ABSTRACT
The question of how the Sun has evolved to its present state and how it will continue to evolve in the future undoubtedly aroused the curiosity of astronomers long before they considered the way in which stars evolve, since it is only comparatively recently in the history of astronomy that the true nature of the stars, as suns in their own right, has been recognized. The Sun, being the nearest of the stars, is the only one to exhibit a measureable disc. Light, travelling at over 186,000 miles every second, takes slightly more than eight minutes to reach us from the Sun, but over four years to cover the distance from the nearest star system, Alpha Centauri. At first sight this would suggest that, if we wish to discover how the stars evolve from the moment they are born to the time they finally die, the Sun is the best candidate of all for us to examine. Certainly we can learn a great deal from a study of the Sun, but when it comes to predicting future events several million years from now, or the way in which the Sun behaved at a similar period in the past, we are forced to turn to the stars in order to obtain this information. A little reflection will show us why this is so.
