Abstracts of Papers Presented in Washington, D.C. Abstracts of Papers Presented At

Total Page:16

File Type:pdf, Size:1020Kb

Abstracts of Papers Presented in Washington, D.C. Abstracts of Papers Presented At Abstracts of Papers Presented in Washington, D.C. Abstracts of Papers Presented at MathFest 2015 Washington, D.C. August 5–8, 2015 Published and Distributed by The Mathematical Association of America Contents Invited Addresses 1 EarleRaymondHedrickLectureSeries. ....................... 1 AlgebraOverFiniteFields . ................. 1 Hendrick Lecture 1 Wednesday,August5,9:30AM-10:20AM,Salon2/3 . ................ 1 Hendrick Lecture 2 Friday,August7,9:30AM-10:20AM,Salon2/3 . ............... 1 Hendrick Lecture 3 Saturday,August8,9:30AM-10:20AM,Salon2/3 . ................ 1 MAACentennialLectures . .................. 1 Lecture 1: Replicators, Transformers, and Robot Swarms: Science Fiction through Geometric Algorithms Wednesday,August5,8:20AM-9:20AM,Salon2/3 . ............... 1 Lecture 2: Network Science: From the Online World to Cancer Genomics Wednesday,August5,10:30AM-11:20AM,Salon2/3 . ................ 1 Lecture 3: Mathematics for Art Investigation Thursday,August6,8:30AM-9:20AM,Salon2/3 . ............... 1 Lecture 4: The Role and Function of Mathematical Models in Interdisciplinary Mentorship through Research: Lessons from the World of Epidemics Thursday,August5,10:30AM-11:20AM,Salon2/3 . ................ 1 Lecture 5: CSHPM Kenneth O. May Lecture “We Are Evidently on the Verge of Important Steps Forward”: The American Mathematical Community, 1915–1950 Friday,August7,10:30AM-11:20AM,Salon2/3 . ................ 1 Lecture 6: Recent Results Toward the Birch and Swinnerton-Dyer Conjecture Saturday,August8,10:30AM-11:20AM,Salon2/3 . ................ 1 AMS-MAA Joint Invited Address Thursday,August6,9:30AM-10:20AM,Salon2/3 . .................... 2 MAA James R. C. Leitzel Lecture Saturday,August8,8:30AM-9:20AM,Salon2/3 . .................... 2 AWM-MAA Etta Z. Falconer Lecture Friday,August7,8:30AM-9:20AM,Salon2/3 . ................... 2 MAA Chan Stanek Lecture for Students Wednesday,August5,1:00PM-1:50PM,Salon2/3 . .................... 2 Pi Mu Epsilon J. Sutherland Frame Lecture Friday,August7,8:00PM-8:50PM,Salon2/3 . .................... 2 NAM David Harold Blackwell Lecture Friday,August7,1:00PM-1:50PM,Salon2/3 . .................... 2 Alder Awards 3 Alder Awards Friday,August7,2:00PM-3:20PM,Salon2/3 . .................... 3 Invited Paper Sessions 4 MAA Invited Paper Session: Generations of Monthly Gems Wednesday,August5,1:00PM-3:50PM,Salon1 . ................... 4 iii iv Contents MAA Invited Paper Session: The Non-Traditional “Traditional NSA Mathematician” Wednesday,August5,1:00PM-3:45PM,DelawareB . .................... 4 MAA Invited Paper Session: Improving Access to Mathematical Modeling Research Thursday,August6,1:00PM-4:20PM,DelawareB . .................... 5 MAA Invited Paper Session: Algebraic Structures Motivated by Knot Theory Friday, August 7, 9:00 AM - 11:20 AM and 1:00 PM - 5:00 PM, DelawareA .................. 6 MAA Invited Paper Session: Concrete Computations in Algebra and Algebraic Geometry Friday,August7,1:00PM-3:20PM,DelawareB. .................... 7 AMS-MAA Invited Paper Session: The Arithmetic of the Spheres Thursday,August6,1:00PM-3:50PM,DelawareA . .................... 7 Special Invited Session: The Geometry of Triangles Saturday,August8,1:00PM-2:50PM,Salon1. .................... 8 Special Session: “Notes of a Native Son”: The Legacy of Dr. Abdulalim A. Shabazz (1927–2014) Saturday,August8,1:00PM-4:50PM,DelawareB . .................... 