Application of Scaling Law to Natural System

Let us look into the small animals in nature. Animals in general eat food proportional to their weight, which is the source of chemical energy. We can assume the generation of thermal energy (Qq) to scale as 

The animals transfer heat toward outside. Assuming the heat ttansfer to take place through a layer of thickness 6 and surface area A, the heat transferred per unit time, Qg, by the animal is 

For smaller organism (I is small) from equations (1.11) and (1.13), we have Qr Qg- Therefore, it is necessary to compensate for thermal losses by eating food and to maintain the internal 

Another application of scaling law is insects walking on water surface. Gravitational force is associated with and surface tension force is associated with 1. Thus, at small scales, the surface tension force dominates in comparison to the gravitational forces. The gravitational force that tends to immerse the foot is compensated by the capillary force. 

Note One may think that in micro world, automobile accidents would not take place by collisions but by drops of water abandoned in the road. One may also be surprised not to have many machines driven by surface tension till now. 

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