Einstein, the Reality of Space, and the Action–Reaction Principle
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On the History of the Radiation Reaction1 Kirk T
On the History of the Radiation Reaction1 Kirk T. McDonald Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (May 6, 2017; updated March 18, 2020) 1 Introduction Apparently, Kepler considered the pointing of comets’ tails away from the Sun as evidence for radiation pressure of light [2].2 Following Newton’s third law (see p. 83 of [3]), one might suppose there to be a reaction of the comet back on the incident light. However, this theme lay largely dormant until Poincar´e (1891) [37, 41] and Planck (1896) [46] discussed the effect of “radiation damping” on an oscillating electric charge that emits electromagnetic radiation. Already in 1892, Lorentz [38] had considered the self force on an extended, accelerated charge e, finding that for low velocity v this force has the approximate form (in Gaussian units, where c is the speed of light in vacuum), independent of the radius of the charge, 3e2 d2v 2e2v¨ F = = . (v c). (1) self 3c3 dt2 3c3 Lorentz made no connection at the time between this force and radiation, which connection rather was first made by Planck [46], who considered that there should be a damping force on an accelerated charge in reaction to its radiation, and by a clever transformation arrived at a “radiation-damping” force identical to eq. (1). Today, Lorentz is often credited with identifying eq. (1) as the “radiation-reaction force”, and the contribution of Planck is seldom acknowledged. This note attempts to review the history of thoughts on the “radiation reaction”, which seems to be in conflict with the brief discussions in many papers and “textbooks”.3 2 What is “Radiation”? The “radiation reaction” would seem to be a reaction to “radiation”, but the concept of “radiation” is remarkably poorly defined in the literature. -
Renewable Energy Partnerships in Development Cooperation: Towards a Relational Theory of Technical Assistance
Sustainability Research Institute SCHOOL OF EARTH AND ENVIRONMENT Renewable energy partnerships in development cooperation: Towards a relational theory of technical assistance Lena J. Kruckenberg January 2015 Sustainability Research Institute Paper No. 77 Centre for Climate Change Economics and Policy Working Paper No. 200 SRI PAPERS SRI Papers (Online) ISSN 1753-1330 A later version of this paper is forthcoming in Energy Policy: Kruckenberg, L.J., 2015. Renewable energy partnerships in development cooperation: Towards a relational understanding of technical assistance. Energy Policy, 77, 11–20. Doi: 10.1016/j.enpol.2014.11.004 First published in 2015 by the Sustainability Research Institute (SRI) Sustainability Research Institute (SRI), School of Earth and Environment, The University of Leeds, Leeds, LS2 9JT, United Kingdom Tel: +44 (0)113 3436461 Fax: +44 (0)113 3436716 Email: [email protected] Web-site: http://www.see.leeds.ac.uk/sri About the Sustainability Research Institute The Sustainability Research Institute conducts internationally recognised, academically excellent and problem-oriented interdisciplinary research and teaching on environmental, social and economic aspects of sustainability. We draw on various social and natural science disciplines, including ecological economics, environmental economics, political science, policy studies, development studies, business and management, geography, sociology, science and technology studies, ecology, environmental science and soil science in our work. The Centre for Climate Change Economics and Policy (CCCEP) brings together some of the world's leading researchers on climate change economics and policy, from many different disciplines. It was established in 2008 and its first phase ended on 30 September 2013. Its second phase commenced on 1 October 2013. -
Classical Mechanics
Classical Mechanics Hyoungsoon Choi Spring, 2014 Contents 1 Introduction4 1.1 Kinematics and Kinetics . .5 1.2 Kinematics: Watching Wallace and Gromit ............6 1.3 Inertia and Inertial Frame . .8 2 Newton's Laws of Motion 10 2.1 The First Law: The Law of Inertia . 10 2.2 The Second Law: The Equation of Motion . 11 2.3 The Third Law: The Law of Action and Reaction . 12 3 Laws of Conservation 14 3.1 Conservation of Momentum . 14 3.2 Conservation of Angular Momentum . 15 3.3 Conservation of Energy . 17 3.3.1 Kinetic energy . 17 3.3.2 Potential energy . 18 3.3.3 Mechanical energy conservation . 19 4 Solving Equation of Motions 20 4.1 Force-Free Motion . 21 4.2 Constant Force Motion . 22 4.2.1 Constant force motion in one dimension . 22 4.2.2 Constant force motion in two dimensions . 23 4.3 Varying Force Motion . 25 4.3.1 Drag force . 25 4.3.2 Harmonic oscillator . 29 5 Lagrangian Mechanics 30 5.1 Configuration Space . 30 5.2 Lagrangian Equations of Motion . 32 5.3 Generalized Coordinates . 34 5.4 Lagrangian Mechanics . 36 5.5 D'Alembert's Principle . 37 5.6 Conjugate Variables . 39 1 CONTENTS 2 6 Hamiltonian Mechanics 40 6.1 Legendre Transformation: From Lagrangian to Hamiltonian . 40 6.2 Hamilton's Equations . 41 6.3 Configuration Space and Phase Space . 43 6.4 Hamiltonian and Energy . 45 7 Central Force Motion 47 7.1 Conservation Laws in Central Force Field . 47 7.2 The Path Equation . -
