In thermodynamics, entropy is a numerical quantity that shows that many physical processes can go in only one direction in time. For example, you can pour cream into coffee and mix it, but you cannot "unmix" it; you can burn a piece of wood, but you cannot "unburn" it. The word 'entropy' has entered popular usage to refer a lack of order or predictability, or of a gradual decline into disorder. A more physical interpretation of thermodynamic entropy refers to spread of energy or matter, or to extent and diversity of microscopic motion. If you reversed a movie of coffee being mixed or wood being burned, you would see things that are impossible in the real world. Another way of saying that those reverse processes are impossible is to say that mixing coffee and burning wood are "irreversible". Irreversibility is described by an important law of nature known as the second law of thermodynamics, which says that in an isolated system (a system not connected to any other system) which is undergoing change, entropy increases over time. Entropy does not increase indefinitely. A body of matter and radiation eventually will reach an unchanging state, with no detectable flows, and is then said to be in a state of thermodynamic equilibrium. Thermodynamic entropy has a definite value for such a body and is at its maximum value. When bodies of matter or radiation, initially in their own states of internal thermodynamic equilibrium, are brought together so as to intimately interact and reach a new joint equilibrium, then their total entropy increases. For example, a glass of warm water with an ice cube in it will have a lower entropy than that same system some time later when the ice has melted leaving a glass of cool water. Such processes are irreversible: An ice cube in a glass of warm water will not spontaneously form from a glass of cool water. Some processes in nature are almost reversible. For example, the orbiting of the planets around the sun may be thought of as practically reversible: A movie of the planets orbiting the sun which is run in reverse would not appear to be impossible. While the second law, and thermodynamics in general, is accurate in its predictions of intimate interactions of complex physical systems behave, scientists are not content with simply knowing how a system behaves, but want to know also why it behaves the way it does. The question of why entropy increases until equilibrium is reached was answered very successfully in 1877 by a famous scientist named Ludwig Boltzmann. The theory developed by Boltzmann and others, is known as statistical mechanics. Statistical mechanics is a physical theory which explains thermodynamics in terms of the statistical behavior of the atoms and molecules which make up the system. The theory not only explains thermodynamics, but also a host of other phenomena which are outside the scope of thermodynamics. (Wikipedia).
Entropy is often taught as a measure of how disordered or how mixed up a system is, but this definition never really sat right with me. How is "disorder" defined and why is one way of arranging things any more disordered than another? It wasn't until much later in my physics career that I
From playlist Thermal Physics/Statistical Physics
Topics in Combinatorics lecture 8.4 --- Entropy axioms and some simple consequences
This is an introduction to the concept of entropy (in the information-theoretic sense of the word). In the next few videos I shall say more about the concept and give a few non-obvious applications of entropy to combinatorial problems. 0:00 Introduction and entropy axioms 15:17 A few simp
From playlist Topics in Combinatorics (Cambridge Part III course)
Physics - Thermodynamics 2: Ch 32.7 Thermo Potential (10 of 25) What is Entropy?
Visit http://ilectureonline.com for more math and science lectures! In this video explain and give examples of what is entropy. 1) entropy is a measure of the amount of disorder (randomness) of a system. 2) entropy is a measure of thermodynamic equilibrium. Low entropy implies heat flow t
From playlist PHYSICS 32.7 THERMODYNAMIC POTENTIALS
Entropy Explained In 60 Seconds!! #Thermodynamics #Chemistry #Physics #Math #NicholasGKK #Shorts
From playlist Heat and Chemistry
Entropy production during free expansion of an ideal gas by Subhadip Chakraborti
Abstract: According to the second law, the entropy of an isolated system increases during its evolution from one equilibrium state to another. The free expansion of a gas, on removal of a partition in a box, is an example where we expect to see such an increase of entropy. The constructi
From playlist Seminar Series
Entropy's role on Thermodynamics
Thermodynamics depends on enthalpy, but it also depends on entropy. Entropy is a quantitative measure of the disorder of a system. We can see how reactions tend to go from order to disorder. At best they can switch between the two reversibly (second law of thermodynamics). There exist reac
From playlist Materials Sciences 101 - Introduction to Materials Science & Engineering 2020
A better description of entropy
I use this stirling engine to explain entropy. Entropy is normally described as a measure of disorder but I don't think that's helpful. Here's a better description. Visit my blog here: http://stevemould.com Follow me on twitter here: http://twitter.com/moulds Buy nerdy maths things here:
From playlist Best of
The ENTROPY EQUATION and its Applications | Thermodynamics and Microstates EXPLAINED
Entropy is a hotly discussed topic... but how can we actually CALCULATE the entropy of a system? (Note: The written document discussed here can be found in the pinned comment below!) Hey everyone, I'm back with a new video, and this time it's a bit different to my usual ones! In this vid
From playlist Thermodynamics by Parth G
Physics - Thermodynamics: (1 of 5) Entropy - Basic Definition
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain and help you understand entropy.
