Bulletin of the American Physical Society
2008 Joint Fall Meeting of the Texas and Four Corners Sections of APS, AAPT, and Zones 13 and 16 of SPS, and the Societies of Hispanic & Black Physicists
Volume 53, Number 11
Friday–Saturday, October 17–18, 2008; El Paso, Texas
Session E4: General Theory II |
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Chair: Dwight Russell, Baylor University Room: Union East, 3rd Floor Elkins |
Friday, October 17, 2008 3:30PM - 3:42PM |
E4.00001: The Geometry of Memory: A Physical Model Willard Maier, Bruce Miller In recent history physicists have become interested in viewing processes in the brain in terms of the nonlinear dynamics of interacting neurons. To achieve this they have explored different levels of fidelity in modeling the interacting neurons. An open question is whether there is a connection between specific firing patterns and the representation of memory. Izhikevich has proposed a possible connection that he has named polychoronous groups and explored it within the context of a specific dynamical model. Here a minimal model of polychronous groups in neural networks is presented. The model is computationally efficient and allows the study of polychronous groups independent of specific neuron models prevalent in the literature. Computational experiments were performed with the model in one- and two-dimensional neural architectures to determine the dependence of the number of polychronous groups on various connectivity options. Our results (arXiv:0806.1070v1 [cond-mat.dis-nn]) suggest that the concept is robust and may therefore play an important role in more realistic systems. The possibility of using polychronous groups as computational elements is also discussed. [Preview Abstract] |
Friday, October 17, 2008 3:42PM - 3:54PM |
E4.00002: An Alternative to Tensors Eric Brown Some of the most beautiful and complex theories in physics are formulated in the language of tensors. While powerful, these methods are sometimes daunting to the uninitiated. I will introduce the use of Clifford Algebra as a practical alternative to the use of tensors. Many physical quantities can be represented in an indexless form. The boundary between the classical and the quantum worlds becomes a little more transparent. I will review some key concepts, and then talk about some of the things that I am doing with this interesting and powerful tool. Of note to some will be the development of rigid body dynamics for a game engine. Others may be interested in expressing the connection on a spin bundle. My intent is to prove to the audience that there exists an accessible mathematical tool that can be employed to probe the most difficult of topics in physics. [Preview Abstract] |
Friday, October 17, 2008 3:54PM - 4:06PM |
E4.00003: Is Sound Also a Property of Space? Venkata Chaganti Absolutist regards SPACE as an entity in its own right with properties of its own. Further more, we (relationist, scientist and laymen) attribute many different sorts of properties to SPACE. In fact, we are able to distinguish every material from the other by its properties. We all know that SPACE is attributed by some of the properties listed below. 1. Electromagnetic Properties like $\varepsilon _{o}$ = 8.55 x 10$^{-12}$ F/m, $\mu _{o}$ = 4$\pi $ x 10$^{-7}$ H/m. 2. Empty Space is a poor conductor. 3. Empty Space is Transparent. 4. Space is penetrable by any particle/ material. 5. Space is incapable of action. 6. Space is immovable fixed. 7. Space is infinite. 8. Space is finite but unbounded. 9. All bodies are place in space. 10. Space is Isotropic. And many more properties can be included. A SPACE is defined by its properties. Many of these properties may be made quite precise without any reference to an embedding space surrounding the SPACE of interest. SPACE as a physical object only makes sense if it can be detected, or if it can exert physical influences. Does the motion of an object through space lead to detectable effects? Can space act on a moving body in the way that the sea acts on a moving fish? In this paper a sincere attempt is made to show mathematically that SOUND is indeed a property of SPACE. [Preview Abstract] |
Friday, October 17, 2008 4:06PM - 4:18PM |
E4.00004: The End of Theory? Does the Data Deluge Make the Scientific Method Obsolete? Vladik Kreinovich, John McClure, John Symons Why do we need theory? One of the purposes of science is to predict: e.g., how a complex material behaves in different situations. There are a lot of records describing how different materials behave in different situations. In the past, it was not possible to find a similar record and simply recall what happened then. The only possibility was to extract, from the data, a simple dependence, and then use this dependence for predictions. For example, we can use Ohm's law $V=I\cdot R$ to predict the voltage $V$ based on the current $I$ and the resistance $R$. Nowadays, computer searches are so fast that there seems to be no need for any theoretical laws anymore: if we want to predict, we can simply search through all the records and find what happened in a similar situation. So maybe we do not need theory at all. This was the argument developed in a recent (June 2008) article in a popular {\it Wired} magazine. In our presentation, we will describe this argument in detail, and give our opinion on whether the computer progress will indeed lead to the end of the theory as we know it. [Preview Abstract] |
