The Nabla of Sir William Rowan Hamilton

Total Page:16

File Type:pdf, Size:1020Kb

The Nabla of Sir William Rowan Hamilton Tutorial, Electric Geometry - Nabla Del Hamilton Page 1 of 27 e-mail: math@ H Y P E R C O M P L E X .COM H << | >> T.Nabla 1846 THE NABLA OF SIR WILLIAM ROWAN HAMILTON ( revision .02, 2001-07-19, new section 2002-05-07 ) Sir William Rowan Hamilton (1805-1865), Irish Mathematician and Physicist, discovered Quaternions, q = w + ix + jy + kz, in 18431, and in 18462 he introduced the differential operator, = i@/@x + j@/@y + k@/@z, to facilitate the special vector differentiation of quaternions. His original symbol, the "horizontal wedge," , was later turned over after his death by mathematicians3 and written as a "vertical wedge," , instead. The came into widspread use, while the names4 "nabla" and "del" were assigned to this operator, and beginning in 1881 the definition of the vector basis (i,j,k) was also changed, this time by physicists5 who objected to Hamilton's mathematical definition of vectors and sought what they thought was a more physically meaningful definition, so that today, the we know, and are so familiar with, bears little resemblence to Hamilton's original differential operator. While Hamilton's Operator may be somewhat unfamiliar to us, we can easily grasp the essential difference between this original operator and its modern incarnation as found in our modern vector calculus. If we agree to use the simple trick6 of matching up only the components of the old and new vectors, then for a vector A = iA1 + jA2 + kA3, we can write; A = -div(A) + curl(A) A = -div(A) - curl(A) where "div()" and "curl()" are the usual differential operations in modern vector analysis. Care must be taken when using these expressions on either side of the equal signs as equivalents, but with the appropriate warnings6 heeded they can be very useful in facilitating easy recognition of quaternion results in terms of things we already know from modern vectors. This allows us to quickly grasp the results of quaternion analysis, something that could otherwize be a rather tedious affair. A glance is all we need to understand the significance of the result. Hamilton's operator produces the sum of a scalar and vector. The vector part changes sign when the direction of the operation is reversed, because quaternions do not commute, but the scalar part is unchanged in sign. This means one cannot indicate the difference of differentiation from left and right with a simple overall minus sign like in cross products7. Mysteriously, although Hamilton dies as much as nineteen years after he first introduces this operator, during which time he is mostly devoted to the development of quaternions, and spends all of his time in the last years working on the Elements8, almost nothing can be found in Hamilton's writings on the topic, apart from two brief references to this operator. Charles Jasper Joly writes9 - "Hamilton's writings on the operator consist, so far as I am aware, and I have searched through his manuscripts in the library of Trinity College, of a communication to the Royal Irish Academy (July 20, 1846), which is published in the proceedings, Vol.iii, p.291, and practically reprinted in the Phil.Mag. of the following year, and of Art.620 of the Lectures on Quaternions."10 Apparently, Hamilton dies before he gets the opportunity to write down what his thoughts are on this differential operator. As Joly says in his preface to Hamilton's Elements11 - "Sir William Rowan Hamilton died on the 2nd of September, 1865, leaving his great work on Quaternions unfinished. He intended to have added some account of the operator , an Index, and an Appendix containing notes on Anharmonic Coordinates, on the Barycentric Calculus, and on proofs of his geometrical theorems stated in Nichol's Cyclopaedia. At the time of his death, with the exception of a fragment of the preface, and a small portion of the table of contents, all the manuscript he had prepared was in type. As he rarely commenced writing before his thoughts were fully matured, he has left no outline http://web.archive.org/web/20070928163722/http://www.hypercomplex.com/educatio... 