A Cultural History of Physics
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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. -
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. -
A Brief Tour Into the History of Gravity: from Emocritus to Einstein
American Journal of Space Science 1 (1): 33-45, 2013 ISSN: 1948-9927 © 2013 Science Publications doi:10.3844/ajssp.2013.33.45 Published Online 1 (1) 2013 (http://www.thescipub.com/ajss.toc) A Brief Tour into the History of Gravity: From Emocritus to Einstein Panagiotis Papaspirou and Xenophon Moussas Department of Physics, Section of Astrophysics, Astronomy and Mechanics, University of Athens, Athens, Greece ABSTRACT The History of Gravity encompasses many different versions of the idea of the Gravitational interaction, which starts already from the Presocratic Atomists, continues to the doctrines of the Platonic and Neoplatonic School and of the Aristotelian School, passes through the works of John Philoponus and John Bouridan and reaches the visions of Johannes Kepler and Galileo Galilei. Then, the major breakthrough in the Theory of Motion and the Theory of Gravity takes place within the realm of Isaac Newton’s most famous Principia and of the work of Gottfried Leibniz, continues with the contributions of the Post- newtonians, such as Leonhard Euler, reaches the epoch of its modern formulation by Ernst Mach and other Giants of Physics and Philosophy of this epoch, enriches its structure within the work of Henry Poincare and finally culminates within the work of Albert Einstein, with the formulation of the Theory of Special Relativity and of General Relativity at the begin of the 20th century. The evolution of the Theory of General Relativity still continues up to our times, is rich in forms it takes and full of ideas of theoretical strength. Many fundamental concepts of the Epistemology and the History of Physics appear in the study of the Theory of Gravity, such as the notions of Space, of Time, of Motion, of Mass, in its Inertial, Active Gravitational and Passive Gravitational form, of the Inertial system of reference, of the Force, of the Field, of the Riemannian Geometry and of the Field Equations. -
Avoiding the Void: Avicenna on the Impossibility of Circular Motion in a Void*
Created on 24 December 2006 at 20.51 hours page 1 Avoiding the Void: Avicenna on the Impossibility of Circular Motion in a Void* Jon McGinnis The topic of the void was of significant philosophical and scientific importance in the ancient and medieval world. Some, such as the atomists, maintained that the void was essential if one were to explain motion. Others, such as Aristotle, argued that the exis- tence of the void would absolutely preclude the possibility of motion. Moreover, there were disputes concerning even how to characterize the void. Thus the atomists claimed that interstitial voids were dispersed throughout every body and existed alongside bo- dies in an infinite space. Others, such as the Stoics, held that all bodies were localized in a plenum that was itself situated in an extra-cosmic, infinite void. Still others, such as the Neoplatonist John Philoponus, thought that the void was finite, and although as a matter of fact it is never devoid of a body, it at least is capable of existing independent of any body. The above roughly provides the gamut of positions concerning the void as it reached the medieval Arabic philosopher Avicenna ( 370–428/ 980–1037). In one form or another, Avicenna was aware of the various moves and counter-moves associated with the notion of the void. Like Aristotle, he maintained that the existence of the void would absolutely preclude the possibility of motion. His arguments in some cases simply rehearse those of Aristotle; in other places they expand on the thought of Aristotle in order to respond to new threats that arose after Aristotle’s own time; and in certain situations Avicenna constructs new arguments against the void used neither by Aristotle nor, from what we can gather, Aristotle’s later Greek commentators. -
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. -
Newton.Indd | Sander Pinkse Boekproductie | 16-11-12 / 14:45 | Pag
