore, should not only employ steam under heavy pressure, but under successive and variable pressures, differing greatly from one another, and progressively decreasing.”

Next more of Carnot’s thoughts:

“It is to heat that must be attributed "mass movements that hit our eyes on the land, so that it has been the cause of unrest in the atmosphere, the rise of clouds, the hush of rain and others meteors, currents of water that criss-cross the earth's surface to which man has reached a use for his own use, a small portion; and earthquakes, volcanic eruptions also recognize because the heat”

“The motive power of a waterfall depends on its height and on the quantity of the liquid; the motive power of heat depends also on the quantity of caloric used, and on what may be termed, on what in fact we will call, the height of its fall,* that is to say, the difference of temperature of the bodies between which the exchange of caloric is made.”

“Everywhere, where there is a difference of temperature, there can be production of power”

“Maximum power resulting from the use of the steam it is also the maximum motive power realize by whatever means.”

“Wherever there exists a difference of temperature, wherever it has been possible for the equilibrium of the caloric to be re-established, it is possible to have also the production of impelling power. Steam is a means of realizing this power, but it is not the only one. All substances in nature can be employed for this purpose; all are susceptible of changes in volume, of successive contractions and dilatations, through the alternation of heat and cold. All are capable of overcoming in their changes of volume certain resistances and of thus developing the impelling power”

“The fall of caloric produces more motive power at inferior than at superior temperatures.”

“Thus a given quantity of heat will develop more motive power in passing from a body kept at 1 degree to another maintained at zero, than if these two bodies were at the temperature of 1010 and 1000. “

“When a gas increases in volume in geometrical progression, its specific heat increases in arithmetical progression.”

“The quantity of motive power developed in a complete cycle of operations is measured by the product of the volume of the vapor multiplied by the difference between the tensions that it possesses at the temperature of the body A and at that of the body B”

“(1) The temperature of the fluid should be made as high as possible, in order to obtain a great fall of caloric, and consequently a large production of motive power.
(2) For the same reason the cooling should be carried as far as possible.
(3) It should be so arranged that the passage of the elastic fluid from the highest to the lowest temperature should be due to increase of volume; that is, it should be so arranged that the cooling of the gas should occur spontaneously as the effect of rarefaction. The limits of the temperature to which it is possible to bring the fluid primarily, are simply the limits of the temperature obtainable by combustion; they are very high.
The limits of cooling are found in the temperature of the coldest body of which we can easily and freely make use; this body is usually the water of the locality.
As to the third condition, it involves difficulties in the realization of the motive power of heat when the attempt is made to take advantage of great differences of temperature, to utilize great falls of heat. In short, it is necessary then that the gas, by reason of its rarefaction, should pass from a very high temperature to a very low one, which requires a great change of volume and of density, which requires also that the gas be first taken under a very heavy pressure, or that it acquire by its dilatation an enormous volume-conditions both difficult to fulfill.”

“… condensation took place also without contact of bodies of different temperatures. It occurred while exerting a constant pressure on the steam brought in contact with the body B of the same temperature as itself. The conditions for a maximum are thus found to be fulfilled.”

“In order to give to air great increase in volume, and by that expansion to produce a great change of temperature, it must first be taken under a sufficiently high pressure; then it must be compressed with a pump or by some other means before heating it. This operation would require a special apparatus, an apparatus not found in steam-engines. In the latter, water is in a liquid state when injected into the boiler, and to introduce it requires but a small pump.”

“If we could find an abundant liquid body which would vaporize at a higher temperature than water, of which the vapor would have, for the same volume, a less specific heat, which would not attack the metals employed in the construction of machines, it would undoubtedly merit the preference. But nature provides no such body.”

“It is thus upon the use of atmospheric air and vapor of water that subsequent attempts to perfect heat-engines should be based. It is to utilize by means of these agents the greatest possible falls of caloric that all efforts should be directed.”

“... we will show how far we are from having realized, by any means at present known, all the motive power of combustibles.”