8 Themed Contributed Paper Sessions 9 TCPS 1A - History of Mathematics Wednesday, August5, 10:30AM-11:55AM, Washington4 . ..................... 9 TCPS 1B - History of Mathematics Wednesday, August5, 10:30AM-11:55AM, Washington5 . ..................... 9 TCPS 1C - History and Philosophy of Mathematics Wednesday,August5,1:00PM- 2:55PM,Washington4 . ..................... 9 TCPS 1D - History and Philosophy of Mathematics Wednesday,August5,1:30PM- 3:55PM,Washington5 . ..................... 10 TCPS 1E - The Mathematics of Euler Wednesday,August5,3:00PM- 5:55PM,Washington4 . ..................... 10 TCPS 1F - Special Session in Memory of Jackie Stedall Thursday,August6,8:30AM-11:25AM,Washington4 . ..................... 11 TCPS 1G - History and Philosophy of Mathematics Thursday,August6,1:00PM-2:25PM,Washington4 . ..................... 11 TCPS 1H - History and Philosophy of Mathematics Thursday,August6,1:00PM-2:25PM,Washington5 . ..................... 11 TCPS 1J - Special Session on Philosophy of Mathematics Thursday,August6,2:30PM-4:55PM,Washington4 . ..................... 12 TCPS 1K - Special Session on Mathematical Communities Friday,August7,8:00AM-10:25AM,Washington4 . .................... 12 TCPS 1M - Special Session in Honor of Karen Parshall Friday,August7,2:00PM-4:55PM,Washington4 . .................... 12 TCPS 1N - History and Philosophy of Mathematics Saturday,August8,8:30AM-11:55AM,Washington4 . ..................... 13 TCPS 1P - History and Philosophy of Mathematics Saturday,August8,8:30AM-11:55AM,Washington5 . ..................... 13 TCPS 1Q - Special Session in Memory of Ivor Grattan-Guinness Saturday,August8,1:00PM-3:25PM,Washington4 . ..................... 14 TCPS 1R - History of Mathematics Saturday,August8,3:30PM-5:25PM,Washington4 . ..................... 14 TCPS 2A - The Contributions of Women to Mathematics: 100 Years and Counting Friday,August7,1:00PM-3:55PM,Washington2 . .................... 14 TCPS 2B - The Contributions of Women to Mathematics: 100 Years and Counting Saturday,August8,1:00PM-3:15PM,Washington2 . ..................... 15 TCPS 3 - Math Circle Problems Involving the Number 100 in Honor of the MAA’s 100th Anniversary Friday,August7,8:30AM-11:05AM,Washington6 . .................... 16 TCPS 4 - Undergraduate Research Activities in Mathematical and Computational Biology Friday,August7,1:20PM-4:15PM,Washington5 . .................... 17 Contents v TCPS 5A - Recreational Mathematics: New Problems and New Solutions Friday,August7,1:00PM-4:55PM,Washington1 . .................... 18 TCPS 5B - Recreational Mathematics: New Problems and New Solutions Saturday,August8,1:00PM-3:15PM,Washington1 . ..................... 19 TCPS 6A - Mathematics and Art Wednesday,August5,1:00PM-4:55PM,MarylandA . .................... 19 TCPS 6B - Mathematics and Art Thursday,August6,8:50AM-11:25AM,MarylandA . .................... 20 TCPS 7 - Financial Mathematics Wednesday,August5,1:00PM- 2:35PM,Washington6 . ..................... 21 TCPS 8 - Mathematics in Video Games Saturday,August8,3:00PM-4:55PM,Washington3 . ..................... 21 TCPS 9 - What Can a Mathematician Do with a 3D Printer? Saturday,August8,1:00PM-4:55PM,VirginiaB . ..................... 22 TCPS 10 - The Scholarship of Teaching and Learning in Collegiate Mathematics Wednesday,August5,1:00PM- 5:35PM,Washington2 . ..................... 23 TCPS 11A - Cultivating Critical Thinking through Active Learning in Mathematics Thursday,August6,8:30AM-11:25AM,Washington1 . ..................... 24 TCPS 11B - Cultivating Critical Thinking through Active Learning in Mathematics Thursday,August6,1:00PM-5:15PM,Washington1 . ..................... 