omslag Newton.indd | Sander Pinkse Boekproductie | 16-11-12 / 14:45 | Pag. 1 e Dutch Republic proved ‘A new light on several to be extremely receptive to major gures involved in the groundbreaking ideas of Newton Isaac Newton (–). the reception of Newton’s Dutch scholars such as Willem work.’ and the Netherlands Jacob ’s Gravesande and Petrus Prof. Bert Theunissen, Newton the Netherlands and van Musschenbroek played a Utrecht University crucial role in the adaption and How Isaac Newton was Fashioned dissemination of Newton’s work, ‘is book provides an in the Dutch Republic not only in the Netherlands important contribution to but also in the rest of Europe. EDITED BY ERIC JORINK In the course of the eighteenth the study of the European AND AD MAAS century, Newton’s ideas (in Enlightenment with new dierent guises and interpre- insights in the circulation tations) became a veritable hype in Dutch society. In Newton of knowledge.’ and the Netherlands Newton’s Prof. Frans van Lunteren, sudden success is analyzed in Leiden University great depth and put into a new perspective. Ad Maas is curator at the Museum Boerhaave, Leiden, the Netherlands. Eric Jorink is researcher at the Huygens Institute for Netherlands History (Royal Dutch Academy of Arts and Sciences). / www.lup.nl LUP Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. 1 Newton and the Netherlands Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. 2 Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. -
Introduction
Introduction Queen's College, the predecessor of Rutgers University, was the eighth college to be founded in the American colonies. The early colonial colleges were founded to meet the emerging needs for an educated clergy, and to provide education to other leaders of the community. The religious leaders of the colonies were foremost in the movements to establish these colleges. Although denominational sponsorship was critical to the founding and early support of the colleges, there were generally no religious tests for students, and the colleges were chartered by the colonies. Leaders of the Puritan Congregational Church founded Harvard College in 1636 with a bequest of £400 from the Massachusetts Bay Colony. The College was organized and named Harvard College in 1639, and chartered in 1650. The traditional list of colonial colleges that followed Harvard College begins with William and Mary College, which was founded in 1693 by leaders of the Anglican Episcopal Church, followed by Yale College, which was founded in 1701 by leaders of the Puritan Congregational Church. The College of Philadelphia (later University of Pennsylvania) was founded in 1740 by Benjamin Franklin and other leading citizens of Philadelphia, and had the weakest religious connections of the colonial colleges. The College of New Jersey (later Princeton College) was founded in 1746 by leaders of the Presbyterian Church, King's College (later Columbia College) was founded in 1754 by leaders of the Anglican Episcopal Church, and the College of Rhode Island (later Brown College) was founded in 1764 by leaders of the Baptist Church. 1 History of Physics and Astronomy Some elements of physics and astronomy were taught in the colonial colleges from the time they opened. -
What's the Problem with the Cosmological Constant?
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Philsci-Archive What’s the problem with the cosmological constant? Mike D. Schneider∗y Abstract The “Cosmological Constant Problem” (CCP) is widely considered a crisis in contemporary theoretical physics. Unfortunately, the search for its resolution is hampered by open disagreement about what is, strictly, the problem. This disagreement stems from the observation that the CCP is not a problem within any of our current theories, and nearly all of the details of those future theories for which the CCP could be made a problem are up for grabs. Given this state of affairs, I discuss how one ought to make sense of the role of the CCP in physics and generalize some lessons from it. ∗To contact the author, write to: Mike D. Schneider, Department of Logic and Philosophy of Science, University of California, Irvine; e-mail: [email protected]. yI would like to thank James Owen Weatherall and Erik Curiel for their steering comments on earlier drafts of this paper. I am also grateful for the many questions and comments from members of the Southern California Philosophy of Physics reading group, as well as for the positive reception of the paper at the Philosophy of Logic, Math, and Physics graduate student conference at the Rotman Institute of Philosophy at Western University. Finally, I am indebted to Jeffrey Barrett, JB Manchak, Hannah Rubin, Kyle Stanford, and John Earman, as well as to an anonymous reviewer and an editor for pushing me to make my punchlines clearer. -
