by Chris Liggett
In 1966, I, Christina Goodale, began my long association with the Mathematics Department at UCLA as Senior Typist Clerk. I was the Receptionist for the Mathematics Department in MS6115 in the old wing of the Mathematics Building. That small office was the center of the Department. It contained the Chair’s Office, his assistant’s office, the office of the Senior Administrative Assistant, and a connecting door to the office of the Graduate Administrative Assistant, MS6103. The Mathematics Department at that time was small, but then something like Sputnik came along, and Russia was in space, and the US decided it needed mathematicians and scientists to catch up rather quickly.
A new mathematics building was planned. New young assistant professors were being hired, as well as more senior faculty, and the government provided many more US fellowships for incoming graduate students. My job changed too. I became Secretary to the Graduate Administrative Assistant, and in 1968, I became the Graduate Administrative Assistant, monitoring 300 graduate students! The staff was expanding too, as we prepared to move into the new wing of the Mathematics Building.
One of my many duties at that time, was to take pictures of all the new faculty and visiting Professors. Their pictures, as they are today, were to be displayed on the department’s main bulletin boards. My camera was an old polaroid that only took black and white photos. Some were priceless and of the times; long sideburns, longish hair, big glasses, and men with ties, and yes, still very few women!
Tom arrived at UCLA on July 1, 1969. He loved to tell the story of how he, a new PhD from Stanford, had asked for an application from UCLA and other institutions, and not only did he get an application from UCLA, he got a job offer as an assistant professor at an academic salary of \$10,200.00! He was coming to UCLA!
I took his picture, and now my story begins…
Tom was tall and thin, had brown hair, long sideburns, big brown glasses, and he wore a tie, and he was very shy.
I was short and thin, had brown hair, brown glasses, and I was fairly outgoing. It was a busy time, lots of students and faculty, and I didn’t see him around all that much until 1971. After all, these young assistant professors were having to prove that they were ready for tenure track positions, publish or perish was the cry! Socialization for the Mathematics Department was very important. The annual Spring Softball Faculty/Graduate student game was always a big draw for a nice Saturday gathering for families, staff, and students. Tom was not a good softball player, and I loved baseball, a Dodger fan forever!
On Fridays after office closing time, sometimes some of the staff, graduate students, and faculty, would walk into the Village to the local Pizza joint and share Pizza and a glass of beer. By the way, Tom never liked beer, and that is when I started to get to know him, Tom Liggett, a music lover as I, who liked to sing as I, and enjoyed books and travel as I, the man I married on August 19, 1972.
Our blossoming courtship in the summer of 1971 was interrupted by Tom’s first sabbatical to Paris to work with Jacques Neveu, a famous probabilist at the University of Paris VI, with stops in Spain and Israel. I would meet him in December, 1971, in Indianapolis to welcome him home, and meet his parents. He wrote me 44 letters between the period of August 20, 1971 to December 28, 1971; letters which I still have and read today…
We became engaged in May of 1972. A relationship between a staff member and a faculty member, especially when a marriage was being planned required administrative approval. NEPOTISM had to be avoided. Academic personnel had to approve of Tom, and it had to be approved that I was a qualified applicant for my current job, and the Department couldn’t afford to do without me, and I was not allowed to have access to Tom’s records, etc. I turned in my master key, but I got to keep my Professor!
Tom became a tenured faculty member in 1973. It was becoming obvious that he was going to have a bright future as a young mathematician. He was awarded an Alfred P. Sloan Research Fellowship in 1973, and plans were emerging that I would retire from UCLA on July 1, 1973. We would plan a visit to Cornell University in early January, 1974 to begin a semester, where Tom would collaborate with the giants in Probability, Frank Spitzer and Harry Kesten. We left LA right after New Year’s Day to drive across the country to Ithaca NY, through the snow and cold of winter. It was fun! Tom and I loved the outdoors, the beauty of the land. This was the beginning of many travels we would share together the rest of our lives.
We had a very pleasant stay in the East. Tom enjoyed his work, and I enjoyed exploring downtown Ithaca and often lived in the Ithaca Library! I had never been this far east, and every weekend we explored central NY, the Lake Cayuga area, and even made a trip to Niagara Falls. When Spring came we headed home after attempting to learn to play tennis, and enjoyed watching Cornell play lacrosse, something you don’t see that often here on the West Coast. This trip would be our only trip we ever took together where we would be gone from Los Angeles for such an extended period of time.