Power Sources Challenge
POWER SOURCES CHALLENGE FUSION PHYSICS! A CLEAN ENERGY Summary: What if we could harness the power of the Sun for energy here on Fusion reactions occur when two nuclei come together to form one Earth? What would it take to accomplish this feat? Is it possible? atom. The reaction that happens in the sun fuses two Hydrogen atoms together to produce Helium. It looks like this in a very simplified way: Many researchers including our Department of Energy scientists and H + H He + ENERGY. This energy can be calculated by the famous engineers are taking on this challenge! In fact, there is one DOE Laboratory Einstein equation, E = mc2. devoted to fusion physics and is committed to being at the forefront of the science of magnetic fusion energy. Each of the colliding hydrogen atoms is a different isotope of In order to understand a little more about fusion energy, you will learn about hydrogen, one deuterium and one the atom and how reactions at the atomic level produce energy. tritium. The difference in these isotopes is simply one neutron. Background: It all starts with plasma! If you need to learn more about plasma Deuterium has one proton and one physics, visit the Power Sources Challenge plasma activities. neutron, tritium has one proton and two neutrons. Look at the The Fusion Reaction that happens in the SUN looks like this: illustration—do you see how the mass of the products is less than the mass of the reactants? That is called a mass deficit and that difference in mass is converted into energy. -
Physics 101 Today Chapter 5: Newton's Third
Physics 101 Today Chapter 5: Newton’s Third Law First, let’s clarify notion of a force : Previously defined force as a push or pull. Better to think of force as an interaction between two objects. You can’t push anything without it pushing back on you ! Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. Newton’s 3 rd Law - often called “action-reaction ” Eg. Leaning against a wall. You push against the wall. The wall is also pushing on you, equally hard – normal/support force. Now place a piece of paper between the wall and hand. Push on it – it doesn’t accelerate must be zero net force. The wall is pushing equally as hard (normal force) on the paper in the opposite direction to your hand, resulting in zero Fnet . This is more evident when hold a balloon against the wall – it is squashed on both sides. Eg. You pull on a cart. It accelerates. The cart pulls back on you (you feel the rope get tighter). Can call your pull the “ action ” and cart’s pull the “ reaction ”. Or, the other way around. • Newton’s 3 rd law means that forces always come in action -reaction pairs . It doesn’t matter which is called the action and which is called the reaction. • Note: Action-reaction pairs never act on the same object Examples of action-reaction force pairs In fact it is the road’s push that makes the car go forward. Same when we walk – push back on floor, floor pushes us forward. -
HW 6, Question 1: Forces in a Rotating Frame
HW 6, Question 1: Forces in a Rotating Frame Consider a solid platform, like a \merry-go round", that rotates with respect to an inertial frame of reference. It is oriented in the xy plane such that the axis of rotation is in the z-direction, i.e. ! = !z^, which we can take to point out of the page. Now, let us also consider a person walking on the rotating platform, such that this person is walking radially outward on the platform with respect to their (non-inertial) reference frame with velocity v = vr^. In what follows for Question 1, directions in the non-inertial reference frame (i.e. the frame of the walking person) are defined in the following manner: the x0-direction points directly outward from the center of the merry-go round; the y0 points in the tangential direction of rotation in the plane of the platform; and the z0-direction points out of the page, and in the same direction as the z-direction for the inertial reference frame. (a) Identify all forces. Since the person's reference frame is non-inertial, we need to account for the various fictitious forces given the description above, as well as any other external/reaction forces. The angular rate of rotation is constant, and so the Euler force Feul = m(!_ × r) = ~0. The significant forces acting on the person are: 0 • the force due to gravity, Fg = mg = mg(−z^ ), 2 0 • the (fictitious) centrifugal force, Fcen = m! × (! × r) = m! rx^ , 0 • the (fictitious) Coriolis force, Fcor = 2mv × ! = 2m!v(−y^ ), • the normal force the person experiences from the rotating platform N = Nz^0, and • a friction force acting on the person, f, in the x0y0 plane. -
On the Ontology of Spacetime: Substantivalism, Relationism, Eternalism, and Emergence
