To understand how the light bulb works one needs to know the basic physics behind light energy. Light is the energy that atoms release. It is composed of small particles or energy packets. These particles have momentum and have zero mass. These are called photons and constitute the basic unit of light. When an atom releases photons, it indicates that the electrons in that atom have become excited or possess a higher level of energy. Electrons are negatively charged particles and orbit around the nucleus of an atom. These electrons have set orbital pattern; an atom has different levels of these orbits.
Each electron revolves in fixed orbit based on the energy it possesses.1 The speed and distance from the nucleus also determined on which level an electron revolves. The general principle is when an electron possesses higher energy level it is further away from the nucleus. In principle when an atom loses or gains energy this energy change is exhibited through the motions of the electrons. An electron might get a temporary boost in its energy level and jump to a higher orbit.
This action is temporary, and an electron holds this position for merely a fraction of a second. And in an instant it returns to its original position. When an electron returns to its lower energy level, it releases this extra energy or a photon; this is the fundamental principle of what goes on inside lightbulb. To understand how this phenomenon is implemented in this tool we need to look at the structure of the lightbulb.
Lightbulb has a simple structure. It has two metal contacts at the base connecting the ends of an electrical circuit. The metal contacts are connected to two stiff wires that are attached to a thin metal filament. This filament sits in the middle of the bulb supported by a glass mount. This filament and the connecting wires are surrounded by a glass bulb2. The glass bulb has no oxygen in it (Nobleman, 2003).