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Energy is something most of us take for granted. You start your car, turn on a light,
or watch TV without thinking too much about the fuel which powers these devices. The
ultimate source of power for these conveniences is 93 million miles away and is
also an important ingredient for that tan which you covet. It is the sun's energy which
is crucial to life on earth. Energy from the sun is responsible for almost all forms of power which we use in our everyday lives. The fossil fuels we use are stored solar energy from plants which grew in sunlight millions of years ago. Winds are generated from weather systems formed under the suns influence. Hydropower comes from free flowing water which wouldn't flow free without the sun's heat. The sun's energy is the driving force behind the processes which governs life on our planet.  The sun is a star, astronomically speaking. Astronomers class it as a G2 - V star. The G2 portion of the classification means the sun is the second hottest type of star in the yellow star class. The V means the sun is a main sequence, or dwarf star.  The solar system is located in the outer portion of the spiral of the galaxy we know commonly as the Milky Way. A glance at the sky at night during the summer months, when it is best seen, shows the reason for its name. The milky band across the sky is plainly visible under clear skies. The suns source of energy comes from a nuclear reaction called fusion. The sun is composed mostly of a gas called hydrogen. Because the sun is so large, the gravitational force it has is incredible. This gravitational force is great enough that hydrogen atoms - the basic component of the gas, are fused together. This compressive force forms the hydrogen into another gas called helium and releases a tremendous amount of energy in the process. It is this energy which races through space to the earth and other planets. How Solar Energy Works Harvesting this solar power efficiently to use is mankind's current challenge. One collection process which has been developed is called the solar cell. In this device, silicon has been manufactured in such a way to convert the sun's rays directly into electricity. This electricity can then be used to power computers, motors, cars, fuel cells, and whatever else we decide to use. Solar power may be a very important source of our future power needs. A number of kits have been developed to aid the curious in their understanding of how solar power might be harnessed to power our devices. Using these kits, experiments may be performed using solar power to run motors and other devices. The solar heating power of the sun can be demonstrated by the solar bag. This is a long black plastic bag which rises like a hot air balloon on heat generated by the sun. Energy from the sun is crucial to life on earth. Without the sun, the earth would be a cold, lifeless rock floating in space. Solar power will become a more important energy souce as we learn more efficient ways of harvesting and utilizing the sun's rays. |