﻿252 
  ANNUAL 
  REPOKT 
  SMITHSONIAN 
  INSTITUTION, 
  1927 
  

  

  stein 
  has 
  worked 
  out 
  the 
  formula 
  for 
  the 
  equivalence 
  of 
  matter 
  and 
  

   energy, 
  so 
  we 
  can 
  now 
  calculate 
  how 
  much 
  heat 
  will 
  be 
  produced 
  if 
  

   a 
  certain 
  mass 
  of 
  matter 
  is 
  annihilated. 
  This 
  idea 
  has 
  been 
  welcomed 
  

   by 
  the 
  astronomers, 
  who 
  have 
  been 
  hard 
  put 
  to 
  it 
  to 
  devise 
  means 
  of 
  

   keeping 
  up 
  the 
  furnace 
  fires 
  of 
  the 
  sun 
  as 
  long 
  as 
  mankind 
  would 
  like 
  

   to 
  live. 
  They 
  have 
  now 
  figured 
  out 
  by 
  Einstein's 
  formula 
  that 
  the 
  

   sun 
  is 
  losing 
  weight, 
  through 
  the 
  destruction 
  of 
  its 
  material 
  and 
  the 
  

   emission 
  of 
  immaterial 
  energy, 
  at 
  the 
  rate 
  of 
  4,000,000 
  tons 
  a 
  second. 
  

   But 
  even 
  though 
  wasting 
  away 
  at 
  this 
  appalling 
  rate 
  the 
  sun 
  can 
  

   hold 
  out 
  for 
  10,000,000 
  million 
  years.- 
  This 
  gives 
  a 
  welcome 
  exten- 
  

   sion 
  of 
  time 
  for 
  the 
  life 
  of 
  our 
  world 
  and 
  permits 
  us 
  to 
  hope 
  that 
  

   we 
  may 
  get 
  our 
  social 
  system 
  perfected 
  before 
  we 
  all 
  become 
  Eskimos. 
  

  

  This 
  principle 
  of 
  the 
  interchangeability 
  of 
  matter 
  and 
  energy 
  must 
  

   apply 
  to 
  all 
  chemical 
  reactions 
  where 
  heat 
  is 
  produced 
  or 
  absorbed. 
  

   Wherever 
  coal 
  burns 
  there 
  matter 
  is 
  being 
  converted 
  into 
  radiant 
  en- 
  

   ergy. 
  Wlierever 
  a 
  green 
  leaf 
  grows 
  there 
  matter 
  is 
  being 
  manufac- 
  

   tured 
  out 
  of 
  solar 
  energy. 
  In 
  such 
  cases 
  of 
  course 
  the 
  quantity 
  of 
  

   matter 
  or 
  energy 
  transmuted 
  is 
  too 
  small 
  to 
  be 
  demonstrated. 
  In 
  

   the 
  burning 
  of 
  coal 
  the 
  heat 
  evolved 
  means 
  a 
  loss 
  of 
  about 
  1 
  part 
  in 
  

   10,000,000,000 
  of 
  the 
  joint 
  mass 
  of 
  the 
  carbon 
  and 
  oxygen 
  combined. 
  

   But 
  this 
  loss 
  of 
  matter 
  becomes 
  appreciable 
  when 
  we 
  consider 
  the 
  

   world-wide 
  consumption 
  of 
  coal. 
  If 
  we 
  assume 
  that 
  all 
  coal 
  is 
  pure 
  

   carbon 
  and 
  that 
  the 
  combustion 
  is 
  always 
  complete, 
  the 
  carbon 
  di- 
  

   oxide 
  produced 
  by 
  all 
  the 
  coal 
  that 
  burned 
  in 
  a 
  year 
  throughout 
  the 
  

   world 
  would 
  weigh 
  about 
  6,000,000,000 
  tons. 
  This 
  would 
  involve 
  

   a 
  disappearance 
  of 
  matter 
  amounting 
  to 
  half 
  a 
  ton. 
  The 
  substance 
  

   of 
  the 
  world 
  is 
  therefore 
  being 
  slowly 
  consumed 
  by 
  the 
  combustion 
  

   of 
  coal. 
  But 
  such 
  loss 
  is 
  continually 
  being 
  replenished 
  by 
  the 
  sun- 
  

   shine 
  that 
  falls 
  upon 
  vegetation 
  and 
  is 
  there 
  fixed 
  in 
  the 
  form 
  of 
  

   cellulose. 
  

  

  The 
  problems 
  we 
  are 
  considering 
  are 
  world-wide 
  questions 
  in 
  

   which 
  the 
  whole 
  human 
  race 
  is 
  concerned, 
  for 
  they 
  deal 
  with 
  the 
  

   subterranean 
  stores 
  of 
  wealth-producing 
  energy 
  which 
  are 
  the 
  com- 
  

   mon 
  inheritance 
  of 
  the 
  population 
  of 
  the 
  planet.. 
  These 
  treasures 
  

   are 
  limited 
  and 
  irreplaceable, 
  and 
  upon 
  them 
  our 
  modern 
  civiliza- 
  

   tion 
  is 
  supported. 
  The 
  main 
  question, 
  and 
  the 
  only 
  one 
  with 
  which 
  

   s^^cience 
  as 
  such 
  is 
  concerned, 
  is 
  to 
  see 
  that 
  this 
  endowment 
  of 
  fossil 
  

   fuel 
  is 
  not 
  wasted 
  but 
  utilized 
  to 
  the 
  greatest 
  advantage 
  of 
  the 
  

   present 
  generation 
  and 
  posterity. 
  Who 
  owns 
  it, 
  and 
  who 
  makes 
  the 
  

   most 
  money 
  out 
  of 
  it, 
  are 
  minor 
  matters 
  that 
  do 
  not 
  affect 
  the 
  main 
  

   question. 
  Germany 
  lost 
  a 
  large 
  part 
  of 
  her 
  coal 
  trade) 
  through 
  the 
  

   world 
  war. 
  England 
  lost 
  a 
  large 
  part 
  of 
  her 
  coal 
  trade 
  through 
  

   the 
  labor 
  war. 
  But 
  neither 
  of 
  these 
  affects 
  directly 
  the 
  coal 
  that 
  is 
  

  

  " 
  Heyl, 
  Fundamental 
  Concepts 
  of 
  Physics, 
  p. 
  72. 
  

  

  