Pierre Auger Observatory

James W. Cronin – Founding Father of the Pierre Auger Observatory, 1931-2016


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James W. Cronin (University of Chicago)


The Pierre Auger Collaboration sadly shares the news that James W. Cronin, Professor Emeritus at the University of Chicago and spokesperson emeritus of Auger died on 25 August, at the age of 84.

Born in Chicago, Illinois, on 29 September 1931, graduated with a PhD in physics in 1955, James Cronin shared the 1980 Nobel Prize for Physics with Val Fitch for their 1964 discovery that decaying subatomic particles called K mesons violate a fundamental principle in physics known as "CP symmetry."

After his prizewinning work, he eventually turned his research to cosmic rays and he was a founding father of the Pierre Auger Observatory, the world's largest cosmic-ray detector, which he conceptualized in 1992 with fellow physicist from the University of Leeds Alan Watson.

In his Nobel biographical statement, he emphasized the importance of his family to his career. “On even the worst days, when nothing was working at the lab, I knew that at home I would find warmth, peace, companionship, and encouragement. As a consequence, the next day would surely be better.”

Our thoughts and deepest sympathy go to his family, his wife, children and grandchildren.

The University of Chicago invites colleagues to honor the life of Professor James Cronin and share with his family, friends, and colleagues memories of his great accomplishments. A Science Symposium will take place on the afternoon of Friday September 30th followed by a Memorial on the morning of October 1st ending with a luncheon.

If you are interested please contact Angela V. Olinto (http://astro.uchicago.edu/people/angela-v-olinto.php).

James Matthews<br/>Louisiana State University, USA

James Matthews
Louisiana State University, USA

     The scientific world is less today than it was yesterday. And we have all
     lost a very good friend.
     Attached picture is from the 1991 Dublin ICRC. This was close to the "birth"
     of Auger, when Jim was first connecting with Alan [Watson]. The picture
     is of the CASA-MIA group in attendance. I recall that when we got together,
     instead of going over our talks, Jim chatted with us about 1020 eV
     cosmic rays!
     Picture: From left to right,
     Back Row: Dave Nitz, Jack van der Velde, Jim Matthews, Jim Cronin, Hans
     Krimm, Corbin Covault;
     Front Row: Brian Fick, Kevin Green, Tim McKay, Rene Ong, Alex Borione
     at the Trinity College, Dublin Ireland, August 1991, for the 22nd
     International Cosmic Ray Conference.

See Picture

David Nitz<br/>Michigan Technological University, USA

David Nitz
Michigan Technological University, USA

     I'm so sorry to hear this news. As you know, to a very large extent, I
     owe my professional career to Jim. He has always been a kind friend and
     benefactor to me, starting from the early days of CASA-MIA. I fondly
     remember the times I accompanied JIm on some trips in the early days to
     sell Auger. The one to Bariloche in October, 1995, on occasion of the
     Argentine Physical Society meeting, where I met Louis Masperi, Alberto
     Etchegoyen, and Ron Shellard especially stands out.

José Valdes Galicia<br/>Universidad Nacional Autónoma de México, México

José Valdes Galicia
Universidad Nacional Autónoma de México, México

     I am very glad to have had the opportunity to meet and become friend of
     an extraordinary scientist and an extraordinary person as Jim Cronin. We
     have all lost a leader and a great human being.
     We will miss him miserably.

James Beatty<br/>Ohio State University, USA

James Beatty
Ohio State University, USA

     Jim’s passing is sad news to all that knew him as a physicist, teacher,
     and friend. The many intellectual and personal moments we shared with
     him left a lasting impact.

Maria Teresa Dova<br/>IFLP, Universidad Nacional de La Plata, Argentina

Maria Teresa Dova
IFLP, Universidad Nacional de La Plata, Argentina

     Jim was a dreamer and a visionary, we owe to him the development of
     the cosmic ray research activities in Argentina, and in particular in La
     Plata. I am very very sad... We will miss him greatly.

