The discussion focuses on the interconnection between energy and work within the context of thermodynamics. Participants explore definitions of work and energy, particularly contrasting mechanical and thermodynamic perspectives, and the implications of these definitions on understanding energy transfer.
Participants express differing views on the definitions of work and energy, indicating that multiple competing perspectives remain without a clear consensus on the definitions or their implications.
Participants reference different theoretical frameworks (mechanical vs. thermodynamic) which may imply varying assumptions about the definitions of work and energy. The discussion also highlights the complexity of energy transfer mechanisms.
hwall95 said:Okay i know that energy is the ability or capacity to do work. But how do you define work, as like the isn't work just the transference of energy in one form to another? Which is kinda circular reasoning. Like the rely on each other for a definition. Is that right?
DaleSpam said:The appropriate definition of work depends on what theory you are using.
One is the mechanical definition: "work is f.d". This definition is used in basic Newtonian mechanics. In it forces are the primary things and everything else is defined based on forces. Then energy is non-circularly defined as the capacity to do work.
The other is the thermodynamic definition: "work is a transfer of energy other than through heat". This definition is used in Lagrangian and Hamiltonian mechanics as well as all field theories. In these, the Lagrangian is the primary thing and everything else is defined based on the Lagrangian. Then energy is non-circularly defined as the conserved quantity associated with time invariance of the Lagrangian.
No, that is just the definition of work in thermodynamics. Energy can be transferred between systems either through heat, or through anything else. Anything else is called work.hwall95 said:hahah yeah thanks i was meaning the thermodynamics definition sorry, okay thanks but when you say "other then heat energy", is that because thermal energy itself is just kinetic energy?
DaleSpam said:No, that is just the definition of work in thermodynamics. Energy can be transferred between systems either through heat, or through anything else. Anything else is called work.
The basic distinction is that heat is a rather disorganized microscopic transfer that you cannot see in detail, as opposed to things like macroscopic fields and forces.