232 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 60 



"forces" whose origins were in the heavenly bodies themselves; and 

 while Newton himself would probably have taken a more philosopliic 

 view of the meaning of this statement than would many of his fol- 

 lowers, those who wished to "understand," and had faith in the 

 meaning of such understanding, felt, for the reasons I have already 

 stated, unhappy about the acceptance of such a philosophy. They 

 demanded some kind of a medium permeating all space between the 

 heavenly bodies, a medium which could transmit the desired force. 

 Later, this medium was charged with the duties of every conceivable 

 kind of phenomenon by which one body appeared to influence an- 

 other body at a distance. It became charged, among other things, 

 with transmitting the light and heat of the sun to earth, and later it 

 was charged with the transmission of radio waves. It was natural to 

 try and understand this medium as something like a solid or a liquid, 

 or a gas of our common experience, but alas, the demands on it did 

 not harmonize with any of these characterizations. And so this me- 

 dimn, this "aether," as it was called, remained as a mystery. As long 

 as one did not inquire too much about the mechanisms of its activities, 

 it served as a balm to the conscience of common sense in seeming to 

 relieve us of the terrors of action at a distance. Many were the 

 attempts to provide inner mechanisms by which man could under- 

 stand, in terms of the common sense of the day, all that seemed to be 

 happening; but the mechanisms for different activities were incon- 

 sistent and all that remained was the apparent potentiality of trans- 

 mitting something from one place to another with a finite velocity, 

 even though one did not know what the something was w^hich was 

 transmitted. It was with this dilemma in mind that, some years ago, 

 I defined the aether as a "medium devised by man for the purpose of 

 transmitting his misconceptions from one place to another." It was 

 during the period of prohibition, and I added an observation to the 

 effect that "of all subtle fluids invented for the stimulation of the 

 imagination, it is the only one which, so far, has not been prohibited." 

 Later, alas, it also became prohibited, when the theory of relativity 

 came upon the scene, declaring that it had no substance in reality, was 

 inconsistent in philosophy, and was a useless encumbrance to the 

 brain which tried to use it. 



And so, it came about that insofar as it was meaningful to speak of 

 one body as "acting upon" another, one had to accept "action at a 

 distance" as something w^hich, while dubiously respectable, was not a 

 thing to be talked about in polite scientific society. I tliink, however, 

 that we must realize that with his banishing of the aether to the 

 realms of nonsense, man took one of his first steps in removing his 

 ideas from the realm of popular understanding in terms of the 

 everyday experiences of the times. 



