### 1976-77

- Dec Duke ”Almost every curve bounds a unique area-minimizing surface”
- Jan/Feb? Amherst ”Almost every curve bounds a unique area-minimizing surface”
- Feb Park City ”Almost every curve bounds a unique area-minimizing surface”
- Spring Rutgers ”Almost every curve bounds a unique area-minimizing surface”
- May Princeton ”Almost every curve bounds a unique area-minimizing surface”
- Summer Trento ”Almost every curve bounds a unique area-minimizing surface”

### 1977-78

- Purdue ”Almost every curve bounds a unique area-minimizing surface”
- MIT ”Almost every curve bounds a unique area-minimizing surface”
- Wellesley ”Almost every curve bounds a unique area-minimizing surface”
- Talbot House ”Geometric measure theory”
- Berkeley ”Almost every curve bounds a unique area-minimizing surface”
- Stanford ”Almost every curve bounds a unique area-minimizing surface”

### 1978-79

- Oct Princeton ”Measures on spaces of surfaces”
- Jan Indiana ”Measures on spaces of surfaces”
- Feb 15 Chicago ”Measures on spaces of surfaces”
- Feb 19 Williams ”Surfaces of least area”
- Apr 9 MIT Topology Seminar “Topology and surfaces of least area”

### 1979-80

- Oct Princeton ”On the singular structure of 2-dimensional area-minimizing surfaces in
**R**“^{n} - Nov/Dec MIT ”GMT solution to Plateau’s problem”
- Jan San Antonio ”On the singular structure of 2-dimensional area-minimizing surfaces in
**R**“^{n} - Jan 25 MIT (IAP) “Plateau’s problem or Why do soap films exists, anyway?”
- Mar 18 MIT Downstairs Colloquium “Simple singularities in area-minimizing surfaces”
- Apr 7 MIT Minimal Surfaces Seminar “Examples of curves bounding infinitely many minimal surfaces”
- Apr 11 Indiana ”Nonuniqueness for minimal surfaces”
- Apr 22 U Mass ”Simple singularities in area-minimizing surfaces”
- July Oberwolfach ”Uniqueness and nonuniqueness”

### 1980-81

- Feb MIT ”Purpose and thrust of geometric measure theory”
- Mar U Mass ”Purpose and thrust of geometric measure theory” and “Rapid introduction to GMT”
- Apr Princeton “Singularities in 3-dimensional area-minimizing surfaces”

### 1981-82

- Jan NY Academy Sci “Soap films and the calculus of variations”
- Mar Wellesley “Soap films and the calculus of variations”

### 1982-83

- Sept 2 Rice U ”Unoriented area-minimizing surfaces”
- Sept 23 Tulane U ”Unoriented area-minimizing surfaces”
- Oct 31 College Park (AMS) ”Unoriented area-minimizing surfaces”
- Apr 3 Texas A&M ”Interesting faces of the Grassmannian of oriented 4-planes in
**R**^{8}“

### 1983-84

- Oct 3 OSU ”Faces of the Grassmannian and area minimization”
- Oct 4 U Oklahoma ”Faces of the Grassmannian and area minimization”
- Nov 9 MIT, BBC ”Faces of the Grassmannian and area minimization”
- Nov 11 Rutgers “Faces of the Grassmannian and area minimization”
- Nov 15 MIT ”Faces of the Grassmannian and area minimization”
- Feb 24 U Mass ”Faces of the Grassmannian and area minimization”
- Mar 1 Haverford ”Can Plateau’s problem have infinitely many solutions?”
- Mar 9 Brown ”Faces of the Grassmannian and area minimization”
- Mar 13 MIT ”Can Plateau’s problem have infinitely many solutions?”
- Apr 18 Princeton ”Faces of the Grassmannian and area minimization”
- Apr 25 MIT ”Boundary regularity for minimal currents and varifolds”
- June 5 Montshire Museum ”Soap bubbles and soap films”
- June 12 Technische U, Berlin ”Faces of the Grassmannian and area minimization”

### 1984-85

- Sept 11 MIT ”Open problems”
- Oct 11 OSU ”Geometric measure theory”
- Oct 17 MIT, BBC ”Surfaces mod nu”
- Oct 19 MIT (Concourse) ”Soap bubble geometry”
- Oct 22 MIT ”Soap bubble geometry”
- Oct 23 MIT ”Surfaces mod nu”
- Feb 12 MIT ”Calibrations mod nu”
- Mar 2 Talcott Mountain ”Soap bubble geometry”
- Mar 9 Newport Art Museum “Soap bubble geometry”
- Mar 18 MIT (undergraduate colloquium) ”Current student research in geometry”
- Mar 31 St Louis MIT Alum Club ”Mathematics and MIT”
- Apr 13 MIT minority spring weekend
- Apr 15 Duke”Calibrations mod nu”
- May 28 AAAS, LA ”Nonuniqueness and nonfiniteness for the number of solutions”

### 1985-86

- Sept 16 MIT ”Calibrations on Grassmannians”
- Feb Swarthmore ”Some undergraduate research in geometry”
- Mar 27-28 Santa Barbara ”A beginner’s guide to geometric measure theory” and “Area-minimizing surfaces in Grassmannians”
- Apr 10 Oberlin “Infinities of soap films”
- Apr 24 Oberwolfach “Area-minimizing surfaces in Grassmannians”

### 1986-87

- Oct Stanford “Calibrations and area-minimizing surfaces”
- Oct I CM, Berkeley “Area-minimizing surfaces in Grassmannians”
- Jan 23 San Antonio “Area-minimizing surfaces in Grassmannians”
- Feb 11 Williams “Can there be infinitely many minimal surfaces with the same boundary?”
- Mar 28 U Hawaii “Calibrations and area-minimizing surfaces”
- Apr 14 Bryn Mawr “Soap bubbles and mathematics”
- Apr 15 Amherst “Can there by infinitely many soap films with the same boundary?”
- Apr 20 Talcott Mountain “Soap bubbles and mathematics”
- July 30-31 Boston Workshop”Probability in a calculus course,” “Applications of systems of ODEs,” and “Research: soap bubble clusters”

### 1987-88

- Sept 16 Williams “Soap bubbles and mathematics”
- Sept 23 U Mass “Calibrations and area-minimizing surfaces”
- Oct 1 Mt Greylock HS “Soap bubbles and mathematics”
- Oct 20 Williams (Science lunch) “Singularities, crystals, and 6-dimensional space”
- Jan 12 Pittsfield Taconic HS “Soap bubbles and geometry”
- Jan 14 Williams “A new singularity in energy-minimizing surfaces”
- Jan 15 Valley Geometry Seminar “Calibrations and new singularities in minimal submanifolds”
- Jan 26 RPI “A new singularity in energy-minimizing hypersurfaces”
- Apr 23 Rochester (Williams alums) “The mathematics of soap bubbles”
- May 20 MSRI Harmonic Maps and Minimal Surfaces Workshop “A Phi-minimizing hypercone in R6″
- May 27 Lehigh U “Size-minimizing surfaces”
- June 7 Paris, Orsay “Singularities in submnaifolds minimizing for general elliptic integrands”
- June 16 CNRS, ENS “Calibrations and new singularities in minimizing submanifolds”

### 1988-89

- Sept 20 Williamstown Elementary School “Soap bubbles and mathematics”
- Oct 22 Williams (family weekend) “Soap bubble geometry contest”
- Nov 30 Boston U “Soap films, pivalic acid, and new singularities in energy-minimizing surfaces”
- Dec 15 MIT “Applications of geometry: fluid flow, phase transitions, and coarsening”
- Jan 6 Princeton “Geometric energy minimization”
- Jan 21 Fairfield Alum Club “Soap bubble geometry contest”
- Mar 3 Howard U “Soap bubble geometry contest” and “Teaching mathematics”
- Mar 28 Providence Williams Alum Club “Soap bubble geometry contest”
- Mar 29 Lehigh U “Geometric energy minimization”
- Apr 18Coast Guard “Soap bubble geometry contest”
- May 5 Williams “Questions on maxima of functions”
- May 16 Greenwich County Day School “Soap bubble geometry contest”
- May 26 Lehigh U “Phase equilibria in alloys”
- June 2 Keene State (MAA) “Soap bubbles and teaching mathematics”
- June 15-19 Boston Workshop “Calculus and materials science,” Discussion on curriculum, “General relativity,” “Differential equatons and rotating bodies,” “Funding of mathematics,” “Undergraduate research” with Ken Hodges, and “Soap bubble geometry contest”

