182 INTRODUCTION TO SCIENCE 



sun is represented by a grain of sand one-hun- 

 dredth of an inch in diameter, and the earth 

 by a quite invisible speck one inch away. Upon 

 this scale the nearest star will be another grain 

 of sand some four miles away." . . . The sun 

 would take at his present speed in space some 

 seventy thousand years to reach his nearest 

 neighbour. . . . "Despite the richness of the 

 sky, the emptiness of space is its most striking 

 characteristic. ' ' 



The great concepts of physics such as the 

 law of gravitation, the luminiferous ether, and 

 the conservation of energy are assets in the life 

 of feeling. "In accordance with the conception 

 of the conservation of energy there is no real 

 cessation of energy motion, there is only an 

 alteration hi its mode; thus the sum total remains 

 for ever the same, one mode changing to another 

 without any energy ceasing or being lost in the 

 transformation." And speaking of this, Prof. 

 Gotch continues: "Such an imaginative flight 

 is far beyond all sense experience. To the thought 

 of a scientific man the universe, with all its suns 

 and worlds, is throughout one seething welter of 

 modes of motion, playing in space, playing in the 

 ether, playing in all existing matter, playing in 

 all living things, playing, therefore, in ourselves. 

 Now locked together in more intimate embrace, 

 potential energy, now unlocked and streaming as 