Found Sci DOI 10.1007/s10699-015-9476-1 On the Ontology of Spacetime: Substantivalism, Relationism, Eternalism, and Emergence Gustavo E. Romero1 Ó Springer Science+Business Media Dordrecht 2015 Abstract I present a discussion of some issues in the ontology of spacetime. After a characterisation of the controversies among relationists, substantivalists, eternalists, and presentists, I offer a new argument for rejecting presentism, the doctrine that only present objects exist. Then, I outline and defend a form of spacetime realism that I call event substantivalism. I propose an ontological theory for the emergence of spacetime from more basic entities (timeless and spaceless ‘events’). Finally, I argue that a relational theory of pre-geometric entities can give rise to substantival spacetime in such a way that relationism and substantivalism are not necessarily opposed positions, but rather complementary. In an appendix I give axiomatic formulations of my ontological views. Keywords Ontology Á Physics Á Spacetime For there neither is nor will be anything else besides what is, since Fate has fettered it to be whole and changeless. Parmenides (Fragment 8. From the translation in Kirk et al.1983). 1 Introduction Discussions and controversies about the nature of space and time in Western thought can be traced to the early Pre-Socratic philosophers (Graham 2006; Jammer 2012; Romero 2012). The position of Aristotle, who understood time as a measure of motion, and its contrast with the Platonic view, shaped the ontological controversy of the Hellenistic period, the Late Antiquity, and even the Middle Ages (see Sorabji 1983). It was not, however, until the development of Newtonian physics and the Leibniz–Clarke corre- spondence (Leibniz and Clarke 2000), that what is now called relationism-substantivalism & Gustavo E. -
A Short History of Physics (Pdf)
A Short History of Physics Bernd A. Berg Florida State University PHY 1090 FSU August 28, 2012. References: Most of the following is copied from Wikepedia. Bernd Berg () History Physics FSU August 28, 2012. 1 / 25 Introduction Philosophy and Religion aim at Fundamental Truths. It is my believe that the secured part of this is in Physics. This happend by Trial and Error over more than 2,500 years and became systematic Theory and Observation only in the last 500 years. This talk collects important events of this time period and attaches them to the names of some people. I can only give an inadequate presentation of the complex process of scientific progress. The hope is that the flavor get over. Bernd Berg () History Physics FSU August 28, 2012. 2 / 25 Physics From Acient Greek: \Nature". Broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves. The universe is commonly defined as the totality of everything that exists or is known to exist. In many ways, physics stems from acient greek philosophy and was known as \natural philosophy" until the late 18th century. Bernd Berg () History Physics FSU August 28, 2012. 3 / 25 Ancient Physics: Remarkable people and ideas. Pythagoras (ca. 570{490 BC): a2 + b2 = c2 for rectangular triangle: Leucippus (early 5th century BC) opposed the idea of direct devine intervention in the universe. He and his student Democritus were the first to develop a theory of atomism. Plato (424/424{348/347) is said that to have disliked Democritus so much, that he wished his books burned. -
The Collaboration of Mileva Marić and Albert Einstein
Asian Journal of Physics Vol 24, No 4 (2015) March The collaboration of Mileva Marić and Albert Einstein Estelle Asmodelle University of Central Lancashire School of Computing, Engineering and Physical Sciences, Preston, Lancashire, UK PR1 2HE. e-mail: [email protected]; Phone: +61 418 676 586. _____________________________________________________________________________________ This is a contemporary review of the involvement of Mileva Marić, Albert Einstein’s first wife, in his theoretical work between the period of 1900 to 1905. Separate biographies are outlined for both Mileva and Einstein, prior to their attendance at the Swiss Federal Polytechnic in Zürich in 1896. Then, a combined journal is described, detailing significant events. In additional to a biographical sketch, comments by various authors are compared and contrasted concerning two narratives: firstly, the sequence of events that happened and the couple’s relationship at particular times. Secondly, the contents of letters from both Einstein and Mileva. Some interpretations of the usage of pronouns in those letters during 1899 and 1905 are re-examined, and a different hypothesis regarding the usage of those pronouns is introduced. Various papers are examined and the content of each subsequent paper is compared to the work that Mileva was performing. With a different take, this treatment further suggests that the couple continued to work together much longer than other authors have indicated. We also evaluate critics and supporters of the hypothesis that Mileva was involved in Einstein’s work, and refocus this within a historical context, in terms of women in science in the late 19th century. Finally, the definition of, collaboration (co-authorship, specifically) is outlined. -
Einstein's Equations for Spin 2 Mass 0 from Noether's Converse Hilbertian