### 1989-90

- Oct 19 Math West “Soap bubbles and teaching math”
- Oct 30 Naval Academy “Soap bubble geometry contest”
- Dec 15 Old Greenwich School “Soap bubble geometry contest”
- Jan 24 Williston Academy “Soap bubble geometry contest”
- Feb 1 Williams Faculty Lecture “Mathematics and soap films: a 100-year search for the right questions and answers”
- Feb 19 AAAS, New Orleans “Soap bubbles and mathematics”
- Mar 27 Princeton “Minimizing surfaces: a personal survey”
- Mar 28 Rutgers “Minimizing surfaces: a personal survey”
- Mar 29 Swarthmore “Crystals, energies, and efficient networks”
- Apr 7 George Washington U “Soap bubble geometry contest”
- Apr 20 Rhodes “Soap films, efficient networks, and undergraduate research” and “Crystals, pivalic acid, and minimal surfaces”
- June 19 TU Berlin “Area-minimizing surfaces, immiscible fluids, and Grassmannians”

### 1990-91

- Oct 8 IAS “Area-minimizing cycles in Grassmannians”
- Oct 20 Williams NY “Soap bubble geometry contest”
- Nov 7 Rutgers Newark “Soap bubbles and open questions”
- Nov 9 Washington and Lee “Shortest networks, minimal surfaces, and undergraduate research”
- Nov 13 Courant (Discrete Geometry Seminar) “Minimal networks and surfaces”
- Nov 15 Bell “Shortest networks, minimal surfaces, and norms on
**R**.”^{n} - Nov 26 Penn “Soap bubble geometry contest”
- Jan 8 IAS “Soap bubble clusters, minimal surfaces, and norms on
**R**.”^{n} - Math Meetings, San Francisco:
- Jan 18 Session on Computing Optimal Geometries”Soap films and immiscible fluids”
- Jan 19 Invited AMS/MAA address”Compound soap bubbles, shortest networks, and minimal surfaces”
- Jan 20 Workshop on Teaching Calculus”Teaching and undergraduate research”
- Jan 30 Stevens Institute of Technology”Minimal surfaces, crystals, and norms on
**R**.”^{n} - Mar 7 NY Academy of Sciences”Soap films, equidistant points, and undergraduate research”
- Mar 15 SUNY Old Westbury”Soap bubble geometry contest”
- Mar 29 Rutgers “Soap bubbles and undergraduate research”
- Apr 4 Penn (PME) “Soap bubble geometry contest”
- Apr 20 NJ MAA “Soap bubble clusters, norms on
**R**, and undergraduate research”^{n} - Apr 29 RPI Allen Lecture “Soap films and mathematics: a 100-year search for the right questions and answers”
- May 7 Geoometry Center (UMTYMP) “Soap bubble clusters and student research”
- May 8 Minnesota “Minimal surfaces, crystals, and norms on
**R**.”^{n} - May 24 Lehigh “Poincaré’s geodesics, soap bubbles, and constant-curvature curves”
- June 8 Lake Forest “Is calculus part of math?”
- June 11 ACM, North Conway “Minimal surfaces, crystals, and norms on
**R**“^{n} - June 20-23 Boston Workshop for Math Faculty “Is calculus part of math?” “Calculus, planets, and general relativity,” and “Soap bubble geometry contest”
- July 1-6 Mt Holyoke RGI “Soap bubbles,” “Crystals and shortest networks,” “Geometric measure theory for beginners,” and “Calibrations and area-minimizing surfaces in manifolds”

### 1991-92

Morgan gave a number of talks, including a lecture series at the Mt. Holyoke Regional Geometry Institute, ”Calibrations for the 90′s” at the Minimal Surfaces Workshop in Granada, Spain, and “The Soap Bubble Geometry Contest,” at Palmer High School.

- Sept 6 Granada “Calibrations for the 90′s: a survey”
- Oct 13 AMS Variational Problems “Poincaré’s geodesics, soap bubbles, and constant-curvature curves”
- Nov 8 U Mass (Gang Seminar) “Surfaces minimizing area plus length of singular curves”
- Dec 5 OSU “Surfaces minimizing area plus length of singular curves”
- Dec 6 OSU (PME) “Soap bubble geometry contest”
- Feb 14 UNH “Soap films, metals, and undergraduate research”
- Feb 25 Williams (Science lunch) “Are soap bubbles and metalic structures the right shape?”
- Mar 13 Palmer HS “Soap bubble geometry contest”
- Apr 11 Lehigh U (AMS) “Surfaces minimizing area plus length of singular curves”
- May 1 Oberlin C “Soap films, metals, and undergraduate research”
- June 5 MAA “Soap films, metals, and undergraduate research”
- June 11 Münster “Surfaces minimizing area plus length of singular curves”

### 1992-93

Morgan gave a number of talks, including “Surfaces minimizing area plus the length of singular curves” at an international conference in Münster, two invited addresses at the MAA meeting in Tacoma, and “The soap bubble geometry contest” for an audience of 300 middle school girls in his hometown of Allentown, Pennsylvania, where he was introduced by his own junior-high and high-school mathematics teachers.

- Sept 18 CUR/NECUSE, Mt Holyoke “Soap bubbles: current research”
- Oct 21 Boston U “Surfaces minimizing area plus length of singular curves”
- Oct 30 BYU “Soap bubbles and area/length minimization” and “Soap bubble geometry contest”
- Jan 29 SUNY Albany “Soap bubble clusters: new results and open questions”
- Feb 18 CMU (Center Nonlinear Analysis) “Clusters minimizing interfacial area plus length of singular curves”
- Feb 19 Indiana “Soap bubble clusters and current research”
- Mar 5 U Washington “Soap bubble clusters and current research”
- Mar 6 MAA, Tacoma “Shortest networks” and “Soap bubble clusters: new results, some by undergraduates”
- Mar 16 Rotary Club, Williamstown “Soap bubbles and popular math”
- Mar 30 Cedar Crest College “Soap bubble geometry contest” and “21st century geometry in your classroom”
- Mar 30 NYU Geometry Seminar “Cost-minimizing networks and surfaces”
- Apr 1 BCC “Soap bubble geometry contest”
- Apr 16 U Texas “Soap bubble clusters: new results and open problems”
- Apr 27 Williamstown Elementary School “Soap bubble geometry contest”
- May 2 Bridgwater State C “Soap bubble geometry contest”
- May 27 Dartmouth “Soap bubble clusters: open problems and new results” and “Soap bubble geometry contest”
- June 19 Princeton (Almgren conference) “Clusters”
- July 6 Smith RGI “Soap bubble clusters”
- July 12-17 MSJ 1st SRI, Sendai, Japan “Introduction to geometric measure theory,” “Techniques of GMT,” “Clusters, calibrations, and undergraduate research,” and “Cluster theory”
- July 30 Upper Valley Alums “Soap bubble geometry contest”

### 1993-94

Morgan gave a number of talks, including a series of lectures as distinguished foreign lecturer at the First Summer Research Institute of the Mathematical Society of Japan, a series of lectures on geometric measure theory at the International Center for Mathematics Research in Trento, Italy, the Taft lectures at the University of Cincinnati, a talk to the Williams Alumni Club of Boston, and about 20 other talks to groups ranging from research conferences to high school teachers and students.He served on the panel of lecturers for the Council on Undergraduate Research.

