Harvard University Department of Physics Newsletter FALL 2016 Taking On The “Big Three” Enigmas in Cosmology Today Faculty News History of the Physics Dept.: Reflections on Sidney Coleman On the Edge of the Unknown: Data from the Large Hadron Collider at CERN Professor Hawking Pays a Visit FALL 2016 “Black holes obey an elegant and simple equation that CONTENTS incorporates quantum mechanics, general relativity, and the laws of thermodynamics.” Andrew Strominger said ON THE COVER: at an April 2016 event inaugurating the Black Hole Initiative. Letter from the Chair .................................................................... 2 The equation, which was developed both by Hawking and Cosmic Expansion. Letters from our Readers ................................................................. 3 the physicist Jacob Bekenstein, shows that the entropy of Observations by the High-z a black hole is proportional to the area of the invisible, Supernova Search Team, described FACULTY DEPARTMENT HIGHLIGHTS by Robert Kirshner, hint that we spherical surface surrounding it called the event horizon. Faculty Prizes, Awards, and Acknowledgments 4 live in a “stop and go” universe ......................................... Strominger ranked this formulation among “the three whose expansion slowed under th Glauber & Wilson’s 90 Birthdays ........................................................ 5 most important equations in the last century,” along with the influence of gravity before Paul Martin’s passing 6 Einstein’s equations of gravity (general relativity) and the accelerating again due to an ..................................................................... unexplained dark energy. This Ashvin Vishwanath: Making All the Right Moves 7 Heisenberg Uncertainty Principle. ......................................... artist’s conception illustrates the Professor Hawking Pays a Visit p. 22 history of the cosmos, from the COVER STORY Big Bang and the recombination epoch that created the microwave Taking on the “Big Three” Enigmas in Cosmology Today ................................8 background, through the Douglas Finkbeiner: Searching for Elusive Dark Matter 11 ................................ formation of galactic superclusters Christopher Stubbs: The Quest to Characterize Dark Energy 12 and galaxies themselves. The .......................... dramatic flaring at right Cora Dvorkin: Uncovering the Explosive Truth Behind the Big Bang 13 ................... emphasizes that the universe’s expansion currently is speeding up. FOCUS Image courtesy: David A. Aguilar, History of the Physics Dept—Reflections on Sidney Coleman 14 Harvard-Smithsonian Center for ......................... Astrophysics FEATURED On the Edge of the Unknown 18 ............................................................ Professor Hawking Pays a Visit 22 ACKNOWLEDGMENTS ......................................................... AND CREDITS: PROGRAMS Newsletter Committee: Undergraduate Program 26 Professor Masahiro Morii ............................................................... Professor Gerald Holton Renewing Leverett House Professor Paul Horowitz Graduate Program 30 Professor John Huth ...................................................................... Professor Howard Georgi Goldhaber & Merit Awards Professor Erel Levine Graduate Awards & Fellowships Dr. Jacob Barandes Recent Graduates Dr. David Morin Anne Trubia Research Scholars 37 ...................................................................... Production Manager Trevor David Rhone: Probing the Nature of Exotic Matter in the Flatlands of Physics Mary McCarthy The Work of this Bershadsky Fellow is Truly Magnetic Science Writer & Editor Steve Nadis NEWS Image and Permissions Lead Faculty in the News 40 ..................................................................... Marina Werbeloff Celebrating Staff ........................................................................ 44 Design Letters from our Readers continued (inside back cover) Alphabetica, Inc. ................................. Department Events (back cover) (back cover) ............................................ Computer-simulated image of a black hole PHYSICS AT HARVARD FALL 2016 1 Credit: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI) Letter from the Chair Letters from our Readers* WE THOROUGHLY ENJOYED HEARING FROM OUR READERS. HERE IS WHAT SEVERAL HAD TO SAY: Dear friends of Harvard Physics, its strength by attracting outstanding scholars of all stripes in a sort of Organic Faculty The spring semester is almost over, and the Law Development. School yard behind the Jefferson Laboratory “I’m delighted with this new publication, “Professor Gerald Holton’s early history of appears to be teeming with life under what is Speaking of faculty development, I am happy to which not only keeps me in touch but also Edward Purcell brought back many happy presently a clear blue sky. Whatever they’ve report that Ashvin Vishwanath, a rising star in revives many fading memories.” memories of my Harvard Physics major been doing with “organic landscaping” seems condensed matter theory, has accepted a frank chen (Field of Concentration in the Harvard-speak to encourage dandelions and clovers to thrive position as Professor with tenure. Ashvin will ab ’50, ma ’51, phd ’54 of 1951–55)… Harvard then had an insidious where there used to be a uniform flatness come to Harvard this fall. You will find his practice of assigning its first/introductory of lawn. It’s less stately, perhaps, but also profile on page 7. less monotonous and, therefore, somewhat courses to the best lecturers. Every course leads Just as we go to press, I received the wonderful more pleasing to the eyes and stimulating to you to want to major in that subject… Professor news that Roxanne Guénette will be joining us “I want to thank you for sending me a copy of the the mind. Purcell’s lectures were so popular that guys as Assistant Professor of Physics, starting July “Harvard Physics Newsletter, which I have just would bring their football game dates to his In this issue of the Department of Physics 2017. Roxanne is an experimental particle spent a very enjoyable hour browsing through. Saturday noon lectures, skipping the Band Newsletter, we are highlighting our faculty in physicist who studies neutrino oscillation. Stay Physics has changed almost unimaginably since pre-game recital, to hear his memorable cosmology. It’s a relatively new field for our tuned for a feature article on her research in the I stopped being active myself… I got my AB in introduction of new topics then. In addition, I Department, which traditionally did not include next issue of the newsletter. Physics from Harvard in 1948. Note that in order astronomy-related disciplines. The Department couldn’t get over having a recent Nobel laureate In the last issue of the newsletter (Fall 2015), to get an AB rather than a SB I had to pass a has been strategically growing its cosmology come by my laboratory bench and ask me about I mentioned the newly-established Bershadsky tough exam in Latin! (The AB was considered to faculty since the early 2000s. The faculty my experiment.” Distinguished Visiting Fellowship in Physics. have more cachet at the time, and I had had four members featured in this issue—Cora Dvorkin, We have had three Fellows in the past year: terry lilly Doug Finkbeiner, and Chris Stubbs—seek years of Latin in secondary school.) I remember Profs. Sergio Cecotti, Malcolm Perry, and ab ’51, mba ’58 answers to the mysteries of cosmic inflation, well taking Norman Ramsey’s graduate course Francesca Ferlaino. (Prof. Ferlaino is profiled dark matter, and dark energy by pushing the (I think it was Physics 33) on “Introduction to on page 39.) More Bershadsky Fellows, technological boundaries of observational the Quantum Theory” in 1947–48 and marveling including Prof. Vaughan Jones, are expected astronomy, drawing upon the latest ideas from in the coming year. over the special functions needed in treating the We would love to hear from you. Please stay fundamental physics, and combing the data for hydrogen atom.” in touch and let us know if you would like to As a part of our effort to build a family-friendly new theoretical insights. william j. childs contribute news items to the newsletter at: department, we held the first Physics Department The other feature article in this issue gives us a ab ’48 [email protected] Reception on October 4, 2015. The gathering, glimpse of a close collaboration between which took place at the MIT Endicott House, experiment and theory, this time in particle Follow us on Twitter: was attended by about 75 faculty, staff, and their physics. John Huth, Matt Reece, Chris Rogan, twitter.com/harvardphysics family members. I would like to thank Cumrun and Matt Schwartz discuss how the interplay “Thank you very much. I really appreciate and Afarin Vafa for their generosity in supporting Like us on Facebook: between theoretical and experimental work is receiving the newsletter.” this and future events. facebook.com/pages/ facilitating the search for physics beyond the john crues HarvardPhysics/154321267932184 Standard Model at the Large Hadron Collider. I hope you will enjoy this newsletter. As always, ab ’72, ms ’75 (univ. of illinois), md ’79 if you happen to be near the campus, please These are but two examples in which faculty Join us on LinkedIn: drop by the Department to see what we’re up to. members with different areas of expertise can www.linkedin.com/groups?gid=4740923