42 The Outline of Science 



supposed dead star registers itself as very much alive. Algol is, 

 rex, interesting in another way. The pair of stars which we 

 have discovered in it are hundreds of trillions of miles away from 

 the earth, yet we know their masses and their distances from each 

 other. 



The Death and Birth of Stars 



We have no positive knowledge of dead stars; which is not 

 surprising when we reflect that a dead star means an invisible 

 star! But when we see so many individual stars tending toward 

 death, when we behold a vast population of all conceivable ages, 

 we presume that there are many already dead. On the other 

 hand, there is no reason to suppose that the universe as a whole 

 is "running down." Some writers have maintained this, but their 

 argument implies that we know a great deal more about the uni- 

 verse than we actually do. The scientific man does not know 

 whether the universe is finite or infinite, temporal or eternal; and 

 he declines to speculate where there are no facts to guide him. 

 He knows only that the great gaseous nebulae promise myriads of 

 worlds in the future, and he concedes the possibility that new 

 nebula- may be forming in the ether of space. 



The last, and not the least interesting, subject we have to 

 notice is the birth of a "new star." This is an event which astron- 

 omers now announce every few years; and it is a far more porten- 

 tous event than the reader imagines when it is reported in his 

 daily paper. The story is much the same in all cases. We say 

 that the star appeared in 1901, but you begin to realise the mag- 

 nitude of the event when you learn that the distant "blaze" had 

 really oeeurred about the time of the death of Luther! The light 

 of the conflagration had been speeding toward us across space 

 at 18<;.(M)0 miles a second, yet it has taken nearly three centuries 

 to reach us. T< he visible at all to us at that distance the fiery 

 outbreak must have heen stupendous. If a mass of petroleum 

 ten tinu^ the size of the earth were suddenly fired it would not 