- Sept 1-4 CIRM, Trento “Geometric measure theory,” “GMT techniques,” “Homology and minimizers,” and “Calibrations”
- Oct 5 Siena “The soap bubble geometry contest”
- Nov 6 ATMNE, Springfield “The soap bubble geometry contest”
- Feb 17-18 Taft Lectures, U Cincinnati “Soap bubble clusters and the geometry of materials” and “Geometric measure theory: minimal surfaces and soap bubble clusters”
- Mar 16 Hudson Valley CC “21st century mathematics in the classroom,” “max-min problems” (for calculus audience), and ”The soap bubble geometry contest”
- Mar 22 CUR, NE Missouri State U “Soap bubble clusters, current research, some by undergraduates”
- Mar 30 Bates “The soap bubble geometry contest”
- Apr 9 Hudson River “The double soap bubble: students show the way”
- Apr 15 OSU “Soap bubble clusters” and “Shortest networks and shapes of materials” (PME address)
- Apr 19 SIAM, CMU “Clusters minimizing energy of interfaces and singular curves”
- Apr 23 MAA, Albany “Soap bubble clusters, including new results by undergraduates”
- Apr 30 Boston “The soap bubble geometry contest” (for Williams alums)
- May 5 UVM “The soap bubble geometry contest” (two versions)
- May 6 TMTA “The soap bubble geometry contest” and “Soap bubbles, mathematics, and students”
- May 14 Williams ”The soap bubble geometry contest” (7th and 8th grade science fair winners)
- May 23-26 Geometry Center “Are standard bubble clusters absolute minima?—Latest news”
- May 31-June 3 MAA workshop, Frostburg State, MD “Surfaces, soap bubbles, and general relativity” (4 lectures)
- June 9 Lehigh U “Minimal surfaces and isoperimetric problems”
- June 23 Math Institute, Bonn “Calibrations”
- June 24 Louvain, Belgium “Soap bubble clusters”
- June 27 Math Institute, Bonn “Soap bubble clusters”
- July 7 Heidelburg “Soap bubble clusters”
- July 26 IX Escola Geometria Direrential, Vitoria, Brazil “Soap bubble clusters, metals, and isoperimetric problems”
- Aug 3 U Sao Paulo “Bolhas de sabao, crystals, and Kelvin’s Conjecture”

### 1994-95

Morgan enjoyed a year on sabbatical at Bonn, Germany; Vitoria, Brazil; Queens College, New York City; Davis, California; Melbourne, Australia; and Trento, Italy. He gave some 50 talks, including a series of lectures on geometric measure theory at the International Center for Mathematics Research in Trento, Italy, and his popular Soap Bubble Geometry Contest at locations around the world, including his old high school in Allentown, Pennsylvania, where he was recognized as “Distinguished Alumnus” at the June graduation.

- Sept 8 Kenyon C “The soap bubble geometry contest” and “Math, soap bubbles, and other materials”
- Sept 30 CIMS “Strict calibrations and singular CMC surfaces”
- Oct 6 Queens “The soap bubble geometry contest”
- Oct 20 Penn State “Undergraduate education” and “Open questions and current work, including some by undergraduates”
- Oct 24 Queens “Soap bubble, math, materials, and undergraduate research”
- Oct 29 Colgate “Soap bubble clusters, crystals, metals, and undergraduate research”
- Nov 3 Queens “Geodesic nets on spheres”
- Nov 7 Queens “Geometric measure theory: a beginner’s guide”
- Nov 10 CUNY Grad Center “Soap bubble clusters, the triple helicoid, and area minimization”
- Nov 14 CUNY Grad Center “The isoperimetric problem”
- Nov 20 NYSMATYC Bronx CC “Soap bubbles, math, and undergraduat research”
- Dec 6 Queens visiting jr high group “Soap bubbles and films”
- Dec 12 Queens SEEK “The soap bubble geometry contest”
- Jan 6 Math meetings, San Francisco “The triple helicoid”
- Jan 10 UC Davis “Geodesics and geodesic nets on spheres”
- Feb 3 ANU “The soap bubble geometry contest”
- Feb 7 ANU “Rectifiable currents”
- Feb 8 ANU “Geometric measure theory ad minimal surfaces”
- Feb 22-24 Melbourne U “Geodesics and geodesic nets on spheres,” ”The soap bubble geometry contest,” and “Calibrations and area-minimizing surfaces”
- Feb 28 Monash U “The triple helicid, soap bubble clusters, and other singular minimal surfaces”
- Mar 2 Monash U “The soap bubble geometry contest”
- Mar 15 Allen HS “The soap bubble geometry contest”
- Mar 21 Congress Exhibit on math research
- Mar 28 Holy Cross “Soap bubbles, salt crystals, and calculus” and “Geodesics and geodesic nets on spheres”
- Mar 29 Boston U “The triple helicoid, soap bubble clusters, and other singular minimal surfaces”
- Mar 30 UMass Lowell “The ideal calculus course” and “Soap bubble clusters and undergraduate research” (dinner talk)
- Apr 4 Princeton “Soap bubbles ane metallic clusters” and “The triple helicoid, soap bubble clusters, and other singular minimal surfaces”
- Apr 7 Duquesne (MAA) “Soap bubble clusters and current research, some by undergraduates”
- Apr 26 Trento “Soap bubble clusters and area minimization”
- May 5 Trento “Calibrations and area-minimizing cycles on Grassmannians”
- May 10 Trento “The soap bubble geometry contest”
- Apr 27-May 22 Trento 8 lectures on geometric measure theory
- May 15 Cortona “Minimizing properties of singular soap films”
- June 9 Lehigh U “The triple helicoid, soap bubble clusters, and other singular minimal surfaces”
- June 28 Rochester “Soap bubble clusters and current research, some by undergraduates”
- July 5 Williams “Minimal surfaces around the world”
- July 10-14 Illinois IMA Summer GS Program10 lectures on GMT and minimal surfaces
- Aug 1 Williams “Geodesics and geodesic nets”
- Aug 6 Burlington MathFes t”Soap bubble geometry”
- Aug 16 William s”Energy-minimizing harmonic maps”
- Aug 16 MTA (Williams) “The soap bubble geometry contest”
- Aug 29 Cedar Crest C “Women in math”

### 1995-96

Morgan gave some 45 talks, including lectures at an IMA regional graduate course summer 1995, an assembly at his old high school on “New geometry for a new century,” and the Bullitt Lecture at the University of Louisville. With Ed Burger he gave a special April Fools Day colloquium at Williams on incorrect proofs of the 1800′s, including Fermat’s Last Theorem and the Four Color Conjecture, and then proved by request that “I am Bill Clinton” (published in March, 1997 American Mathematical Monthly).Morgan launched a live call-in Math Chat on local cable TV, which is already the talk of the town. The production team includes Eric Watson ’97, Aaron Dupuis ’99, Charmaine Mangram ’99, Liz Claflin ’99, Ted Melnick ’98, Ramona Nicholson ’98, and Alexei Erchak (SMALL ’96).

- Sept 20 Williams “An isoperimetric theorem for the thread problem and a $100 challenge”
- Sept 28 Bowdoin “Soap bubble clusters and the recent end of two conjectures” and ”The soap bubble geometry contest”
- Oct 6 Williams “Does an optimal honeycomb exist?”
- Oct 20 New Chairs Workshop, DC “…math for new and future chairs”
- Nov 3 U Richmond “The soap bubble geometry contest” and “Can math be rigorous and popular?”
- Nov 4 MAA, DC “Soap bubble clusters”
- Dec 21 William Allen HS “New gometry for anew century” and “Higher dimensional volumes”
- Jan 13 Math meetings, Orlando “Least area partitions of Rn,” “Recruiting math majors,” and “Soap bubble and salt crystals” (student workshop)
- Jan 17 Williams “Hexagonal honeycomb conjecture continues”
- Jan 29 U Georgia “Minimal surfaces and calibrations” and “The soap bubble geometry contest”
- Feb 16 U Maryland “The double soap bubble conjecture”
- Mar 8 Princeton “Soap bubble conjectures for the 90s”
- Mar 9 Tenacre “Soap bubbles, math, and Principle”
- Mar 22 BYU “Soap bubble conjectures for the 90s”
- Mar 28 Geometry Center “Soap bubble conjectures for the 90s”
- Mar 29/30 St John’s and St Benedict “Soap bubble clusters and the recent fall of two conjectures” and “The geometry ofsalt crystals, including recent advances by undergraduates”
- Apr 1 Williams “Mathematical fools”
- Apr 5 Williams “Quasi-measures”
- Apr 14 Courant “The hexgaonal honeycomb: an existence theorem”
- Apr 20 Hudson River “The hexagonal honeycomb conjecture”
- Apr 26 U Louisville Bullitt Lec”The double soap bubble breakthrough”
- May 4 Williams “The soap bubble geometry contest”
- May 29 Foam Euroconf, Arcachon “The hexagonal honeycomb conjecture”
- June 3 NAS German-American Frontiers of Science “Soap bubble clusters and the recent fall of two conjectures”
- June 25 Williams “The double soap bubble breakthrough”
- June 29 Water St Books “The soap bubble geometry contest”
- July 1 Expl Jr Pgm (Grades 4-5) “The soap bubble geometry contest”
- July 3 Williams “Soap bubbles in surfaces”
- July 9 Rio “Minimal structures”
- July 25 Hanover NH “The soap bubble geometry contest”
- Aug 7 Traverse City “The wet X soap film is unstable”
- Aug 11 Seattle MathFestModerated “The double bubble conjecture”

### 1996-97

Morgan gave some forty talks, ranging from mathematics seminars to his popular Soap Bubble Geometry Contest. Morgan’s live call-in Math Chat TV show on local cable TV has spawned a national Math Chat column every other Friday in The Christian Science Monitor. In February he was interviewed on a Mutual Radio Network radio program on “Coffee bubbles.” Morgan chaired the steering committee for the 1997 Hudson River Undergraduate Mathematics Conference, held for the first time at Williams. Some 400 students and faculty from schools throughout New York and New England participated in 120 talks in sixteen simultaneous sessions. About 600 attended the keynote address by Professor Benoit Mandelbrot, “Father of Fractals” and the most popular mathematics speaker in the world.