The rest of 1974 became a blur of activity. We decided we wanted to buy a house when we returned from Ithaca, and between Tom’s increased mathematical activity and mathematical trips, we managed to buy our Stanwood house in September, 1974. We also wanted to start a family, and bingo, Timothy Jackson Liggett was born July 27, 1975, into another blossoming family, “Interacting Particle Systems.” We were so proud!
I have been very fortunate to have met a variety of incredibly, interesting people in my life, of course, including mathematicians, and in 1976 I had the pleasure to meet some of the best and brightest with their families, at the Saint-Flour Probability Summer School in Saint-Flour, France. This two-week summer school was held in an “old” eighteenth-century seminary building on top of a mountain. Tom had been one of the invited lecturers to teach a short course, for a group consisting of doctoral students, instructors and researchers interested in probability.
I can’t remember how I felt as a new mom with a 12-month-old little boy, hesitating about flying with Tom to Paris with Tim, but somehow, the three of us, with only an old-fashioned stroller, compared to today’s standards, flew off to Paris, took a train through the rugged mountains and ended up in an eighteenth-century seminary! Thankfully, paper diapers had just become available, but Tim was not used to drinking milk that was sitting in the kitchen, unrefrigerated in a wooden vat full of flies, and Tom the proud Dad he was, was not going to have his son drink that milk! (Tom loved to tell this story!) Yes, we were able to get milk in a carton, and fruit from the small local grocery store, and a bassinet was provided for us, and yes I could rinse out Tim’s clothes from the sink in our room, and lay them on the bushes outside our window to dry. Those were the days, my friends… Mathematics ruled the daytime. We would play cards at night, wine and conversations around the table, good food for meals, and at the end of the conference, the cooking of a lamb on a spit, the culmination of a successful meeting. Lasting friendships were made. Tom’s Saint-Flour notes were first published in 1977; the spreading of “Interacting Particle Systems” had begun.
Tom became a full professor of mathematics at UCLA in 1976. His mathematical stature was growing and in that same year he became a fellow of the Institute of Mathematical Statistics. He also loved being a dad, having our own home, and he became the gardener of the family. He loved being outside and working with his hands. He did all the painting, but was not great with plumbing or electrical work!
We had also thought about having another child and Tom was beginning to become involved with departmental administration. In 1978, he became Vice-Chair for Administration, working with Ted Gamelin, the Chair at that time. He would hold that position until 1981.
1978 became a momentous year for us, Tim would be three and our second child, our beloved daughter Amy, was born on May 31, 1978, three and a half months before she was supposed to make her debut! Knowing the amazing woman she has become, she obviously wanted to be involved with the growing accomplishments of this young Liggett family. Amy was never kept in a bubble. Yes, it was hard, raising a child with special needs; but we took her everywhere, National Park Trips, concerts, museums, Disneyland, the zoo, airplane rides to visit grandparents. We learned how to modify our lives, getting results but, with different sets of “how to do.”
As I stated earlier, Tom loved being a Dad, he was also one of the most organized, and disciplined persons I ever knew. He attended t-ball, little league games, BB games, Amy’s choral concerts, all the kids school activities, and still was able to maintain his high profile in mathematical research and teaching. He was taking on more departmental administrative duties, as well as professional duties, becoming an associate editor of the Annals of Probability in 1979–1984. Yes, and he still liked to work in the garden!
It seems like after Amy’s birth, there became a burst of activity in the Liggett household. Tom and I realized that more space would be needed in our 1947 home, and plans were emerging to add a second story. Tim’s toys were overtaking Tom’s desk, which was interrupting his mathematical output. So, plans were underway to procure an architect and a builder. A contract was signed on 7/15/80, and we were a go for construction! Tom knew every detail of the plans, and his mathematical mind certainly helped. The job was completed through sweat and tears, but it indeed was the right project to do for the family. Personally, I don’t know how we managed the early years after Amy’s birth, but with our supportive parents and dear friends, and amazing therapists and teachers for her, and yes love, and compassion for one another, we were heading toward an exciting and amazing life for our family after all.
