What is “a computation”?
Computation is a physical process
- We use physical quantities to represent information
- e.g. charge on a capacitor
- There is an energy associated with the physical quantity
- We process the physical quantities to reduce the entropy
- We decrease the entropy of a symbol stream
- and increase the (thermal) entropy of the environment
- Computation in finite time consumes energy
Computation consumes energy (? thermodynamics) to reduce or to destroy information (? information theory) according to an algorithmic set of rules