- Sept 6 Williams “Fluid cluster regularity”
- Oct 3 Math Mania, Kansas City “Bubble explorations: news and contest”
- Oct 19 Williams Family Weekend “The soap bubble geometry contest”
- Oct 29 AMTNYS “The soap bubble geometry contest”
- Nov 1 Williams Today “Math Chat”
- Nov 9 Rice “The double soap bubble breakthrough and undergraduate research,” “Soap bubble geometry,” and “Soap bubble clusters, fluids, and math in the news”
- Nov 15 Williams “Clusters of fluids”
- Nov 16 ATMNE “The soap bubble geometry contest”
- Nov 21 Northfield Mt Hermon “Soap bubble geometry: recent breakthroughs from student research”
- Jan 10 Math meetings, San Diego “Soap bubbles, fluid clusters, and undergraduate research”
- Jan 11 Math meetings, San Diego “Fluid cluster regularity”
- Jan 24/25 Young Scholars Program keynote, Valparaiso U “The double soap bubble breakthrough and undergraduate research” and “The soap bubble geometry contest”
- Feb 1 MathCounts, Hartford “The soap bubble geometry contest”
- Feb 4 Why Is It Mutual RadioCoffee bubbles interview
- Feb 14 AAAS, Seattle “Soap bubble geometry”
- Feb 28 KYMATY “The soap bubble geometry contest”
- Mar 13 Simon’s Rock “The double soap bubble breakthrough” and “The soap bubble geometry contest”
- Mar 25 Cape Cod Com College “The soap bubble geometry contest”
- Apr 2/3 Lafayette College “The soap bubble geometry contest” and “Soap bubble clusters and the recent fall of two conjectures”
- Apr 4/5 Geneseo “The double soap bubble breakthrough” and “Efficient clusters and networks” (two talks)
- Apr 12 Hudson River “Immiscible fluid clusters”
- Apr 22 Williams Science Lunch “Immiscible fluid clusters”
- May 12 SIAM, Philadelphia “Clusters of soap bubbles, crystals, and immiscible fluids”
- May 16 Williams “Generalizing the circle”
- June 20 Lehigh U “New isoperimetric theorems”
- June 30 Upward Bound, S Vt College “The soap bubble geometry contest”
- July 15 Williams “Generalizing the circle”

### 1997-98

Morgan spent the year as Princeton University’s new 250-anniversary Visiting Professor for Distinguished Teaching. Over 100 graduate students, faculty, and undergraduates, from Mathematics and other departments (notably Molecular Biology), participated in his innovative teaching seminar, videotaped model teachers and each other, and discussed strengths and weaknesses.Morgan took his call-in Math Chat TV show to Princeton, broadcast before a live audience off a dining hall. An interview of Morgan was featured as the cover story of the September, 1997 issue of Math Horizons. In addition he gave some forty talks, ranging from mathematics seminars to his popular Soap Bubble Geometry Contest.

- Oct 23 Princeton “New isoperimetric inequalities”
- Oct 24 AAPMT, Milton Academy “The isoperimetric problem and freshman calculus”
- Oct 30 Penn “New isoperimetric theorems”
- Nov 7 Princeton “The double soap bubble breakthrough”
- Nov 11 Princeton “Acquainting undergraduates with the frontiers of research”
- Dec 4 NCTM, Long Island “The soap bubble geometry contest”
- Feb 11 Duke “New classical isoperimetric theorems” and “The soap bubble geometry contest”
- Feb 18 Stuart Country Day School “The soap bubble geometry contest”
- Feb 21 Princeton Alum Day “The soap bubble geometry contest”
- Feb 24 Princeton Rotary Club “The soap bubble geometry contest”
- Mar 9 Riverside Elementary School, Princeton “The soap bubble geometry contest”
- Mar 14 MathCounts, Hartford “The soap bubble geometry contest”

### 1998-99

Morgan’s sabbatical travels included California, Italy, Germany, and Spain. From his base at Lehigh University in Pennsylvania, he visited the Universities of Trento, Pisa, Freiburg, Tübingen, and Granada. Indeed, he spent the whole spring under the shadow of the Alhambra in Granada, presenting his famous Soap Bubble Geometry Contest in Spanish (“El Concurso de Geometría de Pompas de Jabón”) to some 500 students and working with Ritoré and Ros on some famous geometry problems. Overall he gave 28 talks.

- Sept 15 Susquehanna Univ “Minimal enclosures and undergraduate research”
- Sept 23/24 Gentry Lectures, Wake Forest Univ “The soap bubble geometry contest,” “Ideal shapes”
- Sept 28 E Kentucky Univ, Richmond “Undergraduate research,” “The soap bubble geometry contest”
- Oct 1 U Miami, Ohio “New classical isoperimetric theorems and undergraduate research”
- Oct 2 PME Conference “The soap bubble geometry contest”
- Oct 2 McGuffey School “The soap bubble gometry contest”
- Oct 5 The Bishop’s School, La Jolla “Students and math in the news and on TV”
- Oct 7 UC Davis “Isoperimetric problems 1998″
- Oct 9 MSRI Math and Media Panel on education
- Oct 21 Lehigh Univ “Spheres, cubes, immiscible fluids, and isoperimetric problems”
- Nov 11 Trento “Isoperimetric theorems 1998″
- Nov 17 Pisa De Giorgi Colloquium “Isoperimetric problems”
- Nov 23 Trento “The soap bubble geometry contest”
- Nov 27/28U Freiburg “Geometric Measure Theory” (3 lectures)
- Nov 30 U Freiburg “Aubin’s Conjecture, Gauss-Bonnet, and immiscible fluids”
- Dec 11 Teubingen “Isperimetric problems”
- Feb 11 Granada “Desegualdades isoperimetricas”
- Feb 18 Granada “Soap bubble clusters and the fall of two conjectures”
- Feb 24 Murcia “Concurso de geometría de pompas de jabón”
- Mar 2 Granada “Concurso de geometría de pompas de jabón”
- Apr 22 Graada “Pompas de jabón y dos conjecturas encontradas en las noticias”
- May 13 Millersville “The double soap bubble conjecture”

### 1999-00

In May 2000 Morgan revisited southeastern Spain, giving popular talks on “The Geometry of Soap Bubbles 2000,” at Alicante, Murcia, Valencia, and Cartagena, as well as a short course for experts. The leading newspaper, El Pais, wrote: “I want to know, for example, how much Morgan’s visit is costing us. . . Unless this gentleman can explain to me how the soap bubbles of 2000 are markedly different from those of 1999, I do not understand why an academic institution would spend money for something like this.” Of course the point was that geometry is advancing rapidly, and that what we learn about the simple geometry of soap bubbles helps us understand the more complicated geometry of the universe. There were a number of excellent responses in newspapers and on TV. Overall he gave over 30 talks:

- “Very Undergraduate Research,” AMS/NSA Undergraduate Research Conference, Washington, DC
- “The Double Bubble Conjecture,” University of Delaware
- “Recent Breakthroughs on Soap Bubble Geometry by Mathematicians and Students,” Williams and Princeton Alumni, Hanover, New Hampshire
- “The Soap Bubble Geometry Contest,” Notre Dame, University of Western Michigan, Math Counts (Hartford, Connecticut), Rose-Hulman Institute of Technology, Richmond School (Hanover, New Hampshire)
- “Recent Breakthroughs on Three Conjectures,” Notre Dame
- “Students and Mathematics in the News and on TV,” University of Western Michigan
- “ContesTV 1,” Water Street Books
- “ContesTV 2,” Williamstown Public Library
- “Bursting the Double Bubble,” Moravian College Student Conference
- “The Double Bubble Conjecture,” Rose-Hulman Institute of Technology, Worcester Polytechnic Institute
- “News on the Double Bubble Conjecture, including Work by Undergraduates.” Worcester Polytechnic Institute
- “The First National High School Calculus Student Award,” Half Hollow Hills High School West
- “Double Bubbles and Crystals, Minimizing Surface Area and More General Norms,” AMS meeting, University of Lowell, New Hampshire
- “Proof of the Double Bubble Conjecture,” University of Connecticut, Storrs
- “Soap Bubbles and Mathematics,” University of Connecticut, Storrs
- “La Geometri’a de Pompas de Jabón 2000 [Soap Bubble Geometry 2000],” University of Alicante, Spain, University of Murcia, Spain, University of Valencia, Spain, University of Cartagena, Spain
- “Geometric Measure Theory” (four lectures), University of Murcia, Spain

### 2000-01

Morgan gave some thirty-five talks, including the address to the US International Mathematics Olympiad team at the National Academy of Sciences and the US State Department. Twenty of his students spoke at the Hudson River undergraduate mathematics conference in April, 2001.

