Electromagnetic waves are energy waves produced by the oscillation or acceleration of an electric charge. They include radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. Their wavelengths in meters are: radio waves (0.1 to 1000), microwaves (1 x 10-3 ~ 1 x 10-1); infrared (7 x 10-7 ~1 x 10-3); visible light (4 x 10-7 ~ 7 x 10-7); ultraviolet rays (1 x 10-8 ~ 4 x 10-7); x-rays (1 x 10-11 ~ 1 x 10-8) and gamma rays (< 1 x 10-11).
Scientists have inferred that such great amounts of energy as produced by the Sun (4x1026 watts per second) can only be the result of nuclear fusion
If such energy were produced through the most efficient chemical reaction, the Sun would not last for more than a few thousand years. Evidence suggests that the lifespan of the Sun is in billions of years; hence the Sun's energy cannot be the result of chemical reaction.
Nuclear fusion occurs when two positively charged atomic nuclei are fused together. In the Sun hydrogen...
Fusion requires extremely high temperatures and densities to overcome the repulsion between positively charged nuclei. Such conditions are present in the core of the Sun (100 times the density of water on Earth, and temperatures of about 27 million degrees F).
5. The factors that make some stars appear brighter than others are their luminosity (how much energy they give out in a given time) and their distance from us. Obviously the stars nearer in distance appear brighter if their luminosity is the same. The luminosity of the stars, in turn, depends on their size, mass, and temperature; hence larger stars may appear brighter than smaller stars although they may be further away.
6. The Sun is an "average" star in terms of its mass, light production, and size. It appears so different from other stars because of its relative proximity to the Earth. All stars including the Sun are balls of hot, glowing gas that are hot and dense enough to…
