﻿COSMICAL 
  PHYSICS 
  JEANS 
  ■ 
  183 
  

  

  of 
  stability. 
  Any 
  substantial 
  step 
  in 
  this 
  direction 
  would 
  render 
  the 
  

   star 
  dynamically 
  unstable. 
  

  

  Combining 
  this 
  purely 
  dynamical 
  result 
  with 
  the 
  physical 
  prin- 
  

   ciples 
  already 
  explained, 
  it 
  becomes 
  clear 
  that 
  we 
  may, 
  to 
  a 
  good 
  

   first 
  approximation 
  at 
  least, 
  suppose 
  that 
  an 
  increase 
  in 
  the 
  tem- 
  

   perature 
  of 
  stellar 
  matter 
  produces 
  no 
  increase 
  at 
  all 
  in 
  its 
  rate 
  of 
  

   generation 
  of 
  energy. 
  

  

  Stellar 
  radiation 
  must 
  either 
  originate 
  in 
  types 
  of 
  matter 
  known 
  to 
  

   us 
  on 
  earth 
  or 
  else 
  in 
  other 
  and 
  unknown 
  types. 
  When 
  once 
  it 
  is 
  

   accepted 
  that 
  high 
  temperature 
  and 
  density 
  can 
  do 
  nothing 
  to 
  accel- 
  

   erate 
  the 
  generation 
  of 
  radiation 
  by 
  ordinary 
  matter, 
  it 
  becomes 
  clear 
  

   that 
  stellar 
  radiation 
  can 
  not 
  originate 
  in 
  types 
  of 
  matter 
  known 
  to 
  

   us 
  on 
  earth. 
  Other 
  types 
  of 
  matter 
  must 
  exist 
  and, 
  unless 
  physics 
  

   and 
  chemistry 
  have 
  gone 
  very 
  far 
  astray 
  in 
  recent 
  years, 
  these 
  other 
  

   types 
  can 
  only 
  be 
  elements 
  of 
  higher 
  atomic 
  weight 
  than 
  uranium. 
  

   The 
  significance 
  of 
  the 
  calculation 
  which 
  showed 
  that 
  stellar 
  atomic 
  

   weights 
  are, 
  in 
  the 
  main, 
  higher 
  than 
  that 
  of 
  uranium 
  now 
  becomes 
  

   apparent. 
  

  

  RECAPITULATION 
  AND 
  INTERPRETATION 
  OF 
  RESULTS 
  

  

  We 
  have 
  now 
  reached 
  the 
  conclusion, 
  by 
  three 
  distinct 
  paths, 
  that 
  

   the 
  atomic 
  weights 
  of 
  stellar 
  atoms 
  must 
  in 
  the 
  main 
  be 
  higher 
  than 
  

   that 
  of 
  uranium: 
  

  

  (1) 
  By 
  direct 
  calculations 
  from 
  Kramers' 
  formula. 
  

  

  (2) 
  From 
  the 
  consideration 
  that 
  the 
  atoms 
  near 
  the 
  center 
  of 
  a 
  

   star 
  must 
  be 
  substantially 
  heavier 
  than 
  those 
  near 
  its 
  surface. 
  

  

  (3) 
  From 
  the 
  consideration 
  that 
  atoms 
  of 
  atomic 
  weight 
  less 
  than 
  

   uranium, 
  no 
  matter 
  how 
  much 
  they 
  were 
  heated 
  or 
  compressed, 
  could 
  

   not 
  provide 
  the 
  intense 
  and 
  lasting 
  radiation 
  emitted 
  by 
  the 
  stars. 
  

  

  The 
  atomic 
  weights 
  of 
  stellar 
  atoms 
  are 
  not 
  only 
  found 
  to 
  be 
  higher 
  

   than 
  that 
  of 
  uranium 
  but 
  also 
  they 
  vary 
  systematically 
  from 
  star 
  to 
  

   star. 
  In 
  brief, 
  the 
  youngest 
  stars 
  are 
  found 
  to 
  have 
  the 
  highest 
  

   atomic 
  weights, 
  and 
  with 
  this 
  clue 
  all 
  the 
  pieces 
  of 
  the 
  puzzle 
  are 
  

   found 
  to 
  fit 
  together. 
  

  

  We 
  have 
  to 
  suppose 
  that 
  matter 
  in 
  its 
  earliest 
  state 
  consists 
  of 
  a 
  

   mixture 
  of 
  elements 
  of 
  different 
  atomic 
  weights, 
  those 
  elements 
  the 
  

   atomic 
  weights 
  of 
  which 
  are 
  highest 
  having 
  the 
  greatest 
  capacity 
  for 
  

   the 
  spontaneous 
  generation 
  of 
  radiation 
  by 
  annihilating 
  themselves, 
  

   and, 
  in 
  consequence, 
  having 
  the 
  shortest 
  lives. 
  These 
  elements 
  will 
  

   be 
  the 
  first 
  to 
  disappear 
  as 
  the 
  star 
  ages, 
  their 
  disappearance 
  reduc- 
  

   ing 
  not 
  only 
  the 
  mean 
  atomic 
  weight 
  in 
  the 
  star 
  but 
  also 
  the 
  mean 
  

   rate 
  of 
  radiation 
  per 
  unit 
  mass, 
  since 
  these 
  heavy 
  elements 
  are 
  the 
  

   most 
  energetic 
  radiators. 
  Just 
  as, 
  on 
  the 
  coast, 
  the 
  hardest 
  rocks 
  

   survive 
  for 
  longest 
  the 
  disintegrating 
  action 
  of 
  the 
  sea, 
  so 
  in 
  a 
  star 
  

  

  