- “Hales’s Proof of the Hexagonal Honeycomb Conjecture,” Eurofoam Conference, Delft, Netherlands
- “The Double Bubble Conjecture, Illustrated,” Art and Mathematics Conference, SUNY Albany
- “The Soap Bubble Geometry Contest,” College of William and Mary
- “Soap Bubbles and the Universe,” The Choate School
- “The Double Bubble Theorem” and ”Soap Bubbles and Mathematics,” Lake Forest College
- “Soap Bubbles and the Universe,” Canterbury High School
- “Double Soap Bubbles,” Mathematical Association of America, American University
- “Area-Minimizing Surfaces through Conical Singularities,” Joint Mathematics Meetings, New Orleans
- “Soap Bubbles and the Universe,” SUNY Potsdam
- “Soap Bubbles and the Universe,” MathCounts (Hartford) and Coast Guard Academy
- “The Double Bubble Theorem,” Brown University
- “The Double Bubble Theorem,” Sarasota College
- “Bubble News and Contest,” Mathematical Association of America, Florida Gulf Coast University
- “Area-Minimizing Surfaces in Cones and Double Bubbles,” American Mathematical Society, University of South Carolina
- “Getting Students Doing Mathematics” and ”The Double Soap Bubble Conjecture,” University of Michigan
- “Proof of the Double Bubble Conjecture,” Mathematical Association of America, University of Mississippi
- “Proof of the Double Bubble Conjecture,” Richard Stockton College, New Jersey
- “Double Bubble Conjecture and Contest,” Mathematical Association of America, Huntington College, Montgomery, Alabama
- “Double Bubbles: Proof and Prizes,” Mathematical Association of America, Rowan University, Glassboro, New Jersey
- “Shortest Paths on the Cylinder I,” ”Exotic Soap Bubbles and Mathematics,” and ”Soap Bubble Newsreel and Contest,” Elizabethtown College, Pennsylvania
- “Shortest Paths on the Cylinder II,” ”The Soap Bubble Geometry Contest,” and ”Disorientations in the Universe,” Millersville State Teachers’ College
- “Soap Bubble Math News and Contest.” Mt Greylock High School
- “The Double Soap Bubble Theorem,” US International Math. Olympiad Team, National Academy of Sciences and US State Department

### 2001-2002

- “Geometric Measure Theory and the Proof of the Double Bubble Theorem” (nine lectures), Clay Mathematics Institute Summer School, Mathematical Sciences Research Institute, Berkeley, California
- “Proof of the Double Bubble Conjecture,” MAA MathFest, University of Wisconsin, Madison
- “Area-minimizing Surfaces in Cones and Other Singular Ambients,” De Giorgi Conference, Pisa, Italy
- “The Soap Bubble Geometry Contest,” Joint Math/Physics PME colloquium, University of Pennsylvania
- “Area-minimizing Surfaces in Cones,” Topology/Geometry Seminar, University of Pennsylvania
- “Fractals and Geometric Measure Theory: Friends or Foes,” Joint Mathematics Meetings, San Diego, California
- “The Soap Bubble Geometry Contest,” Grand Valley State University, Grand Rapids, Michigan
- “Soap Bubbles, Immiscible Fluids, and Coefficient Groups,” Calvin College, Grand Rapids, Michigan
- “Double Bubbles,” Michigan Undergraduate Mathematics Conference, Calvin College, Grand Rapids, Michigan
- “Soap Bubbles and Contest,” California State University, Fresno

### 2002-2003

During his sabbatical year, Morgan visited Peru, the Newton Institute in Cambridge England, Argentina, the Max Planck Institute in Leipzig Germany, the Renyi Institute in Budapest Hungary, the University of Trento in Italy, and the University of Granada in Spain. He gave many mathematical talks on his recent proof of the Double Bubble Conjecture and popular talks on soap bubbles and mathematics. While in Peru he took the famous four-day hike on the Inca Trail to the long-lost city of Machu Picchu.

- “Geometric Measure Theory and the Proof of the Double Bubble Theorem” (nine lectures), Clay Mathematics Institute Summer School, Mathematical Sciences Research Institute, Berkeley, California
- “Proof of the Double Bubble Conjecture,” MAA MathFest, University of Wisconsin, Madison
- “Area-minimizing Surfaces in Cones and Other Singular Ambients,” De Giorgi Conference, Pisa, Italy
- “The Soap Bubble Geometry Contest,” Joint Math/Physics/PME colloquium, University of Pennsylvania
- “Area-minimizing Surfaces in Cones,” Topology/Geometry Seminar, University of Pennsylvania
- “Fractals and Geometric Measure Theory: Friends or Foes,” Joint Mathematics Meetings, San Diego, California
- “The Soap Bubble Geometry Contest,” Grand Valley State University, Grand Rapids, Michigan
- “Soap Bubbles, Immiscible Fluids, and Coefficient Groups,” Calvin College, Grand Rapids, Michigan
- “Double Bubbles,” Michigan Undergraduate Mathematics Conference, Calvin College, Grand Rapids, Michigan
- “Soap Bubbles and Contest,” California State University, Fresno
- “The Soap Bubble Geometry Contest,” Bay Area Math Adventures (for high school students), Santa Clara, California
- “Soap Bubble Conjectures and Immiscible Fluids,” MAA sectional meeting, Davis, California
- “The Soap Bubble Geometry Contest” and “Proof of the Double Bubble Conjecture,” University of Kentucky, Lexington
- “Soap Bubbles,” MAA sectional meeting, McKendree College, Lebanon, Illinois
- “Soap Bubbles 2002 Selbbub Paos,” MAA sectional meeting, Eastfield College, Dallas, Texas
- “2000 Proof of the Double Bubble Theorem,” University of North Texas, Denton, Texas

### 2003-04

- “Proof of the Double Bubble Conjecture,” Tulane Unversity
- “Soap Bubbles and Mathematics,”“Pizzas, Bubbles, and other “Isoperimetric” Shapes,” “The Double Bubble Theorem,” and “Soap Bubbles in other Universes,” Texas Christian University
- “Area-minimizing Surfaces in Singular Manifolds” (Geometry Seminar) and “Double Bubbles” (MASS Colloquium), Penn State
- “Area-minimizing Surfaces in 3D Polytopes in
**R**^{4}and Invariant Minimizers in**R**,” Special Session on PDEs and Variational Problems, Joint Mathematics Meetings, Phoenix^{n} - “Double Bubbles in a Torus” and “Soap Bubbles and Mathematics,” Millsaps College
- “Soap Bubbles and Mathematics,” Staff luncheon
- “Soap Bubbles and Mathematics,” Framingham State College
- “The Soap Bubble Geometry Contest,” MathCounts, Springfield
- “Pompas de Jabón y Matemáticas” and “El Teorema de la Pompa Doble,” University of Mexico
- “Soap Bubbles and Mathematics,” “Proof of the Double Bubble Conjecture” (Kempner Colloquium), and “Soap Bubbles in the Torus” (Math Club), University of Colorado, Boulder
- “Invariant Minimizers in R3 and Isoperimetric Regions in Polytopes,” University of Trento, Italy
- “Isoperimetric Problems in Rn and Riemannian Manifolds” (4 lectures) and “Soap Bubbles and Mathematics for Everyone,” University of Padova, Italy
- “Geometric Measure Theory and Isoperimetric Problems” (4 lectures), Institut de Mathématiques de Jussieu, Paris, France
- “Sixteen Years of the SMALL Undergraduate Research Project: 1988—2004,” Special Session on “SMALL” Mathematics, SMALL Reunion, MathFest, Providence

### 2004-05

Morgan gave a dozen talks this year, including a talk on Family Weekend on “Soap Bubbles and Mathematics,” replete with demonstrations, explanations, and prizes.

