Events Archive

Mar
09
2015
Origin of life: From Geophysics to Biology
One of the deepest and most controversial questions of our time is that of the origin of life. In this lecture a hypothesis is presented, according to which the temperature gradients existing deep in the earth (which leads to plate tectonics and the formation of undersea thermal vents), also led to the origin and evolution of life around those vents. Movies and data will be shown of experiments in which various stages of this scenario are presented: how thermal gradients led to plate tectonics, to DNA possible amplification in the thermal vents, and to huge increase of molecular...
Mar
09
2015
Ken Burch
Feb
26
2015
Attosecond Science: Probing electron dynamics in complex systems
The emergence of attosecond spectroscopy has offered researchers a new experimental tool, which provides unprecedented temporal resolution for the direct measurement and control of electronic processes. Pioneering studies have obtained unique physical insights by taking...
Feb
24
2015
The Salt Life of Sea Snakes
Dehydration and lack of fresh water are key problems for vertebrates that have secondarily invaded marine environments. However, recent investigations of 9 species representing the principal clades of sea snakes indicate these reptiles do not drink seawater but will drink fresh water at variable thresholds of dehydration, which these snakes tolerate well. Marine reptiles were previously thought to remain in water balance without consuming fresh water owing to the ability of extrarenal salt glands to excrete excess salts obtained either from prey or from drinking sea water directly. Thus, species of marine snakes which...
Feb
23
2015
Enormous magnetic fields with bosons in hybrid lattices
  The integer quantum Hall effect (IQHE) is often described in terms of skipping orbits: 2-D electrons begin nascent cyclotron orbits, only to be interrupted by the material’s boundary, and instead reflect from the edge, beginning a partial orbit anew.  These classical skipping trajectories follow the systems boundary, and in the quantum limit connect to the...
Feb
19
2015
Studying superfluidity in cold-atom circuits
  Superfluidity, or flow without resistance, is a macroscopic quantum effect that is present in a multitude of systems, including liquid helium, superconductors, and ultra-cold atomic gases.  Here, I will present our work studying superfluid flow in a Bose-Einstein condensate (BEC) of sodium atoms....
Feb
18
2015
Inverse Design of Swimming Dynamics
We introduce an inverse design approach based on minimal theoretical modeling, direct numerical simulations and artificial intelligence techniques for the investigation of biolocomotion in fluids. Its application to the characterization of inertial aquatic phenomena and to the identification of optimal swimming gaits and morphologies is presented.
Feb
17
2015
Collective Motion of Interacting Random Walkers
The collective motion of a large group of individuals has two different scales. Individuals move and interact on a local scale, while the motion of the group as a whole occurs on a global scale. All the movement of the group on the global scale is produced by the many movements of its members, and so a good model for the global behaviour should arise from local models for the individuals. We investigate the link between the two scales, and create formulae for producing a global model for any particular lattice-based local model using mean-field approximations.
Feb
16
2015
Magnetism, Rotons, and Beyond: Engineering Atomic Systems with Lattice Shaking
Conventional methods of quantum simulation rely on kinectic energy determined by free particle dispersions or simple sinusoidal optical lattices. Solid state systems, by contrast, exhibit a plethora of band structures which differ quantitatively, qualitatively, and even topologically....
Feb
12
2015
Magnetic Structure Solution of Frustrated Spin Systems
In frustrated magnetic materials, geometry and magnetic interactions combine to suppress conventional magnetic order. Instead, disordered "spin liquid" states can host exotic magnetic phenomena which persist to the lowest measurable temperatures. Neutron scattering is an ideal experimental technique to understand spin-liquid states, but the absence of conventional magnetic order means that standard data-analysis methods cannot be used. Two limitations have traditionally restricted our understanding spin liquids at the atomic scale: (i) the magnetic interactions must be anticipated, and (ii) single-crystal samples must be available....

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