78 THE ANATOMY OF SCIENCE 



a use in science, but only after it is purged of 

 all its misleading implications.^ 



Einstein's theory of relativity can be ex- 

 pressed in many ways. Perhaps the simplest is 

 the statement that, of all the possible velocities 

 with which matter or energy can travel, the ve- 

 locity of light is the maximum. In other words, 

 if we reckon velocities in centimeters per jiffy, 

 all velocities lie between zero and one. Now there 

 are some who have been irritated by this state- 

 ment, and especially by the statement that no 

 velocity greater than the velocity of light can 

 be properly conceived. It seemed to them, as the 

 Volstead act seems to others, to be an arbitrary 



5 Historically the Michelson-Morley experiment was di- 

 rectly responsible for the discovery of relativity, but, as so 

 often happens in science, it was almost immediately seen 

 that there were plenty of other data, some of which had 

 been in the possession of physicists for over half a century, 

 from which the same principle could have been deduced. 

 Now the experiments of Michelson and Morley are being 

 repeated with a care even exceeding their own, and certain 

 effects are being observed, small compared with the ones 

 Michelson and Morley sought in vain, but nevertheless of 

 great consequence to physics and astronomy if they can be 

 thoroughly corroborated. But whatever interpretation may 

 be placed upon these results, it seems hardly conceivable 

 that the principle of relativity could be taken from us, 

 although our ideas of kinematics might be extended; nor is 

 it at all likely that physicists will be obliged to adopt once 

 more the luminiferous ether. 



