﻿Moving 
  Force 
  of 
  Terrestrial 
  and 
  Celestial 
  Bodies. 
  523 
  

  

  arbitrary 
  way 
  in 
  which 
  we 
  have 
  assumed 
  this 
  point 
  or 
  that 
  

   point 
  to 
  be 
  at 
  rest, 
  while 
  at 
  the 
  same 
  time 
  we 
  have 
  asserted 
  

   that 
  a 
  condition 
  of 
  rest 
  in 
  the 
  absokite 
  sense 
  possesses 
  no 
  

   significance. 
  

  

  I£ 
  onr 
  ideas 
  possess 
  a 
  certain 
  degree 
  o£ 
  artificiality, 
  this 
  is 
  

   also 
  true 
  o£ 
  others 
  which 
  have 
  long 
  since 
  been 
  adopted 
  into 
  

   mechanics. 
  The 
  apparent 
  change 
  in 
  rate 
  of 
  a 
  moving 
  clock, 
  

   and 
  the 
  apparent 
  change 
  in 
  length 
  and 
  mass 
  of 
  a 
  moving 
  body, 
  

   are 
  completely 
  analogous 
  to 
  that 
  apparent 
  change 
  in 
  energy 
  

   of 
  a 
  body 
  in 
  motion 
  which 
  we 
  have 
  long 
  been 
  accustomed 
  to 
  

   call 
  its 
  kinetic 
  energy. 
  We 
  may 
  with 
  equal 
  reason 
  speak 
  o£ 
  

   the 
  kinetic 
  mass 
  found 
  by 
  Kautmann 
  and 
  Bucherer, 
  or 
  the 
  

   kinetic 
  length 
  assumed 
  by 
  Lorentz. 
  We 
  say 
  that 
  the 
  heat 
  

   evolved 
  when 
  a 
  moving 
  body 
  is 
  brought 
  to 
  rest 
  comes 
  from 
  

   the 
  kinetic 
  energy 
  which 
  it 
  possessed. 
  We 
  thus 
  preserve 
  the 
  

   law 
  of 
  conservation 
  of 
  energy. 
  It 
  is 
  in 
  order 
  to 
  maintain 
  

   such 
  fundamental 
  conservation 
  laws, 
  and 
  to 
  reconcile 
  them 
  

   with 
  the 
  Principle 
  of 
  Relativity, 
  which 
  rests 
  on 
  the 
  experi- 
  

   ments 
  of 
  Michelson 
  and 
  Morley 
  and 
  of 
  Bucherer, 
  that 
  we 
  

   have 
  adopted 
  the 
  principles 
  of 
  non-Newtonian 
  Mechanics. 
  

  

  These 
  principles, 
  bizarre 
  as 
  they 
  may 
  appear, 
  offer 
  the 
  only 
  

   method 
  o£ 
  preserving 
  the 
  science 
  of 
  mechanics 
  substantially 
  

   in 
  its 
  present 
  form. 
  If 
  later, 
  when 
  more 
  complex 
  systems 
  

   are 
  considered, 
  and 
  especially 
  when 
  we 
  deal 
  with 
  acceleration, 
  

   these 
  views 
  prove 
  untenable, 
  it 
  will 
  then 
  be 
  necessary 
  to 
  

   revolutionize 
  the 
  whole 
  o£ 
  mechanics. 
  

  

  Research 
  Laboratory 
  of 
  Physical 
  Chemistry, 
  

  

  Mass. 
  Inst, 
  of 
  Technolooy, 
  Boston, 
  

  

  May 
  11th, 
  1909. 
  

  

  LYIII. 
  On 
  the 
  Moving 
  Force 
  of 
  Terrestrial 
  and 
  Celestial 
  

   Bodies 
  in 
  Relation 
  to 
  the 
  Attraction 
  of 
  Gravitation. 
  Bij 
  

   Henry 
  Wilde, 
  D.Sc, 
  D.C.L., 
  F.R.S.* 
  

  

  1. 
  T 
  X 
  the 
  course 
  of 
  a 
  lecture 
  which 
  I 
  delivered 
  before 
  the 
  

   X 
  Society 
  in 
  1902, 
  "On 
  the 
  Evolution 
  of 
  the 
  Mental 
  

   Faculties 
  in 
  relation 
  to 
  some 
  Fundamental 
  Principles 
  of 
  

   Motion,^' 
  prominence 
  was 
  given 
  to 
  the 
  historic 
  controversy 
  

   respecting 
  the 
  measure 
  of 
  moving 
  force 
  of 
  terrestrial 
  bodies 
  

   which 
  has 
  exercised 
  the 
  minds 
  of 
  distinguished 
  men 
  of 
  science 
  

   and 
  learning 
  for 
  more 
  than 
  two 
  centuries. 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  Reprinted 
  from 
  the 
  Memoirs 
  and 
  

   Proceedings 
  of 
  the 
  Manchester 
  Literary 
  and 
  Philosophical 
  Society, 
  

   vol. 
  liii. 
  pt. 
  ii. 
  (1909). 
  

  

  2N2 
  

  

  