The Idea of Energy Conservation Amidst New Discoveries

within the scientific community that investigated this multitude of new phenomena, the idea that all these effects really represented the transformation of one indestructible quantity, the energy, began to take shape (see the article Energy Conservation as an Example of Simultaneous Discovery in [1]). This law of conservation of energy is the First Law of thermodynamics. We will see details of its formulation in the following sections. 

The mechanical view of nature holds that all energy is ultimately reducible to kinetic and potential energy of interacting particles. Thus, the law of conservation of energy may be thought of as essentially the law of conservation of the sum of kinetic and potential energies of all the constituent particles. Cornerstones for the formulation of the First Law are the decisive experiments of James Prescott Joule (1818-1889) of Manchester, a brewer and an amateur scientist. Here is how Joule expressed his view of conservation of energy [2, 3]  

In practice, however, we measure energy in terms of heat and changes in macroscopic variables. Energy can take many forms mechanical work, heat, chemical energy and energy associated with electric and magnetic fields. For each of these forms we can specify the energy in terms of macroscopic variables. 

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