Second Law Of Thermodynamics | Britannica ~ Legacy News

The first law of thermodynamics defines the relationship between the various forms of kinetic and potential energy present in a system, the work which the system can perform and the transfer of heat. The second law states that there exists a useful state variable called entropy.Second law of thermodynamics when considered strictly contradicts both with quantum and the classical mechanics which predict that both quantum and the As the whole is a thermodynamical system with the low (ordered) life entropy, she will live till she ages and dies, she will undergo natural...The Second Law of Thermodynamics describes the limitations of heat transfer . Most importantly, it sets out the specific idea that heat cannot be converted The second law of thermodynamics claims that it is impossible for heat to spontaneously flow from a cold body to a hot body, but it can move in...Second Law of Thermodynamics: It is not possible for heat to flow from a colder body to a warmer body without any work having been done to accomplish this flow. It is important to note that when it is stated that energy will not spontaneously flow from a cold object to a hot object, that statement is...The first law of thermodynamics states that energy can neither be created nor destroyed; it can only change forms. However, it has certain limitations. The only case the engine can work is when the is positive or is positive, as stated by the second law of thermodynamics.

Thermodynamics/The Second Law of Thermodynamics - Wikiversity

The second law of thermodynamics states that the entropy of an isolated system or any cyclic process never decreases; it will either increase or remain the same. Because of this, the second law provides a definitive direction in which time must progress by saying that time may only pass in the...As we remarked then, the second law of thermodynamics can be stated in several different ways, and all of them can be shown to imply the others. This is known as the Kelvin statement of the second law of thermodynamics. This statement describes an unattainable "perfect engine," as...The laws of thermodynamics are a grand-sounding term often bandied around in discussions of science, pseudoscience and general woo. Despite being scientific laws themselves, they are often cited by pseudoscientists (e.g., creationists) as a reason for why some other bit of science must be wrong.Like all natural laws, the second law of thermodynamics gives insights into nature, and its several statements imply that it is broadly applicable, fundamentally affecting many apparently disparate processes. The already familiar direction of heat transfer from hot to cold is the basis of our first...

Second law of thermodynamics - Energy Education

The classical Carnot heat engine. Book. Category. v. t. e. The second law of thermodynamics establishes the concept of entropy as a physical property of a thermodynamic system.Do two bricks at a medium temperature ever go to a state where one is hot and one is cold? Will the gas in the unrestrained expansion ever spontaneously return to occupying only the left side of the volume? There are several ways in which the second law of thermodynamics can be stated.The classical Carnot heat engine. Book. Category. v. t. e. The laws of thermodynamics define a group of physical quantities, such as temperature, energy, and entropy...Second law of thermodynamics states that "It is impossible to make the heat flow from a cold body to hot body without the expenditure of energy. Hence from the first law of thermodynamics, the network done should be equal to the net heat absorbed. W=Q 1_Q 2 In practice, the petrol engine of a...The Second Law of Thermodynamics states that the state of entropy of the entire universe, as an isolated system, will always increase over time. Thus, the thermodynamic reversibility concept was proven wrong, proving that irreversibility is the result of every system involving work.

The laws of thermodynamics describe the relationships between thermal energy, or warmth, and different kinds of energy, and the way energy affects topic. The First Law of Thermodynamics states that energy cannot be created or destroyed; the overall quantity of energy in the universe remains the similar. The Second Law of Thermodynamics is ready the quality of energy. It states that as energy is transferred or remodeled, increasingly more of it is wasted. The Second Law also states that there's a natural tendency of any remoted gadget to degenerate into a extra disordered state.

Saibal Mitra, a professor of physics at Missouri State University, reveals the Second Law to be the most attention-grabbing of the 4 rules of thermodynamics. "There are a number of ways to state the Second Law," he said. "At an excessively microscopic degree, it simply says that if you have a machine that is remoted, any herbal process in that gadget progresses in the course of increasing dysfunction, or entropy, of the device."

Mitra explained that all processes result in an increase in entropy. Even when order is higher in a particular location, for instance by way of the self-assembly of molecules to form a dwelling organism, when you're taking the whole device including the environment into consideration, there may be always a net building up in entropy. In any other example, crystals can shape from a salt solution as the water is evaporated. Crystals are more orderly than salt molecules in answer; alternatively, vaporized water is a lot more disorderly than liquid water. The process taken as a whole leads to a web building up in disorder.

History

In his e book, "A New Kind of Science," Stephen Wolfram wrote, "Around 1850 Rudolf Clausius and William Thomson (Lord Kelvin) stated that warmth does now not spontaneously glide from a chillier frame to a hotter body." This became the basis for the Second Law.