TALKS ON CAMPUS

- “Soap Bubbles and Mathematics” (Family weekend)
- “What I learned from my Math Chat TV show” (PET luncheon)
- “Compactness” (math colloquium)
- “Manifolds with Density” (Faculty seminar)
- “Soap Bubbles in Product Spaces” (Faculty seminar)
- summer colloquium, June 2005

TALKS OFF CAMPUS

- “Proof of the Double Bubble Conjecture” and ”Soap Bubbles and Mathematics,” Purdue University
- “Isoperimetric Double Bubbles in R^n and Other Spaces,” Indiana University, Bloomington
- “Double Bubbles in R^n and Other Spaces,” University of Michigan
- “Soap Bubbles in Euclidean Space and Other Universes,” Loyola University, Chicago
- “Soap Bubble Geometry 200 BC—2005 AD,” MAA/Sulski Lecture, Holy Cross
- “Double Bubbles and Gauss Space,” MAA invited speaker, Bates College

### 2005-06

Morgan gave over twenty talks this year, including an invited lecture at the Geometry Festival, some lectures at the National Autonomous University in Mexico, and a talk on “Soap Bubbles and Mathematics” at MathCounts, where the following picture was taken by Jeff Bauer of Citco (please credit him).

TALKS ON CAMPUS

- “Math Jamboree: The Fun Part of What It Means to Be a Mathematician,” Summer Science lunch talk
- “Gauss space,” Mathematics Colloquium
- “Manifolds with Density,” Mathematics Faculty Seminar

TALKS OFF CAMPUS

- “The Double Bubble Theorem” (Mathematics Colloquium) and ”Geometric Measure Theory and Isoperimetric Problems” (graduate student seminar), University of Houston
- “Manifolds with Density,” Rice University Colloquium
- “Soap Bubbles and Mathematics,” Harvey Mudd College
- “Double Bubbles and Gauss Space,” MAA Invited Speaker, California State University, Channel Islands
- “National High School Calculus Student Award,” Jackson Preparatory School, Mississippi
- “Manifolds with Density” and ”Undergraduate Mathematics Research,” National Mathematics Meetings, San Antonio
- “Double Bubbles in the Torus” (Mathematics Club) and ”Manifolds with Density” (Mathematics Colloquium), Vanderbilt University
- “The Mathematics of Soap Bubbles,” Ensworth High School, Nashville
- “Soap Bubbles and Mathematics,” MathCounts, Hartford
- “Soap Bubbles, Mathematics, and Williams,” Hilton Head Mini-Reunion Class of 1957
- “Manifolds with Density,” Geometry Festival, Univ. of Penn.
- “Bounds on the Partition Function,” Hudson River Undergraduate Mathematics Conference, Westfield State College
- “Geometric Measure Theory and Open Problems” (3 lectures), Universidad Nacional Autónoma de México
- “Isoperimetric Problems: an Introduction and Challenge,” Lafayette College
- “Isoperimetric Problems, including Open Problems for Mathematicians and Undergraduates,” Invited speaker, Geometry-Topology Conference, Lehigh University

### 2006-07

Morgan spent his sabbatical year traveling the globe, consulting with other mathematicians and giving forty talks on manifolds with density, isoperimetric problems, and other related topics, at the International Congress in Madrid, across Europe, to mathematicians and business schools in Seoul Korea, in Vietnam (Hanoi and Hue), and elsewhere. He taught a short course for new PhDs in Mexico and another in Italy.

Morgan was in Hue Vietnam for Teacher’s Day, a marvelous national celebration in which apparently everyone takes delight in thanking and honoring teachers past and present. On his arrival they escorted him to a student Teacher’s Day musical celebration and asked him to sing for them. The photo below shows him singing “The Mountains,” with Ho Chi Minh presiding behind.

TALKS ON CAMPUS

- “Honeycombs and Planes with Density” (with Geometry Group), Summer Mathematics Colloquium
- “Banff and Partitioning Problems,” Mathematics Faculty Seminar

TALKS OFF CAMPUS

- “Geometric Measure Theory and Open Problems” (three lectures), Universidad Nacional Autónoma de México
- “Isoperimetric problems,” Lafayette College (REU)
- “Isoperimetric problems, including open problems for mathematicians and undergraduates,” Lehigh University Geometry-Topology Conference
- “Isoperimetric problems,’ Knoxville MAA MathFest
- “Isoperimetric problems,” Münster, Germany
- “Manifolds with density,” Madrid International Congress of Mathematicians
- “Geometric Measure Theory and Soap Bubbles,” Granada Spain International Seminar on Applied Geometry in Andalusia
- “The Double Bubble Theorem,” Lisbon Portugal Instituto Superior Tecnico
- “Manifolds with Density,” Trento Italy
- “Manifolds with Density,” Zurich
- “Manifolds with density,” “Bubbles and bagels,” and “Bubble clusters and mathematics,” St Mary’s College Maryland
- “Bubbles and bagels,” Brigham Young University
- “Manifolds with density,” Korea Institute for Advanced Study, Seoul
- “Black-Scholes option pricing and other topics,” Korea Development Institute, Seoul
- “Black-Scholes option pricing and other topics,” Korea Advanced Institute of Science and Technology, Seoul
- “Soap bubbles and mathematics,” Seoul National University Epsilon Lecture
- “Differential geometry,” Vietnam National University, Hanoi
- “Area-minimizing surfaces,” Institute of Mathematics, Hanoi
- “Soap bubbles, students, and mathematics,” “Double bubbles and student research,” and “Area-minimizing surfaces and manifolds with density,” Hue University, Vietnam
- “Minimal surfaces in singular ambients,” Levico Italy (CIRM)
- “Bolle di Sapone e Matematica” for the public, “Bolle di Sapone e Matematica” for high school teachers and students, and “Manifolds with Density” two lectures for young mathematicians, Modena Italy
- “Manifolds with density,” Pisa Italy
- “Soap Bubbles and Mathematics,” Sweetwood, Williamstown
- “Soap Bubbles and Mathematics,” Bard College
- “Partitioning Problems,” Banff Scientific Research Station, Canada
- “Soap Bubbles and Mathematics,” Georgia Tech
- “Doubles Bubbles in the Torus,” Millersville University-Franklin and Marshall joint colloquium
- “Manifolds with Density,” Lancaster PA Tetrahedral Seminar
- “Soap Bubbles and Mathematics,” Connecticut College

### 2007-08

Morgan taught a Winter Study course on Tournament Bridge. His students participated in local tournaments and in regional events in Boston and New York. One student, Edward Newkirk ’09, wrote up a bridge hand and found it published in Phillip Alder’s column in The New York Times, January 26, 2008. William Jannen ‘09 and Bryant.Renaud ‘11 had a write-up published in the Bulletin of the American Contract Bridge League, with the following photo:

Morgan gave over thirty talks at venues ranging from high schools to mathematics colloquia. For an undergraduate student workshop at Millersville University, Morgan had asked the students to try to reproduce computer-predicted minimal surfaces with soap films in a plexiglass box. Their resulting article and photographs appear in the April 2008 issue of Math Horizons.

TALKS ON CAMPUS

- “Partitions, Densities, and Canadians” (with 2007 Geometry Group), Summer Mathematics Colloquium
- “Improving on the Circle in Surfaces with Density,” Science lunch
- “Isoperimetric Comparison Theorems and Manifolds with Density,” Mathematics Faculty Seminar
- “Teachers and Students,” Currier Neighborhood first-years’ dinner
- “Soap Bubbles,”Mills-Dennett entry
- “Soap Bubbles and Mathematics,” Currier Neighborhood High Tea
- “Twenty Years of the SMALL Undergraduate Research Project,” Mathematics/Statistics/Computer Science Mini-Conference/Reunion