From playlist PHYSICS - THERMODYNAMICS
A brief introduction to sofic entropy theory – Lewis Bowen – ICM2018
Analysis and Operator Algebras | Dynamical Systems and Ordinary Differential Equations Invited Lecture 8.15 | 9.16 A brief introduction to sofic entropy theory Lewis Bowen Abstract: Sofic entropy theory is a generalization of the classical Kolmogorov–Sinai entropy theory to actions of a
From playlist Dynamical Systems and ODE
Introduction to entropy | Energy and enzymes | Biology | Khan Academy
Introduction to entropy, and how entropy relates to the number of possible states for a system. Watch the next lesson: https://www.khanacademy.org/science/biology/energy-and-enzymes/the-laws-of-thermodynamics/v/the-second-law-of-thermodynamics?utm_source=YT&utm_medium=Desc&utm_campaign=bi
From playlist Energy and enzymes | Biology | Khan Academy
Dynamics of fractional excitations in Kitaev's spin liquid by Masafumi Udagawa
Program The 2nd Asia Pacific Workshop on Quantum Magnetism ORGANIZERS: Subhro Bhattacharjee, Gang Chen, Zenji Hiroi, Ying-Jer Kao, SungBin Lee, Arnab Sen and Nic Shannon DATE: 29 November 2018 to 07 December 2018 VENUE: Ramanujan Lecture Hall, ICTS Bangalore Frustrated quantum magne
From playlist The 2nd Asia Pacific Workshop on Quantum Magnetism
Entropy (for data science) Clearly Explained!!!
Entropy is a fundamental concept in Data Science because it shows up all over the place - from Decision Trees, to similarity metrics, to state of the art dimension reduction algorithms. It's also surprisingly simple, but often poorly explained. Traditionally the equation is presented with
From playlist StatQuest
Matrix Entanglement by Vaibhav Gautam
PROGRAM NONPERTURBATIVE AND NUMERICAL APPROACHES TO QUANTUM GRAVITY, STRING THEORY AND HOLOGRAPHY (HYBRID) ORGANIZERS: David Berenstein (University of California, Santa Barbara, USA), Simon Catterall (Syracuse University, USA), Masanori Hanada (University of Surrey, UK), Anosh Joseph (II
From playlist NUMSTRING 2022
PUBLIC OPENING featuring Cédric Villani: The Many Facets of Entropy [2014]
Video taken from: http://www.fields.utoronto.ca/programs/scientific/fieldsmedalsym/14-15/
From playlist Mathematics
Generic uniqueness of expanders with vanishing relative entropy - Felix Schulze
Workshop on Mean Curvature and Regularity Topic: Generic uniqueness of expanders with vanishing relative entropy Speaker: Felix Schulze Affiliation: University College London Date: November 8, 2018 For more video please visit http://video.ias.edu
From playlist Workshop on Mean Curvature and Regularity
A New Generalization of Entanglement Entropy by Tadashi Takayanagi
COLLOQUIUM A New Generalization of Entanglement Entropy SPEAKER: Tadashi Takayanagi (Yukawa Institute for Theoretical Physics, Kyoto University, Japan) DATE & TIME: 31 January 2022, 15:30 to 17:00 VENUE: Online ABSTRACT: The idea of holography in string theory provides a simple geo
From playlist ICTS Colloquia
Measuring the configurational entropy in computer... (Lecture 1) by Ludovic Berthier
PROGRAM ENTROPY, INFORMATION AND ORDER IN SOFT MATTER ORGANIZERS: Bulbul Chakraborty, Pinaki Chaudhuri, Chandan Dasgupta, Marjolein Dijkstra, Smarajit Karmakar, Vijaykumar Krishnamurthy, Jorge Kurchan, Madan Rao, Srikanth Sastry and Francesco Sciortino DATE: 27 August 2018 to 02 Novemb
From playlist Entropy, Information and Order in Soft Matter
Teach Astronomy - Entropy of the Universe
http://www.teachastronomy.com/ The entropy of the universe is a measure of its disorder or chaos. If the laws of thermodynamics apply to the universe as a whole as they do to individual objects or systems within the universe, then the fate of the universe must be to increase in entropy.
From playlist 23. The Big Bang, Inflation, and General Cosmology 2