MIRACLES OF SCIENCE t 



observed to form about it a nebulous haze which 

 spread rapidly outward in all directions until an oval 

 nebula of large dimensions was formed. The rate of 

 seeming growth of this nebula, spreading outward in 

 all directions from the star, was comparable to the 

 speed of light. 



At first astronomers were at a loss to explain this 

 curious phenomenon. If the blazing up of the new 

 * star had been due to the collision of two dark bodies, 

 the incandescent mass formed would presumably 

 blaze out as a permanent star, instead of fading quick- 

 ly away. And if the seeming spread of the nebula 

 marked an actual dispersion of gaseous or other mat- 

 ter, its rate of progression exceeded what had been 

 believed to be the speed limit of particles of matter. 



So the most plausible explanation of the phenomena 

 seemed to be that a dark star in plunging through the 

 body of a pre-existing nebula had been rendered in- 

 candescent at its surface only and hence quickly lost 

 brilliancy after passing through the nebula ; and that 

 the seeming growth of the nebula month by month 

 as viewed from the earth marked the spread of light 

 which thus illuminated the pre-existing but hitherto 

 dark nebula in due course from center to circum- 

 ference. The size of the nebula may be judged from 

 the fact that it required several months for the light 

 to reach its borders, and light travels, it will be re- 

 called, 186,000 miles per second. 



WHY NEBULAE ARE NUMEROUS 



We must not take leave of the new star in Perseus 

 without noting that a somewhat different explanation 



26 