Statistical Mechanics
3 d rB rB 3 d rA rA Statistical Mechanics Daniel F. Styer December 2007 Statistical Mechanics Dan Styer Department of Physics and Astronomy Oberlin College Oberlin, Ohio 44074-1088 [email protected] http://www.oberlin.edu/physics/dstyer December 2007 Although, as a matter of history, statistical mechanics owes its origin to investigations in thermodynamics, it seems eminently worthy of an independent development, both on account of the elegance and simplicity of its principles, and because it yields new results and places old truths in a new light. | J. Willard Gibbs Elementary Principles in Statistical Mechanics Contents 0 Preface 1 1 The Properties of Matter in Bulk 4 1.1 What is Statistical Mechanics About? . 4 1.2 Outline of Book . 4 1.3 Fluid Statics . 5 1.4 Phase Diagrams . 7 1.5 Additional Problems . 7 2 Principles of Statistical Mechanics 10 2.1 Microscopic Description of a Classical System . 10 2.2 Macroscopic Description of a Large Equilibrium System . 14 2.3 Fundamental Assumption . 15 2.4 Statistical Definition of Entropy . 17 2.5 Entropy of a Monatomic Ideal Gas . 19 2.6 Qualitative Features of Entropy . 25 2.7 Using Entropy to Find (Define) Temperature and Pressure . 34 2.8 Additional Problems . 44 3 Thermodynamics 46 3.1 Heat and Work . 46 3.2 Heat Engines . 50 i ii CONTENTS 3.3 Thermodynamic Quantities . 52 3.4 Multivariate Calculus . 55 3.5 The Thermodynamic Dance . 60 3.6 Non-fluid Systems . 67 3.7 Thermodynamics Applied to Fluids . 68 3.8 Thermodynamics Applied to Phase Transitions . -
Verification, Validation, and Predictive Capability in Computational Engineering and Physics
SAND REPORT SAND2003-3769 Unlimited Release Printed February 2003 Verification, Validation, and Predictive Capability in Computational Engineering and Physics William L. Oberkampf, Timothy G. Trucano, and Charles Hirsch Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000. Approved for public release; further dissemination unlimited. Issued by Sandia National Laboratories, operated for the United States Department of Energy by Sandia Corporation. NOTICE: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government, nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, make any warranty, express or implied, or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represent that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government, any agency thereof, or any of their contractors or subcontractors. The views and opinions expressed herein do not necessarily state or reflect those of the United States Government, any agency thereof, or any of their contractors. Printed in the United States of America. This report has been reproduced directly from the best available copy. -
Separate Material Intellect in Averroes' Mature Philosophy Richard C
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by epublications@Marquette Marquette University e-Publications@Marquette Philosophy Faculty Research and Publications Philosophy, Department of 1-1-2004 Separate Material Intellect in Averroes' Mature Philosophy Richard C. Taylor Marquette University, [email protected] Published version. "Separate Material Intellect in Averroes' Mature Philosophy," in Words, Texts and Concepts Cruising the Mediterranean Sea. Eds. Gerhard Endress, Rud̈ iger Arnzen and J Thielmann. Leuven; Dudley, MA: Peeters, 2004: 289-309. Permalink. © 2004 Peeters Publishers. Used with permission. ORIENTALIA LOVANIENSIA ANALECTA ---139--- 'WORDS, TEXTS AND CONCEPTS CRUISING THE MEDITERRANEAN SEA Studies on the sources, contents and influences of Islamic civilization and Arabic philosophy and science Dedicated to Gerhard Endress on his sixty-fifth birthday edited by R. ARNZEN and J. THIELMANN UITGEVERIJ PEETERS en DEPARTEMENT OOSTERSE STUDIES LEUVEN - PARIS - DUDLEY, MA 2004 SEPARATE MATERIAL INTELLECT IN A VERROES' MATURE PHILOSOPHY Richard C. T AYLOR Marquette University, Milwaukee The doctrine of the material intellect promulgated by Averroes (i126- 1198) in his latest works is surely the teaching for which he has been most maligned both in the medieval era and in modern times. In medi eval times Duns Scotus spoke of "That accursed Averroes" whose "fan tastic conception, intelligible neither to himself nor to others, assumes the intellective part of man to be a sort