CHEMICAL CLOCK I73 



This is our only reality. But there is, behind this shadow, the 

 object which projects it, and which ever since Plato we have 

 vainly tried to conceive. The intersideral spaces are black 

 and cold. 'Energy quanta' circulate through them in every 

 direction and in infinite numbers.^ Without an adequate 

 receptor to intercept, accumulate, totalize and transform them, 

 they are nothing but quanta. In the absence of human beings, 

 light, heat, sound, do not exist as such. In the absence of 

 radio sets, waves emitted by the broadcasting stations are 

 inexistent for us. Each one of our senses acts as a receiving 

 set and translates for our consciousness the silent, invisible, 

 and abstract message of the quanta of energy. It is in this 

 sense that we have occasionally called our physiological time 

 real time. It is owing to this time that the summation of 

 quanta takes place in our brain, and that we perceive the 

 universe as we perceive it. The other, the time of things, the 

 time of the obscure and mute universe, unknown and un- 

 knowable, has no more reality for us than radio waves in the 

 absence of receiving sets. 'In this time without duration, 

 events could not succeed each other, nor things subsist, nor 

 beings age' (Bergson). If it governs us as a combination of 

 atoms and molecules, it does not govern us as a living individual 

 destined to die. It is, on the contrary, our physiological time 

 which enables us to conceive, through our intelligence, the 

 uniformity of flow impossible of perception. Should it be 

 demonstrated some day that universal time can be resolved 

 into quanta, then the same would be true of our physiological 

 time. The quantum of physiological time would then be a 

 function of the period of our existence, and would be different 

 for each species. The picture of a ciirve, or of a wave front, 

 which we have proposed in order to explain our concept of 

 universal time would, in this case, be materially strengthened. 

 But this draws us into a speculative domain, and that is pre- 

 cisely what we have tried to avoid. 



• • • • • 



^ Before Planck and Einstein one would have said, '^waves or 

 vibrations of ether'. 