“We should not expect ever to utilize in practice all the motive power of combustibles. The attempts made to attain this result would be far more hurtful than useful if they caused other important considerations to be neglected. The economy of the combustible is only one of the conditions to be fulfilled in heat-engines. In many cases it is only secondary. It should often give precedence to safety, to strength, to the durability of the engine, to the small space which it must occupy, to small cost of installation, etc. To know how to appreciate in each case, at their true value, the considerations of convenience and economy which may present themselves; to know how to discern the more important of those which are only accessories; to balance them properly against each other, in order to attain the best results by the simplest means: such should be the leading characteristics of the man called to direct, to co-ordinate among themselves the labors of his comrades, to make them co-operate towards one useful end, of whatsoever sort it may be. “

“Finally, it is natural that an invention should have its birth and especially be developed, be perfected, in that place where its want is most strongly felt. “

Dr. Robert H. Thurston 1890 by John Wiley and Sons
Published in the internet

Sunday, November 11, 2007


Thoughts of great Minds; Odum, Einstein and Spinoza

"Truth is a state of mind in which there is no contradiction. A person perceives his idea as true because he has heard no contradiction. The less one knows, the easier it is to be dogmatic and to be sure that what one knows is true. We tend to defend dogmatically as true the things we are taught, whereas the things we learn from experience and experiments tend to be properly couched in sometimes-contradictory reality."

Howard T. Odum

“Concepts that have proven useful in ordering things easily achieve such authority over us that we forget their earthly origins and accept them as unalterable givens.”
“Subtle is the Lord, but malicious He is not.”
“Nature hides her secret because of her essential loftiness, but not by means of ruse.”
“I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.”
“Life is like riding a bicycle. To keep your balance you must keep moving.”
“What humanity owes to personalities like Buddha, Moses, and Jesus ranks for me higher than all the achievements of the enquiring and constructive mind.”
”What these blessed men have given us we must guard and try to keep alive with all our strength if humanity is not to lose its dignity, the security of its existence, and its joy in living.”
“Great spirits have always encountered violent opposition from mediocre minds. The mediocre mind is incapable of understanding the man who refuses to bow blindly to conventional prejudices and chooses instead to express his opinions courageously and honestly.”
“So many people today — and even professional scientists — seem to me like someone who has seen thousands of trees but has never seen a forest. A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is — in my opinion — the mark of distinction between a mere artisan or specialist and a real seeker after truth.”
“I cannot hate him, because he must do what he does.”
“Never do anything against conscience even if the state demands it.”
“Taken on the whole, I would believe that Gandhi's views were the most enlightened of all the political men in our time. We should strive to do things in his spirit... not to use violence in fighting for our cause, but by non-participation in what we believe is evil.”
“A human being is a part of the whole, called by us the "Universe", a part limited in time and space. He experiences himself, his thoughts and feelings, as something separate from the rest — a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody is able to achieve this completely, but the striving for such achievement is in itself a part of the liberation and a foundation for inner security.”
“I have no special talents. I am only passionately curious.”
“The important thing is not to stop questioning; curiosity has its own reason for existing. One cannot help but be in awe when contemplating the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of the mystery every day. The important thing is not to stop questioning; never lose a holy curiosity.”
“The world is a dangerous place to live, not because of the people who are evil, but because of the people who don't do anything about it.”
“The state of mind which enables a man to do work of this kind is akin to that of the religious worshiper or the lover; the daily effort comes from no deliberate intention or program, but straight from the heart.”
“The supreme task of the physicist is to arrive at those universal elementary laws from which the cosmos can be built up by pure deduction. There is no logical path to these laws; only intuition, resting on sympathetic understanding of experience, can reach them.”
“Imagination is more important than knowledge … I maintain that the cosmic religious feeling is the strongest and noblest motive for scientific research… I am convinced that God does not play dice”
“A hundred times every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving...”
Schopenhauer's saying, that "a man can do as he will, but not will as he will," has been an inspiration to me since my youth up, and a continual consolation and unfailing well-spring of patience in the face of the hardships of life, my own and others'. This feeling mercifully mitigates the sense of responsibility which so easily becomes paralyzing and it prevents us from taking ourselves and other people too seriously; it conduces to a view of life in which humor, above all, has its due place.”
“Science without religion is lame, religion without science is blind.”
“a new type of thinking is essential if mankind is to survive and move to higher levels."
“Today we must abandon competition and secure cooperation. This must be the central fact in all our considerations of international affairs; otherwise we face certain disaster. Past thinking and methods did not prevent world wars. Future thinking must prevent wars.”
“A person starts to live when he can live outside himself.”
“Any fool can know. The point is to understand.”
“A clever person solves a problem. A wise person avoids it.”
“A little knowledge is dangerous. So is a lot.”
“Anyone who has never made a mistake has never tried anything new.”
“As our circle of knowledge expands, so does the circumference of darkness surrounding it.”
“Before God we are all equally wise — and equally foolish.”
“Computers are incredibly fast, accurate and stupid. Human beings are incredibly slow, inaccurate and brilliant. Together they are powerful beyond imagination.”
“Education is what remains after one has forgotten everything he learned in school.”
“God does not care about our mathematical difficulties. He integrates empirically.”
“I want to know God's thoughts; the rest are details.”
“Innovation is not the product of logical thought, even though the final product is tied to a logical structure.”
“It's not that I'm so smart; it's just that I stay with problems longer.
One thing I have learned in a long life: All our science, measured against reality, is primitive and childlike — and yet it is the most precious thing we have.”
“Peace cannot be kept by force. It can only be achieved by understanding.”
“The mass of a body is a measure of its energy content.”
“The whole of science is nothing more than a refinement of everyday thinking.”
“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.”
“When I read the Bhagavad Gita and reflect about how God created this universe everything else seems so superfluous.”
“Wisdom is not a product of schooling but of the lifelong attempt to acquire it.”
“Buddhism has the characteristics of what would be expected in a cosmic religion for the future: It transcends a personal God avoids dogmas and theology; it covers both the natural and the spiritual, and it is based on a religious sense aspiring from the experience of all things, natural and spiritual, as a meaningful unity.”
“Evil is the absence of God.”
“When a man sits with a pretty girl for an hour, it seems like a minute. But let him sit on a hot stove for a minute and it's longer than any hour. That's relativity.”
“Astrology is a science in itself and contains an illuminating body of knowledge. It taught me many things, and I am greatly indebted to it. Geophysical evidence reveals the power of the stars and the planets in relation to the terrestrial. In turn, astrology reinforces this power to some extent. This is why astrology is like a life-giving elixir to mankind.”
"I believe in Spinoza's God who reveals himself in the orderly harmony of what exists, not in a God who concerns himself with the fates and actions of human beings."
Albert Einstein

