Search results
Results from the WOW.Com Content Network
A light bulb is suspended in the center of the cylinder with the rotation speed making light emanate from the holes at a consistently pulsating frequency range of 8–13 flickers per second. It is meant to be looked at through closed eyelids, upon which moving yantra -like mandala visual patterns emerge, and an alpha wave mental state is induced.
youtube-dl <url> The path of the output can be specified as: (file name to be included in the path) youtube-dl -o <path> <url> To see the list of all of the available file formats and sizes: youtube-dl -F <url> The video can be downloaded by selecting the format code from the list or typing the format manually: youtube-dl -f <format/code> <url>
A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the surroundings. The more transparent the lighting fixtures are, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability.
In visual perception, flicker is a human-visible change in luminance of an illuminated surface or light source which can be due to fluctuations of the light source itself, or due to external causes such as due to rapid fluctuations in the voltage of the power supply (power-line flicker) or incompatibility with an external dimmer.
The spectrum of light emitted from a fluorescent lamp is the combination of light directly emitted by the mercury vapor, and light emitted by the phosphorescent coating. The spectral lines from the mercury emission and the phosphorescence effect give a combined spectral distribution of light that is different from those produced by incandescent ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Help; Learn to edit; Community portal; Recent changes; Upload file
The fluorescent chemicals in fluorescent paint absorb the invisible UV radiation, then emit the energy as longer wavelength visible light of a particular color. Human eyes perceive this light as the unusual 'glow' of fluorescence. The painted surface also reflects any ordinary visible light striking it, which tends to wash out the dim ...
Fluorescent lamps using conventional magnetic ballasts flicker at twice the supply frequency. Electronic ballasts do not produce light flicker since the phosphor persistence is longer than a half cycle of the higher operation frequency of 20 kHz. The 100–120 Hz flicker produced by magnetic ballasts is associated with headaches and eyestrain. [8]