Stephane Coutu<br/>Pennsylvania State University, USA

Stephane Coutu
Pennsylvania State University, USA

     We at Penn State are reeling from the shocking news. Jim was an
     astounding physicist, preeminent but always approachable, just an
     all-around wonderful human being. We all owe him a great debt of
     gratitude. Our thoughts are with all who were closest to him.

Valerio Verzi<br/>INFN, Sezione di Roma, Italy

Valerio Verzi
INFN, Sezione di Roma, Italy

     No words for this sad news. Please give the condolences to his family
     and friends also from my family who had the lucky chance to know Jim
     in a beautiful dinner in Malargue.

Paul Mantsch<br/>Fermi National Accelerator Laboratory, USA

Paul Mantsch
Fermi National Accelerator Laboratory, USA

     We have all lost an exceptional physicist, a wise leader and good friend.
     It was a great privilege and honor to work with Jim Cronin on the Pierre
     Auger Observatory. What follows are some of my recollections of the
     tevents hat, under Jim’s inspired leadership, led to the construction
     and operation the world’s largest cosmic ray observatory.

Read More

Lawrence Wiencke, Fred Sarazin<br/>for the Colorado School of Mines, USA

Lawrence Wiencke, Fred Sarazin
for the Colorado School of Mines, USA

     This is very sad news. Jim was a fearless scientist, and visionary who
     inspired many of us. As David Nitz noted, Jim made a real difference in
     opening opportunities many of scientists in their careers. I'm another
     of the many who owe a lot to Jim, over decades at this point.
     Jim was inspiring in may ways. For example, he holds the distinction of
     having been awarded an (honorary) doctorate from Mines years before any
     doctorates for astrophysics research were awarded.
     This is a somber day for me and Fred and the Mines group.

Glennys Farrar<br/>New York University, USA

Glennys Farrar
New York University, USA

     This feels like a chapter of physics ending, and is very poignant
     professionally. Its hard to imagine today -- Christenson, Cronin, Fitch
     and Turlay 1964: four people "accidentally" discover CP violation! Yet,
     to Jim's and Alan's huge credit, they recognized that some problems
     require big collective efforts and together they had the courage to
     create Auger and pioneer a new paradigm of such effort, putting UHECR
     research onto a totally new footing. Jim’s conviction that comparably
     deep and unexpected discoveries may await us in UHECRs as for kaons,
     should be an inspiration for AugerPrime — now pushed forward by an
     upcoming generation of young (joined by not-so-young, but equally
     committed) physicists.
     I feel blessed personally to have known Jim. He was a giant among
     experimentalists: what an incisive mind and with such a sense of
     elegance! It forced theorists to appreciate him, in spite of his
     professed distain for theory ;-) !
     Tony* [Glennys' husband] joins me in sending condolences to
     Jim’s wife and children for this painful loss.
     *I don’t know whether I ever mentioned it, but Jim was one of Tony’s
     professors as an undergrad at U. Chicago; Jim urged him to stay at U.
     Chicago and become an experimentalist — advice that Tony came to fully
     appreciate only much later, after having chosen instead to go to Caltech
     and get a Ph. D. with Gell-Mann.

Carola Dobrigkeit<br/>for the Brazilian Auger Collaboration

Carola Dobrigkeit
for the Brazilian Auger Collaboration

     This is so very sad news.
     Probably we are not able to value correctly the dimension of Jim's
     contributions to Physics, particularly to the conception, construction
     and operation of the Auger Observatory.
     He visited Brazil many times, always giving seminars, talks, and
     lectures. He was always engaged in getting support for his ideas. His
     enthusiasm touched so many of us and inspired us to join the collaboration.
     His presence in our meetings in Malargüe contributed to create an
     atmosphere of excellence in research that will remain long after the
     goals of the Observatory have been fulfilled.
     We send sincere condolences from all Brazilian friends and collaborators
     to Jim's family.
     The Brazilian Auger Collaboration -
     Carola Dobrigkeit, Ronald Shellard, Carlos Escobar, José Augusto
     Chinellato, Vitor de Souza, Anderson Fauth, Ernesto Kemp, Edivaldo
     Santos, Ernesto Kemp, João Torres, Marcelo Leigui, Rogerio Menezes,
     Carla Bonifazi, Ivone Albuquerque, Philippe Gouffon, Carlos Todero,
     Germano Guedes, Rita dos Anjos, Iuri Pepe.

