subject: Light is? [print this page] We all know the great importance of lights in our lives. Ever since the beginning of life in the universe, light has already been at work to cast its illumination on all lifeforms. Even in the theories of creation, like the creation according to Genesis and the Big Bang Theory, began by using or creating light sources which led to more profound conception of various matters. Ever since then, ways of living has been enhanced through the utilization of light.
As a natural source of light, the Sun could probably supply the most forcible light due to the fact that sunlight provides energy to all forms of life on Earth. Besides the Sun, more astronomical stuffs which serve as sources of natural light are meteors (meteor showers), stars (clusters, galaxies, quasars), nebulae and accretion disks. Yet another light source is Bio-luminescence, the production and emission of light is made possible by a living organism. A few bio-luminescent creatures are fireflies, glow worms, mollusk, firefox (mushroom), cookie-cutter shark, flashlight fish, corals and vampire squids
Triboluminescence is an optical occurrence that happens as soon as the material is jerked apart, split, scraped, crushed, or chafed, the chemical bonds collapse and produce light. An illustration of this is the glow produced when a diamond is rubbed is an example. Air-glow is the weak light emitted by the planetary atmosphere. Auroras, or at times named northern and southern lights are actual light spectacles in the sky at night, particularly in the polar regions. A magma is a molten rock beneath the surface of the earth that also emit light such as in black body radiation. In physics, light emission is also produced when certain particles of a gas is ionized/plasma. Also another natural light forms are fire and lightning.
Men have also discovered the use of chemicals in order to produce light. Chemiluminescence is the chemical reaction that produces light when a limited amount of heat is applied on a substance. When a certain substance has taken in light of a different wavelength, it rapidly re-emits observable light and is termed Fluorescent. At the same time Phosphorescence is the manner where energy absorbed by a particular matter is released gradually as a light form.
Another incidence of light emission through chemicals, combustion is the exothermic chemicals reaction of a fuel and oxidant, producing not only light but also heat. Light sources which are Combustion-based are ">lighting and lamps, candles, flash powder, gas lighting, lanterns and torches.
Electricity is another discovery of men that effectively plays an important part in society today. With the use of electricity, many forms of light were devised and acquired for different reasons.
Light is emitted by a particular object when it becomes hot. This is described as Incandescence. Carbon conventional incandescent bulbs, button lamp, halogen lamps, glowbar and nerst lamp are examples of light sources employing Incandescence.
Electroluminescence, both an optical and electrical occurrence, which happens when a material emits light as a reaction to an electric current passing through it. Light sources using this concept are Light-emitting diodes (LEDs), Electroluminescent sheets and wires.
Another artificial light source powered by electricity are gas-discharge lamps that generate light discharged electrically out of an ionized gas or plasma. Lamps employing the process of gas discharge black light and plasma lamps.
