172 THE ALUMNI JOURNAL 



Our extra-atomic world consists of the motions of molecules and 

 atoms. Temperature is a measure of the amount of. this motion. 

 We, on the earth, are fairly well familiar with a range of temperature 

 extending from absolute zero to say 2000° Centigrade. The upper 

 limit of temperature velocities is given by the velocity of light. No 

 electron and hence no molecule can move with any greater velocity. 

 But before such velocities are reached electrons and even other atoms 

 begin to move -"through each other" (e. g., the alpha particles). We 

 no longer have ordinary molecular collisions any more. Thus when 

 the temperature becomes sufficiently high the relations l^etween the 

 phenomena of the intra- and extra-atomic worlds become very inti- 

 mate. Our world is one of great inanition compared with a world at 

 2000° C. A world at 2000° is one of comparative rest compared with 

 a world at a temperature of 200,000° or higher, one where the average 

 kinetic energy of atoms is equal to that of an electron moving with a 

 velocity almost equal to that of light. It is in this latter temperature 

 region that things really become interesting and it is probably under 

 these conditions that atoms are born. If there is an evolution of the 

 elements it must be expected under these conditions. At our ordinary 

 temperatures the intra-atomic world is surrounded by an almost per- 

 fect refrigerator — there is practically no relation with the outside 

 world at all. 



Recently quite a number of interesting papers have appeared 

 which indicate that matter may be much more complex than we con- 

 sider it to be and that all the elementary atoms are closely related 

 through their origin by radio-active evolution. Soddy and others con- 

 sider that many of the elements are practically identical from a chem- 

 ical point of view. Among these groups are Ur X, radio-actinium and 

 thorium ; mesothoriunn and actinium ; Th B, lead and possibly Ra B 

 and Ac B ; and probably Th C, R|a C, Ac C, and bismuth. According 

 to Fajans the expulsion of an alpha particle moves an element two 

 places to the left in the periodic system, while the expulsion of a beta 

 particle moves the element one place to the right without changing 

 the atomic weight. Following this rule the radio-active products can 

 all be placed in the periodic system. That this can be done is a very 

 strong indication that every element originated by a process of radio- 

 active disintegration such as takes place in the thorium and radium 

 families. 