During this time, we entertained many mathematical guests who came through UCLA, and it was always a pleasure to meet them. We also established a pattern of inviting postdocs and visiting scholars for Thanksgiving dinners. I didn’t realize that my life would be changing from home organizer, cook and bottle washer to a technical typist, but Tom needed my technical skills to complete a project he had been working on in 1985; his classic book, Interacting Particle Systems. He always gave me credit for convincing him to write this book, and now he needed a typist, someone he could work with every day who was not a technical typist in the Mathematics Department. I agreed. As Tim always said, “My Mom is just a typist!”
Technical typing was an art at that time. It involved changing symbol wheels with alphabetical wheels, and stencils were used to fill in figures not found on the symbol wheel. You needed to know how to break a theorem or a proof; it was indeed a challenge, and indeed an art. Any changes were time consuming! (My warning to Tom.) The book was published in 1985. He dedicated it to our family.
Not only was Tom’s book published in 1985, he became Editor of the Annals of Probability, and he needed an editorial assistant. Amazingly, Tom and I worked very well together on the book, and since Tim and Amy were established in their respective work part-time. The powers to be of the Editorial Board didn’t like the idea of me working at home, nor Tom hiring his wife, but Tom insisted. I was hired through the Mathematics Department which provided me with an office, but my salary was paid for by the IMS, which was also the funding source for the Annals. The Annals provided me with an old friend, a trusty IBM electric typewriter. No computers yet! No email! Everything was typed by me; editorial reports, all correspondence, of course with carbon paper copies. We had a budget for stamps! I was mailing documents all over the world.
In 1986 Tom was an invited speaker at the International Congress of Mathematicians which was a great honor for him, and it happened to be at UC Berkeley! Fortunately, with the help of a wonderful babysitter, I was able to fly up during the day to hear his talk and leave early the next day to get home to Tim and Amy. Tom was a wonderful speaker, his enthusiasm for his subject was very evident and I was so glad I could share this wonderful moment with him, and many more memorable mathematical moments during our 48 years together.
Tom’s editorship ended in 1988, as did my position, but the Mathematics Department kept me on as a casual employee for typing, and learning a new system, a computer technical typing program, AMS\( \mathrm{\TeX} \)!! Yikes!
In 1991, Tom, who was 47, became Chair of the Mathematics Department and served until 1994. During that time as Chair, he had 16 papers published, and Tim and I accompanied him one summer to Chile, Argentina, and Brazil for meetings and sight-seeing.
This was a very difficult time for the UC systems throughout California with tight budgets for the whole state. The Dean at that time was very difficult and not particularly friendly to the Mathematics Department. There were few positions available to all of physical sciences. Those were lean years, and Tom did his best to keep the morale of the Department up, and be its strong advocate. He always was a man of high standards and high principles. During this time, I was working part time as Student Affairs Assistant for undergraduate students, and then in 1992, I went back to my roots as the Graduate Student Affairs Assistant until 1998, when I officially retired again on July 1st. Our son Tim was getting married on July 11, 1998, a year after he graduated from Harvey Mudd College, and Amy had just finished her first year of college at Cal State Northridge. My how they had grown!
During Tom’s Chairmanship, we hosted many faculty dinners, and yearly Chair’s parties, and a special dinner party for an incredible staff that has always worked for the Mathematics Department. We even hosted a Colloquium Party during a power outage by candlelight, one of our highlight moments of hosting! I had to use my neighbor’s stove to bake my cake; hers was gas, mine was electric!
Tom was tired when he finished being Chair, and after he took some time off to enjoy our family pool built in 1992, he was looking forward to teaching again, and of course getting back to full-time research. In 1996 he was chosen as the IMS Wald Memorial Lecturer, and in 1997, he was awarded a Guggenheim Fellowship through 1998.
During his fellowship year, he was contemplating another book, and his second book, Stochastic Interacting Systems: Contact, Voter, and Exclusion Processes was published in 1999. This book became his 74th published work, and he typed it himself!
In the Fall of 2000, at age 56, Tom was diagnosed with diabetes. His father was a diabetic, diagnosed later in his life, and as disciplined as Tom was, he needed to make changes. No more sweets, less carbs, and more exercise. I needed to become a more creative cook; Tom did love to eat! He became a biker, first in the neighborhood, then down to the beach, and the bike path, up and down the coast he went! With a new diet, and biking, his sugar levels were under control.