25 TCPS 12 - Improving Undergraduate Math Writing Wednesday,August5,1:00PM-5:15PM,VirginiaA . ..................... 26 TCPS 13 - Successful STEM Programs for Elementary Education Majors Thursday,August6,1:00PM-3:15PM,Washington2 . ..................... 27 TCPS 14 - Projects, Applications and Demonstrations to Enhance a Numerical Analysis or Computational Mathe- matics Course Saturday,August8,1:00PM-2:35PM,Washington3 . ..................... 28 TCPS 15 - Democratizing Access to Authentic Mathematical Activity Friday,August7,1:20PM-3:35PM,MarylandA . ................... 29 TCPS 16 - Curriculum Development to Support First Year General Education Mathematics Students Wednesday,August5,1:00PM- 3:35PM,Washington3 . ..................... 29 TCPS 17 - Curriculum and Course Development to Support First Year STEM Students Friday,August7,1:00PM-2:55PM,Washington3 . .................... 30 TCPS 18 - Using Modeling for Teaching Differential Equations: Before, During, After Saturday,August8,1:00PM-4:35PM,VirginiaA . ..................... 31 TCPS 19A - Innovative Approaches in the Calculus Sequence Friday,August7,1:00PM-3:35PM,Washington6 . .................... 32 TCPS 19B - Innovative Approaches in the Calculus Sequence Saturday,August8,1:00PM-3:35PM,Washington6 . ..................... 33 TCPS 20 - Evidence-Based Approaches to the Mathematical Preparation of Secondary Teachers Wednesday,August5,1:00PM- 1:55PM,Washington1 . ..................... 34 TCPS 21 - Show Me Geometry: Geometry Software and Tablet Demonstrations Wednesday,August5,1:00PM-2:55PM,VirginiaC . ..................... 34 General Contributed Paper Sessions 36 Algebra and Linear Algebra Wednesday,August5,1:00PM-3:40PM,VirginiaB . ..................... 36 Analysis and Other Friday,August7,8:30AM- 11:10AM,Salon1,BalconyB . ..................... 36 Applied Mathematics Thursday,August6,1:00PM-4:55PM,Washington3 . ..................... 37 Geometry Thursday, August6,1:00PM-4:40PM, Salon1, BalconyB . ...................... 39 Graph Theory Thursday,August6,8:30AM-11:25AM,Washington3 . ..................... 40 vi Contents History or Philosophy of Mathematics Thursday, August6,9:15 AM - 11:25AM, Salon 1,Balcony A . ...................... 40 Interdisciplinary Topics in Mathematics and Modeling or Applications Friday,August7,1:00PM-4:25PM,MarylandB . ................... 41 Mathematics and Technology Saturday,August 8,8:45AM - 11:25AM,Salon 1, Balcony A . ...................... 42 Mentoring and Outreach Thursday,August6,8:15AM-11:10AM,MarylandB .
Recommended publications
  • Fractions of Numerical Semigroups
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2010 Fractions of Numerical Semigroups Harold Justin Smith University of Tennessee - Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Algebra Commons, and the Number Theory Commons Recommended Citation Smith, Harold Justin, "Fractions of Numerical Semigroups. " PhD diss., University of Tennessee, 2010. https://trace.tennessee.edu/utk_graddiss/750 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Harold Justin Smith entitled "Fractions of Numerical Semigroups." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Mathematics. David E. Dobbs, Major Professor We have read this dissertation and recommend its acceptance: David F. Anderson, Pavlos Tzermias, Michael W. Berry Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a dissertation written by Harold Justin Smith entitled \Fractions of Numerical Semigroups." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the require- ments for the degree of Doctor of Philosophy, with a major in Mathematics.