TALKS OFF CAMPUS

- “Soap Bubble Clusters and Mathematics”, University of Iowa
- “Soap Bubbles and Mathematics”, Canadian Undergraduate Mathematics Conference, Vancouver
- Panel on “What THEY Think is Good Teaching”
- Invited paper session on “Manifolds with Density, Partitioning Problems, and the SMALL undergraduate research project”
- “The Double Bubble Theorem” (Research with Undergraduates panel), MAA MathFest, San José
- “Soap Bubbles and Mathematics”, Bethel College
- “Double Bubbles in the Torus,” Notre Dame
- “Manifolds with Density,” Notre Dame
- “Soap Bubbles and Mathematics,” Burr & Burton Academy, Manchester, Vermont
- “Surfaces with Density and the Poincaré Conjecture,” Penn State
- “Soap Bubbles and Mathematics,” Mount Greylock High School
- “Soap Bubble Geometry Contest,” MAA meeting, Framingham
- “The Double Bubble Theorem,” SAC Capital Management, New York
- “Soap Bubbles and Mathematics,” Case Western Reserve
- “Soap Bubbles and Mathematics,” MathCounts, Hartford
- “Manifolds with Density after Perelman’s Proof of the Poincaré Conjecture,” George Washington University
- “Soap Bubbles and Mathematics,” The University of Virginia
- “Introduction to Soap Bubbles and Mathematics (two presentations at Fayetteville HS)
- “Soap Bubbles and Mathematics” (public lecture at Univ Arkansas)
- “The Isoperimetric Problem in Surfaces with Density,” Hudson River Undergraduate Mathematics Conference, St. Lawrence University
- “Soap Bubbles and Mathematics,” Suffolk University science banquet
- “Soap Bubbles and Mathematics,” Wright State University, Dayton, Ohio
- “Surfaces with Density and the Poincaré Conjecture,” Montclair State University, New Jersey

### 2008-09

- June 8 Math/Stats/CS Miniconference “Twenty Years of the SMALL Undergraduate Research Project”
- July 31 Madison MathFest “Isoperimetric problems, manifolds with density, and the SMALL undergraduate research project”
- Sept 25-26 Calgary “Manifolds with Density,” “The plane with Density r
and the Poincaré Conjecture”^{p} - Oct 14 Central Conn. State U. “Surfaces with Density and the Poincaré Conjecture”
- Nov 8 GluckFest, Newark “Area-minimizing Surfaces”
- Nov 21 Williams Faculty Seminar “Easy? open question workshop”
- Dec 19 Mt Greylock HS assembly “Soap bubbles and mathematics”
- Jan 5 Joint math meetings, DC “Isoperimetric balls in cones over tori”
- Mar 22 Fairfield U, “Soap bubbles and math”

- Apr 10 Bennington C, “Soap bubbles and math”

### 2009-10

- Jun 1-5 Tipos de superficies y curvatura,” Escuela de Análisis Geométrico, University of Granada, Spain (3 lectures)
- July 3 Palermo, Italy, “Manifolds with density and Perelman’s proof of the Poincaré Conjecture”
- July 7 DMI, Catania, Italy, “Manifolds with density and Perelman’s proof of the Poincaré Conjecture”
- July 7 Scuola Superiore, Catania, Italy, “Soap bubbles and isoperimetric problems”
- Jul 29 ”Granada Math Report,” Math Colloquium, Williams College
- Jul 31 Hampshire College, ”Surfaces with density and Perelman’s proof of the Poincaré Conjecture”
- Aug 19 IMPA, Río, Brazil, “Manifolds with Density and Perelman’s Proof of Poincaré”
- Sept 22 Union College, ”Surfaces with Density, Isoperimetric Problems, and Perelman’s Proof of the Poincaré Conjecture”
- Oct 12 Dixie Heights High School, “Introduction to Soap Bubbles & Math”; Northern Kentucky University, “Soap Bubbles & Math”
- Oct 26 Williams math colloquium, “Baserunner’s Optimal Path”
- Oct 31 Florida Atlantic University, “Manifolds with Density and Isoperimetric Problems”
- Dec 16-20 1st AMS/KMS, Seoul, South Korea, Public lecture: “From Soap Bubbles to the Poincaré Conjecture”
- Dec 23 Pittsfield HS faculty workshop, “The Soap Bubble Geometry Contest”
- Jan 14 San Francisco University Club, “Baserunner’s Optimal Path”
- Jan 16 San Francisco, Joint Math Meetings, “Generalized Steiner and Schwarz Symmetrization”
- Feb 18 University of Oklahoma, “From Soap Bubbles to the Poincaré Conjecture,” “Baserunner’s Optimal Path”
- Mar 18 Georgia Tech, “From Soap Bubbles to the Poincaré Conjecture”
- Mar 19-20 BYU CURM, “From Soap Bubbles to the Poincaré Conjecture”
- Mar 22-23 Georgia Southern University, “The Double Bubble Theorem” and ”Densities from Geometry to Poincaré’s Conjecture”
- Apr 1 Banff Conference on Volume Inequalities, ”The Isoperimetric Problem in Spaces with Density” (Talk 704)
- Apr 16 Williams Faculty Seminar, “Pseudo-bubbles in Manifolds” with Stefano Nardulli
- May 25 Dido conference, Carthage, “Isoperimetric Problems in Spaces with Density,” interview on Tunisian national TV.

- June 1 Napoli, “Soap Bubbles and Isoperimetric Problems”
- June 3 Firenze, “Densities from Isoperimetry to Poincaré”
- June 8 Pavia, “Densities from Isoperimetry to Poincaré”
- June 10 Pavia, “Soap Bubbles and Mathematics”
- June 11 Como, “Densities from Isoperimetry to Poincaré” (Talk 711)

## 2010-11 Sabbatical

- July 7 Canadian Undergraduate Math Conf, Toronto “Densities from Geometry to Poincaré”
- July 12-16 Teach Geometric Measure Theory course Sao Paulo (4 lectures)
- July 21 Williams, “Optimal Shapes” with the 2010 Geometry Group
- July 26 Hampshire College, “New Isoperimetric Theorems”
- Aug 5-7 MathFest, Pittsburgh “Baserunner’s Optimal Path”
- Sept 28 Kent State, “Densities from Isoperimetry to Poincaré”
- Oct 5-14 Fields Institute, Five lectures on geometric measure theory, densities, and soap bubbles.
- Oct 10 UCLA, “Log Convex Density Conjecture”
- Oct 25 Fields, “Densities from Isoperimetry to Poincaré”
- Oct 27 U Toronto, “Pentagonal Tilings and Other Parition Problems”
- Nov 12 U Toronto, “Double Bubbles from Euclidean to Gauss Space”
- Jan 9 New Orleans Joint Math Meetings, “Isoperimetric Problems with Density”

### Jan-Feb 2011 BYU

- Jan 11 Westside HS, Provo, “Soap Bubble Geometry Contest”
- Jan 25 Brigham Young University, “Double Soap Bubble Theorem”
- Feb 4 Centennial Congress RSME, Avila, “Isoperimetry and the Log-convex Density Conjecture”
- Feb 8 Brigham Young University, “My Math Chat Live Call-in TV Show”
- Feb 10 University of Arizona, Tucson, “Double Soap Bubble Theorem” and hands-on activities at Flandreau Planetarium Theater (see video)
- Feb 24 AMC recognition program, BYU<
- Mar 18 UConn, Storrs, “Soap Bubble Clusters” [talk 737]
- April/May 2011 Speaking tour of Asia, including Pakistan, Vietnam, Thailand, Singapore, Malaysia, and the Philippines
- March 28-31 Islamabad, Pakistan
- March 28 11 am “Soap Bubbles and Mathematics” for teachers of All Pakistan Mathematical Association, at Pakistan Academy of Sciences
- March 29 1:15 pm “The Double Soap Bubble Theorem” at Quaid-i-Azam University
- March 30 11 am “Isoperimetric Problems with Densities” at Center for Advanced Mathematics and Physics
- April 2-8 Lahore at Abdus Salam School of Mathematical Sciences, National Center for Mathematics
- April 2,4,6,8 four lectures on Geometric Measure Theory
- April 6 “Soap Bubbles and Mathematics” at Punjab University
- April 9 “Baserunner’s Optimal Path” [talk 746]
- April 10-23 Vietnam
- April 14 Institute of Math. “Densities from Geometry to the Poincaré Conjecture,” National University “Baserunner’s Optimal Path”
- April 15 Thai Nguyen, “Soap Bubbles and Mathematics”

