Escape Velocity Dance Company Presents: Emerge

Escape Velocity is a student run dance company that provides students the opportunity to choreograph for, dance in, and/or produce performances for the Ursinus College community throughout the year. This program, Emerge, consists of ten individual pieces. Firelight was choreographed by Elizabeth Kandler and performed by Elizabeth Kandler, Kalina Witkowska, and Alexa Alessandrini. Always was choreographed by Kathryn Bjorklund and performed by Bailey Hann, Sarah Bell, Kathryn Bjorklund, Jackie Henigan, Megan DePaul and Rileigh Klein. Movement was choreographed by Kalina Witkowska and performed by Angelina Mazza, Elizabeth Kandler, Samirah Deshields, Taylor Tobin and Kalina Witkowska. Everybody was choreographed by Mo’Dayna Hercules and performed by Mo’Dayna Hercules and Azari. Bruises was choreographed by Jackie Henigan and Raeann Risko and performed by Raeann Risko, Jackie Henigan, Bailey Hann, Sarah Bell, Carly Rodriguez, Rileigh Klein, Elizabeth Kandler and Maia Michalashvili. Childhood Theme Song Mashup was choreographed by the Escape Velocity Executive Board and performed by Amanda Paul, Emmy Selfridge, Gabby DeMelfi, Jess Doorly, Mariah Lesh, Carly Rodriguez, Angelina Mazza, Mary Fuchs, Shira Levin, Raeann Risko, Jackie Henigan, Rileigh Klein and Megan D. Cannon in D was choreographed by Chelsea Stitt and performed by Jackie Henigan, Raeann Risko, Kathryn Bjorklund and Elizabeth Kandler. One with the Wind was choreographed by Kevin Harris II and performed by Kalina Witkowska. When I was Older was choreographed by Shira Levin and performed by Jackie Henigan, Taylor Tobin and Raeann Risko. Closing Time was choreographed by Jackie Henigan and performed by Angelina Mazza, Megan DePaul, Rileigh Klein, Raeann Risko, Kathryn Bjorklund, Jackie Henigan and Elizabeth Kandler.https://digitalcommons.ursinus.edu/dance_videos/1000/thumbnail.jp

Statistics of Velocity from Spectral Data: Modified Velocity Centroids

We address the problem of studying interstellar turbulence using spectral line data. We find a criterion when the velocity centroids may provide trustworthy velocity statistics. To enhance the scope of centroids applications, we construct a measure that we term ``modified velocity centroids'' (MVCs) and derive an analytical solution that relates the 2D spectra of the modified centroids with the underlying 3D velocity spectrum. We test our results using synthetic maps constructed with data obtained through simulations of compressible magnetohydrodynamical (MHD) turbulence. We show that the modified velocity centroids (MVCs) are complementary to the the Velocity Channel Analysis (VCA) technique. Employed together, they make determining of the velocity spectral index more reliable and for wider variety of astrophysical situations.Comment: 4 pages, 1 figure, Accepted for publication in ApJ Letters. minor change

Spatiotemporal velocity-velocity correlation function in fully developed turbulence

Turbulence is an ubiquitous phenomenon in natural and industrial flows. Since the celebrated work of Kolmogorov in 1941, understanding the statistical properties of fully developed turbulence has remained a major quest. In particular, deriving the properties of turbulent flows from a mesoscopic description, that is from Navier-Stokes equation, has eluded most theoretical attempts. Here, we provide a theoretical prediction for the {\it space and time} dependent velocity-velocity correlation function of homogeneous and isotropic turbulence from the field theory associated to Navier-Stokes equation with stochastic forcing. This prediction is the analytical fixed-point solution of Non-Perturbative Renormalisation Group flow equations, which are exact in a certain large wave-number limit. This solution is compared to two-point two-times correlation functions computed in direct numerical simulations. We obtain a remarkable agreement both in the inertial and in the dissipative ranges.Comment: 8 pages, 4 figures, improved versio

Velocity and velocity bounds in static spherically symmetric metrics

We find simple expressions for velocity of massless particles in dependence of the distance $r$ in Schwarzschild coordinates. For massive particles these expressions put an upper bound for the velocity. Our results apply to static spherically symmetric metrics. We use these results to calculate the velocity for different cases: Schwarzschild, Schwarzschild-de Sitter and Reissner-Nordstr\"om with and without the cosmological constant. We emphasize the differences between the behavior of the velocity in the different metrics and find that in cases with naked singularity there exists always a region where the massless particle moves with a velocity bigger than the velocity of light in vacuum. In the case of Reissner-Nordstr\"om-de Sitter we completely characterize the radial velocity and the metric in an algebraic way. We contrast the case of classical naked singularities with naked singularities emerging from metric inspired by noncommutative geometry where the radial velocity never exceeds one. Furthermore, we solve the Einstein equations for a constant and polytropic density profile and calculate the radial velocity of a photon moving in spaces with interior metric. The polytropic case of radial velocity displays an unexpected variation bounded by a local minimum and maximum.Comment: 20 pages, 5 figure

Velocity package Patent

High velocity guidance and spin stabilization gyro controlled jet reaction system for launch vehicle payload

Velocity and velocity bounds in static spherically symmetric metrics

We find simple expressions for velocity of massless particles in dependence of the distance $r$ in Schwarzschild coordinates. For massive particles these expressions put an upper bound for the velocity. Our results apply to static spherically symmetric metrics. We use these results to calculate the velocity for different cases: Schwarzschild, Schwarzschild-de Sitter and Reissner-Nordstr\"om with and without the cosmological constant. We emphasize the differences between the behavior of the velocity in the different metrics and find that in cases with naked singularity there exists always a region where the massless particle moves with a velocity bigger than the velocity of light in vacuum. In the case of Reissner-Nordstr\"om-de Sitter we completely characterize the radial velocity and the metric in an algebraic way. We contrast the case of classical naked singularities with naked singularities emerging from metric inspired by noncommutative geometry where the radial velocity never exceeds one. Furthermore, we solve the Einstein equations for a constant and polytropic density profile and calculate the radial velocity of a photon moving in spaces with interior metric. The polytropic case of radial velocity displays an unexpected variation bounded by a local minimum and maximum.Comment: 20 pages, 5 figure

Negative Group Velocity

The group velocity for pulses in an optical medium can be negative at frequencies between those of a pair of laser-pumped spectral lines. The gain medium then can amplify the leading edge of a pulse resulting in a time advance of the pulse when it exits the medium, as has been recently demonstrated in the laboratory. This effect has been called superluminal, but, as a classical analysis shows, it cannot result in signal propgation at speeds greater than that of light in vacuum.Comment: v3 adds discussion of "rephasing", and adds a figure. v4 adds references to the early history of negative group velocity, and adds a figure; thanks to Alex Grani