Giorgio Matthiae<br/>INFN, Sezione di Roma, Italy

Giorgio Matthiae
INFN, Sezione di Roma, Italy

     This is indeed very sad news. I have read your message with great
     sorrow. We all know that Auger is the result of the brilliant vision
     of Jim, a great scientist and a dear friend.
     My most sincere condolences to the family.

Sijbrand de Jong<br/>for the Dutch Auger Collaboration

Sijbrand de Jong
for the Dutch Auger Collaboration

     With great sadness we heard about the passing away of Jim Cronin.
     But also with gratitude for the paramount role Jim played in
     establishing the Pierre Auger Observatory. And with affection we
     remember Jim's kind and gentle personality combined with his sharpness
     and precision on the physics.
     The Dutch Auger group -
     Ad van den Berg, Stijn Buitink, Heino Falcke, Joerg Hoerandel, Sijbrand
     de Jong, Olaf Scholten and Charles Timmermans.

Iliana Brancus<br/>for the Romanian Auger Collaboration

Iliana Brancus
for the Romanian Auger Collaboration

     This is a very sad news.
     Jim Cronin had the vision and the force to put the international
     community in collaboration to make alive Auger Observatory. He
     encouraged Romania to participate in such complex unique experiment.
     We remember him as a kind person and an excellent scientist.

Henryk Wilczynski<br/>for the Polish Auger Collaboration

Henryk Wilczynski
for the Polish Auger Collaboration

     It is with deep sorrow that I read the message.
     Jim was an extraordinary scientist, leader and friend. We owe him a lot.
     I think we all are very grateful to Jim for the great scientific adventure
     we are involved in. The Pierre Auger Observatory will remain a
     monument to his visionary leadership, scientific ingenuity and
     We will miss him very much.

Thomas Hebbeker, Martin Erdmann<br/>for RWTH Aachen University, Germany

Thomas Hebbeker, Martin Erdmann
for RWTH Aachen University, Germany

     With great sadness we read the news. With Jim we have met an
     outstanding scientist with major influence on particle and
     astroparticle physics - connected to his way of actively contributing
     at all levels and his charisma. With all physics achievments Jim was
     approachable for everyone, it was pleasant to talk to him - he took
     seriously every person from the youngest to the oldest.

Corinne Berat<br/>for the French Auger Collaboration

Corinne Berat
for the French Auger Collaboration

     We are all very sad to hear that Jim passed away. It is difficult to
     add to the nice words of everyone. Jim was indeed the father of our
     project but he was much more than that, such an inspiring example,
     so bright and enthusiastic, dedicated and convincing, but at the
     same time human and kind with everyone. Although this would have
     hurt his legendary modesty, we owe him so much.
     We French colleagues would also like to recall the friendly link that
     Jim had with France, his frequent visits to Paris and his crucial role,
     together with his very close friend Murat Boratav, in fostering a
     French participation.
     Jim, Murat, Gianni, we indeed feel orphan, but with an immense human
     and intellectual heritage to keep alive. We will remember one of Jim's
     favourite sentences : "You just have to look to the data", that was
     saying everything.
     Our sincere condolences to the family.

Read More

Markus Risse, Peter Buchholz<br/>for the Universität Siegen, Germany

Markus Risse, Peter Buchholz
for the Universität Siegen, Germany

     We are very sad about the passing of Jim. Our sincere condolences to
     his family and close friends.
     We all owe Jim a lot, as very well described in the "Festschrift"
     Alan circulated just recently about the genesis of the Auger Observatory.
     It was a great privilege to work together with him.
     Jim dedicated his 2003 TAUP report to the memory of John Linsley,
     writing: "I only wish that he could witness the progress that is going
     to be made. I cannot avoid the fantasy that he is now in a position to
     know all the answers!"
     Jim is leaving many good tracks, both in science and in our hearts.
     May he rest in peace.