08.01.2012 Tutorial, Electric Geometry - Nabla Del Hamilton Page 2 of 27 of the additions contemplated." Not only could Joly not find any further reference to , but even in refering to this operator he is already using the modern vertical wedge symbol, , a symbol Hamilton chose not to use, as if they were totally interchangeable. And although he does remark later in footnotes of the 2nd edition of the Elements that Hamilton's symbol was different, and renders the symbol correctly then as , Joly nevertheless adopts the modern mathematicians vertical wedge in all his own writings, consistent with everyone else of the times, and never seems to be aware of the subtle difference in meaning introduced by the new symbol, even though he is forced to invent an alternate mechanism to distinguish left and right differentiations later in Art.57 of his own 1905 work A Manual of Quaternions12. This modern vertical wedge was in fact considered by Hamilton himself, and actually used for the differential operator in Hamilton's very first communication on the subject. The paper, prepared for a meeting of the British Association at Southampton, never made it to its intended destination, and so was never published. But, we know of it because Hamilton refers to this first paper when discussing the operator in the October 1847 edition of the Philosophical Magazine. On page 291, Hamilton writes13, "In the paper* designed for Southampton it was remarked, as an illustration, that this result enables us to put the known thermological equation, d2v/dx2 + d2v/dy2 + d2v/dz2 + a dv/dt = 0, under the new and more symbolic form, ( 2. - a d/dt)v = 0; . (d.) when v denotes, in quantity and in direction, the flux of heat, at the time t and at the point xyz." And on this same page, in the corresponding footnote to the referenced Southampton 'paper*', he explains, "* In that paper itself, the characteristic was written ; but this more common sign has been so often used with other meanings, that it seems desirable to abstain from appropriating it to the new signification here proposed." Hamilton feels the need to explain here why he has just changed the symbol from , which he had only very recently used in that Southampton Paper, and is now writing instead, giving a plausible argument. But, his explanation is a bit puzzling, since no one else is using the symbol for anything. Where are all these other meanings that cause confusion? Only Hamilton has used this symbol before, and he used it in two different contexts, once as a permutation symbol, and once as an arbitrary function, but certainly "so often used with other meanings" is definitely an exaggeration on his part here. Why did he feel the need to exaggerate? He was constructing a plausable argument for his readers, because he was not prepared to reveal his ideas and the real reason for making the change, as we shall argue below.9 The Southampton paper was never published. So in fact, all Hamilton's public writings use , and were it not for that one footnote, we would not have known that Hamilton actually considered and rejected it in favor of the rotated . We get an explanation of what happened to the Southampton Paper from Hamilton's very extensive biography written by Graves; it was misdirected to Sir John Herschel's home at Collingwood and never made it to Southampton. In discussing the year 1846, Graves writes14, "From the letters which passed at this time between Hamilton and Herschel, I gather that Hamilton was prevented by the illness, which proved the mortal illness, of his sister Eliza from attending the Meeting of the Association at Southampton, and that he sent to Herschel, as President of Section A, a communication 'respecting the application of my new algebraic geometry to the mathematics of Heat, and to some parts of the general theory of curves and surfaces, especially as respects Ellipsoids and Cones of the Second Degree.' The communication, through mistake, was not forwarded from Collingwood; and Herschel, finding it there on his return home, writes to express his regret, and adds, 'it looks very beautiful. Go on and prosper.'" Peter Guthrie Tait (1831-1901), the Scottish Mathematician and Physicist, close friend of James Clerk Maxwell, and understudy of Hamilton, was the first person to take up Hamilton's Operator and attempt to develop the theory. But, Tait seems not to have understood why Hamilton used the http://web.archive.org/web/20070928163722/http://www.hypercomplex.com/educatio... 08.01.2012 Tutorial, Electric Geometry - Nabla Del Hamilton Page 3 of 27 symbol, for he was one of the first to change this symbol to the modern , if not the very first person to do so, and it seems he never considered the profound implications of the switch. In his 1898 Scientific Papers15 Tait writes - "I was originally attracted to the study of Quaternions by Sir W. R. Hamilton's = i d/dx + j d/dy + k d/dz to which he called special attention (Lectures on Quaternions, $ 620) on account of its promise of usefulness in physical applications. But I soon found that in order that its full power may be applied, in general investigations, it is necessary that we should have processes of definite integration, of the kinds required in physics, applicable to quaternion symbols and not merely to scalar variables. I often consulted Hamilton about this want, and he promised to endeavour to supply it at some future time.