Subsequent works by way of Daniel Bernoulli, James Clerk Maxwell, and Ludwig Boltzmann ended in the construction of the kinetic principle of gases, during which a gas is known as a cloud of molecules in movement that can be treated statistically. This statistical approach lets in for exact calculation of temperature, force and quantity according to the perfect fuel law.

This way also resulted in the conclusion that while collisions between particular person molecules are utterly reversible, i.e., they work the identical when performed forward or backward, for a large quantity of fuel, the speeds of individual molecules tend over time to shape a normal or Gaussian distribution, infrequently depicted as a "bell curve," around the average speed. The consequence of that is that when hot fuel and cold gasoline are positioned in combination in a container, you in the end end up with heat gas. However, the heat fuel will never spontaneously separate itself into cold and hot fuel, that means that the process of mixing hot and cold gasses is irreversible. This has frequently been summarized as, "You can't unscramble an egg." According to Wolfram, Boltzmann discovered around 1876 that the reason why for this is that there must be many extra disordered states for a gadget than there are ordered states; due to this fact random interactions will inevitably result in larger dysfunction.

Work and energy

One thing the Second Law explains is that it is not possible to transform heat energy to mechanical energy with 100 % efficiency. After the process of heating a gas to extend its force to pressure a piston, there may be all the time some leftover heat in the gasoline that can't be used to do any further paintings. This waste heat will have to be discarded by means of moving it to a warmth sink. In the case of a car engine, that is carried out by way of onerous the spent gas and air combination to the environment. Additionally, any software with movable parts produces friction that converts mechanical energy to warmth that is most often unusable and should be removed from the system through shifting it to a heat sink. This is why claims for perpetual movement machines are summarily rejected by the U.S. Patent Office.

When a sizzling and a chilly body are introduced into touch with each and every other, heat power will flow from the scorching frame to the cold body until they reach thermal equilibrium, i.e., the identical temperature. However, the warmth won't ever move back the opposite direction; the distinction in the temperatures of the two our bodies will never spontaneously increase. Moving warmth from a chilly frame to a sizzling frame requires work to be done by an exterior energy supply corresponding to a heat pump.

"The most efficient engines we construct right now are massive fuel generators," said David McKee, a professor of physics at Missouri State University. "They burn natural gas or other gaseous fuels at very high temperature, over 2,000 levels C [3,six hundred F], and the exhaust coming out is just a stiff, warm breeze. Nobody tries to extract energy from the waste warmth, because there's simply now not that a lot there."

The arrow of time

The Second Law indicates that thermodynamic processes, i.e., processes that contain the transfer or conversion of warmth power, are irreversible because all of them lead to an build up in entropy. Perhaps one of the most consequential implications of the Second Law, according to Mitra, is that it offers us the thermodynamic arrow of time.

In theory, some interactions, similar to collisions of inflexible bodies or certain chemical reactions, look the same whether or not they are run forward or backward. In follow, on the other hand, all exchanges of energy are subject to inefficiencies, equivalent to friction and radiative warmth loss, which building up the entropy of the gadget being noticed. Therefore, as a result of there is no such thing as a wonderfully reversible process, if somebody asks what's the route of time, we will resolution with self assurance that time at all times flows in the path of expanding entropy.

The fate of the universe

The Second Law additionally predicts the finish of the universe, according to Boston University. "It implies that the universe will end in a 'heat death' in which everything is at the same temperature. This is the ultimate level of disorder; if everything is at the same temperature, no work can be done, and all the energy will end up as the random motion of atoms and molecules."

In the far distant future, stars will have used up all of their nuclear fuel ending up as stellar remnants, such as white dwarfs, neutron stars or black holes, according to Margaret Murray Hanson, a physics professor at the University of Cincinnati. They will eventually evaporate into protons, electrons, photons and neutrinos, ultimately reaching thermal equilibrium with the rest of the Universe. Fortunately, John Baez, a mathematical physicist at the University of California Riverside, predicts that this process of cooling down could take as long as 10(10^26) (1 followed by 1026(100 septillion) zeros) years with the temperature dropping to around 10−30 K (10−30 C above absolute zero).

Additional resources

Here are every other explanations of the Second Law of Thermodynamics:

NASA's Glenn Research Center offers a lesson because it relates to aerodynamics.The University of California, Davis' ChemWiki Dynamic Textbook describes the law, its historical past and applications.FT Exploring, a science education useful resource, explains the Second Law in simple phrases.