3 2 TWO NEW WORLDS 



Now an infra- year is what we call a thousand 

 billionth of a second. Hence the lives of countless 

 generations of beings would have time to accom- 

 plish themselves in a small fraction of our second 

 of time. 



5. The solar system is calculated to be 1000 

 million years old, meaning that the planets have 

 existed in approximately their present state and 

 distribution for that length of time. It is esti- 

 mated that they will last as long again. But 

 even this vast span, transferred to the time scale 

 of the infra-world, only brings us up to about a 

 millionth of a second, or the smallest interval we 

 can measure with our present instruments. When, 

 therefore, we deal with molecular orbits and atomic 

 systems, we must remember not only that we are 

 dealing with average instantaneous values, but with 

 average time values as well. In the shortest time 

 taken in observing, say, the Zeeman magneto-optic 

 effect, countless atomic systems, symbols of our 

 own solar system, are made and unmade. Could 

 we confine observations to a millionth of a second 

 by a species of ultra-instantaneous photography, 

 we might hope to observe the effect as exhibited 

 by atomic systems as stable as our own solar 

 system. 



The stability of our own solar system is greatly 

 increased by its distance from other fixed stars, 

 which is over a thousand times the distance of 



