Im Englisch mussten wir letzten Winter einen Vortrag in Partnerarbeit über ein beliebiges Thema in Eng-lischer Sprache abhalten. Dies ist zwar schon ein Weilchen her, nichtsdestotrotz möchte ich euch unsere Arbeit in diesem Artikel präsentieren, in Englisch versteht sich. Es war mein allererster Vortrag in einer Fremdsprache, daher bitte ich um Verständnis, falls der Text über ein paar Rechtschreibe- oder Grammatik-fehler verfügt. Ich habe den Text bewusst nicht nachkorrigiert, es liegt das Original zum Zeitpunkt unserer Präsentation vor. Ich hoffe, dass ich euer Interesse geweckt habe und wünsche viel Spass beim Lesen.

The Light Bulb

History

In 1809 Sir Humphry Davy presented the first light bulb, but it didn’t work very well. A few years later in 1820 Auguste-Arthur De La Rive developed a lamp with an evacuated bulb. This light bulb is also known as the De la Rue Lampe or De la Rive Lampe.
In the year 1841 Frederick de Moleyns received the very first patent on a light bulb. In 1854 Heinrich Göbel invented the very first fully functional light bulb. Göbel is a German mechanic, who moved to America in the age of 30. Because electric power wasn’t yet available in buildings, the lamp was more or less unusable. At that time the lamp operated on batteries and burnt only a few minutes. In 1860 Joseph Wilson Swan a British physicist and chemist, developed a light bulb, for which he used charred paper for the filament. Eighteen years later he succeeded the development of a useable light bulb. In the same year he got his patent in England. Edison received his similar patent two years later in the United States. After some patent conflicts between Edison and Swan, they founded a common company in London.
Thomas Edison improved the light bulb and received the basic patent number 223 898 for it on January 27th in 1880. The 21st of October 1879 is accounted as date of invention of the light bulb. In contrary to Swan's bulbs, Edison's light bulbs were fitted with high-resistance filaments. This simplified the use in electrical circuits. These lamps were similar to Göbel’s light bulbs. However, Edison was able to use generators for the power supply instead of batteries. Therefore, Thomas Edison has been credited as the inventor of the light bulb. Edison's construction was the first light bulb which was not only manufactured in small numbers in workshops, but went into series production in his own factory. The light bulb was born.
In the 19th century the light bulb and the electric power was way too expensive for households. Only rich people and companies could afford the luxurious lamps. To the beginning of the 20th century the light bulb and the power supply became cheaper. Therefore, the light bulb was affordable for normal people. Shortly after, it became present all over the world. Today a life without it is almost impossible.

Construction

The light bulb consists of three main parts: The cap, the glass bulb and the filament.
The cap is the holder of the light bulb which also establishes the electrical contact.
In the normal environment the filament would burnout immediately. Therefore, the filament is shielded from oxygen by the glass bulb, which is filled with a protective gas.
Since 1910 the filament is made out of wolfram. Wolfram has a high melting point; it melts at a temperature of 3422°C. In addition wolfram can be shaped in any form. The filament is connected with two contact wires, the green one goes in and the blue one goes out of the filament. In addition there are two support wires connected with the filament. The other ends of these wires go into the stem which is made out of glass. Finally the green wire is connected with the contact on the bottom of the light bulb while the blue wire is connected with the cap.

Advantages & Disadvantages

The advantages of the classic light bulb are: You immediately get the full brightness when you turn it on. The light bulb is dimmable and very cheap. It is very easy to handle and doesn’t need any additional devices. Finally the light of these lamps is very similar to the light of the sun.
Now to the disadvantage: The life time of light bulbs is rather short; it burns only approximately 1’000 hours. The light bulb consumes a lot of energy and is inefficient, due to the fact that the most energy is lost in heat. Because of the high temperature, light bulbs could only consists of metal, ceramic or glass. Therefore, light bulbs are very fragile. By applying to much force the glass will break and could cause serious injuries. In addition the filament is very sensitive too; even the smallest vibrations could destroy it.

Different forms and types

There are lots of different forms and types of the classic light bulb. Because of their purpose they have various forms, colors and even functions. Now we will present you a few of these forms:
The most common one has the shape of a pear. Then there is the so-called spotlight. Technically both are similar, but the glass of the latter one is designed to a collecting lens which throws the light in a preferred direction.
A completely other form of the light bulb is the electron tube. In the year 1883, Edison accidentally invented the electron tube, but he didn’t have any usage for it. This kind of the light bulb didn’t shine brightly it just glowed a little bit. A few years later, scientists discovered that electric signals could be amplified. With this knowledge it was possible to build electronic amplifiers and make music hearable by loudspeaker. A major disadvantage was that the tube consumed a lot of energy thereby getting very hot. In the 1950s it was replaced by the electronic transistor which didn’t have anything in common with the light bulb. However, even today these tubes are still used in amplifiers of the premium class because of their unreachable music quality.
These are the most important forms of light bulbs. Mentioning all the existing forms and types would exceed the duration of this presentation just too much.

Environmental Aspects

The light bulb isn’t really environmental friendly. To make it light, the filament must be heated to an extremely high temperature. This wastes a huge amount of energy in relation to its lighting power. More than 98% is lost as heat.
Because energy is rare and valuable, the environmental aspects are becoming more and more important. That's why the light bulb is already banned in many countries. As the first country, the government of Australia forbade the sale of every kind of light bulbs in the year 2010. In Switzerland light bulbs with an energy efficiency class less than E are banned since the year 2009. From 2012 all light bulbs that consume more than 40 Watt are forbidden in Switzerland.

The Future

In more and more countries light bulbs are being banned. The reason we have already pointed out to you. Therefore, the light bulb will disappear in the near future. In a few years it could be that the light bulb won’t be available on the worldwide market anymore.
But are there any other possibilities to making light? Of course there are! The science is actually looking forward to new alternatives for the economic light generation. Till now, the light emitting diode aka LED is one of the most innovative invention. The LED works like a common diode, it lets the electrical current flow in only one direction. The difference to the diode is that the LED emits light during that process. As soon as the diffusion voltage about 0.75 volts is exceeded, the LED lights up and doesn’t get hot. As a result, the LED consumes a minimum of electricity. Another benefit is that the frequency of light can be exactly specified. Therefore, it is possible that the light shines in exactly one way, like a laser. Alternatives to the LED are the neon tube and the energy saving lamp.

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