    [Show full text]
  • “Gödel's Modernism: on Set-Theoretic Incompleteness,” Revisited
    “G¨odel'sModernism: on Set-Theoretic Incompleteness," revisited∗ Mark van Atten and Juliette Kennedy As to problems with the answer Yes or No, the con- viction that they are always decidable remains un- touched by these results. —G¨odel Contents 1 Introduction 1.1 Questions of incompleteness On Friday, November 15, 1940, Kurt G¨odelgave a talk on set theory at Brown University.1 The topic was his recent proof of the consistency of Cantor's Con- tinuum Hypothesis, henceforth CH,2 with the axiomatic system for set theory ZFC.3 His friend from their days in Vienna, Rudolf Carnap, was in the audience, and afterward wrote a note to himself in which he raised a number of questions on incompleteness:4 (Remarks I planned to make, but did not) Discussion on G¨odel'slecture on the Continuum Hypothesis, November 14,5 1940 There seems to be a difference: between the undecidable propo- sitions of the kind of his example [i.e., 1931] and propositions such as the Axiom of Choice, and the Axiom of the Continuum [CH ]. We used to ask: \When these two have been decided, is then everything decided?" (The Poles, Tarski I think, suspected that this would be the case.) Now we know that (on the basis of the usual finitary rules) there will always remain undecided propositions. ∗An earlier version of this paper appeared as ‘G¨odel'smodernism: on set-theoretic incom- pleteness', Graduate Faculty Philosophy Journal, 25(2), 2004, pp.289{349. Erratum facing page of contents in 26(1), 2005. 1 1. Can we nevertheless still ask an analogous question? I.e.
    [Show full text]
  • Lecture 9: Newton Method 9.1 Motivation 9.2 History
    10-725: Convex Optimization Fall 2013 Lecture 9: Newton Method Lecturer: Barnabas Poczos/Ryan Tibshirani Scribes: Wen-Sheng Chu, Shu-Hao Yu Note: LaTeX template courtesy of UC Berkeley EECS dept. 9.1 Motivation Newton method is originally developed for finding a root of a function. It is also known as Newton- Raphson method. The problem can be formulated as, given a function f : R ! R, finding the point x? such that f(x?) = 0. Figure 9.1 illustrates another motivation of Newton method. Given a function f, we want to approximate it at point x with a quadratic function fb(x). We move our the next step determined by the optimum of fb. Figure 9.1: Motivation for quadratic approximation of a function. 9.2 History Babylonian people first applied the Newton method to find the square root of a positive number S 2 R+. The problem can be posed as solving the equation f(x) = x2 − S = 0. They realized the solution can be achieved by applying the iterative update rule: 2 1 S f(xk) xk − S xn+1 = (xk + ) = xk − 0 = xk − : (9.1) 2 xk f (xk) 2xk This update rule converges to the square root of S, which turns out to be a special case of Newton method. This could be the first application of Newton method. The starting point affects the convergence of the Babylonian's method for finding the square root. Figure 9.2 shows an example of solving the square root for S = 100. x- and y-axes represent the number of iterations and the variable, respectively.
    [Show full text]
  • Page 1 of 1 Geometry, Student Text and Homework Helper 11/7/2016
    Geometry, Student Text and Homework Helper Page 1 of 1 Skip Directly to Table of Contents | Skip Directly to Main Content Change text size Show/Hide TOC Page Unit 1 Logical Arguments and Constructions; Proof and Congruence > Topic 3 Parallel and Perpendicular Lines > 3-5 Parallel Lines and Triangles 3-5 Parallel Lines and Triangles Teks Focus TEKS (6)(D) Verify theorems about the relationships in triangles, including proof of the Pythagorean Theorem, the sum of interior angles, base angles of isosceles triangles, midsegments, and medians, and apply these relationships to solve problems. TEKS (1)(F) Analyze mathematical relationships to connect and communicate mathematical ideas. Additional TEKS (1)(G) Vocabulary • Auxiliary line – a line that you add to a diagram to help explain relationships in proofs • Exterior angle of a polygon – an angle formed by a side and an extension of an adjacent side • Remote interior angles – the two nonadjacent interior angles corresponding to each exterior angle of a triangle • Analyze – closely examine objects, ideas, or relationships to learn more about their nature ESSENTIAL UNDERSTANDING The sum of the angle measures of a triangle is always the same. take note Postulate 3-2 Parallel Postulate Through a point not on a line, there is one and only one line parallel to the given line. There is exactly one line through P parallel to ℓ. take note Theorem 3-11 Triangle Angle-Sum Theorem The sum of the measures of the angles of a triangle is 180. m∠A + m∠B + m∠C = 180 For a proof of Theorem 3-11, see Problem 1.