Recommended publications
  • Arxiv:1001.0240V1 [Math.RA]
    Fundamental representations and algebraic properties of biquaternions or complexified quaternions Stephen J. Sangwine∗ School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, United Kingdom. Email: [email protected] Todd A. Ell† 5620 Oak View Court, Savage, MN 55378-4695, USA. Email: [email protected] Nicolas Le Bihan GIPSA-Lab D´epartement Images et Signal 961 Rue de la Houille Blanche, Domaine Universitaire BP 46, 38402 Saint Martin d’H`eres cedex, France. Email: [email protected] October 22, 2018 Abstract The fundamental properties of biquaternions (complexified quaternions) are presented including several different representations, some of them new, and definitions of fundamental operations such as the scalar and vector parts, conjugates, semi-norms, polar forms, and inner and outer products. The notation is consistent throughout, even between representations, providing a clear account of the many ways in which the component parts of a biquaternion may be manipulated algebraically. 1 Introduction It is typical of quaternion formulae that, though they be difficult to find, once found they are immediately verifiable. J. L. Synge (1972) [43, p34] arXiv:1001.0240v1 [math.RA] 1 Jan 2010 The quaternions are relatively well-known but the quaternions with complex components (complexified quaternions, or biquaternions1) are less so. This paper aims to set out the fundamental definitions of biquaternions and some elementary results, which, although elementary, are often not trivial. The emphasis in this paper is on the biquaternions as an applied algebra – that is, a tool for the manipulation ∗This paper was started in 2005 at the Laboratoire des Images et des Signaux (now part of the GIPSA-Lab), Grenoble, France with financial support from the Royal Academy of Engineering of the United Kingdom and the Centre National de la Recherche Scientifique (CNRS).
    [Show full text]
  • Hypercomplex Numbers
    Hypercomplex numbers Johanna R¨am¨o Queen Mary, University of London [email protected] We have gradually expanded the set of numbers we use: first from finger counting to the whole set of positive integers, then to positive rationals, ir- rational reals, negatives and finally to complex numbers. It has not always been easy to accept new numbers. Negative numbers were rejected for cen- turies, and complex numbers, the square roots of negative numbers, were considered impossible. Complex numbers behave like ordinary numbers. You can add, subtract, multiply and divide them, and on top of that, do some nice things which you cannot do with real numbers. Complex numbers are now accepted, and have many important applications in mathematics and physics. Scientists could not live without complex numbers. What if we take the next step? What comes after the complex numbers? Is there a bigger set of numbers that has the same nice properties as the real numbers and the complex numbers? The answer is yes. In fact, there are two (and only two) bigger number systems that resemble real and complex numbers, and their discovery has been almost as dramatic as the discovery of complex numbers was. 1 Complex numbers Complex numbers where discovered in the 15th century when Italian math- ematicians tried to find a general solution to the cubic equation x3 + ax2 + bx + c = 0: At that time, mathematicians did not publish their results but kept them secret. They made their living by challenging each other to public contests of 1 problem solving in which the winner got money and fame.
    [Show full text]
  • Split Quaternions and Spacelike Constant Slope Surfaces in Minkowski 3- Space
    Split Quaternions and Spacelike Constant Slope Surfaces in Minkowski 3- Space Murat Babaarslan and Yusuf Yayli Abstract. A spacelike surface in the Minkowski 3-space is called a constant slope surface if its position vector makes a constant angle with the normal at each point on the surface. These surfaces completely classified in [J. Math. Anal. Appl. 385 (1) (2012) 208-220]. In this study, we give some relations between split quaternions and spacelike constant slope surfaces in Minkowski 3-space. We show that spacelike constant slope surfaces can be reparametrized by using rotation matrices corresponding to unit timelike quaternions with the spacelike vector parts and homothetic motions. Subsequently we give some examples to illustrate our main results. Mathematics Subject Classification (2010). Primary 53A05; Secondary 53A17, 53A35. Key words: Spacelike constant slope surface, split quaternion, homothetic motion. 1. Introduction Quaternions were discovered by Sir William Rowan Hamilton as an extension to the complex number in 1843. The most important property of quaternions is that every unit quaternion represents a rotation and this plays a special role in the study of rotations in three- dimensional spaces. Also quaternions are an efficient way understanding many aspects of physics and kinematics. Many physical laws in classical, relativistic and quantum mechanics can be written nicely using them. Today they are used especially in the area of computer vision, computer graphics, animations, aerospace applications, flight simulators, navigation systems and to solve optimization problems involving the estimation of rigid body transformations. Ozdemir and Ergin [9] showed that a unit timelike quaternion represents a rotation in Minkowski 3-space.
