94 SCIENCE AND METHOD. 



been covered by our globe in its motion in relation 

 to the sun, and the sun in its turn moves in relation 

 to the Milky Way, and the Milky Way itself is no 

 doubt in motion without our being able to recognize 

 its velocity. So that we are, and shall always be, 

 completely ignorant how far the Place du Pantheon 

 moves in a day. In fact, what I meant to say was, 

 " To-morrow I shall see once more the dome and 

 pediment of the Pantheon," and if there was no 

 Pantheon my sentence would have no meaning and 

 space would disappear. 



This is one of the most commonplace forms of the 

 principle of the relativity of space, but there is another 

 on which Delbeuf has laid particular stress. Suppose 

 that in one night all the dimensions of the universe 

 became a thousand times larger. The world will 

 remain similar to itself, if we give the word similitude 

 the meaning it has in the third book of Euclid. 

 Only, what was formerly a metre long will now measure 

 a kilometre, and what was a millimetre long will 

 become a metre. The bed in which I went to sleep 

 and my body itself will have grown in the same 

 proportion. When I wake in the morning what will 

 be my feeling in face of such an astonishing trans- 

 formation ? Well, I shall not notice anything at all. 

 The most exact measures will be incapable of revealing 

 anything of this tremendous change, since the yard- 

 measures I shall use will have varied in exactly the 

 same proportions as the objects I shall attempt to 

 measure. In reality the change only exists for those 

 who argue as if space were absolute. If I have argued 

 for a moment as they do, it was only in order to make 

 it clearer that their view implies a contradiction. In 



