We propose a model of the Earth’s torqueless precession, the “Chandler wobble,” as a self-oscillation driven by positive feedback between the wobble and the centrifugal deformation of the portion of the Earth’s mass contained ...

In the early 18th century, J. E. E. Bessler, known as Orffyreus, constructed several wheels that he claimed could keep turning forever, powered only by gravity. He never revealed the details of his invention, but he ...

A solar cell is a heat engine, but textbook treatments are not wholly satisfactory from a thermodynamic standpoint, since they present solar cells as directly converting the energy of light into electricity, and the current ...

When a real fluid is expelled quickly from a tube, it forms a jet separated from the surrounding fluid by a thin, turbulent layer. On the other hand, when the same fluid is sucked into the tube, it comes in from all ...

El invento trata de un componente óptico, que comprende un primer reflector esférico y un segundo reflector esférico, el cual está colocado para reflejar un rayo de luz varias veces entre el primer reflector y el segundo ...

In this paper the Hubble parameter and the deceleration parameter are analyzed for a group of anisotropic homogeneous solutions of the Petrov type-D. It is obtained that for the said set of solutions can be constructed a ...

Previous studies have shown that most of Central America has been experiencing warming trends during the last 30-50 years, while precipitation annual totals have not changed much. Warming alone can exacerbate the effects ...

The linear coupling of a rotating heat bath to a quantum field is studied in the framework of the Markovian master equation for the field's non-unitary time evolution. The bath's rotation induces population inversion for ...

In this document a set of exact solutions is obtained by using the model of a perfect fluid on an homogeneous and anisotropic space-time that belongs to (Local Rotational Symmetry) Petrov’s type D. This solutions represent ...