    [Show full text]
  • Analogy in William Rowan Hamilton's New Algebra
    Technical Communication Quarterly ISSN: 1057-2252 (Print) 1542-7625 (Online) Journal homepage: https://www.tandfonline.com/loi/htcq20 Analogy in William Rowan Hamilton's New Algebra Joseph Little & Maritza M. Branker To cite this article: Joseph Little & Maritza M. Branker (2012) Analogy in William Rowan Hamilton's New Algebra, Technical Communication Quarterly, 21:4, 277-289, DOI: 10.1080/10572252.2012.673955 To link to this article: https://doi.org/10.1080/10572252.2012.673955 Accepted author version posted online: 16 Mar 2012. Published online: 16 Mar 2012. Submit your article to this journal Article views: 158 Citing articles: 1 View citing articles Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=htcq20 Technical Communication Quarterly, 21: 277–289, 2012 Copyright # Association of Teachers of Technical Writing ISSN: 1057-2252 print/1542-7625 online DOI: 10.1080/10572252.2012.673955 Analogy in William Rowan Hamilton’s New Algebra Joseph Little and Maritza M. Branker Niagara University This essay offers the first analysis of analogy in research-level mathematics, taking as its case the 1837 treatise of William Rowan Hamilton. Analogy spatialized Hamilton’s key concepts—knowl- edge and time—in culturally familiar ways, creating an effective landscape for thinking about the new algebra. It also structurally aligned his theory with the real number system so his objects and operations would behave customarily, thus encompassing the old algebra while systematically bringing into existence the new. Keywords: algebra, analogy, mathematics, William Rowan Hamilton INTRODUCTION Studies of analogy in technical discourse have made important strides in the 30 years since Lakoff and Johnson (1980) ushered in the cognitive linguistic turn.
    [Show full text]
  • Quaternion Algebra and Calculus
    Quaternion Algebra and Calculus David Eberly, Geometric Tools, Redmond WA 98052 https://www.geometrictools.com/ This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. Created: March 2, 1999 Last Modified: August 18, 2010 Contents 1 Quaternion Algebra 2 2 Relationship of Quaternions to Rotations3 3 Quaternion Calculus 5 4 Spherical Linear Interpolation6 5 Spherical Cubic Interpolation7 6 Spline Interpolation of Quaternions8 1 This document provides a mathematical summary of quaternion algebra and calculus and how they relate to rotations and interpolation of rotations. The ideas are based on the article [1]. 1 Quaternion Algebra A quaternion is given by q = w + xi + yj + zk where w, x, y, and z are real numbers. Define qn = wn + xni + ynj + znk (n = 0; 1). Addition and subtraction of quaternions is defined by q0 ± q1 = (w0 + x0i + y0j + z0k) ± (w1 + x1i + y1j + z1k) (1) = (w0 ± w1) + (x0 ± x1)i + (y0 ± y1)j + (z0 ± z1)k: Multiplication for the primitive elements i, j, and k is defined by i2 = j2 = k2 = −1, ij = −ji = k, jk = −kj = i, and ki = −ik = j. Multiplication of quaternions is defined by q0q1 = (w0 + x0i + y0j + z0k)(w1 + x1i + y1j + z1k) = (w0w1 − x0x1 − y0y1 − z0z1)+ (w0x1 + x0w1 + y0z1 − z0y1)i+ (2) (w0y1 − x0z1 + y0w1 + z0x1)j+ (w0z1 + x0y1 − y0x1 + z0w1)k: Multiplication is not commutative in that the products q0q1 and q1q0 are not necessarily equal.
