How Eggs Got Their Shapes

June 23, 2017
bird eggs of various shapes

Image credit: Harvard Museum of Comparative Zoology

The evolution of the amniotic egg — complete with membrane and shell — was key to vertebrates leaving the oceans and colonizing the land and air. Now, 360 million years later, bird eggs come in all shapes and sizes, from the almost perfectly spherical eggs of brown hawk- owls to the tear-drop shape of sandpipers’ eggs. The question is, how and why did this diversity in shape evolve?


Bloch Oscillations in the Absence of a Lattice

June 8, 2017

Concept of the experiment, A: an ensemble of 1D Bose gases in tubes formed by two pairs of counterpropagating and interfering laser beams. In each tube, a single strongly interacting impurity (green sphere) is immersed in the correlated host gas (black spheres) and is accelerated by gravity (green arrow). Inset: Scattering length as for collisions between the atoms in the host gas (dashed line) and between the impurity and the host atoms (solid line) as a function of the magnetic field B.* [Reprinted by permission from AAAS ©2017.]


Congratulations to the 2016-17 Physics Graduates!

May 22, 2017
group photo of graduating physics PhD students

Physics Concentrators: Michael Albergo, Eric Anschuetz, Stephanie Carr, Daniel Chen, Francesca Childs, Andrew Cho, Jeremy Dietrich, Deanna Emery, Shadi Fadaee, Benjamin Garber, Juliana Garcia-Mejia, Julia Grotto, Christian Hallas, Constantin Knoll, Richard Koh, Elgin Korkmazhan, Charles Law, Max L'Etoile, Jiang Li, Henry Lin, Eric Lu, Andrew Mayo, Saahil Mehta, Alexander Nie, Jenny Nitishinskaya, Maxwell Nye, Eugene O'Friel, Makinde Ogunnaike, Meg Panetta, Gregory Parker, Thomas Peeples, Gray Putnam, Jason Qu, Steven Rachesky, Daniel Rothchild, George Torres, Shreya Vardhan, Jennifer Walsh, Jonathan Ward, Noah Wuerfel, and Wayne Zhao.


Parametric Instability Rates in Periodically Driven Band Systems

May 8, 2017

At very low temperatures, quantum matter can show radically different, and often counterintuitive, behavior compared to traditional liquids, solids, and gases. Such quantum phases of matter (e.g., superfluids and superconductors) are used in practical applications such as levitating trains and medical imaging. In the field of quantum simulation, researchers are attempting to engineer phases of matter that are even more exotic. One appealing approach is to start with a standard quantum fluid and "drive it" by shaking it, rotating it, or subjecting it to an external field. However, this method faces a serious difficulty: the phase is unstable.