Jammed States of Matter

Almost any system composed of discrete pieces large enough that thermal fluctuations can be ignored can have a jamming transition: a point at which fluid flow is impeded by a change of state into a stable amorphous solid.  The behavior is general enough to explain a pile of sand, a jar of candies, or cars in a traffic jam.  Professor Andrea Liu was involved in recent theoretical breakthroughs in the study of this phenomenon.

 

Kirigami Topology

Professor Randall Kamien studies the physics and mathematics of kirigami — an extension of origami that allows cutting holes into the paper.  By treating the sheet of paper as a two-dimensional crystalline lattice, the folds, cuts, and pleats, can be understood in terms of topological defects in the underlying structure.

Supernovae from the Sloan Digital Sky Survey

Part of the images of all the supernovae from the 2005-2007 observing campaigns of the Sloan Digital Sky Survey.

 

Bioluminescence

Professor Alison Sweeney studies bio-optical properties of cephalopods and the cellular and biochemical mechanisms of dynamic camouflage.

 

Alternatives to Dark Energy

Perhaps the deepest mystery in physics today is the origin of the accelerating expansion of the universe.  Professors Khoury and Trodden work, among other things, on the possibility that it is due to a dark sector with new light degrees of freedom.  Screening mechanisms, such as chameleon and symmetron, may explain why such scalars, if light, have escaped detection.