The decade of 2000 became monumental for our family. Tim and Amber had bought a house in 1999, Amy graduated from Northridge in 2003 and would start her fall semester at the Claremont School of Theology, and our first grandchild, a granddaughter, Amanda Virginia Liggett was born on October 19, 2004! Wow, this was big for Tom and me. At this juncture in his mathematical career, he now had 82 published writings. He also decided that at age 60 he would accept the position of Undergraduate Vice-Chair from 2004–2006, one more administrative position he would serve for the Department. In June of 2007, Amy graduated from Seminary with a M.A. Degree in Religious Education, following in her Grandmother Liggett’s footsteps, and to top that, our second granddaughter, Jenna Ruth Liggett was born on November 1, 2007! Grandma Chris and Granddad Tom were so proud!
In early April, 2008, the magical mathematical moment came to Tom; a 6 AM phone call congratulating HIM on his election to the National Academy of Sciences!!!! At age 64, 39 years of being a UCLA mathematics professor, 88 publications, two of which were books, the crowning achievement of his career! Our family was incredibly happy for him, and he was so pleased that he could share this moment with his dad, who was able to attend a reception for him and two other Physical Science nominees at UCLA. In late April, Tom and I flew to Washington, DC for the induction ceremony, one of the most glorious and happiest occasions in our life, to be wined and dined, and even dance together at an elegant dinner held at the National Portrait Gallery.
In 2009, Tom would turn 65, and one of his former PhD students, Dayue Chen, who was now a prominent Mathematics Professor at Peking University flew to Los Angeles in late 2008 to see if Tom and I would fly to Beijing in June of 2009. Together with Enrique Andjel, another of Tom’s students, and Tom Mountford, a former UCLA colleague, Dayue wanted to host and organize a 65th birthday workshop in Interacting Particle Systems from June 15–19, 2009. Tom and I were getting tired of long-distance flying, but it was such a special occasion for Tom that we both said yes. It turned out to be an AMAZING trip and workshop with many of Tom’s mathematical friends present and former students, and of course, the students of China. Turning 65 wasn’t half that bad!
Tom decided he had one last book he would write and in 2010, Continuous Time Markov Processes: An Introduction was published. He also was very pleased with a paper that he wrote with Pietro Caputo, and Thomas Richthammer, “Proof of Aldous’ spectral gap conjecture,” which was also published in 2010.
Tom was still active in research, but teaching and administrative duties were beginning to wear him down, and I was concerned about his health. Even though his diabetes was under control, it does take a certain toll on one’s body. I was discussing with him that perhaps it was time to retire, enjoy his research and challenges of solving problems and puzzles, but take time to smell the flowers! He loved the back yard, our kids, granddaughters, and cruising. In 2010, he already had put in 41 years of teaching, research, and administrative work, served on University committees, editorial work; you name it, he did it!!
On July 1, 2011 he officially retired. He was 67, and had 100 publications, three of which were books. To help out the Mathematics Department, he came back to teach two more courses in 2012, one in the Winter, and one in the Spring. Then finally, he really was retired, but his interest in research never stopped. In 2012, he was elected to the American Academy of Arts and Sciences, another great achievement. We flew to Boston to be part of the induction ceremony at Harvard to honor the new nominees. It was a very historic moment! It also gave us a chance to rent a car and take a breathtaking trip during the changing of the colors through Massachusetts, New Hampshire and Vermont. It was beautiful.
On October 17, 2012, Tom’s appointment as Distinguished Research Professor in Mathematics for the period beginning 11/1/2012 through 6/30/15 was approved by Dean Joseph Rudnick, Physical Sciences, on authority delegated by Chancellor Gene Block. We again were so proud! Then, Tom was selected as a Fellow of the American Mathematical Society in 2013!
Life was golden for us! We were heading toward a 50th wedding anniversary, and what could be sweeter than Tom walking our beloved Amy down the aisle to marry Darren on July 13, 2013! It was magical and beautiful!!
Tom was enjoying his weekly seminar visits to UCLA, lunching with colleagues, friends at the Faculty Center, and still working in his study upstairs and talking with postdocs and fellows. He expanded his publication list to over 100, not for the count, but from enjoyment of solving of a puzzle. We were planning two exciting cruises down south, one through the Panama Canal, and then one to Lima, Peru. Tom was brushing up on his Spanish! We also planned a trip to Sedona in 2016, which would be a wonderful car trip, and also a future trip to outside of Flagstaff to take a train to the Grand Canyon! We loved traveling together, whether it was just up the coast to San Simeon, or wherever our Acura RDX would take us that wasn’t too far away.
