Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound. The sonoluminescence effect was first discovered at the University of Cologne in 1934 as a result of work on sonar, H. Frenzel and H. Schultes put an ultrasound transducer in a tank of photographic developer fluid. They hoped to speed up the development process, they noticed tiny dots on the film after developing and realized that the bubbles in the fluid were emitting light with the ultrasound turned on. It was too difficult to analyze the effect in experiments because of the complex environment of a large number of short-lived bubbles. This phenomenon is now referred to as multi-bubble sonoluminescence, in 1960 Dr. Peter Jarman from Imperial College of London proposed the most reliable theory of SL phenomenon. The collapsing bubble generates a shock wave that compresses and heats the gas at the center of the bubble to extremely high temperature. In 1989 an experimental advance was introduced by D.
Felipe Gaitan and Lawrence Crum, in SBSL, a single bubble trapped in an acoustic standing wave emits a pulse of light with each compression of the bubble within the standing wave. This technique allowed a systematic study of the phenomenon, because it isolated the complex effects into one stable, predictable bubble. It was realized that the temperature inside the bubble was hot enough to melt steel, interest in sonoluminescence was renewed when an inner temperature of such a bubble well above one million kelvins was postulated. This cavity may take the form of a bubble, or may be generated through a process known as cavitation. For this to occur, an acoustic wave is set up within a liquid. The frequencies of resonance depend on the shape and size of the container in which the bubble is contained, some facts about sonoluminescence, The light flashes from the bubbles are extremely short—between 35 and a few hundred picoseconds long—with peak intensities of the order of 1–10 mW. The bubbles are very small when they emit the light—about 1 micrometre in diameter—depending on the ambient fluid, single-bubble sonoluminescence pulses can have very stable periods and positions.
In fact, the frequency of light flashes can be more stable than the frequency stability of the oscillator making the sound waves driving them. However, the stability analyses of the show that the bubble itself undergoes significant geometric instabilities, due to, for example. The addition of an amount of noble gas to the gas in the bubble increases the intensity of the emitted light. Spectral measurements have given bubble temperatures in the range from 2300 K to 5100 K, detection of very high bubble temperatures by spectral methods is limited due to the opacity of liquids to short wavelength light characteristic of very high temperatures. Writing in Nature, chemists David J. Flannigan and Kenneth S. Suslick describe a method of determining temperatures based on the formation of plasmas, the ionization and excitation energy of dioxygenyl cations, which they observed, is 18 electronvolts
Triboluminescence is an optical phenomenon in which light is generated through the breaking of chemical bonds in a material when it is pulled apart, scratched, crushed, or rubbed. The phenomenon is not fully understood, but appears to be caused by the separation and reunification of electrical charges, the term comes from the Greek τρίβειν and the Latin lumen. Triboluminescence can be observed when breaking sugar crystals and peeling adhesive tapes, triboluminescence is often used as a synonym for fractoluminescence. Triboluminescence differs from piezoluminescence in that a piezoluminescent material emits light when it is deformed and these are examples of mechanoluminescence, which is luminescence resulting from any mechanical action on a solid. The Ute constructed special ceremonial rattles made from buffalo rawhide which they filled with quartz crystals collected from the mountains of Colorado. The scientist Robert Boyle reported on some of his work on triboluminescence in 1663, in the late 1790s, sugar production began to produce more refined sugar crystals.
These crystals were formed into a solid cone for transport. This solid cone of sugar had to be broken into usable chunks using a known as sugar nips. People began to notice that as sugar was nipped in low light, a historically important instance of triboluminescence occurred in Paris in 1675. Astronomer Jean-Felix Picard observed that his barometer was glowing in the dark as he carried it and his barometer consisted of a glass tube that was partially filled with mercury. Whenever the mercury slid down the tube, the empty space above the mercury would glow. While investigating this phenomenon, researchers discovered that electricity could cause low-pressure air to glow. This discovery revealed the possibility of electric lighting, when the charges recombine, the electric discharge ionizes the surrounding air, causing a flash of light. Research further suggests that crystals which display triboluminescence must lack symmetry, there are substances which break this rule, and which do not possess asymmetry, yet display triboluminescence anyway, such as hexakisterbium iodide.
It is thought that these materials contain impurities, which properties of asymmetry to the substance. The biological phenomenon of triboluminescence is conditioned by recombination of free radicals during mechanical activation, a diamond may begin to glow while being rubbed. This occasionally happens to diamonds while a facet is being ground or the diamond is being sawn during the cutting process, diamonds may fluoresce blue or red. Some other minerals, such as quartz, are triboluminescent, emitting light when rubbed together, ordinary Pressure-sensitive tape displays a glowing line where the end of the tape is being pulled away from the roll