Thermodynamics: 2nd law (second law)

Tutoring physics, and in everyday explanations, thermodynamics can arise. The tutor mentions its second law.

The second law of thermodynamics states that, when a change happens that won’t go back on its own, the total entropy of the universe increases. (For an idea about entropy, see my post here.)

A change that will go back on its own can bring one to the idea of a perpetual motion machine: in a frictionless system, a pendulum will swing back and forth forever. Since no position in such a case is permanent, every stroke of the pendulum will be self-correcting.

A change that won’t self-reverse, such as a cup of coffee cooling down, or the example of burning fuel, will always be accompanied by an increase in entropy.

Since entropy essentially means disorder, the idea of the second law of thermodynamics is that there needs to be some order present in order to facilitate a change, because the change will inevitably make the universe less orderly. When total chaos has been reached, nothing further can happen, since part of the very definition of change is an increase in entropy. Some believe, therefore, that the universe will eventually become stagnant.


Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

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