    [Show full text]
  • Tempered Monoids of Real Numbers, the Golden Fractal Monoid, and the Well-Tempered Harmonic Semigroup
    Tempered Monoids of Real Numbers, the Golden Fractal Monoid, and the Well-Tempered Harmonic Semigroup Published in Semigroup Forum, Springer, vol. 99, n. 2, pp. 496-516, November 2019. ISSN: 0037-1912. Maria Bras-Amoros´ November 5, 2019 Abstract This paper deals with the algebraic structure of the sequence of harmonics when combined with equal temperaments. Fractals and the golden ratio appear surprisingly on the way. + The sequence of physical harmonics is an increasingly enumerable submonoid of (R ; +) whose pairs of consecutive terms get arbitrarily close as they grow. These properties suggest the definition of a new mathematical object which we denote a tempered monoid. Mapping the elements of the tempered monoid of physical harmonics from R to N may be considered tantamount to defining equal temperaments. The number of equal parts of the octave in an equal temperament corresponds to the multiplicity of the related numerical semigroup. Analyzing the sequence of musical harmonics we derive two important properties that tempered monoids may have: that of being product-compatible and that of being fractal. We demonstrate that, up to normal- ization, there is only one product-compatible tempered monoid, which is the logarithmic monoid, and there is only one nonbisectional fractal monoid which is generated by the golden ratio. The example of half-closed cylindrical pipes imposes a third property to the sequence of musical har- monics, the so-called odd-filterability property. We prove that the maximum number of equal divisions of the octave such that the discretizations of the golden fractal monoid and the logarithmic monoid coincide, and such that the discretization is odd- filterable is 12.
    [Show full text]
  • Program of the Sessions San Diego, California, January 9–12, 2013
    Program of the Sessions San Diego, California, January 9–12, 2013 AMS Short Course on Random Matrices, Part Monday, January 7 I MAA Short Course on Conceptual Climate Models, Part I 9:00 AM –3:45PM Room 4, Upper Level, San Diego Convention Center 8:30 AM –5:30PM Room 5B, Upper Level, San Diego Convention Center Organizer: Van Vu,YaleUniversity Organizers: Esther Widiasih,University of Arizona 8:00AM Registration outside Room 5A, SDCC Mary Lou Zeeman,Bowdoin upper level. College 9:00AM Random Matrices: The Universality James Walsh, Oberlin (5) phenomenon for Wigner ensemble. College Preliminary report. 7:30AM Registration outside Room 5A, SDCC Terence Tao, University of California Los upper level. Angles 8:30AM Zero-dimensional energy balance models. 10:45AM Universality of random matrices and (1) Hans Kaper, Georgetown University (6) Dyson Brownian Motion. Preliminary 10:30AM Hands-on Session: Dynamics of energy report. (2) balance models, I. Laszlo Erdos, LMU, Munich Anna Barry*, Institute for Math and Its Applications, and Samantha 2:30PM Free probability and Random matrices. Oestreicher*, University of Minnesota (7) Preliminary report. Alice Guionnet, Massachusetts Institute 2:00PM One-dimensional energy balance models. of Technology (3) Hans Kaper, Georgetown University 4:00PM Hands-on Session: Dynamics of energy NSF-EHR Grant Proposal Writing Workshop (4) balance models, II. Anna Barry*, Institute for Math and Its Applications, and Samantha 3:00 PM –6:00PM Marina Ballroom Oestreicher*, University of Minnesota F, 3rd Floor, Marriott The time limit for each AMS contributed paper in the sessions meeting will be found in Volume 34, Issue 1 of Abstracts is ten minutes.
    [Show full text]
  • The Newton Fractal's Leonardo Sequence Study with the Google
    INTERNATIONAL ELECTRONIC JOURNAL OF MATHEMATICS EDUCATION e-ISSN: 1306-3030. 2020, Vol. 15, No. 2, em0575 OPEN ACCESS https://doi.org/10.29333/iejme/6440 The Newton Fractal’s Leonardo Sequence Study with the Google Colab Francisco Regis Vieira Alves 1*, Renata Passos Machado Vieira 1 1 Federal Institute of Science and Technology of Ceara - IFCE, BRAZIL * CORRESPONDENCE: [email protected] ABSTRACT The work deals with the study of the roots of the characteristic polynomial derived from the Leonardo sequence, using the Newton fractal to perform a root search. Thus, Google Colab is used as a computational tool to facilitate this process. Initially, we conducted a study of the Leonardo sequence, addressing it fundamental recurrence, characteristic polynomial, and its relationship to the Fibonacci sequence. Following this study, the concept of fractal and Newton’s method is approached, so that it can then use the computational tool as a way of visualizing this technique. Finally, a code is developed in the Phyton programming language to generate Newton’s fractal, ending the research with the discussion and visual analysis of this figure. The study of this subject has been developed in the context of teacher education in Brazil. Keywords: Newton’s fractal, Google Colab, Leonardo sequence, visualization INTRODUCTION Interest in the study of homogeneous, linear and recurrent sequences is becoming more and more widespread in the scientific literature. Therefore, the Fibonacci sequence is the best known and studied in works found in the literature, such as Oliveira and Alves (2019), Alves and Catarino (2019). In these works, we can see an investigation and exploration of the Fibonacci sequence and the complexification of its mathematical model and the generalizations that result from it.
