V* 



ASTRO-PHYSICS 301 



The mathematical possibilities of development 

 of these isolated masses, shows that they will not 

 repeat the story of their parent. They are smaller 

 beings, and instead of giving birth to a million 

 new stars, or even a modest solar system, if left 

 alone they will become covered with a gaseous 

 atmosphere, or, if rotating rapidly enough, break 

 up into two partners that spend their lives waltz- 

 ing round each other, and are represented in 

 nature by the countless host of binary stars. 



No analogue of our solar system has been 

 seen in the sky. Indeed, if one exists, it would 

 be too small for the planets to be detected at the 

 distance of even the nearest star. We have no 

 model then by which its history may be illus- 

 trated, and can but turn to unconfirmed mathe- 

 matical speculation. 



Jeans has shown that the facts may be 

 explained by the influence of a foreign body at 

 an early stage of solar evolution. When the sun 

 was a tenuous mass of nebulous substance, lately 

 cast forth into space from the arms of some 

 primordial spiral nebula, it may have passed near 

 one of its brother stars or some other wandering 

 body, which raised a tidal wave on its glowing 

 surface. If the body came within a certain range, 

 the tide would not subside as the body passed, 

 but would surge upward, till finally the crest of 

 the wave would fly off as a long streamer into 

 space. This, being much denser than a mass 

 detached by centrifugal action, might be held 

 together by gravity, and would itself break up 

 into masses which may have formed our family 

 of planets. 



Leaving this speculative account of the origin 