Ralph Engel<br/>for the KIT, Germany

Ralph Engel
for the KIT, Germany

     We all have read the news with deep sadness. Jim was a visionary
     leader, excellent scientist, a humble person, and dear friend to many
     us. And as all of us know, he was not only a very sharp thinker but
     also working extremely hard. Even frequent travel and time shifts
     could not reduce his enthusiasm and his charisma. It is very hard
     loosing such a special person, not only from the perspective of the
     Pierre Auger Project.
     We will always remember Jim as an absolutely outstanding scientist
     and person, and will continue following his vision on UHECR science.
     We express our condolences to his family and close friends.

Lorenzo Cazon<br/>LIP, Portugal

Lorenzo Cazon
LIP, Portugal

     These are so sad news.
     It was an honour to have known Jim and worked with him in Chicago
     as a post-doc. It was so easy to approach him and discuss anything,
     despite he was order of magnitudes above you. I specially remember
     him encouraging the young people to achieve the best, and to dare.
     He will always be an inspiration.
     My deepest sympathies to you, his friends and family.

Sendic Estrada Jiménez<br/>for the Universidad Autónoma de Chiapas, México

Sendic Estrada Jiménez
for the Universidad Autónoma de Chiapas, México

     We are deeply sorry for the death of Prof. Cronin. From the colleagues
     in Chiapas we know he has always supported the participation of the
     Mexican cosmic ray community in the Pierre Auger Observatory and
     encouraged the development of science in Latinamerica.
     We transmit to Prof. Cronin’s family our sincere condolences.
     In the name of the Chiapas Auger group (Arnulfo, Karen, Itzel, Pedro
     and Hernán).

Karen Salome Caballero Mora<br/>Universidad Autónoma de Chiapas, México

Karen Salome Caballero Mora
Universidad Autónoma de Chiapas, México

     I met Prof. Cronin during several conferences and collaboration
     meetings and I was very glad to hear his opinion on the work we were
     doing on mass composition in a time when the topic started to reveal
     very new and unexpected results. He was very excited and happy about
     our efforts. I remember him very bright, listening to most of the
     meeting's talks and dancing during the dinners in Malargüe.
     We will miss him a lot.

Paolo Privitera<br/>University of Chicago, USA

Paolo Privitera
University of Chicago, USA

     Many here in Chicago – including Angela and I – worked closely with
     Jim and had the privilege of his friendship. Jim was a "magister" of
     science and life, of a disarming modesty that pertains only to the
     greatest souls.
     I will deeply miss his humanity and his tender affection for my family.

Guenter Sigl<br/>Universität Hamburg, Germany

Guenter Sigl
Universität Hamburg, Germany

     I am shocked to see these bad news after coming back from a few days
     without internet.
     I still vividly remember my great time as a postdoc at Chicago when
     from time to time I would just spontaneously walk up to Jim's office
     to discuss cosmic rays with him. It struck me that he always took the
     time to talk although he surely had more important things to do than
     ground the sometimes rather crazy speculations of a theorist.
     He will sorely be missed.

Ronald Shellard<br/>Centro Brasileiro de Pesquisas Fisicas (CBPF), Brazil

Ronald Shellard
Centro Brasileiro de Pesquisas Fisicas (CBPF), Brazil

     Jim, came many times to Brazil and delivered many talks to big
     audiences. It was always a success, even when the audience came from
     other areas of science.
     An image that is always associated to Jim is his habit of rubbing his
     long fingers when explaining something, as if he was immersed in a dream.
     His inspiration, for us Brazilians, was essential for a strong
     participation on the construction and operation of the Pierre Auger
     Observatory, which we are very proud of.
     He will be missed by all of us, who were already longing from his
     presence in the Auger meetings in Malargue.

Read More

Sergio Petrera<br/>Università dell'Aquila, Italy

Sergio Petrera
Università dell'Aquila, Italy

     We are very sorry for the sad news. Jim's heritage will remain for ever
     in Auger.

