physics & astronomy

Particle-wave duality with and without quantum spookiness.

Quantum interference explains the stability of matter, guided the construction of the laser, and its application led to medical imaging techniques. So what is this quantum interference about? The double-slit experiments for electrons is considered to be “the only mystery”, insofar as it concerns quantum interference. Feynman's account of these experiments is one of the most popular. To get as close to Feynman's description of double-slit diffraction we did some experiments. This includes closing individual slits on demand, and taking a movie of the build-up of the diffraction pattern one particle at a time. In recent work done in Paris, macroscopic particle-wave duality with bouncing oil droplets was demonstrated for the first time ever. This was supposed not to be possible. What does that mean for microscopic or quantum-mechanical particle-wave duality for electrons? This means a lot to an international group of physicists labeled to be a “band of rebels” according to Morgan Freeman’s show “Through the Wormhole”. However this is not what we have taught in the past three years to more than 100,000 high school students through our movie “The Challenge of Quantum Reality.” What is going on?

Skype with an Astronaut at A&S Sneak Peek

Catch a sneak peek of the amazing opportunities with the College of Arts & Sciences!

Dr. Ravat's Exploring the Solar System class had the privilege of doing a Skype interview with NASA Astronaut Dr. Drew Feustel. The Mission Specialist veteran detailed his drive to become an astronaut, his experiences in Space, and how NASA research connects to life on Earth.

Watch the full video here!

Unveiling the Mystery of Mass

One of the prime reasons the Large Hadron Collider (LHC) was built is to resolve the question of how particles acquire their mass. While it is very simple to measure particle masses and we have a model -- the Standard Model of Particle Physics -- which explains quite accurately all presently available measurements the seemingly trivial mechanism of how particle acquire their mass remains a mystery. The Standard Model invokes a new scalar gauge field to resolve this mystery but we have until recently not been able to find experimental evidence for its existence. On July 4, 2012, the CMS and ATLAS experiments have announced the discovery of a new Higgs-like particle at a mass of about 125 GeV. I will review our knowledge about the Higgs boson before the LHC started, discuss the discovery and the most recent updates from the LHC experiments.

Skype with Astronaut Andrew Feustel

Dr. Ravat's AST/EES 310 class had the opportunity to speak with Dr. Andrew Feustel, NASA Astronaut and Mission Specialist for STS-125 and STS-134, on April 2nd, 2013. During this fascinating hour-long conversation, Dr. Feustel described what it is like to go into space, the importance of the scientific advances enabled by NASA, and recounted his experiences on the International Space Station and on the last human service mission to the Hubble Space Telescope.

UK Awards Four Research Professorships

The University of Kentucky Board of Trustees today approved University Research Professorships for 2013-14 for four faculty members. The professorships carry a $40,000 award to support research.

Colloquium: The Future of the Sloan Digital Sky Survey

I describe plans for the next-generation Sloan Digital Sky Survey, to begin in July 2014, and which consists of three programs, APOGEE-2, MaNGA and eBOSS. APOGEE-2 will use both the Sloan Foundation Telescope at Apache Point and the du Pont Telescope at Las Campanas to study Galactic archaeology with high-resolution near-infrared spectroscopy. MaNGA will develop fiber bundle technology for the BOSS spectrograph to perform multiplexed spatially resolved spectroscopy with an unprecedented combination of wavelength coverage and resolution for 10,000 nearby galaxies. eBOSS will study the Universe�s expansion using a massive survey of galaxies and quasars. eBOSS will also perform follow-up spectroscopy on X-ray and variable sources, making it both the largest and most broadly selected quasar survey. I will show how this innovative set of programs will lead to a better understanding of cosmology and galaxy formation, as well as stellar and exoplanetary astronomy.

Speaker / Presenter: Michael Blanton, Dept of Physics, New York University

Colloquium: New Dialogues: Entanglement, Holography & Renormalization

In science, we often see new advances and deep insights emerging from the collision or intersection of what appeared to be separate research areas. The theme of my colloquium will be an ongoing collision between the three ideas listed in my title which has been generating interesting new insights into a variety of fields, eg, condensed matter physics, quantum field theory and even quantum gravity. I will give an introduction to each of these three ideas separately and then discuss the intersections that have been generating new insights in recent years. Speaker/Presenter: Robert Myers, Perimeter Institute for Theoretical Physics

Colloquium: Organic (Plastic!) Semiconductors

Organic materials are finding an increasing number of possible niches in electronic devices. I will give a very brief overview of some of the present and anticipated applications of organic semiconductors and issues in understanding their application. I will then discuss some of our recent experiments on using infrared electro-optics to measure the mobility of charges in organic thin-film transistors and conclude by describing our ongoing experiments to measure the thermal conductivities of organic semiconductors, important for possible applications as thermoelectric power generators.

Speaker / Presenter: Joseph Brill, Dept of Physics & Astronomy, University of Kentucky

Spin and Pseudo-Spin in Graphene

Graphene, a single atomic layer of graphite, has been provided physicists opportunities to explore an interesting analogy to the relativistic quantum mechanics. The unique electronic band structure of graphene lattice yields a linear energy dispersion relation where the Fermi velocity replaces the role of the speed of light and pseudo spin degree of freedom for the orbital wavefunction replaces the role of real spin in usual Dirac Fermion spectrum. The exotic quantum transport behavior discovered in these materials, such as unusual half-integer quantum Hall effect and Klein tunneling effect, are a direct consequence of the pseudo-spin rotation in graphene. Interacting systems with internal symmetries will tend to break those symmetries in order to lower their energy. In graphene, the strong Coulomb interactions and approximate spin-pseudo spin symmetry are predicted to lead to a variety of quantum Hall ferromagnetic ground states and excitations which manifest as integer quantum Hall plateaus appearing within a graphene. In this presentation I will discuss various experimental evidence support the importance of spin and pseudo-spin structures in graphene at the strong quantum limit.

The story of the Black Hole Information Paradox

Some 40 years ago Bekenstein argued that black holes should have an enormous entropy. Shortly thereafter, Hawking showed that black holes evaporate in a way that violates quantum mechanics. The latter result has been a long standing problem, known as the black hole information paradox. Recent results in string theory has shown that the microstates corresponding to Bekenstein's entropy are 'fuzzballs' that do not have a regular horizon; the horizon of the hole arises as an emergent statistical concept. Further, the large entropy of these states leads to a violation of the semiclassical approximation at the horizon of a black hole; this alters Hawking's computation and provides a resolution of the information paradox.


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