    [Show full text]
  • Lecture 1: What Is Calculus?
    Math1A:introductiontofunctionsandcalculus OliverKnill, 2012 Lecture 1: What is Calculus? Calculus formalizes the process of taking differences and taking sums. Differences measure change, sums explore how things accumulate. The process of taking differences has a limit called derivative. The process of taking sums will lead to the integral. These two pro- cesses are related in an intimate way. In this first lecture, we look at these two processes in the simplest possible setup, where functions are evaluated only on integers and where we do not take any limits. About 25’000 years ago, numbers were represented by units like 1, 1, 1, 1, 1, 1,... for example carved in the fibula bone of a baboon1. It took thousands of years until numbers were represented with symbols like today 0, 1, 2, 3, 4,.... Using the modern concept of function, we can say f(0) = 0, f(1) = 1, f(2) = 2, f(3) = 3 and mean that the function f assigns to an input like 1001 an output like f(1001) = 1001. Lets call Df(n) = f(n + 1) − f(n) the difference between two function values. We see that the function f satisfies Df(n) = 1 for all n. We can also formalize the summation process. If g(n) = 1 is the function which is constant 1, then Sg(n) = g(0) + g(1) + ... + g(n − 1) = 1 + 1 + ... + 1 = n. We see that Df = g and Sg = f. Now lets start with f(n) = n and apply summation on that function: Sf(n) = f(0) + f(1) + f(2) + ..
    [Show full text]
  • Georg Kreisel Papers SC0136
    http://oac.cdlib.org/findaid/ark:/13030/kt4k403759 No online items Guide to the Georg Kreisel Papers SC0136 Daniel Hartwig & Jenny Johnson Department of Special Collections and University Archives October 2010 Green Library 557 Escondido Mall Stanford 94305-6064 [email protected] URL: http://library.stanford.edu/spc Note This encoded finding aid is compliant with Stanford EAD Best Practice Guidelines, Version 1.0.This encoded finding aid is compliant with Stanford EAD Best Practice Guidelines, Version 1.0. Guide to the Georg Kreisel Papers SC0136 1 SC0136 Language of Material: English Contributing Institution: Department of Special Collections and University Archives Title: Georg Kreisel papers creator: Kreisel, Georg Identifier/Call Number: SC0136 Physical Description: 24.75 Linear Feet Date (inclusive): 1957-1984 Language of Material: English Language of Material: English Abstract: Correspondence with professional colleagues, collaborators, students, and others, primarily from 1962 to 1984, lecture notes, manuscripts and other writings. Ownership & Copyright All requests to reproduce, publish, quote from, or otherwise use collection materials must be submitted in writing to the Head of Special Collections and University Archives, Stanford University Libraries, Stanford, California 94304-6064. Consent is given on behalf of Special Collections as the owner of the physical items and is not intended to include or imply permission from the copyright owner. Such permission must be obtained from the copyright owner, heir(s) or assigns. See: http://library.stanford.edu/depts/spc/pubserv/permissions.html. Restrictions also apply to digital representations of the original materials. Use of digital files is restricted to research and educational purposes. Biographical/Historical Sketch Professor of Logic and the Foundations of Mathematics at Stanford University.
