The mechanisms of pigeon homing are still not understood, in particular how they determine their position at unfamiliar locations. The "gravity vector" theory holds that pigeons memorize the gravity vector at their home loft and deduct home direction and distance from the angular difference between memorized and actual gravity vector. However, the gravity vector is tilted by different densities...

The gravity field dedicated satellite missions like CHAMP, GRACE, and GOCE are supposed to map the Earth’s global gravity field with unprecedented accuracy and resolution. New models of Earth’s static and time-variable gravity field will be available every month as one of the science products from GRACE. Here we present an alternative method to estimate the gravity field efficiently using the i...

This article wants to be two things. On the one hand it wants to review a number of approaches to the problem of quantum gravity that are new and have not been widely discussed so far. On the other hand it wants to offer a new look at the problem of quantum gravity. The different approaches can be organized according to how they answer the following questions: Is the concept of a spacetime fund...

Petrophysical properties of 585 rock samples from the Suhbaatar-Ulaanbaatar-Dalandzadgad geophysical profile in Mongolia are presented. Based on the rock classifications and tectonic units, petrophysical parameters (bulk density, magnetic susceptibility, intensity of natural remanent magnetization, and Köenigsberger ratio) of these rocks are summarized. Results indicate that (1) significant den...

We measured the amount of visual movement judged consistent with translational head movement under normal and microgravity conditions. Subjects wore a virtual reality helmet in which the ratio of the movement of the world to the movement of the head (visual gain) was variable. Using the method of adjustment under normal gravity 10 subjects adjusted the visual gain until the visual world appeare...

Gravitational physics of VLBI experiment conducted on September 8, 2002 and dedicated to measure the speed of gravity (a fundamental constant in the Einstein equations) is treated in the first post-Newtonian approximation. Explicit speedof-gravity parameterization is introduced to the Einstein equations to single out the retardation effect caused by the finite speed of gravity in the relativist...

Gravitational physics of VLBI experiment conducted on September 8, 2002 and dedicated to measure the speed of gravity is treated in the first post-Newtonian approximation. Explicit speed-of-gravity parameterization is introduced to the Einstein equations to single out the retardation effect caused by the finite speed of propagation of gravity in the relativistic time delay of light, passing thr...

We obtain the induced action F[h, b] for chiral W3 gravity in the c ~ ___ limit from the induced action of a gauged Sl(3, R) Wess-Zumino-Witten model by imposing constraints on the currents of the latter. In the process we find a closed gauge algebra for the gauge sector of W3 gravity in which the currents T and W become auxiliary fields. An explicit realization of T and W in terms of the gauge...