Session C2: General Session

The Data Matrix: Dynamic Analysis of Remote Sensing Measurements

The nature of experimental science is to inevitably present unanticipated problems to the researcher. Solving these problems requires an understanding of the physics of the experiment, the analytical skills to conceive a solution, and the technical knowledge necessary to execute the plan efficiently. Remote atmospheric sensing research produces a 3 dimensional data set that can be interpreted from a variety of perspectives. Proper handling of the data matrix is helpful in its ability to automate vital analysis steps such as cloud clearing and clean air region selection, but it is also an invaluable tool in addressing systematic issues uncovered throughout the experimental process.   

Observation of Multiple Activation in Tg of Se90In8Ag2 Glassy Alloy

In the present study, multiple activation energy is reported for glass transition (Tg) of Se90In8Ag2 glassy alloy during cooling. The Tg shows a linear relationship with cooling rates whereas the linearity of the transition follows three different linear trends for three different cooling ranges mentioned as (a) low range, (b) medium range, and (c) high range where they are defined as low range for 5 oC/min to 20 oC/min, medium range for 20 oC/min to 30 oC/min and high range for 30 oC/min to 50 oC/min. The activation energy is found to be positive for all three ranges and indicates that the Se90In8Ag2 is a sensitive material to cooling rates and may bring the significance of being reused after multiple use of heating runs in memory devices. \textbf{Keywords:} Activation Energy, Kinetics, calorimetry, cooling, heat flow, glass transition.   

Properties of White Light generated by near infrared excitation of Yttrium silicates undoped and doped with Ytterbium

In the presented study, we have investigated the optical properties of two nanopowder samples, one of Y2Si2O7 (YSO) doped with 10{\%} Yb3$+$ and one of undoped YSO. The samples were prepared by the sol gel method. The size of the nanoparticles of the samples was found to be \textasciitilde 80 nm from Scherrer equation. 10{\%} Yb3$+$ doped sample was illuminated with the 975 nm output of a diode laser with power ranging from 0.12 to 1.45 W under 0.01 mbar pressure. At low power, the spectrum showed a complex structure due to Yb3$+$ and other possible unwanted impurities. At high power, the spectrum loses its details and approaches the spectrum of white light. Under the same conditions the undoped sample showed only the white light when using the power of at least 1.45 W of the 975 nm diode. The effect of pressure on the white light emitted from the 10{\%} Yb3$+$ doped sample and from the undoped sample were also investigated when the diode power was set at 3.38 W. The low pressure on the sample is a favorable condition for the emission of white light. The same behavior was manifested by the undoped sample.   

Human Population Growth and the Mass of the Earth

Albert A. Bartlett, late Professor Emeritus of Physics at the University of Colorado, spent the latter half of his life alerting both the community of physicists and the wider society to implications of unchecked exponential growth. Among the areas he addressed were the effects of exponential growth in human papulations and, as an illustration, calculated when the mass of human beings on Earth would equal that of the Earth itself. In the present work we refine this analysis to take into account the fact that human beings are made of Earth material and that total human mass grows at the expense of Earth mass. Assuming continued exponential population growth we find the time for this equality of masses to be substantially shorter than that calculated Bartlett's method [1,2]. Other growth scenarios such as a linear projection tangent to the exponential curve are also discussed. We hope that, with Bartlett's passing in 2013, a new generation of physicists will continue this educational effort.\\ \\ $[1]$ A. A Bartlett, Am. J. Phys. \underline{46}, 887 (1978).\\ $[2]$ D. W. Kraft, \underline {http://asee-ne.org/proceedings/2014/index.htm}.   

A Unified Mathematical Field Theory

The century old problem of getting gravity to play gracefully with the rest of physics may not have to do with a physics field theory. Instead it may have to do with the math tools used for any physics field theory. By third grade, we had all learned how to add, subtract, multiply, and divide any number. By the end of physics graduate school, the tools of differential geometry no longer allow one such freedom to play with expressions. Here is how one calculates the interval between two events in flat space-time using a metric tensor and a 4-vector: $ g_{\mu \nu} de^\mu de^\nu = dt^2 - (dx^2 + dy^2 + dz^2)/c^2 $ This looks like a square. Design an algebra (similar to quaternions) that removes the Greek letters along with the metric tensor: $ de^2 = (dt^2 - (dx^2 + dy^2 + dz^2)/c^2, 2 dt dx/c, 2 dt dy/c, 2 dt dz/c) $ The first term is known as the Lorentz invariant interval of special relativity. Two inertial observers will agree to that. This expression has more information than just the interval. The other three terms I call space-times-time. Having two observers agree about space-times-time but disagree about the interval may be the new math for gravity.