8 



LAWS OF ENERGY 



above the ground may perform work in falling if sufficient free energy 

 be applied to tip it over. The quantity of work done in tipping over the 

 weight bears no relation whatever to the amount of energy liberated in 



falling. 



The following scheme may help to make the matter clear : 



Total Energy of the Universe 



U) I 

 Available for work, 



i.e. Free Kinetic Energy 



4- (2) 



Not directly available for work 



I (4) 



Potential Energy 

 Add trigger Energy from (1) 



I (3) 



Degraded Heat 



(Entropy) 

 Totally unavailable 



Free Energy 

 Total Available Energy 



(3) Called " bound " 



/Q I A \ follarl " Virviim 



1 



Total Unavailable 

 Energy 



(3) Called " bound " energy by Helmholtz in 1882. 

 (3 + 4) Called " bound " energy by later workers. 



(4) Called " bound " energy by Physicists. 



One of the most important problems in biology is the means 

 by which potential energy is translated into work and the 

 mechanism by which this translation is controlled. 



" The struggle for existence is the struggle for free energy " (Boltzmann). 

 Of potential energy there is an abundant supply. Some of 

 it, e.g. coal, requires the employment of only small quantities 

 of free energy to render it immediately available for work, while 

 other varieties, e.g. radio-active minerals, have their energy bound 

 in such a way that it is evolved with excessive slowness. Uranium 

 contains the same amount of energy as 250,000 times its weight 



1 



of coal (or more), but little more than 



part of 



10,000,000,000 



this is given out in a year (Chap. XI.). To enable mankind to 

 avail himself of this kind of energy, some means will have to 

 be devised for speeding up and controlling the output. As 

 Professor Soddy puts it : " Primitive man froze on the site of 

 what are now coal mines, and starved within sound of the water- 

 falls that are now working to provide our food. The energy 

 was there, the knowledge to utilise it was not. So w r hile we are 



