Eric Sembrat's Test Bonanza

The 21st Century has seen an explosion of bio-inspired technology and devices. Perhaps no where has this approach been more transformative than in the field of mobile robotics. Geckos, snakes, and even cockroaches have motivated new sticky, stable, steerable robots. Yet inspiration means more than curiosity. As scientists we must unravel the scientific principles and mechanisms underlying animal performance. By studying the physics of these living systems we can inform a systematic approach to animal-inspired robotics. By doing so, we discover new properties and dynamics of complex systems -- the robots themselves even become experimental platforms to test hypotheses. We can learn the pitfalls of ignoring the evolutionary context that shaped animal locomotion and the power of non-dimensional ratios that scale across biology. In this talk, we will first explore how human technology is taking on more characteristics for which the natural world is a better teacher. We will then use several examples over the past decade of robotics research where animals have served as the inspiration, but where identification of the underlying physics has led to innovation. Finally we will discuss how new bio-physical insights emerged from studying the resulting robots as physical models for the biological systems.

Photosynthesis is one of the great-impact inventions of biological evolution.  Indeed, life on Earth is fueled energy-wise mainly by sun light.  Many, so-called photosynthetic, life forms harvest sun light directly, for example, plants, algae and bacteria; other life forms use sun light indirectly, like herbivorous animals.  This lecture tells the story a particular simple, yet amazing photosynthetic apparatus, the chromatophore, found in purple bacteria.

The photosynthetic chromatophore is a spherical shell of 50 nm diameter that exists in hundreds of copies in the bacterial cell and converts sun light into chemical synthesis of an energy-rich molecule, adenosin triphosphate (ATP). Each chromatophore is made of over hundred protein complexes with thousands of light absorbing and electron conducting molecules embedded in them; the complexes are held together by a membrane made of 20,000 lipid molecules. Despite its complexity and heterogeneity the chromatophore can be viewed today through advances in experimental and computational biology at atomic- and electronic-level detail in its entire structure and function. One sees a clockwork of linked, mostly rather elementary processes: light absorption, coherent and incoherent exciton formation, intermolecular electron and proton transfer, charge carrier diffusion, electrostatic steering of protein- mediated electron conduction, molecular motor action driven by proton conduction, and lastly mechanically driven ATP synthesis.

For the first time a major part of a biological cell has been resolved in its entirety at the level of truly basic physics, showcasing how Angstrom- scale processes lead to 100-nm-scale intelligent overall function. In viewing the chromatophore through a beautifully detailed movie one can recognize in an exemplary fashion how evolution engineered an apparatus crucial for solar energy-driven life on Earth, utilizing amazing processes on the small scale by linking them together in a clock-work fashion such that an efficient, robust and adaptive cell-scale function emerges.

In this talk we will revisit the science known at the time that inspired Mary Shelly to write her novel. Hers is one of the best examples of rigorous science fiction writing as she based it on the most up to date scientific theories and experiments of her era. We will talk about some of Luigi Galvani’s experiments that inspired Mary Shelly and use several hands on demonstrations to explain them and describe how electricity is the driver of muscle activity. Furthermore we will show how electricity can either lead to death or actual resuscitation, and explain the physics behind it and how it is being applied by physicist and engineers to solve Biological, Physiological and Medical problems. 

Black holes are perhaps the most mysterious and enigmatic objects that one can imagine. Their gravitational fields are so strong that light is unable to escape their grasp, and even fundamental quantities such as space and time are severely disrupted by their presence.  Yet, despite their fantastical nature, astronomers have compiled significant evidence that black holes are actually quite common and are lying at the centers of almost all massive galaxies. Therefore, black holes are no longer the theoretical subjects of mathematical physicists; they are now known to be crucial to our understanding of how galaxies and other structures in the Universe formed and evolved. This talk will provide an overview of our understanding of black holes in the observable universe, and outline how astrophysicists are using them to probe some of the deepest questions in the cosmos.

In Kondo insulator samarium hexaboride SmB6, strong correlation and band hybridization lead to a diverging resistance at low temperature. The resistance divergence ends at about 3 Kelvin, a behavior recently demonstrated to arise from the surface conductance. However, questions remain whether and where a topological surface state exists. Quantum oscillations have not been observed to map the Fermi surface. We solve the problem by resolving the Landau Level quantization and Fermi surface topology using torque magnetometry. The observed angular dependence of the Fermi surface cross section suggests two-dimensional surface states on the (101) and (100) plane. Furthermore, similar to the quantum Hall states for graphene, the tracking of the Landau Levels in the infinite magnetic field limit points to -1/2, the Berry phase contribution from the 2D Dirac electronic state.

In this talk we will bring parallels of science and cooking to the fore.  Using a wide variety of kitchen cooking techniques whose inner workings on the molecular level can be explained through chemistry and physics we hope to make the science and the food more easily understandable.  We will cover topics ranging from surface tension, diffusion processes, gelation, crystallization and viscoelasticity. The overall goal of the talk is to make you a better cook by better understanding your ingredients and how to manipulate them and to learn science through the prism of cooking.