Mário Pimenta<br/>for the Portuguese Auger Collaboration

Mário Pimenta
for the Portuguese Auger Collaboration

     We are all in Portugal deep sorrow for such sad new. Jim will remain
     for all of us an extraordinary human and scientific example.

Tiina Suomijärvi<br/>IPN-Orsay, France

Tiina Suomijärvi
IPN-Orsay, France

     We are all very sorry to hear this sad news.
     Jim interacted with everybody in the Auger observatory. He knew by
     name most of the collaborators, students and staff members. I
     remember how honored and pleased the observatory technicians were
     when Jim went to the field to work with them and then joined their
     families in the evening for dinner. For Jim, the contribution of
     everybody was important and he knew all the details of instruments,
     data analysis and Physics.
     Jim Cronin will remain in our memories as not only an extraordinary
     scientist but also a kind and caring person.
     Sincere condolences to Jim’s wife and family.

Antoine Letessier-Selvon<br/>LPNHE, France

Antoine Letessier-Selvon
LPNHE, France

     Jim is and will remain the heart of Auger, I do not see our future

Lukas Nellen<br/>UNAM, Brazil

Lukas Nellen
UNAM, Brazil

     These are sad news indeed and a great loss for Auger and the scientific
     community. At the UNAM, we remember him warmly as a great person, as an
     excellent scientist, and as our mentor when we started on Auger. Our
     thoughts are with him and his family.

Enrique Zas<br/>Universidad de Santiago de Compostela, Spain

Enrique Zas
Universidad de Santiago de Compostela, Spain

     It is so sad to hear this news.
     We all owe so much to Jim and he will remain always in our minds.
     He lead us by example as a scientist and also as a person.

Ingo Allekotte<br/>for the Centro Atómico Bariloche, Argentina

Ingo Allekotte
for the Centro Atómico Bariloche, Argentina

     In the Bariloche group we are all very sad for this news. We will
     always remember Jim, not only as a scientist who made fundamental
     contributions to physics, but also as a wonderful person who shaped
     this beautiful international endeavour which is the Auger
     Collaboration. We send to his family and close friends our condolences,
     and our everlasting thankfulness to Jim.
     Diego, Silvia, Xavier, Esteban, Mariano, Hernan, Geraldina, Ingo

Arnulfo Zepeda<br/>Universidad Autónoma de Chiapas, México

Arnulfo Zepeda
Universidad Autónoma de Chiapas, México

     Professor James W. Cronin (Jim Cronin), was the person that invited
     Mexico to join the Pierre Auger Project.
     From this invitation the first national involvement of Mexico in a
     international project was born. Jim honored further Mexico by
     accepting the honorary membership (member correspondent) of the
     Mexican Academy of Sciences.
     The contributions of Jim, to the development of cosmic ray physics,
     to the establishment of the first international collaboration at a
     global level, to the design of physics courses in experimental
     physics, and to the establishment of the fundamental laws of
     physics that distinguish matter from antimatter, for which he
     received the Nobel Prize, are highly valued by all of as who had
     the opportunity of interacting closely with Jim, as well as by many
     who had the chance of attending his lectures, public talks, his
     participation in the Science Auger fair and in many other aspects of
     live, education and science.
     Mexico was highly benefited from his friendly and dedicated attention.

Paul Clark<br/>Leeds University, UK

Paul Clark
Leeds University, UK

     It was such a privilege to have met and worked with Jim. His record
     of life achievment is of course stellar but he was just such a nice
     guy to know too. Looking back now, it was obvious that Auger would
     succeed right? No, not true at all, it required the sustained belief
     and commitment of many teams of hardworking bright people from all
     round the world to achieve the reality. And what was it that set
     these teams of bright people on the path? It was the vision, passion
     and belief of Jim and Alan that drew together the unique collaboration
     that built Auger and went and got the data. We all shared that dream
     together, and what a rare opportunity it was too. We have all lost a
     father and friend today, but what a legacy he left us.