“All things in nature proceed from certain necessity and with the utmost perfection".
“Reality is perfection”
“Three types of knowledge - opinion, reason, intuitive”
Benedict de Spinoza

Spinoza's last 'twenty' propositions in the Ethics, as translated by Edwin Curley

EVP21: The mind can neither imagine anything, nor recollect past things, except while the body endures.
EVP22: Nevertheless, in God there is necessarily an idea that expresses the essence of this or that human body, under a species of eternity [sub specie aeternitatis].
EVP23: The human mind cannot be absolutely destroyed with the body, but something of it remains which is eternal.

EVP24: The more we understand singular things, the more we understand God.
EVP25: The greatest striving of the mind, and its greatest virtue is understanding things by the third kind of knowledge. (intuitive)
EVP26: The more the mind is capable of understanding things by the the third kind of knowledge, the more it desires to understand them by this kind of knowledge.
EVP27: The greatest satisfaction of mind there can be arises from this third kind of knowledge.

EVP28: The striving, or desire, to know things by the third kind of knowledge cannot arise from the first kind of knowledge, but can indeed arise from the second.
EVP29: Whatever the mind understands under a species of eternity, it understands not from the fact that it conceives the body's present actual existence, but from the fact that it conceives the body's essence under a species of eternity.
EVP30: Insofar as our mind knows itself and the body under a species of eternity, it necessarily has knowledge of God, and knows that it is in God and is conceived through God.
EVP31: The third kind of knowledge depends on the mind, as on a formal cause, insofar as the mind itself is eternal.
EVP32: Whatever we understand by the third kind of knowledge we take pleasure in, and our pleasure is accompanied by the idea of God as a cause.
EVP33: The intellectual love of God, which arises from the third kind of knowledge, is eternal.

EVP34: Only while the body endures is the mind subject to affects which are related to the passions.
EVP35: God loves himself with an infinite intellectual love.
EVP36: The mind's intellectual love of God is the very love of God by which God loves himself, not insofar as he is infinite, but insofar as he can be explained by the human mind's essence, considered under a species of eternity; that is, the mind's intellectual love of God is part of the infinite love by which God loves himself.
EVP37: There is nothing in Nature which is contrary to this intellectual love, or which can take it away.

EVP38: The more the mind understands things by the second and third kind of knowledge, the less it is acted on by affects which are evil, and the less it fears death.
EVP39: He who has a body capable of a great many things has a mind whose greatest part is eternal.
EVP40: The more perfection each thing has, the more it acts and the less it is acted on, and conversely, the more it acts, the more perfect it is.
EVP41: Even if we did not know that our mind is eternal, we would still regard as of the first importance morality, religion, and absolutely all the things we have shown (in Part IV) to be related to tenacity and nobility.
EVP42: Blessedness is not the reward of virtue, but virtue itself; nor do we enjoy it because we restrain our lusts; on the contrary, because we enjoy it, we are able to restrain them.