Cherenkov radiation permeability and formula_16 is the index of refraction of the material the charge particle moves through. Unlike fluorescence or emission spectra that have characteristic spectral peaks, Cherenkov radiation is continuous. Around the visible spectrum, the relative intensity per unit frequency is approximately proportional to the frequency. That is, higher frequencies (shorter wavelengths) are more intense in Cherenkov radiation. This is why visible Cherenkov radiation is observed to be brilliant blue. In fact, most Cherenkov radiation is in the ultraviolet spectrum—it is only with sufficiently accelerated charges that it even becomes visible; the sensitivity of the human eye peaks at green,
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,