Paradox of radiation of charged particles in a gravitational field electric field has an accompanying magnetic field, and the whole oscillating electromagnetic radiation field propagates independently of the accelerated charge, carrying away momentum and energy. The energy in the radiation is provided by the work that accelerates the charge. The theory of general relativity is built on the equivalence principle of gravitation and inertia. This principle states that it is impossible to distinguish through any local measurement whether one is in a gravitational field or being accelerated. An elevator out in deep space, far from any planet, could mimic a gravitational field to its occupants if it could be accelerated
Sound of a Woman a slowed down version, with a video showing her and others, slowly revealed to be without clothes, to express "raw emotions". Kiesza described "Sound of a Woman" as having grunge, rock, and folk influences in addition to her usual house or dance genre and that some songs on the album would be surprising to people. "Hideaway" was released on 11 April 2014 as Kiesza's debut single. Both the song and its accompanying music video have been met with general acclaim from contemporary music critics. "Hideaway" topped the UK Singles Chart upon release, selling over 136,000 copies in its first week,