Physics at Brown NEWS FOR ALUM N I an D FRIE N DS 2007 ISSUE GREETINGS FROM THE CHAIR - SP RING 2008 elcome to another issue of the Brown Physics newsletter. the rank of Associate Professor with tenure. We also report on WI wrote three years ago, during my first term as the some notable faculty achievements for the past year. department chair--with a committed faculty, dedicated staff, enthusiastic students, supportive administration, and engaged e continue the tradition of highlighting the research of alumni and friends--that the future of physics at Brown looked Wour 2007 Galkin Foundation Fellow on page 2. Also bright. Many things have taken place since then. Here we the effort in enriching our physics instruction continues. Three highlight some of the activities of the past year. new courses are offered this year and proposals for three new physics concentrations are under way. Other noteworthy 007 marked the 50th anniversary of the BCS Theory activities include WiSE, Poster Session, UTRA Awards, 2of Superconductivity. We honored Prof. Leon Resource Center, etc. In addition, community outreach Cooper with a two-day symposium on April remains a priority for the Department with a weekly 12-13. A brief description of this event is open house at Ladd and a greatly expanded five- provided on page 3. year NSF supported GK-12 program. e also report on the establishment hanks to a generous gift from his family, an Wof the Institute for Molecular and TAnthony Houghton Prize will be awarded Nanoscale Innovation, which represents an annually for the best theoretical thesis. Thanks to expansion for the newly created Center for gifts from friends of Prof. Kyungsik Kang, a special Nanoscience and Soft matter (CNSSM), initially lecture on High Energy Particle Physics will be held proposed by physics, chemistry and engineering. I on April 25, 2008. Lastly, we also welcome two new am pleased to announce that Prof. Gang Xiao has agreed to members of our staff, Ms. Elizabeth Barlow and Ms. Susan serve as the first Director of CNSSM. In addition, please join Mattraw as Financial Administrator and System Administrator, me in congratulating Professor Jay Tang for his promotion to respectively. FALL 2007 IN C OMING CLASS Mr. Michael Antosh Mr. Pengyu Liu University of New Hampshire, University of Sci. & Durham Tech. of China Ms. Saptaparna Bhattacharya Mr. David Malling Indian Inst. of Tech., Madras Syracuse University Mr. Andrew Blaeser Mr. Ryan Michney Boston University Dartmouth College Mr. Jeremy Chapman Ms. Mirna Mihovilovic Syracuse University University of Zagreb Mr. Richard Cook Mr. Florian Sabou University College, London Babes-Bolyai University Mr. Alex Geringer-Sameth Mr. Antun Skanata Washington University University of Zagreb Mr. Carlos Hernandez Faham Mr. Son Le Mr. Chenjie Wang Arizona State University Hanoi University of Technology University of Sci. & Tech. of China Mr. Ilyong Jung Mr. Chao Li Mr. Congkao Wen Kyungpook National University University of Sci. & Tech. of China Zhejiang University PAGE 1 PHYSI C S AT BROWN 2007 GALKIN FELLOW - YONGXING GUO ongxing Guo, the 2007-2008 Galkin foundation fellow, is correspond to periodic variations of the fluorescence and Ycompleting his Ph.D. dissertation research on Microtubule birefringence intensity. Moreover, the variations could be birefringence patterns. For the past four years Yongxing has explained by presuming that the MT’s form bundles that take conducted research at Brown on a sinusoidal shape. The University, with his advisor sinusoidal undulations produce Prof. James Valles, in frequent the striations provided all of collaboration with Prof. Jay Tang the sine waves are locally in and his graduate student Yifeng phase and neighboring sine Liu. waves “nest” together. The predicted density variations he viability of cells relies on from this nested geometry Tlarge molecules self organizing are in quantitative accord into structures that support their with the measured data. The shape and carry out the functions temporal evolution of the essential to life. A great deal patterns revealed a surprising of effort has focused on the mechanism. It showed that mechanisms controlling and driving MTs that are aligned by their self assembly. Yongxing Guo, magnetic field or flow during a Galkin Fellow, has been investigating how a ubiquitous bio- the initial stages of polymerization form bundles. The bundles, polymer manages to self assemble into a macroscopically which polarize light, elongate and buckle in coordination with visible structure. His work, while carried out in a test tube, their neighbors. These buckled bundles create the birefringent nevertheless has provided insight into mechanical processes stripes. This work was published in Proceedings of the that can underlie