    [Show full text]
  • Towards Energy Principles in the 18Th and 19Th Century – from D’Alembert to Gauss
    Towards Energy Principles in the 18th and 19th Century { From D'Alembert to Gauss Ekkehard Ramm, Universit¨at Stuttgart The present contribution describes the evolution of extremum principles in mechanics in the 18th and the first half of the 19th century. First the development of the 'Principle of Least Action' is recapitulated [1]: Maupertuis' (1698-1759) hypothesis that for any change in nature there is a quantity for this change, denoted as 'action', which is a minimum (1744/46); S. Koenig's contribution in 1750 against Maupertuis, president of the Prussian Academy of Science, delivering a counter example that a maximum may occur as well and most importantly presenting a copy of a letter written by Leibniz already in 1707 which describes Maupertuis' general principle but allowing for a minimum or maximum; Euler (1707-1783) heavily defended Maupertuis in this priority rights although he himself had discovered the principle before him. Next we refer to Jean Le Rond d'Alembert (1717-1783), member of the Paris Academy of Science since 1741. He described his principle of mechanics in his 'Trait´ede dynamique' in 1743. It is remarkable that he was considered more a mathematician rather than a physicist; he himself 'believed mechanics to be based on metaphysical principles and not on experimental evidence' [2]. Ne- vertheless D'Alembert's Principle, expressing the dynamic equilibrium as the kinetic extension of the principle of virtual work, became in its Lagrangian ver- sion one of the most powerful contributions in mechanics. Briefly Hamilton's Principle, denoted as 'Law of Varying Action' by Sir William Rowan Hamilton (1805-1865), as the integral counterpart to d'Alembert's differential equation is also mentioned.
    [Show full text]
  • 2012 Summer Workshop, College of the Holy Cross Foundational Mathematics Concepts for the High School to College Transition
    2012 Summer Workshop, College of the Holy Cross Foundational Mathematics Concepts for the High School to College Transition Day 9 { July 23, 2012 Summary of Graphs: Along the way, you have used several concepts that arise in the area of mathematics known as discrete mathematics or combinatorics. Here is a list of them: • Going from Amherst to the Mass Maritime academy is the equivalent of moving along a collection of edges in order from one vertex to another so that the vertex at the end of one edge is the vertex of the beginning of the next. This is called a path. • Starting at Worcester and ending at Worcester gives a path that starts at one vertex and ends at the same vertex. This is called a circuit or cycle. • A route that allows you to visit every school is called a Hamiltonian path (if it has a different start and end points) or a Hamiltonian circuit (if it has the same starting and ending point). These are named after the 19th century British physicist, astronomer, and mathematician William Rowan Hamilton. Among other things, he is known for inventing his own system of numbers (can you imagine that!), called quarternions, which are important in mathematics and physics. Figure 1: The bridges of Konigsberg, Prussia. (Wikipedia, entry for Leonhard Euler.) • A route that allows you to drive every road between schools once is called an Eulerian path (if it has a different starting and ending points) or a Eulerian circuit (if it has the same start and end point). These are named after the 18th century German mathematician and physicist Leonhard Euler.
    [Show full text]
  • A Tutorial on Euler Angles and Quaternions
    A Tutorial on Euler Angles and Quaternions Moti Ben-Ari Department of Science Teaching Weizmann Institute of Science http://www.weizmann.ac.il/sci-tea/benari/ Version 2.0.1 c 2014–17 by Moti Ben-Ari. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/ by-sa/3.0/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA. Chapter 1 Introduction You sitting in an airplane at night, watching a movie displayed on the screen attached to the seat in front of you. The airplane gently banks to the left. You may feel the slight acceleration, but you won’t see any change in the position of the movie screen. Both you and the screen are in the same frame of reference, so unless you stand up or make another move, the position and orientation of the screen relative to your position and orientation won’t change. The same is not true with respect to your position and orientation relative to the frame of reference of the earth. The airplane is moving forward at a very high speed and the bank changes your orientation with respect to the earth. The transformation of coordinates (position and orientation) from one frame of reference is a fundamental operation in several areas: flight control of aircraft and rockets, move- ment of manipulators in robotics, and computer graphics. This tutorial introduces the mathematics of rotations using two formalisms: (1) Euler angles are the angles of rotation of a three-dimensional coordinate frame.