Einstein’s Equations for Spin 2 Mass 0 from Noether’s Converse Hilbertian Assertion October 4, 2016 J. Brian Pitts Faculty of Philosophy, University of Cambridge [email protected] forthcoming in Studies in History and Philosophy of Modern Physics Abstract An overlap between the general relativist and particle physicist views of Einstein gravity is uncovered. Noether’s 1918 paper developed Hilbert’s and Klein’s reflections on the conservation laws. Energy-momentum is just a term proportional to the field equations and a “curl” term with identically zero divergence. Noether proved a converse “Hilbertian assertion”: such “improper” conservation laws imply a generally covariant action. Later and independently, particle physicists derived the nonlinear Einstein equations as- suming the absence of negative-energy degrees of freedom (“ghosts”) for stability, along with universal coupling: all energy-momentum including gravity’s serves as a source for gravity. Those assumptions (all but) imply (for 0 graviton mass) that the energy-momentum is only a term proportional to the field equations and a symmetric curl, which implies the coalescence of the flat background geometry and the gravitational potential into an effective curved geometry. The flat metric, though useful in Rosenfeld’s stress-energy definition, disappears from the field equations. Thus the particle physics derivation uses a reinvented Noetherian converse Hilbertian assertion in Rosenfeld-tinged form. The Rosenfeld stress-energy is identically the canonical stress-energy plus a Belinfante curl and terms proportional to the field equations, so the flat metric is only a convenient mathematical trick without ontological commitment. Neither generalized relativity of motion, nor the identity of gravity and inertia, nor substantive general covariance is assumed. -
Exploring the Social Processes of Leadership and Organizing
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UNL | Libraries University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Leadership Institute Faculty Publications Leadership Institute 12-2006 Relational Leadership Theory: Exploring the social processes of leadership and organizing Mary Uhl-Bien University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/leadershipfacpub Part of the Management Sciences and Quantitative Methods Commons Uhl-Bien, Mary, "Relational Leadership Theory: Exploring the social processes of leadership and organizing" (2006). Leadership Institute Faculty Publications. 19. https://digitalcommons.unl.edu/leadershipfacpub/19 This Article is brought to you for free and open access by the Leadership Institute at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Leadership Institute Faculty Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in The Leadership Quarterly 17:6 (December 2006), pp. 654-676: The Leadership Quarterly Yearly Review of Leadership; doi 10.1016/j.leaqua.2006.10.007 Copyright © 2006 Elsevier Inc. Used by permission. http://www.sciencedirect.com/science/journal/10489843 Published online November 16, 2006. Relational Leadership Theory: Exploring the social processes of leadership and organizing Mary Uhl-Bien Department of Management University of Nebraska–Lincoln Lincoln, NE 68588 USA Abstract Relational leadership is a relatively new term in the leadership literature, and because of this, its meaning is open to interpretation. In the present article I describe two perspectives of relational leadership: an entity perspective that fo- cuses on identifying attributes of individuals as they engage in interpersonal relationships, and a relational perspec- tive that views leadership as a process of social construction through which certain understandings of leadership come about and are given privileged ontology. -
Biology Assessment
Master thesis Biology Assessment on the feasibility of anticipating Synthetic Biology Wietse Hage Under the supervision of dr. Y. Saghai and dr. M.A.J. MacLeod January 21, 2021 ”It is not down on any map; true places never are.” Moby-Dick, or, the Whale Herman Melville MSc Philosophy of Science, Technology and Society - PSTS Faculty of Behavioural, Management, and Social Sciences, University of Twente, Enschede, the Netherlands Acknowledgements Arnhem, January 21, 2021 What a fascinating journey we’ve had. First and foremost, I would like to thank Yashar Saghai. During the one and a half year this thesis took to write, Yashar and I met almost every two weeks! This adds up to 40 plus meet- ings, not including our trip to the Anticipation conference in Oslo. It is hard for me to find words that convey my gratitude towards you Yashar: I hope that my future work shows the influence you had on me, both as a philosopher and a writer. The second person who played a crucial part lifting this thesis up to the level it standstoday is Miles MacLeod. Having someone with your background take a critical look at my work is a true gift: thank you for the insightful comments and the time you took to discuss Robert Rosen’s controversial ideas with me. Another individual who deserves mentioning is Virgil Rerimassie, who took the time to sit down over coffee to explain his work in his own words. I would like to thank my girlfriend Iris, who during all of these months remained patient, caring and loving; thank you for sticking by my side piertje, definitely during my grumpier phases.