Electrical resistance and conductance

The electrical resistance of an object is a measure of its opposition to the flow of electric current. The inverse quantity is electrical conductance, is the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with the notion of mechanical friction; the SI unit of electrical resistance is the ohm, while electrical conductance is measured in siemens. The resistance of an object depends in large part on the material it is made of—objects made of electrical insulators like rubber tend to have high resistance and low conductivity, while objects made of electrical conductors like metals tend to have low resistance and high conductivity; this material dependence is quantified by conductivity. However and conductance are extensive rather than bulk properties, meaning that they depend on the size and shape of an object. For example, a wire's resistance is higher if it is long and thin, lower if it is short and thick. All objects show some resistance, except for superconductors.

The resistance R of an object is defined as the ratio of voltage U across it to current I through it, while the conductance G is the reciprocal: R = U I, G = I U = 1 R For a wide variety of materials and conditions, U and I are directly proportional to each other, therefore R and G are constants. This proportionality is called Ohm's law, materials that satisfy it are called ohmic materials. In other cases, such as a transformer, diode or battery, U and I are not directly proportional; the ratio U over I is sometimes still useful, is referred to as a "chordal resistance" or "static resistance", since it corresponds to the inverse slope of a chord between the origin and an I–U curve. In other situations, the derivative d U d. In the hydraulic analogy, current flowing through a wire is like water flowing through a pipe, the voltage drop across the wire is like the pressure drop that pushes water through the pipe. Conductance is proportional to how much flow occurs for a given pressure, resistance is proportional to how much pressure is required to achieve a given flow.

The voltage drop, not the voltage itself, provides the driving force pushing current through a resistor. In hydraulics, it is similar: The pressure difference between two sides of a pipe, not the pressure itself, determines the flow through it. For example, there may be a large water pressure above the pipe, which tries to push water down through the pipe, but there may be an large water pressure below the pipe, which tries to push water back up through the pipe. If these pressures are equal, no water flows; the resistance and conductance of a wire, resistor, or other element is determined by two properties: geometry, materialGeometry is important because it is more difficult to push water through a long, narrow pipe than a wide, short pipe. In the same way, a long, thin copper wire has higher resistance than a thick copper wire. Materials are important as well. A pipe filled with hair restricts the flow of water more than a clean pipe of the same shape and size. Electrons can flow and through a copper wire, but cannot flow as through a steel wire of the same shape and size, they cannot flow at all through an insulator like rubber, regardless of its shape.

The difference between copper and rubber is related to their microscopic structure and electron configuration, is quantified by a property called resistivity. In addition to geometry and material, there are various other factors that influence resistance and conductance, such as temperature. Substances in which electricity can flow are called conductors. A piece of conducting material of a particular resistance meant for use in a circuit is called a resistor. Conductors are made of high-conductivity materials such as metals, in particular copper and aluminium. Resistors, on the other hand, are made of a wide variety of materials depending on factors such as the desired resistance, amount of energy that it needs to dissipate and costs. For many materials, the current I through the material is proportional to the voltage U applied across it: I ∝ U over a wide range of voltages and currents. Therefore, the resistance and conductance of objects or electronic components made of these materials is constant.

This relationship is called Ohm's law, materials which obey it are called ohmic materials. Examples of ohmic components are resistors; the current–voltage graph of an ohmic device consists of a straight line through the origin with positive slope. Other components and materials used in electronics do not obey Ohm's law; these are called nonohmic. Examples include fluorescent lamps; the current-voltage curve of a nonohmic device is a curved line. The resistance of a given object depends on two factors: What ma

Paradox of hedonism

The paradox of hedonism called the pleasure paradox, refers to the practical difficulties encountered in the pursuit of pleasure. For the hedonist, constant pleasure-seeking may not yield the most actual pleasure or happiness in the long run—or in the short run, when consciously pursuing pleasure interferes with experiencing it; the utilitarian philosopher Henry Sidgwick was first to note in The Methods of Ethics that the paradox of hedonism is that pleasure cannot be acquired directly. Variations on this theme appear in the realms of ethics, philosophy and economics, it is said that we fail to attain pleasures if we deliberately seek them. This has been described variously, by many: John Stuart Mill, the utilitarian philosopher, in his autobiography:But I now thought that this end was only to be attained by not making it the direct end; those only are happy who have their minds fixed on some object other than their own happiness Aiming thus at something else, they find happiness along the way Ask yourself whether you are happy, you cease to be so.

Viktor Frankl in Man's Search for Meaning:Happiness cannot be pursued. The more a man tries to demonstrate his sexual potency or a woman her ability to experience orgasm, the less they are able to succeed. Pleasure is, must remain, a side-effect or by-product, is destroyed and spoiled to the degree to which it is made a goal in itself. Philosopher Friedrich Nietzsche in The Antichrist and The Will to Power:What is good? Everything power itself. What is bad? Everything, born of weakness. What is happiness? The feeling that power increases—that a resistance is overcome, it is enlightening to substitute for the individual'happiness' power joy is only a symptom of the feeling of attained power Psychologist Alfred Adler in The Neurotic Constitution:Nietzsche's "will to power" and "will to seem" embrace many of our views, which again resemble in some respects the views of Féré and the older writers, according to whom the sensation of pleasure originates in a feeling of power, that of pain in a feeling of feebleness.

