Refer to:
- [[Entropy]] the measure of disorder and randomness in a system. The change when energy is transferred at a constant temperature
- [[Phase Space]] a graph that represents the whole state of a system
### Zeroth Law
> “If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.”
- Basically, if A=B and C=B then A=C.
- w/o which we couldn't define temperature / have thermometers
### First Law of Thermodynamics
> “The total amount of energy in an isolated system is conserved.”
- The law of conservation of energy - energy is conserved; it can neither be created nor destroyed, just changed from one form to another,
- The total amount of energy in the universe is constant
### Second Law of Thermodynamics
> “The entropy of the universe tends to a maximum.”
- Entropy either stays the same or gets bigger, the entropy of the universe can never go down.
- The disorder of the universe always increases and energy gets transformed into less useful forms
- The efficiency of any process will always be less than a 100%
### Third Law of Thermodynamics
> “As the temperature of a system approaches absolute zero (−273.15°C, 0 K), then the value of the entropy approaches a minimum.”
- An absolute reference point for measuring entropy
- All molecular movement stops at absolute zero temperature.
- As temperature is a measure of molecular movement, there can be no temperature lower than absolute zero. At this temperature a perfect crystal has no disorder.
#firstprinciple