    [Show full text]
  • Classification of Left Octonion Modules
    Classification of left octonion modules Qinghai Huo, Yong Li, Guangbin Ren Abstract It is natural to study octonion Hilbert spaces as the recently swift development of the theory of quaternion Hilbert spaces. In order to do this, it is important to study first its algebraic structure, namely, octonion modules. In this article, we provide complete classification of left octonion modules. In contrast to the quaternionic setting, we encounter some new phenomena. That is, a submodule generated by one element m may be the whole module and may be not in the form Om. This motivates us to introduce some new notions such as associative elements, conjugate associative elements, cyclic elements. We can characterize octonion modules in terms of these notions. It turns out that octonions admit two distinct structures of octonion modules, and moreover, the direct sum of their several copies exhaust all octonion modules with finite dimensions. Keywords: Octonion module; associative element; cyclic element; Cℓ7-module. AMS Subject Classifications: 17A05 Contents 1 introduction 1 2 Preliminaries 3 2.1 The algebra of the octonions O .............................. 3 2.2 Universal Clifford algebra . ... 4 3 O-modules 6 4 The structure of left O-moudles 10 4.1 Finite dimensional O-modules............................... 10 4.2 Structure of general left O-modules............................ 13 4.3 Cyclic elements in left O-module ............................. 15 arXiv:1911.08282v2 [math.RA] 21 Nov 2019 1 introduction The theory of quaternion Hilbert spaces brings the classical theory of functional analysis into the non-commutative realm (see [10, 16, 17, 20, 21]). It arises some new notions such as spherical spectrum, which has potential applications in quantum mechanics (see [4, 6]).
    [Show full text]
  • Hypercomplex Numbers and Their Matrix Representations
    Hypercomplex numbers and their matrix representations A short guide for engineers and scientists Herbert E. M¨uller http://herbert-mueller.info/ Abstract Hypercomplex numbers are composite numbers that sometimes allow to simplify computations. In this article, the multiplication table, matrix represen- tation and useful formulas are compiled for eight hypercomplex number systems. 1 Contents 1 Introduction 3 2 Hypercomplex numbers 3 2.1 History and basic properties . 3 2.2 Matrix representations . 4 2.3 Scalar product . 5 2.4 Writing a matrix in a hypercomplex basis . 6 2.5 Interesting formulas . 6 2.6 Real Clifford algebras . 8 ∼ 2.7 Real numbers Cl0;0(R) = R ......................... 10 3 Hypercomplex numbers with 1 generator 10 ∼ 3.1 Bireal numbers Cl1;0(R) = R ⊕ R ...................... 10 ∼ 3.2 Complex numbers Cl0;1(R) = C ....................... 11 4 Hypercomplex numbers with 2 generators 12 ∼ ∼ 4.1 Cockle quaternions Cl2;0(R) = Cl1;1(R) = R(2) . 12 ∼ 4.2 Hamilton quaternions Cl0;2(R) = H ..................... 13 5 Hypercomplex numbers with 3 generators 15 ∼ ∼ 5.1 Hamilton biquaternions Cl3;0(R) = Cl1;2(R) = C(2) . 15 ∼ 5.2 Anonymous-3 Cl2;1(R) = R(2) ⊕ R(2) . 17 ∼ 5.3 Clifford biquaternions Cl0;3 = H ⊕ H .................... 19 6 Hypercomplex numbers with 4 generators 20 ∼ ∼ ∼ 6.1 Space-Time Algebra Cl4;0(R) = Cl1;3(R) = Cl0;4(R) = H(2) . 20 ∼ ∼ 6.2 Anonymous-4 Cl3;1(R) = Cl2;2(R) = R(4) . 21 References 24 A Octave and Matlab demonstration programs 25 A.1 Cockle Quaternions . 25 A.2 Hamilton Bi-Quaternions .
