FREE ESSAY ON LIGHT: A FUNDAMENTAL FORCE

LIGHT: A FUNDAMENTAL FORCE

Light: A Fundamental Force In Our World If asked what light is, one could say that it's
one of the most basic elements of our world and our universe as we perceive it. It is
through sight that we receive 90% of our information. It is through the use of telescopes
aiding the naked eye that we are aware of the heavenly bodies around us. It is through
light that the energy from the sun is transferred to us. The sun's energy supports the
food chain; plants use it to turn water and CO2 into energy usable by other organisms.
Solar energy was also used, indirectly, to produce all of the fossil fuels that we
consume daily. Since light is such a basic part of our existence, we should have a basic
understanding of what it is. What we call light, the intangible, powerful force that
powers our world, is somewhat hard to define in real terms. It shares properties with
both particles and waves. It follows the same rules as a wave does--it moves in a regular
fashion, in a perfect sine wave at a certain frequency. It travels in a straight line,
and is subject to refraction. All of these characteristics are found in waves of any
type, from radio frequency waves, up to Gamma and X- rays. Light, however, also exhibits
qualities characteristic of particles such as neutrons and protons. A photon, or quanta,
is the packet of energy that is sent in a light wave. Like a particle, the photon is
believed to have a finite mass, and has the ability to affect other matter. As light
strikes a photovoltaic solar cell, it knocks electrons in the silicon atoms on the
surface into a higher state of energy. When these return to their normal, or ground
state, energy is produced in the form of electricity. Thus, light is termed a wave-
particle, and this property is called the wave-particle duality of nature. Many questions
concerning what makes up light still lie unanswered, but this much is thought to be true.
Light can be produced in a variety of ways. Our sun, like other stars, uses nuclear
fusion to produce energy in the form of light and radiation. We can produce light
artificially using several methods. If one starts a fire, it produces light and heat.
(Heat, which is infrared radiation, is another type of light energy.) The light and heat
are a result of a chemical reaction, the combining of oxygen with the carbon in the wood.
This reaction leaves behind products which have less potential energy than they started
with. The energy, which left as light and heat, was produced when electrons dropped in
energy levels during the reaction. The excess energy from one atom was given off as a
photon, producing light. If one examines a fluorescent or incandescent light bulb, one
can see that all it is doing is having electricity stimulate a metallic or gaseous
substrate, causing it to give off photons. The principle is the same as it was with the
fire, only it is more controlled. Still more controlled is the laser, which puts out its
photons in a single frequency. This is achieved through a carefully designed apparatus
which stimulates materials in a way that allows them to only put out light at a certain
wavelength. Laser light is, therefore, of all one color. White light, or sunlight, is a
broad mixture of wavelengths. All methods of producing light, natural and artificial,
share one common feature: they rely on electrons changing energy levels to produce the
photons. As there are a variety of methods of producing light, so are there a multitude
of ways it can be applied. The most obvious use of light is in supporting our food chain.
Without light energy, nothing could live on our planet. The plants, which are at the
bottom of the food chain, supply energy to all other organisms. We as humans are adapted
to having sunlight around us, and taking in information with our eyes. Aside from keeping
us alive, light is also employed in highly specialized applications. Laser light is being
used in surgery. The highly concentrated beam of light is far more precise than any
surgeon's hand, and much finer than the sharpest blade. In the area of communications,
light is used in fiber optic networks for fast, crystal-clear connections. (Fiber optics
allow light to travel in a finely directed path with very little distortion.) Optical
components in computers are starting to see use. Also, lasers are being used to produce
holographic images, both for industrial and commercial markets. Holographic pictures can
show an object three dimensionally, and in great detail. Finally, new ways of utilizing
the sun's energy are being developed that will allow light to be more efficiently
converted to electricity. Thus, light indeed has a wealth of applications. It must be
remembered that, like most other things around us, light is something utilized on a daily
basis, yet little understood. With continued research, we may someday unravel the
mysteries surrounding this unique force which is constantly at work in our universe. The
applications of light in the present are nothing compared with what could be gained if we
could understand this strange mechanism; it may someday be the key to solving our energy
problems, or unlocking the secret of the universe. 
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