A Little Light Music Essay, Research Paper
Light in the Modern World
Since the beginning of time, mankind has made use of light, from simple things such as planting crops in areas of abundant light to things as well thought out as Stonehenge on the Salisbury plains. Not being content with having to rely on natural light from the sun and stars alone, we have created our own light. Our first method was fire, in such things as candles and oil lamps. More recently, however, we have relied mainly on electricity to provide us with artificial light. The research and technology that has been invested in the making of light has discovered several things that are used everyday by people, and yet remain shrouded in mystery, not least of these, is the laser. The laser (Light Amplification by Stimulated Emission of Radiation) is made possible by the fact that if an electron absorbed energy for any reason, it can only release it again at a specific frequency. In its simplest form, a laser consists of a rod of transparent crystal or a tube filled with gas or a liquid. A mirror is placed at one end and a half-silvered mirror at the other. The laser is “pumped” by adding energy – for example, by adding electrical energy, shining another light source into it, or by stimulating a chemical reaction. These all give the electrons enough extra energy for them to release it (when appropriate) in the form of photons. Some of the electrons spontaneously release their excess energy, emitting photons. The photons that travel toward the sides of the laser are quickly lost, but those travelling along the length of the rod or tube are refl
·Car bodies are now welded together using ultra powerful lasers.
·Astronomers can now use lasers to determine the exact position of other stars, planets and even galaxies.
·The “Star-Wars” project (a joint USA and UK venture) uses a laser to destroy nuclear and thermo-nuclear weapons once they are airborne.
·Lasers are becoming a tool of surgery (eye surgery, brain surgery, etc).
·Weaker lasers are even being used as pointing devices in lessons and lectures across the globe.
What lays ahead, in the future, nobody knows; but light will always be made use of and will always have a purpose.