Search results
Results From The WOW.Com Content Network
Sonoluminescence is the emission of light from imploding bubbles in a liquid when excited by sound. Sonoluminescence was first discovered in 1934 at the University of Cologne . It occurs when a sound wave of sufficient intensity induces a gaseous cavity within a liquid to collapse quickly, emitting a burst of light.
Examples of pump sources include electrical discharges, flashlamps, arc lamps, light from another laser, chemical reactions and even explosive devices. The type of pump source used principally depends on the gain medium , and this also determines how the energy is transmitted to the medium.
A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave ultraviolet light and very little visible light. [ 1 ] [ 2 ] [ 3 ] One type of lamp has a violet filter material, either on the bulb or in a separate glass filter in the lamp housing, which blocks most visible light and allows through UV ...
Light can be approximately collimated by a number of processes, for instance by means of a collimator. Perfectly collimated light is sometimes said to be focused at infinity. Thus, as the distance from a point source increases, the spherical wavefronts become flatter and closer to plane waves, which are perfectly collimated.
Ambient light falling on the photoresistor causes the streetlight to turn off. Thus energy is saved by ensuring the light is only on during hours of darkness. Photoresistors are also used in laser-based security systems to detect the change in the light intensity when a person or object passes through the laser beam.
A flicker light bulb, flicker flame light bulb or flicker glow lamp is a gas-discharge lamp which produces light by ionizing a gas, usually neon mixed with helium and a small amount of nitrogen gas, by an electric current passing through two flame shaped electrode screens coated with partially decomposed barium azide. The ionized gas moves ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Radium was used to make self-luminous paint from the early 20th century to about 1970. Promethium briefly replaced radium as a radiation source. Tritium is the only radiation source used in radioluminescent light sources today due to its low radiological toxicity and commercial availability. [3]