John Toner (physicist)

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John Toner
Born(1955-10-12)October 12, 1955
Mineola, New York, United States
Alma mater
Awards
Scientific career
FieldsCondensed matter physics
Institutions
Thesis Defects and Other Topological Effects on Phase Transitions in Solids, Liquid Crystals, He3 Films, and Magnetic Systems
Doctoral advisorDavid Robert Nelson
Websitehttps://cas.uoregon.edu/directory/physics/all/jjt

John Joseph Toner (born October 12, 1955)[1] is an American physicist and professor emeritus at the University of Oregon in Eugene, Oregon. Toner's broad interests in condensed matter physics span the gamut from topics in "statistical physics and the hydrodynamics of systems ranging from hard to soft condensed matter and from passive to active systems".[2]

Education and career[edit]

Toner earned a bachelor's degree in mathematics from Massachusetts Institute of Technology in 1977. He did post-baccalaureate work in physics at Harvard University earning a master's degree in 1979 and a doctorate in 1981.[3] After his PhD Toner was the James Franck Postdoctoral Fellow at the James Franck Institute, University of Chicago, 1981–-1983. From 1983 he was at IBM's Thomas J. Watson Research Center. In 1985 and 1993 he was a visiting researcher at the University of Bordeaux, CNRS, in Bordeaux, France. He has been researching and teaching at the University of Oregon since 1995. He retired from full-time teaching in December 2023.[4]

Research and innovation[edit]

In 1995, with Yuhai Tu [de], he created what are known as the Toner–Tu equations for swarm behavior (more precisely for collective behavior of self-propelled objects that follow the behavior of their neighbors as they move).[5][6] They combined properties of the Navier-Stokes equations of the hydrodynamics of compressible fluids with simple spin models of ferromagnets and found a failure of the linearized hydrodynamic equations triggered by strong fluctuations. In contrast, their equation was able to predict the scaling exponents in the limiting case of long wavelengths. An important point is the movement of the individual objects. If one asks a large collection of people arranged in two dimensions, each of whom can only see a few nearest neighbors, to all point in the same direction, they could not do so (this is the Mermin-Wagner theorem). However, they can all walk in the same direction. The Toner–Tu equations are applicable, for example, to swarms of birds and fish, bacteria, molecular motors in cells, cancer cells and, as a model demonstration, collections of small plastic rods moving in the same direction on a vibrating table.[5]

In addition to this phase described by the Toner-Tu equation, there are other phases of active matter that Toner studies theoretically (for example, a phase corresponding to liquid crystal layers, smectic P).[7] In the incompressible case (constant density) this corresponds to a smectic liquid crystal in equilibrium, which in turn can be described by the KPZ equation (which is mostly used to describe interfaces). He also dealt with the reaction of swarms (herds) to external influences and on disordered surfaces and in disordered media.[5]

With Niladri Sarkar and Abhik Basu, Toner developed the hydrodynamic theory of flocking at a solid-liquid interface.[8] This theory has many applications to crucial movements inside the body including how carpets of cilia lining the interior of fallopian tubes give sperm a boost swimming up the tubes and how mucus is removed from the lungs.[9]

In addition to formulating the Toner–Tu equations, Toner has made contributions to a wide range of areas of condensed matter physics, including the theory of melting,[10] quasicrystals,[11] fluctuating membranes,[12] and disordered superconductors.[13]

Recognition[edit]

In 2006 Toner was elected a Fellow of the American Physical Society "for a wealth of contributions to the theory of correlations, fluctuations, topological defects, and anomalous elasticity and hydrodynamics of partially ordered phases."[14]

In 2021 Toner was chosen a Simons Fellow in Theoretical Physics by the Simons Foundation.[15]

In 2020 he received the Lars Onsager Prize with Yuhai Tu and Tamás Vicsek.[6]

In 2019–-20 he was a Gutzwiller Fellow at the Max Planck Institute for the Physics of Complex Systems in Dresden.[16]

Selected publications[edit]

  • Toner, J.,Long-Range Order in a Two-Dimensional Dynamical Model: How Birds Fly Together, Phys. Rev. Lett., Vol. 75, 1995, p. 4326
  • Toner, J. and Tu, Y. Flocks, herds, and schools: A quantitative theory of flocking, Phys. Rev. E, Vol. 58, 1998, p. 4828, [1]
  • Toner, J. and Ramaswamy, S., Hydrodynamics and phases of flocks, Annals of Physics, Vol. 318, 2005, S. 170–244
  • Toner, J. The Physics of Flocking: Birth, Death, and Flight in Active Matter, Cambridge University Press; 2024.[2]

References[edit]

  1. ^ Toner, John (2005). "Birth and career dates". American Men and Women in Science. Gale Thomson.
  2. ^ "L a u d a t i o: Prof. Dr. John Toner" (PDF). Retrieved 2024-03-20.
  3. ^ "John Toner". The Mathematics Genealogy Project. Retrieved 2024-03-20.
  4. ^ "College of Arts and Sciences". John Toner. Retrieved 2024-03-20.
  5. ^ a b c "John Toner". University of Oregon WordPress Hosting – Educational blogs from our community. Retrieved 2024-03-19.
  6. ^ a b "A short equation delivers a big award for a UO physicist". Around the O. 2019-11-12. Retrieved 2024-03-19.
  7. ^ Ngo, S.; Romanczuk, P.; Chen, L.; Toner, J.; Chaté, H. (2016). "Emergent smectic order in simple active particle models". New Journal of Physics. 18 (071001).
  8. ^ Sarkar, Niladri; Basu, Abhik; Toner, John (2021-12-23). "Hydrodynamic theory of flocking at a solid-liquid interface: Long-range order and giant number fluctuations". Physical Review E. 104 (6). arXiv:2102.02534. doi:10.1103/PhysRevE.104.064611. ISSN 2470-0045.
  9. ^ "Physics of cilia explain sperm's successful swimming". Around the O. 2022-01-18. Retrieved 2024-03-19.
  10. ^ Logan, Jack; Michelson, Aaron; Paattammattel, Ajith; Yen, Hanfei; Gang, Oleg; Tkachenko, Alexei (2023). "Symmetry-specific characterization of bond orientation order in DNA-assembled nanoparticle lattices". The Journal of Chemical Physics. 159: 154905.
  11. ^ Widom, Michael; Mihalkovič, Marek (2023-10-16). "Quasicrystal Structure Prediction: A Review". Israel Journal of Chemistry. arXiv:2308.09192. doi:10.1002/ijch.202300122. ISSN 0021-2148.
  12. ^ Toner, J. (1989). "Elastic anisotropies and long ranged interactions in solid membranes". Phys. Rev. Lett. 62: 905.
  13. ^ Le Doussal, Pierre (2010-08-30). "NOVEL PHASES OF VORTICES IN SUPERCONDUCTORS". International Journal of Modern Physics B. 24 (20n21): 3855–3914. doi:10.1142/S0217979210056384. ISSN 0217-9792.
  14. ^ "APS Fellow Archive". American Physical Society. Retrieved 19 March 2024.
  15. ^ "Simons Fellows in Theoretical Physics". Simons Foundation. 2017-07-18. Retrieved 2024-03-20.
  16. ^ "Martin Gutzwiller Fellow". Welcome to the Max Planck Institute for the Physics of Complex Systems. 2023-12-11. Retrieved 2024-03-12.

External links[edit]

  • University of Oregon departmental website [3]
  • John Toner's website [4]
  • John Toner on Google Scholar [5]
  • John Toner's page on German Wikipedia [6]
  • John Toner's profile on MathSciNet [7]
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