| Show tahe dihe EARTH muff MUST DIE an showing allowing that tile 11 solar will expire consider a flywheel or clockwork as driven by a weight weigh tand and the ho heat generated by friction against the motion of wheels and pendulum and by impacts of teeth a against ainest the pallets ballets of an escapement our ott r knowledge of ties ol of matter aad of modes of propagation of heat by bv radiation or conan conduction tion and of the th efficiency of heat beat as a motor discovered by several thousand years of ob enervation eer and several hundred years of experiment and dynamical theory suffices to show that when tile the weight is rundown run down and the potential energy or capacity to do v work ork which it hall had in the beginning las has been all pent in the beat tins this heat is IB not available tor for raising sing the weight and giving the a renewed lease of the solar si item according to the best modem modera scientific f belief is dynamically na ria analogous to the clockwork in all the assent essentials bals of our consideration not going back in thought to a beginning of which cc knows nothing let us compare the solar system as it was years ago with tile tho solar system as it is ii now let our analogue be a clockwork winch which three hours ago was known to be going with its weight partially run down and which is still going with its weight not yet wholly run down during these years the sun has been giving ou out t radiant heat light being included in the designation radiant heat beat in all directions propagated at the rate of about nine and a half million million kilometers per year and there fore twenty eight and a halt half million million kilometers in years we do not know whether the light which left the sun years ago is still traveling outward with almost undiminished all is already 0 energy or whether nearly dissipated in heat beat warming the ether or bodies which have obstructed its course we may I 1 think feel that it is partly still traveling outward as radiant heat and partly spent or dissipated in warming matter or matter and the ether the running down of the weight in the clockwork has its perfect analogue as helmholtz was I 1 believe in reality the very first to point out in the shrinkage of the sun from century to century under the influence of the mutual gravitational attractions between its parts the heat beat producing efficiency of the fire which there would be if the sun were a globe of gunpowder or guncotton burning from its outward surface inward that is to say the work done by the potential energy of the chemical affinity between uncombined oxygen and carbon and hydrocarbons attractive forces as aa truly forces and subject to dynamic law as is the force of gravity itself is absolutely infinitesimal in comparison with the work done by the gravitational attraction on tho the shrinking mass adduced 5 icv a J beat the tha rea real 0 tue the no whole story of energy now in the sun run whether of actual heat beat corresponding to the suns high temperature or of potential energy as of the not run down weight of the clockwork potential energy of gravitation depending on the extent of future shrinkage which the sun bun is destined to experience is essentially finite and there is much less of w iv no now w than there was years ago I 1 I 1 similar considerations of action on I 1 vastly smaller scale are of course opp aepli cje cable to terr terrestrial estial plutonic energy ann thoroughly dispose of the terrestrial terr estial pet pein letual motion by which lyell and othal followers follower of hutton I 1 on oil as sound prins i a caples as those of till the h humblest mech ical perpetual mot tried to fin fini that the earth can go on forever as it ls is illuminated by tho the sun from infinity of time past to infinity of time future always ways a habitation for race after race of pi plants ants and animals built on the ruins of the habitations of preceding races of plants and animals the doctrine of the dissipation energy gy forces upon us the conclusion that within a finite period of time past part the earth must have been and within a finite period of time to come must again be unfit for the habitation of roan man as at present constituted unless operations have been and are to be performed which are i possible impossible under the laws governing the known operations going on at present in the material world fortnightly review |
