THE EVOLUTION OF THE UNIVERSE 19 



normally, must be hundreds, if not thousands, of 

 millions of years. Of course, the great sudden blaze 

 which we call a new star is a blaze of white-hot gas; 

 not the star itself. Still, these things seem to be 

 "accidents." A few think that two stars have come 

 into partial collision — "grazed" each other, so to say. 

 If two masses of metal, each weighing trillions of 

 tons and travelling at a hundred or more miles 

 a second, were to do this, we would certainly expect 

 a terrific "blaze." But collisions must be very rare, 

 and new stars are frequent. Probably a dead or 

 invisible star has rushed into one of the great dust 

 clouds (nebulae) and been raised to white heat, in 

 part, by friction. Whatever be the real explanation, 

 the fact is impressive. The millions of stars of our 

 universe are living, dying, and being born again all 

 round us. 



Modern science goes a step further than this. 

 Here I am going to say something which is by no 

 means settled, but the speculation is so vast and 

 interesting, and gives such a wonderful unity to 

 the evolution of the universe, that it cannot be 

 omitted. 



Everybody now knows that a mysterious some- 

 thing called "ether" runs from end to end of the 

 universe, and passes through the most solid matter 

 that we know. The stars are like great sponges in 

 an ocean of ether. It contains those other "island- 

 universes" (if they are such) of which I spoke, as 