- April 17-21 Hue, covered on TV: see video and website
- April 19, 8:30-10:30 ”Isoperimetric Problems” for students and faculty
- April 20, 8:30-10:30 ”Students and Current Research” for students and faculty
- April 21, 8:30-10:30 ”Soap Bubbles and Soap Films” activity
- April 22 Hochiminh City, “Proof of the Double Bubble Conjecture”
- April 24-30 Thailand
- Mon April 25 10-noon Chulalongkorn U.”The Proof of the Double Bubble Conjecture”
- Tues April 26 13:30-15:30 Mahidol U. “Densities from Geometry to the Poincaré Conjecture”
- Wed April 27 9:30-10:30 Math. Assn. Thailand “Soap Bubbles and Mathematics”
- Thur April 28 13:30-15:30 Thammasat U. “Isoperimetric Problems”
- May 1-7 Singapore
- 3rd May (Tuesday) – “Isoperimetric Problems,” 2nd Singapore Mathematical Symposium, Nanyang Technological University
- 4th May (Wednesday) – ‘Teaching Geometry by Guessing What Soap Bubbles Will Do’ Clementi Town Secondary School
- 5th May (Thursday) – ‘Students and Current Research’ at National Institute of Education
- 6th May – Public Lecture ‘Soap Bubbles and Mathematics’ at National University of Singapore High School.
- May 8 Universiti Malaysia Terengganu, “Soap Bubbles and Mathematics,” “Popularization of Mathematics and MathChat TV”
- May 9 Universiti Putra Malaysia, “Innovative Teaching in Mathematics,” “Soap Bubbles and Mathematics”
- May 10 Universiti Teknologi Mara, “Soap Bubbles and Mathematics,” “Current Research and Innovation in Mathematics,” “Research Proposals”
- May 11 National Science Center (PSN), “Soap Bubbles and Mathematics”
- May 11 Al-Amin School, “Soap Bubbles and Mathematics”
- May 12 Universiti Malaya, “Baserunner’s Optimal Path”
- May 12 National Science Center, “Popularization of Mathematics and MathChat TV”
- May 13 Universiti Kebangsaan Malaysia, “Innovative Teaching of Calculus: Max-Min Problems,” “Soap Bubbles and Mathematics”
- May 15-22 Philippines, Visiting Professor, UPD, Manila
- May 16: Fidel Nemenzo’s Science and Society Class, UP, 150 Students, “Soap Bubbles”
- May 17: UP Inst. Math., “Densities from Geometry to the Poincaré Conjecture”
- May 18: Ateneo de Manila University, “The Double Soap Bubble Theorem”
- May 20: “Soap Bubbles and Mathematics,” Annual Convention, MSP
- June 8: Museum of Mathematics, NYC, “Soap Bubbles and Mathematics: The Amazing Shapes of Minimal Surfaces”, featured in the New York Times in Pradeep Mutalik’s Numberplay: Bubble Magic

- June 15, Williams Math Colloquium, “Tilings, Densities, and Asia” with the 2011 SMALL Geometry Group
- June 21, Williams Science lunch talk, ”Minimal Tilings”
- June 26, Exeter, “Baserunner’s Optimal Path” [talk 781]

## 2011-2012

- July 10, SurpriZing Science: AmaZing Bubbles with Professor Frank Morgan and the Geometry Group, Spring Street, Williamstown
- Sept 23, St. Michael’s College, “Soap Bubbles and Mathematics”
- Nov 1, Williams Science lunch, “Pentagonal Tilings”
- Dec 13, Williams MathBlast, “Soap Bubbles and Mathematics”
- Dec 14, Pine Cobble HS, “Soap Bubbles and Mathematics”
- Jan 5, Annual Math. Meetings, Boston, “Existence of Isoperimetric Regions in
**R**with Density,” 8:30 am, Room 303, Hynes^{n} - Jan 26, Washington St. U., Pullman, ”Densities from Geometry to the Poincaré Conjecture”
- Feb 4, MathCounts, Hartford, “Soap Bubbles and Mathematics”
- Feb 20, Williams math colloquium, “Stokes Theorem”
- Feb 22, CUNY Staten Island, “Soap Bubbles and Mathematics” [talk 791]
- Mar 21, Edinburgh, ICMS Isoperimetric Problems, “Soap Bubbles and Mathematics” at Dynamic Earth for some 60 high school students from Auchmuty and Falkirk high schools
- Apr 12, Tufts U, “Soap Bubbles and Mathematics”
- Apr 21, MAA meeting, U. of Portland, “Densities from Geometry to the Poincaré Conjecture,” “Optimal Pentagonal Tilings”
- May 16, Northwestern U, Undergraduate Prize Lecture, “Optimal Tilings”
- May 23, Bridgewater State U, “Optimal Tilings”
- May 25, Lehigh U, “The Isoperimetric Problem with Density”
- June 9, MIT ’87 Reunion dinner, “Soap Bubbles and Mathematics”
- June 19, Granada, “Isoperimetric Problem with Density” [talk 800]

## 2012-2013

- July 11, Williams colloquium, “Tilings and Isoperimetric Problems”
- Sept 7, Williams Faculty Seminar, “Optimal Pentagonal Tilings”
- Sept 21, NEMATYC dinner, “Baserunner’s Optimal Path”
- Oct 19, Princeton, “Densities in Geometry, Including Isoperimetric Problems and the Poincaré Conjecture”
- Nov 15-16, U Oklahoma, “Soap Bubbles and Mathematics,” “Optimal Pentagonal Tilings”
- Dec 11, Williams MathBlast, “The Soap Bubble Geometry Contest” (3 workshops)
- Jan 7, Williams colloquium, “My Huffington Post Blog”
- Jan 12, San Diego joint math meetings, “My Huffington Post Blog”
- Jan 30, Fordham Univ, “Optimal Pentagonal Tilings”
- Feb 16, Moravian College Student Conference, “Optimal Pentagonal Tilings”
- Feb 22, Williams Faculty Seminar, “The Convex Body Isoperimetric Conjecture”
- Mar 14, Univ. New Haven, “Soap Bubbles and Mathematics”
- Mar 22, Pitt Michalik Lecture, “Soap Bubbles, Tilings, and Other Partitioning Problems”
- Mar 27, Penn, ”Soap Bubbles, Tilings, and Other Partitioning Problems”
- Mar 28, Muhlenberg, “Optimal Pentagonal Tilings” [Talk 817]
- May 25, Lehigh Geometry Topology Conference, “The Log-Convex Density Conjecture”
- June 9, SIAM, Philadelphia, “Minimal Interface Structures”
- June 26, Williams, Minimizing Perimeter with Density
- July 1, Fairfield Univ., Densities from Geometry to Poincaré
- July 7, Williamstown Spring Street Summer Sundays, Soap Bubbles and Mathematics with Geometry Group
- July 11, 4 pm, Williams MathCamp, Soap Bubbles and Mathematics
- Aug 1, MathFest Student Lecture, Optimal Pentagonal Tilings

## 2013-2014

- Sept 3, Barcelona, The Log-Convex Density Conjecture
- Sept 24, Siena College, Optimal Pentagonal Tilings
- Oct 4, Williams Faculty Seminar, Barcelona (Optimal Transportation with Constraint)
- Oct 8, UC Irvine, Baserunner’s Optimal Path, The Isoperimetric Problem with Density
- Nov 19, Union C, Isoperimetric Problems with Densities [talk 829]
- Dec 8, Vijyoshi National Science Camp, Bangalore, India, Optimal Tilings; see blog post
- Jan 16, 1 pm, Baltimore joint math meetings, Log-Convex Density Conjecture Proved
- Feb 27, Newton Institute, Cambridge, England, The Least-Perimeter Tile with
*n*Faces - Mar 13, Berkshire Community College, Soap Bubbles and Mathematics
- Mar 24, Southwestern U, President Burger inauguration, The Soap Bubble Geometry Contest
- Apr 3, Northampton Community College, “Soap Bubbles and Mathematics” in the Zone and “Soap Bubbles and Snacks” in the dorm
- Apr 5, MAA meeting, Rowan U, Optimal Pentagonal Tilings
- Apr 12, Utah State—Blanding, Soap Bubbles and Mathematics
- Apr 26, Hudson River Undergraduate Mathematics Conference, The Convex Body Isoperimetric Conjecture [talk 839]
- May 1, Millersville U, “Best 3D Tiles” and “Optimal Tilings”
- May 2, Tetrahedral Geometry/Topology Seminar, PA, “Chambers Proves LCD Conjecture”
- June 2-6, CIME course, Cetraro Italy, “Geometric Measure Theory, Isoperimetric Problems, and Manifolds with Density”
- June 16-20, SNS Pisa Italy, Isoperimetric Problems Between Analysis and Geometry
- Aug 6-9, MathFest, Portland OR, The Convex Body Isoperimetric Conjecture
- Aug 13-21, ICM, Seoul South Korea, The Isoperimetric Problem in Manifolds with Density
- Aug 16, Bridges, Seoul South Korea, “Bubbles and Tilings: Art and Mathematics”