30 HOLISM AND EVOLUTION chap. 



curved and non-Euclidean. Taking the variations of the 

 spaces and times on the rotating disc together, we conclude 

 that the disc is not a Euclidean space but a non-Euclidean 

 Space-Time continuum. 



As we have seen that the phenomena of acceleration 

 (including rotation) and gravitation are equivalent, these 

 considerations in reference to the rotating disc apply also to 

 every gravitational body. We know that gravitation acts 

 at a distance from the centre of the gravitational body; 

 in fact every such body is surrounded by a gravitational 

 field far larger than itself. Therefore the non-Euclidean 

 characters will also distinguish the Space-Time continuum 

 in this field. In other words, movements and happenings in 

 this field will not follow the law of a uniform time and a 

 homogeneous identical space in all directions. They will 

 take place in curves, exactly as on our rotating disc. A body 

 falling in space through such a field will on entering 

 it and while in it, follow not a straight path, but 

 the curve which coincides most closely with its original 

 straight path; a ray of light passing through the field will 

 similarly follow the nearest curve instead of a straight line. 

 And indeed any physical event within that field will, in so 

 far as it is of a translational character, follow the curve on 

 which it happens to take place. These deductions from 

 theory have been experimentally verified in the most impor- 

 tant particulars. 



According to this theory the mysterious "attractive " 

 power of matter, which is called gravitation, assumes quite 

 a different character. The apparent attraction is simply 

 due to the movements in the universe of masses charged 

 with energy, which (except as pushes and pulls on our 

 bodies) we ourselves do not particularly notice as we happen 

 to partake of the same movements as the observed phenom- 

 ena. This, however, does not make of gravitation an unreal- 

 ity, due to the subjective vagaries of the observer. Gravita- 

 tion, as we have seen, now becomes the curves of the real 

 Space-Time world; it marks the inevitable paths which all 

 events must follow in the physical universe. So far from 