Poet and satirist Edward Young:The love of praise, howe'er concealed by art,Reigns more or less supreme in every heart. Politician William Bennett:Happiness is like a cat, if you try to coax it or call it, it will avoid you, but if you pay no attention to it and go about your business, you'll find it rubbing against your legs and jumping into your lap. Novelist João Guimarães Rosa:Happiness is found only in little moments of inattention. Happiness is imprecisely equated with pleasure. If, for whatever reason, one does equate happiness with pleasure the paradox of hedonism arises; when one aims towards pleasure itself, one's aim is frustrated. Henry Sidgwick comments on such frustration after a discussion of self-love in the above-mentioned work: I should not, infer from this that the pursuit of pleasure is self-defeating and futile. While not addressing the paradox directly, Aristotle commented on the futility of pursuing pleasure. Human beings are actors whose endeavors bring about consequences, among these is pleasure.

Aristotle argues as follows: How is it that no one is continuously pleased? Is it that we grow weary? All human things are incapable of continuous activity; therefore pleasure is not continuous. Sooner or finite beings will be unable to acquire and expend the resources necessary to maintain their sole goal of pleasure. Evolutionary theory explains that humans evolved through natural selection and follow genetic imperatives that seek to maximize reproduction, not happiness; as a result of these selection pressures, the extent of human happiness is limited biologically. David Pearce argues in his treatise The Hedonistic Imperative that humans might be able to use genetic engineering and neuroscience to eliminate suffering in all human life and allow for peak levels of happiness and pleasure that are unimaginable. Altruism Easterlin paradox False pleasure Hedonic treadmill Intrinsic value Leisure satisfaction Psychological egoism Willpower paradox Aristotle, Nicomachean Ethics 1175, 3–6 in The Basic Works of Aristotle, Richard McKeon ed. John Stuart Mill, Autobiography in The Harvard Classics, Vol. 25, Charles Eliot Norton, ed. Henry Sidgwick, The Methods of Ethics Konow, James, & Joseph Earley.

"The Hedonistic Paradox: Is homo economicus happier?" Journal of Public Economics 92, 2008

Giuseppe Ferretto

Giuseppe Antonio Ferretto was an Italian Cardinal of the Roman Catholic Church who served as Major Penitentiary in the Roman Curia from 1967 to 1973, was elevated to the rank of cardinal in 1961. Ferretto was born in Rome to Adele Ferretto, he studied at the Pontifical Roman Seminary, the Pontifical Lateran University, the Pontifical Institute of Christian Archeology in Rome. Ordained to the priesthood on 24 February 1923, Ferretto finished his studies in 1926 and taught at the Pontifical Lateran University and the Pontifical Urbaniana University until 1958, he served as an official in the Vicariate of Rome from 1929 to 1939, when he was made a referendary of the Apostolic Signatura on 23 April. Before becoming a canon of St. Peter's Basilica on 1 May 1953, he was named substitute and assessor of the Sacred Consistorial Congregation, he was a noted archaeologist. On 14 December 1958, Ferretto was appointed Titular Archbishop of Serdica by Pope John XXIII, he received his episcopal consecration in St. Peter's Basilica on the following 27 December from Pope John, with Bishops Girolamo Bortignon, OFM Cap and Gioacchino Muccin serving as co-consecrators.

Ferretto was named Secretary of the College of Cardinals on 20 January 1959. He was created Cardinal-Priest of Santa Croce in Gerusalemme by Pope John in the consistory of 16 January 1961. There had been speculation that he had been one of the cardinals appointed in pectore on 28 March 1960, but he would have gotten seniority dating back to that 1960 consistory if the in pectore appointment was true. Ferretto was named Cardinal Bishop of Sabina e Poggio Mirteto on 26 March 1961. Pope John had changed the way cardinals were raised to the rank of cardinal bishop. Only the senior cardinal dean and the senior cardinal priest had the right to the title of cardinal bishop when one of the sees assigned to a cardinal bishop became vacant. Pope John made the appointment the prerogative of the pope without reference to seniority within the College of Cardinals. While the older method had ensured that only senior clerics of advanced age held the title of cardinal bishop, Pope John's first appointment under the new rule was Ferretto, who had just turned 62.

He attended the Second Vatican Council from 1962 to 1965. He participated in the 1963 papal conclave, where he was thought to be a possible candidate for election to the papacy, he was appointed Major Penitentiary on 7 April 1967. Pope Paul named him a participant in the first post-Vatican II Synod of Bishops in 1967. On 1 March 1973, he resigned as Major Penitentiary. Ferretto died on 17 March 1973 in Rome, at age 74, he had been suffering from a heart condition. He is buried in the church of Immacolata e S. Benedetto Giuseppe Labre a via Taranto. Cardinals of the Holy Roman Church Catholic-Hierarchy