Friday, October 17, 2008 4:18PM - 4:30PM |
E4.00005: The Role and Meaning of the Energy-Time Relations Juan Ferret While the Heisenberg relation between position and momentum seems to rest on solid footing, the energy-time relation (ETUR) has yet to receive a formal mathematical treatment. The trouble for ETUR began when Pauli showed that a self-adjoint time operator does not exist. Some find this sufficient to doubt the foundational value of ETUR. In spite of this void, experimental evidence now sets the energy-time relation on solid physical grounds. The extraordinarily fast decay of resonance particles, for instance, indicates that the time indeterminacy $\Delta t$ is given by its short lifetime. The decay of the nuclei of $^{57}$Co into $^{57}$Fe gives an indeterminate width $\Delta E$ for the intermediate state of decay with lifetime $\Delta t$. Their product results in Planck's constant confirming the particular relation between energy and time. Recently there have been some theoretical attempts at circumventing Pauli's theorem and dealing with this foundational void of ETUR. Paul Busch, for instance, introduced a positive operator value (POV) measure for time that does not commute with the Hamiltonian of a system. After a brief survey of these different approaches and critiques of ETUR, I show that ETUR holds universally. [Preview Abstract] |
Friday, October 17, 2008 4:30PM - 4:42PM |
E4.00006: Laws of the Universe - are they laws of physics or just rules of mathematics? Alexander Panin Physics is an experimental science in which we make objective observations (measurements) and discover certain rules and laws that the Universe obeys. But after a close look at these rules (or after new experimental discoveries are made) we find that they actually are the direct mathematical consequences of more simple rules, which we call symmetries. In some cases laws are even just mathematical consequences of definitions (!). So, it seems that if the mathematical origin of some phenomenon is known - then we call it mathematics, but if it is (yet) unknown - then we call it physics. To only discover later that it is also mathematics after all. So, is there any physics in our Universe, or it is just all mathematics? Examples of various ``laws of physics'' with the analysis of their mathematical origin, and the insight in what actually mathematics is (and why it is so powerful in describing and predicting the behavior of our Universe) are discussed in the presentation. [Preview Abstract] |
Friday, October 17, 2008 4:42PM - 4:54PM |
E4.00007: Equations Without Equations: Towards Formalizing Physicists' Reasoning Vladik Kreinovich, Roberto Araiza Not all mathematical solutions to physical equations are physically meaningful: e.g., if we reverse all the molecular velocities in a breaking cup, we get pieces self-assembling into a cup. The resulting initial conditions are ``degenerate'': once we modify them, self-assembly stops. So, in a physical solution, the initial conditions must be ``non- degenerate''. A challenge in formalizing this idea is that it depends on the representation. Example~1: we can use the Schr\"odinger equation ${\rm i}\hbar\displaystyle\frac{\partial\Psi}{\partial t}= -\displaystyle\frac{\hbar^2}{2m}\Delta\Psi+V(\vec r)\Psi$ (1) to represent $V(\vec r)$ as $F(\Psi,\ldots)$. The new equation $dF/dt=0$ is equivalent to (1) but now $V(\vec r)$ is in the initial conditions. Example 2: for a scalar field $\varphi$, we describe a new ``equation'' which is satisfied iff $\phi$ satisfies the Euler-Lagrange equations for some Lagrangian $L(\varphi,\varphi_{,i}\varphi^{,i})$. So, similarly to Wheeler's cosmological ``mass without mass,'' we have ``equations without equations.'' [Preview Abstract] |
Friday, October 17, 2008 4:54PM - 5:06PM |
E4.00008: A Neutrosophic Logic View to Schrodinger's Cat Paradox Florentin Smarandache, V. Christianto This article discusses Neutrosophic Logic interpretation of the Schrodinger's cat paradox. Neutrosophic Logic is a generalization of Fuzzy Logic (and especially of Intuitionistic Fuzzy Logic). We argue that this paradox involves some degree of indeterminacy (unknown) which Neutrosophic Logic could take into consideration. For a balanced discussion, other interpretations have also been discussed. [Preview Abstract] |
Friday, October 17, 2008 5:06PM - 5:18PM |
E4.00009: Modeling electron capture rates using charge-exchange data LeShawna Uher I use an electron capture program created by the exchange group and the National Superconducting Cyclotron Laboratory to calculate the electron capture rates in stars with densities $\rho $Y$_{e}$, ranging from log$\left( {1\times 10^9} \right)$ g/cm$^{3}$ to log$\left( {14\times 10^9} \right)$ g/cm$^{3}$, using data gathered from charge-exchange reaction experiments. This will eventually be used in the creation of a publicly-available electron capture rate database. I have also written a program that optimizes the original program by automatically creating its initialization files. [Preview Abstract] |
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