Energetics time course

From the perspective of general energetics, the long span of human prehistoric development can be seen as the quest for a more efficient use of somatic energy, the muscular exertions used primarily to secure a basic food supply and then to gradually improve shelters, acquire more material possessions, and evolve a variety of cultural expressions. This quest was always limited by fundamental bioenergetic considerations Fifty to ninety watts is the limit of nsefnl work that healthy adults can snstain for prolonged periods of time (of course, short bursts of effort could reach hundreds of watts). 

The energy liberated in fission is, of course, to some degree dependent upon the target used and the product nuclei which are formed. In a typical fission of U285, about 200 Mev of energy is released, almost 20 times the energy of the most energetic simple nuclear reactions. 

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