    [Show full text]
  • Neutral Geometry
    Neutral geometry And then we add Euclid’s parallel postulate Saccheri’s dilemma Options are: Summit angles are right Wants Summit angles are obtuse Was able to rule out, and we’ll see how Summit angles are acute The hypothesis of the acute angle is absolutely false, because it is repugnant to the nature of the straight line! Rule out obtuse angles: If we knew that a quadrilateral can’t have the sum of interior angles bigger than 360, we’d be fine. We’d know that if we knew that a triangle can’t have the sum of interior angles bigger than 180. Hold on! Isn’t the sum of the interior angles of a triangle EXACTLY180? Theorem: Angle sum of any triangle is less than or equal to 180º Suppose there is a triangle with angle sum greater than 180º, say anglfle sum of ABC i s 180º + p, w here p> 0. Goal: Construct a triangle that has the same angle sum, but one of its angles is smaller than p. Why is that enough? We would have that the remaining two angles add up to more than 180º: can that happen? Show that any two angles in a triangle add up to less than 180º. What do we know if we don’t have Para lle l Pos tul at e??? Alternate Interior Angle Theorem: If two lines cut by a transversal have a pair of congruent alternate interior angles, then the two lines are parallel. Converse of AIA Converse of AIA theorem: If two lines are parallel then the aliilblternate interior angles cut by a transversa l are congruent.
    [Show full text]
  • Geometry ­ Ch 5 ­ Exterior Angles & Triangle Inequality December 01, 2014
    Geometry ­ Ch 5 ­ Exterior Angles & Triangle Inequality December 01, 2014 The “Three Possibilities” Property: either a>b, a=b, or a<b The Transitive Property: If a>b and b>c, then a>c The Addition Property: If a>b, then a+c>b+c The Subtraction Property: If a>b, then a‐c>b‐c The Multiplication Property: If a>b and c>0, then ac>bc The Division Property: If a>b and c>0, then a/c>b/c The Addition Theorem of Inequality: If a>b and c>d, then a+c>b+d The “Whole Greater than Part” Theorem: If a>0, b>0, and a+b=c, then c>a and c>b Def: An exterior angle of a triangle is an angle that forms a linear pair with an angle of the triangle. A In ∆ABC, exterior ∠2 forms a linear pair with ∠ACB. The other two angles of the triangle, ∠1 (∠B) and ∠A are called remote interior angles with respect to ∠2. 1 2 B C Theorem 12: The Exterior Angle Theorem An Exterior angle of a triangle is greater than either remote interior angle. Find each of the following sums. 3 4 26. ∠1+∠2+∠3+∠4 2 1 6 7 5 8 27. ∠1+∠2+∠3+∠4+∠5+∠6+∠7+ 9 12 ∠8+∠9+∠10+∠11+∠12 11 10 28. ∠1+∠5+∠9 31. What does the result in exercise 30 indicate about the sum of the exterior 29. ∠3+∠7+∠11 angles of a triangle? 30. ∠2+∠4+∠6+∠8+∠10+∠12 1 Geometry ­ Ch 5 ­ Exterior Angles & Triangle Inequality December 01, 2014 After proving the Exterior Angle Theorem, Euclid proved that, in any triangle, the sum of any two angles is less than 180°.
    [Show full text]
  • Kreisel and Wittgenstein
    Kreisel and Wittgenstein Akihiro Kanamori September 17, 2018 Georg Kreisel (15 September 1923 { 1 March 2015) was a formidable math- ematical logician during a formative period when the subject was becoming a sophisticated field at the crossing of mathematics and logic. Both with his technical sophistication for his time and his dialectical engagement with man- dates, aspirations and goals, he inspired wide-ranging investigation in the meta- mathematics of constructivity, proof theory and generalized recursion theory. Kreisel's mathematics and interactions with colleagues and students have been memorably described in Kreiseliana ([Odifreddi, 1996]). At a different level of interpersonal conceptual interaction, Kreisel during his life time had extended engagement with two celebrated logicians, the mathematical Kurt G¨odeland the philosophical Ludwig Wittgenstein. About G¨odel,with modern mathemat- ical logic palpably emanating from his work, Kreisel has reflected and written over a wide mathematical landscape. About Wittgenstein on the other hand, with an early personal connection established Kreisel would return as if with an anxiety of influence to their ways of thinking about logic and mathematics, ever in a sort of dialectic interplay. In what follows we draw this out through his published essays|and one letter|both to elicit aspects of influence in his own terms and to set out a picture of Kreisel's evolving thinking about logic and mathematics in comparative relief.1 As a conceit, we divide Kreisel's engagements with Wittgenstein into the \early", \middle", and \later" Kreisel, and account for each in successive sec- tions. x1 has the \early" Kreisel directly interacting with Wittgenstein in the 1940s and initial work on constructive content of proofs.
    [Show full text]