﻿COSMICAL 
  PHYSICS 
  JEANS 
  189 
  

  

  Indeed, 
  our 
  whole 
  knowledge 
  of 
  the 
  really 
  fundamental 
  physical 
  

   conditions 
  of 
  the 
  universe 
  in 
  which 
  we 
  live 
  is 
  a 
  growth 
  of 
  the 
  last 
  

   quarter 
  of 
  a 
  century. 
  

  

  The 
  simple 
  explanation 
  of 
  this 
  situation 
  is 
  to 
  be 
  found 
  in 
  the 
  

   fact 
  that 
  life, 
  naturally 
  enough, 
  begins 
  its 
  exploration 
  of 
  Nature 
  by 
  

   studying 
  the 
  conditions 
  which 
  immediately 
  surround 
  it; 
  the 
  study 
  of 
  

   the 
  general 
  conditions 
  of 
  the 
  universe 
  as 
  a 
  whole 
  is 
  a 
  far 
  morp 
  

   difficult 
  task 
  which 
  life 
  on 
  this 
  planet 
  is 
  only 
  now 
  approaching. 
  

   Now 
  the 
  physical 
  conditions 
  under 
  which 
  life 
  is 
  possible 
  form 
  only 
  

   & 
  tiny 
  fraction 
  of 
  the 
  range 
  of 
  physical 
  conditions 
  which 
  prevail 
  in 
  

   the 
  universe 
  as 
  a 
  whole. 
  The 
  very 
  concept 
  of 
  life 
  implies 
  duration 
  

   in 
  time; 
  there 
  can 
  be 
  no 
  life 
  where 
  the 
  atoms 
  change 
  their 
  make-up 
  

   millions 
  of 
  times 
  a 
  second 
  and 
  no 
  pair 
  of 
  atoms 
  can 
  ever 
  become 
  

   joined 
  together. 
  It 
  also 
  implies 
  a 
  certain 
  mobility 
  in 
  space, 
  and 
  

   these 
  two 
  implications 
  restrict 
  life 
  to 
  the 
  small 
  range 
  of 
  physical 
  

   conditions 
  in 
  which 
  the 
  liquid 
  state 
  is 
  possible. 
  Our 
  survey 
  of 
  the 
  

   universe 
  has 
  shown 
  how 
  small 
  this 
  range 
  is 
  in 
  comparison 
  with 
  

   the 
  range 
  of 
  the 
  whole 
  universe. 
  Primeval 
  matter 
  must 
  go 
  on 
  trans- 
  

   forming 
  itself 
  into 
  radiation 
  for 
  millions 
  of 
  millions 
  of 
  years 
  to 
  

   produce 
  an 
  infinitesimal 
  amount 
  of 
  the 
  inert 
  ash 
  on 
  which 
  life 
  can 
  

   exist. 
  Even 
  then, 
  this 
  residue 
  of 
  ash 
  must 
  not 
  be 
  too 
  hot 
  or 
  too 
  

   cold, 
  or 
  life 
  will 
  be 
  impossible. 
  It 
  is 
  difficult 
  to 
  imagine 
  life 
  of 
  any 
  

   high 
  order 
  except 
  on 
  planets 
  warmed 
  by 
  a 
  sun, 
  and 
  even 
  after 
  

   a 
  star 
  has 
  lived 
  its' 
  life 
  of 
  millions 
  of 
  millions 
  of 
  years, 
  the 
  chance, 
  

   so 
  far 
  as 
  we 
  can 
  calculate 
  it, 
  is 
  still 
  about 
  a 
  hundred 
  thousand 
  

   to 
  one 
  against 
  its 
  being 
  a 
  sun 
  surrounded 
  by 
  planets. 
  In 
  every 
  

   respect 
  — 
  space, 
  time, 
  physical 
  conditions 
  — 
  life 
  is 
  limited 
  to 
  an 
  almost 
  

   inconceivably 
  small 
  corner 
  of 
  the 
  universe. 
  

  

  What, 
  then, 
  is 
  life? 
  Is 
  it 
  the 
  final 
  climax 
  toward 
  wdiich 
  the 
  whole 
  

   creation 
  moves, 
  for 
  which 
  the 
  millions 
  of 
  millions 
  of 
  years 
  of 
  trans- 
  

   formation 
  of 
  matter 
  in 
  uninhabited 
  stars 
  and 
  nebulae, 
  and 
  of 
  waste 
  

   radiation 
  into 
  desert 
  space, 
  have 
  been 
  only 
  an 
  incredibly 
  extrava- 
  

   gant 
  preparation? 
  Or, 
  is 
  it 
  a 
  mere 
  accidental 
  and 
  possibly 
  quite 
  

   unimportant 
  by-product 
  of 
  natural 
  processes, 
  which 
  have 
  some 
  other 
  

   and 
  more 
  stupendous 
  end 
  in 
  view? 
  Or, 
  to 
  glance 
  at 
  a 
  still 
  more 
  

   modest 
  line 
  of 
  thought, 
  is 
  it 
  of 
  the 
  nature 
  of 
  a 
  disease 
  which 
  affects 
  

   matter 
  in 
  its 
  old 
  age, 
  when 
  it 
  has 
  lost 
  the 
  high 
  temperature 
  and 
  

   capacity 
  for 
  generating 
  high-frequency 
  radiation 
  with 
  which 
  younger 
  

   and 
  more 
  vigorous 
  matter 
  would 
  at 
  once 
  destroy 
  life? 
  Or, 
  throwing 
  

   humility 
  aside, 
  is 
  it 
  the 
  only 
  reality, 
  which 
  creates, 
  instead 
  of 
  being 
  

   created 
  by, 
  the 
  colossal 
  masses 
  of 
  the 
  stars 
  and 
  nebulae 
  and 
  the 
  almost 
  

   inconceivably 
  long 
  vistas 
  of 
  astronomical 
  time? 
  There 
  are 
  too 
  many 
  

   w^ays 
  even 
  to 
  enumerate 
  of 
  interpreting 
  the 
  conclusions 
  we 
  have 
  

   reached; 
  I 
  do 
  not, 
  however, 
  think 
  there 
  is 
  any 
  one 
  way 
  of 
  evading 
  

   them. 
  

  

  