Light energy can come from many different sources.
Light Energy
We have always had a need for light. Even going back 500 years BC, Ancient Romans used lamps filled with vegetable oil in front of their houses.
The first organised method of public lighting was in 1417 in London.
Another method of constant illumination was link-boys. Rich individuals would pay children servants to carry lanterns and accompany them while walking.
The sun. This is the ultimate form of light energy. It takes roughly 8 minutes for the light to leave the sun and hit the earth. It travels at roughly 300,000 km/s.
Light however is made of small particles called Photons.
We can break light up into different types, depending on how much the photon oscillates.
Gamma rays, are the most intense and energetic form of light. As you can see by the animation to the right, the photon oscillates rapidly. As we move down the spectrum, the photons decrease how much they oscillate and decrease in energy.
As you can see by the image to the left, the visible light spectrum is only a small portion of light.
This is called the electro magnetic spectrum
In fact each colour has its own wave length. Click here to see
Electric lighting.
The law of conservation states that we can’t create or destroy energy, but we can convert it.
Light bulbs convert electric energy, into light energy.
A light bulb is made up of a few key components.
A positive and negative terminal
Glass casing
Tungsten filament
The electricity flows through the light bulb from positive to the negative terminal.
As the electricity flows through the tungsten filament it heats it up.
This heating causes it to change colour and brighten up a room.
The bulb is important because it keep a small amount of inert gas surrounding the filament. This means the filament won’t over heat and break.
