Seminario de Fisica Aplicada
Fecha: Jueves 30 de Mayo de 2013, 2 pm
Lugar: ICIMAF, Calle 15 entre C y D, Vedado
Ponente: Alejandro Cabo
Titulo: Shockwave bullets generation by means of the relativistic time dilation effect
Resumen:
The known increase of the meson lifetime with its velocity is combined with
the acoustical Lorentz symmetry of the sound propagation D Alembert equation, in order to construct acoustic shockwave beams which can propagate nearly undistorted over appreciable distances. Firstly, an isotropic in 3D superposition of one dimensional traveling waves of gaussian shapes along the propagation direction, is constructed in the reference frame in which the acoustical medium is at rest. The resulting wave, as it can be expected, relaxes in a rotational invariant way within a characteristic time interval, which increases with the spatial width of the gaussian shape defining the traveling waves. Afterwards, the acoustical Lorentz symmetry transformation of the coordinates and time is performed, in order to generate a new solution of the D Alembert equation for the medium at rest. It follows that, if the velocity parameter defining the Lorentz transformation tends to approach the sound velocity of the medium, the new solution is able to propagate nearly undistorted for increasing distances along the direction of the velocity defining the Lorentz transformation. The small lateral distortion of the ways is helped by the time variation of the form of the wave in the propagation direction. The presented nearly soliton kind of propagation is a direct consequence of the same relativistic time dilation effect which determines the enhancing of the meson lifetime due to its velocity.