In 2016, our son Tim was appointed Principal of Whittier High School, and Tom and I went to the meeting of the Superintendents acknowledging his appointment and we heard Tim’s speech, and we saw the influence of our family values brought forth in his commitment to the best in education for his students. Tom and I held hands, and I of course was reaching for a Kleenex.
I have been dreading writing the end of this story. It started with a decision to visit Maui, an annual trip we took for ten years before, where we rented a beautiful condo from a Canadian couple and enjoyed the lazy, hazy days for a week or so of beaches, and total relaxation from the mainland. In 2018, we rented a condo in Kihei, and on the 2nd day, Tom fell down a flight of stairs and shattered his wrist, and when we returned to the mainland he had reconstructive wrist surgery, with weeks of occupational therapy. The fall had left him with a concussion, which could have influenced other health problems along the way. We had planned a November month-long cruise touring the Amazon. Fortunately, we were able to go, due to Tom’s disciplined home wrist exercises!
When we came home at the end of 2018, he lost total hearing in his left ear, which involved seeing a hearing specialist at UCLA, and an MRI. Everything was proving negative, but the specialist wanted to either give him a shot of steroids in his ear, or have him take steroids by mouth, with the warning that it would disrupt his sugar readings. He chose the latter, and his sugar levels went wild, and our February trip to our time-share in Palm Springs was not good. When we returned home from Palm Springs, he decided to take the shot in the ear to try and help restore his hearing, and his sugar readings began to stabilize.
We knew that his former PhD students, Amber and Paul, and colleagues Marek [Biskup] and Georg [Menz] were planning a 75th birthday meeting at UCLA in his honor in March, 2019. Tom was thrilled, because many of his friends and colleagues from around the world would be coming. He was so looking forward to this meeting, and then came the worst of all things, he caught what we thought was a cold. It wasn’t, it was bronchitis, which turned into pneumonia, which turned into a hospital stay of ten days.
Tom went into the hospital on February 28, 2019, and was discharged on March 10, 2019. Saturday, March 9th was the final day of the conference, ending with a delightful dinner. We were so hoping that he would be able to attend, but it was not to be. It was a very successful conference, and Tim’s family, and Amy and Darren, and I represented the Liggetts. Darren videotaped the speeches given by Amber, Marek, Tim, Amy, and Amanda, our oldest granddaughter, and Paul. Of course, there was the entertaining Higgledy/Piggledy presented by Alexander Holroyd and Robin Pemantle! Tom and I so enjoyed watching those videos many times.
Recovery was slow. Tom had lost a lot of weight, and even though the pneumonia had been cured he still had a cough, and very low energy. He was on oxygen for four months after his discharge. We also discovered that he had suffered permanent scarring of the lungs, pulmonary fibrosis, due to an unspecified condition. Our philosophy became “one day at a time.” I say that to myself now every day.
My goal was to keep him as comfortable as possible at all times. Our last family outing was Christmas 2019, when we, with Amy and Darren, went to celebrate Christmas at Tim’s house. We knew Tom wasn’t getting any better, the doctors were not telling us that, but we knew they were thinking that. Friends were stopping by for visits. We really appreciated their friendships.
In early February, we decided I needed some extra help, and we had Gina, a very nice Latina woman come in the morning for four hours to give a helping hand. Of course, she was Spanish speaking, and she and Tom got along very well. We also decided, after discussion with our family and our primary care doctor, to enroll Tom in a hospice program. It was a very difficult decision, but it is what we both wanted for him. He was losing who he was, and he did not like that.
Tom turned 76 on March 29, 2020. Covid-19 was beginning to rage in the nation and our family took part in video calls. I especially made infrequent outings, and Darren or Gina did some shopping for me. I wanted to spend most of my time with Tom. I didn’t want to lose him, but I knew it had to be. He was ready to leave…and he did, peacefully, on May 12, 2020 at 9:35 PM.
He lives on in his publications, contributions to mathematics, and in Tim and Amber, Amy and Darren, Amanda, Jenna and me, 48 years of a lifetime of incredible memories and journeys. Your family thanks you Tom for a life well lived! We love you and miss you so!