    [Show full text]
  • Leonhard Euler - Wikipedia, the Free Encyclopedia Page 1 of 14
    Leonhard Euler - Wikipedia, the free encyclopedia Page 1 of 14 Leonhard Euler From Wikipedia, the free encyclopedia Leonhard Euler ( German pronunciation: [l]; English Leonhard Euler approximation, "Oiler" [1] 15 April 1707 – 18 September 1783) was a pioneering Swiss mathematician and physicist. He made important discoveries in fields as diverse as infinitesimal calculus and graph theory. He also introduced much of the modern mathematical terminology and notation, particularly for mathematical analysis, such as the notion of a mathematical function.[2] He is also renowned for his work in mechanics, fluid dynamics, optics, and astronomy. Euler spent most of his adult life in St. Petersburg, Russia, and in Berlin, Prussia. He is considered to be the preeminent mathematician of the 18th century, and one of the greatest of all time. He is also one of the most prolific mathematicians ever; his collected works fill 60–80 quarto volumes. [3] A statement attributed to Pierre-Simon Laplace expresses Euler's influence on mathematics: "Read Euler, read Euler, he is our teacher in all things," which has also been translated as "Read Portrait by Emanuel Handmann 1756(?) Euler, read Euler, he is the master of us all." [4] Born 15 April 1707 Euler was featured on the sixth series of the Swiss 10- Basel, Switzerland franc banknote and on numerous Swiss, German, and Died Russian postage stamps. The asteroid 2002 Euler was 18 September 1783 (aged 76) named in his honor. He is also commemorated by the [OS: 7 September 1783] Lutheran Church on their Calendar of Saints on 24 St. Petersburg, Russia May – he was a devout Christian (and believer in Residence Prussia, Russia biblical inerrancy) who wrote apologetics and argued Switzerland [5] forcefully against the prominent atheists of his time.
    [Show full text]
  • Working with 3D Rotations
    Working With 3D Rotations Stan Melax Graphics Software Engineer, Intel Human Brain is wired for Spatial Computation Which shape is the same: a) b) c) “I don’t need to ask A childhood IQ test question for directions” Translations Rotations Agenda ● Rotations and Matrices (hopefully review) ● Combining Rotations ● Matrix and Axis Angle ● Challenges of deep Space (of Rotations) ● Quaternions ● Applications Terminology Clarification Preferred usages of various terms: Linear Angular Object Pose Position (point) Orientation A change in Pose Translation (vector) Rotation Rate of change Linear Velocity Spin also: Direction specifies 2 DOF, Orientation specifies all 3 angular DOF. Rotations Trickier than Translations Translations Rotations a then b == b then a x then y != y then x (non-commutative) ● Programming with rotations also more challenging! 2D Rotation θ Rotate [1 0] by θ about origin 1,1 [ cos(θ) sin(θ) ] θ θ sin cos θ 1,0 2D Rotation θ Rotate [0 1] by θ about origin -1,1 0,1 sin θ [-sin(θ) cos(θ)] θ θ cos 2D Rotation of an arbitrary point Rotate about origin by θ = cos θ + sin θ 2D Rotation of an arbitrary point 푥 Rotate 푦 about origin by θ 푥′, 푦′ 푥′ = 푥 cos θ − 푦 sin θ 푦′ = 푥 sin θ + 푦 cos θ 푦 푥 2D Rotation Matrix 푥 Rotate 푦 about origin by θ 푥′, 푦′ 푥′ = 푥 cos θ − 푦 sin θ 푦′ = 푥 sin θ + 푦 cos θ 푦 푥′ cos θ − sin θ 푥 푥 = 푦′ sin θ cos θ 푦 cos θ − sin θ Matrix is rotation by θ sin θ cos θ 2D Orientation 풚 Yellow grid placed over first grid but at angle of θ cos θ − sin θ sin θ cos θ 풙 Columns of the matrix are the directions of the axes.
    [Show full text]