Second Law of Thermodynamics
What is Second Law of Thermodynamics?
The second law of thermodynamics states that in any spontaneous process, the total entropy of the universe (system + surroundings) always increases. Equivalently, heat does not spontaneously flow from a cold object to a hot object. The law implies that no heat engine can be 100% efficient. Entropy is a measure of disorder or dispersal of energy, and the second law provides the 'arrow of time' in thermodynamics.
Key Facts
Frequently Asked Questions
The second law of thermodynamics states that in any spontaneous process, the total entropy of the universe (system + surroundings) always increases. Equivalently, heat does not spontaneously flow from a cold object to a hot object. The law implies that no heat engine can be 100% efficient. Entropy is a measure of disorder or dispersal of energy, and the second law provides the 'arrow of time' in thermodynamics.