But energy is readily transformed from one form to another. And if we take the sum of the energy of the system and the surroundings, it is always equal to a constant value the energy of our universe. And that never actually changes. Now, what about the second law of thermodynamics? Well, the second law of thermodynamics is commonly described by using a term known as entropy. And entropy is this quantity that we use to basically measure the amount of randomness or disorder that is found in our universe.