Science Corner: An Idea for the Ages

By Alaina Grantham
Rotunda ReporterImagine it is 1879; you are sitting in your living room quietly reading the newest novel from your favorite author. You have been reading nonstop all afternoon and have just started to start the climax of the novel, but it's getting hard to see. The natural light from the window is fading as the sun sets, and soon it will be to dark to see much of anything. With a heavy sigh you put the book down and stand up and start to fiddle with the oil lamp beside you on the desk.

Before the lamp can be lit there is a simple checklist to follow. First, the oil level in the lamp needs to be adequate to keep the lamp lit. Second the wick needs to be checked, and possibly trimmed. Third, anything that looks remotely flammable needs to be removed from the immediate area. Then finally the lamp can be lit.

Now, apply the same situation to today, the daylight starts to fade and, you calmly get up, walk across the room and flip a switch, and then magically there is light.

Comparing the two scenarios it seems obvious which involves the greater effort, and for us it is almost impossible to imagine the first. Our entire lives have been built around the easy access of light after dark. This 'let there be light' lifestyle is largely due to a single invention, the light bulb. The light bulb we know today isn't too different from the light bulb invented by Thomas Edison. I

The technology behind the light bulb is surprisingly simplistic. At its simplest a light bulb relies heavily on the basic knowledge electrical circuits. Electricity enters the light bulb at one end of the circuit; it is then run through a specific filament to create a glow, before the current exits the light bulb to complete the circuit.

At its most complex the light bulb reacts with the gas composition within the bulb, the type of amount of electricity being run through the bulb, the shape and substance of the filament and the atomic structure of the filament. When all of these complex reactions work together a longer lasting light bulb is the sure result.

Over a century of study, all of these complex reactions have lead to the development of the modern light bulb. The modern light bulb consists of a screw to connect the light bulb to the electric current, with a bulb full of some type of inert gas to minimize external reactivity.

The electric current is then free to run across a tungsten coil, which acts as a filament in most incandescent, or average, light bulbs. This tungsten coil is extremely thin and is approximately 2 meters, or 6.5 feet in length but coiled to fit within an inch sized area within the light bulb. The extreme base length of the filament allows for more surface area for the electric current to cross, creating a stronger glow.

The glow itself comes from a reaction between the atoms within the tungsten filament and the electric current flowing through it. The electrical current moves energy through the tungsten, which creates heat. This heat energy excites the atoms of the tungsten causing them to vibrate within their structure.

This vibration from the heat energy creates waves within the atom that will release photons, or light, as part of their cycle. Finding the right atoms to act as a filament can be tricky, if the filament receives energy too quickly it will over heat and catch fire, if the filament is resistant to receiving energy nothing will happen and the circuit won't be complete.

The light bulb as we know it today has come a long way, while essentially keeping the same ageless design. This basic design continues to be prominent in even the new energy efficient light bulbs, which in part focus on finding new filaments that give off the same amount of light while taking less energy.