biological pattern formation. National Academy of Sciences, U.S.A. ore than 10 years ago, workers discovered the he observations suggested a mechanical model for the Mspontaneous development of zebra-like stripes (see Tprocess, which Yongxing went on to develop aided by figure) in a solution of polymerizing Microtubules (MTs). discussions with Professor Alan Bower. The model asserts MTs are hollow cylindrical filaments composed of protein that an individual MT bundle elongates through continued subunits (tubulin) that form and grow rapidly in length when polymerization and buckles within the elastic network formed their solution is warmed to near body temperature. Because by the other bundles and unbundled microtubules. The stress these bio-polymers serve as major driving the buckling originates components of the eukaryotic cell in the elongating bundle pressing cytoskeleton, the stripe finding against its surroundings. A normal suggested an origin for structures mode stability analysis of the observed in some cells. Models model shows that the characteristic for the symmetry breaking process wavelength and critical buckling giving rise to the striated pattern force are determined by the were proposed, but none had been properties of the bundles and their quantitatively verified. Yongxing, neighboring elastic network. By in close collaboration with fellow graduate student Yifeng analyzing the time lapse phase contrast microscopy images of Liu and supported by NASA, initially attacked this pattern the pattern and using cutting edge image analyzing algorithms formation problem using quantitative microscopy techniques. created by Yongxing, the local MT bundle alignment directions Those experimental investigations led to a microscopic view were obtained, from which the MT bundle contour lengths of and a quantitative model for the pattern formation. were measured. The same growth rates among different MT bundles revealed that the MT bundles elongate uniformly ongxing applied quantitative fluorescence and along their contour during buckling and polymerization occur Ybirefringence (i.e. polarization) imaging techniques to uniformly along the bundles. This work was published in see the MT striations develop. He found that the striations Physics Review Letters. continued on page 10 he Galkin Foundation Fellowships are funded through a generous donation by Mr. Warren Galkin, Class of 1951. Each year T the Fellowship recognizes exceptional promise and achievement in physics by a senior graduate student. PAGE 2 PHYSI C S AT BROWN AO WILLIAMS The A. O. Williams lecture of 2007 was of Illinois at Urbana-Champaign. He delivered by Prof. Joseph Taylor from received his Ph.D. from the University Princeton to a packed auditorium. During of Cambridge (U.K.) in 1982, and for the the day, Prof. Taylor met with faculty and years 1982-1985 was a postdoctoral fellow engaged in a lively lunchtime discussion at the Institute for Theoretical Physics, with graduate students on science and University of California at Santa Barbara. careers in science. Prof. Goldenfeld has been an Alfred P. Sloan Foundation Fellow, a University Prof. Taylor and Russell Hulse (his Scholar of the University of Illinois, a former graduate student) were jointly recipient of the Xerox Award for research, awarded the 1993 Nobel Prize in Physics and a recipient of the A. Nordsieck award for their discovery of a binary pulsar which enabled many tests for excellence in graduate teaching. In of general relativity, and, in particular, the first evidence for the 1996, he co-founded NumeriX, a company that specializes in existence of gravitational waves. high-performance software for the derivatives marketplace. The Department is looking forward to the A. O. Williams lecture Prof. Goldenfeld is a member of the Editorial Board of the of 2008, which will be delivered by Prof. Nigel Goldenfeld from International Journal of Theoretical and Applied Finance and is a the University of Illinois. Prof. Goldenfeld holds a Swanlund Fellow of the American Physical Society. Endowed Chair and is a Professor of Physics at the University 2007 COO P ER CONFEREN C E condensation. A A series of two-day symposium, public lectures under “50 Years of the BCS Theory “Superconductivities; from Mystery of Superconductivity”, was held to Mastrery” was held in the afternoon. during April 12-13, 2007 at Brown, Dr. Alexis P. Malozemoff, (American highlighting and celebrating the 50th Superconductor Corporation), lectured on: “New anniversary of the theory of superconductivity. The Horizons for Superconductor Applications: the BCS theory stands as an outstanding achievement Electric Power Grid”. Prof. Leon Cooper also gave in the development of twentieth century knowledge a lecture on: “Supercondutivity