Bio:

William (Bill) Yosses held the prestigious title of the White House Executive Pastry Chef from 2006 to 2014. Other executive pastry chef experience includes, The Dressing Room in Westport Connecticutt, Tavern on the Green and Bouley Restaurant in New York City. Yosses spent his early career in France in such highly recognized landmarks as Fauchon, La Maison du Chocolat, and LeNotre.

As Pastry Chef of the White House, he was closely involved with Mrs Obama’s Let’s Move initiative, with the goal of reducing childhood health problems related to diet, and conducted bi-weekly tours of the White House vegetable garden for school groups. In a related project, he has given lectures on Science and Cooking in the School of Engineering and Applied Sciences at Harvard University, and was instrumental in building a program in the Physics Department of Harvard University in conjunction with Chop Chop Magazine called Camp Chop Chop, in which healthy foods and innovative exercise are used to introduce scientific concepts to 4th and 5th graders.

Bill earned his A.A.S. degree at New York City College of Technology in Hotel Management, a Master of Arts at Rutgers University in French Language and a Bachelor of Arts at the University of Toledo in French Language. He has published two books, Desserts for Dummies 1997, and The Perfect Finish, Special Desserts for Every Occasion, 2010. He is the recipient of the James Beard Who’s Who Award and Food Arts Magazine Silver Spoon Award.

Previous studies of women in physics mostly focused on the lack of women in the field. The Global Survey of Physics goes beyond the obvious shortage of women and shows that there are much deeper issues. For the first time, a multinational study was conducted with 15000 respondents from 130 countries, showing that problems for women in physics transcend national borders. Across all countries, women have fewer resources and opportunities and are more affected by cultural expectations concerning child care. We show that limited resources and opportunities hurt career progress, and because women have fewer opportunities and resources, their careers progress more slowly. We also show the disproportionate effects of children on women physicists' careers. Cultural expectations about home and family are difficult to change. However, for women to have successful outcomes and advance in physics, they must have equal access to resources and opportunities.

An article based on these findings can be found at: http://www.physicstoday.org/resource/1/phtoad/v65/i2/p47_s1


Bio:

Rachel Ivie is Associate Director of the Statistical Research Center (SRC) at the American Institute of Physics. She received her PhD in sociology from the University of North Carolina at Chapel Hill, where she specialized in research methods, statistics, gender, and the life course. Over the past sixteen years at SRC, she has studied careers of physicists, particularly the careers of women in physics. She authored the first ever thematic report on women in physics (Ivie and Stowe, 2000), bringing together data from AIP’s surveys with data from outside sources. She has designed and carried out numerous studies: from the impact of tenure and promotion practices on male and female faculty to a longitudinal study of astronomy graduate students.

Effects of dipolar and spin-exchange interactions are entangled in spin-1 Bose-Einstein condensates, due to their coexistence. We propose to independently manipulate the magnetic dipolar and the spin-exchange interactions by applying generalized WAHUHA sequences of rf pulses and by applying periodic dynamical decoupling sequences of optical Feshbach resonance pulses, respectively. While suppressing one interaction, we can make the other interaction dominate the spin dynamics in the condensates. Furthermore, by suppressing both interactions, this method can be harnessed to realize spinor-condensate-based magnetometers with a higher sensitivity.

Reference: [1] W. Zhang, B. Sun, M. S. Chapman, and L. You, Phys. Rev. A 81, 033602 (2010). [2] Bo-Yuan Ning, J. Zhuang, J. Q. You, W. Zhang£¬ Phys. Rev. A 84, 013606 (2011). [3] Bo-Yuan Ning, S. Yi, J. Zhuang, J. Q. You, and W. Zhang, Phys. Rev. A 85, 053646 (2012).

Bio:

Dr. Wenxian Zhang received his Bachelor and Master of Science degree in Fudan University in 1997 and 2000, respectively. He obtained his Ph. D degree in Georgia Institute of Technology in 2005. After that he did post-doctoral research in Ames Lab and Iowa State University in 2005-2007 and in Department of Physics and Astronomy of Dartmouth College in 2007-2008.  He worked in the department of Optical Science and Technology of Fudan University as an associate researcher in 2008-2011. He visited Department of Physics of the Chinese University of Hong Kong in 2009 and RIKEN, Japan in 2010/2011 for several months. He moved to School of Physics and Technology of Wuhan University as a professor in 2012.

 Wenxian's research interests include quantum optics, quantum computation and quantum information processing, light and matter interaction, and so on. He has published over 40 peer-reviewed journal papers, including 1 Nat. Phys. and 3 Phys. Rev. Lett., with a total 1000+ citations and H-index of 16. He has been funded by MOST, NSFC, MOE, etc..