What is Entropy?
When an ice cube is left outside, it eventually melts into a
puddle. This is an example of the second law of thermodynamics, entropy. Entropy
is a measure of spontaneous disorder or randomness in a closed system and the
energy, or heat, flows from an area of high temperature to an area of low
temperature. In the case of the ice cube, the heat from the outside went into
the ice cube, which had a lower temperature, therefore exciting the molecules
in the ice cube and melting it. The ice cube went from an orderly cubic state
to a disordered puddle.
Additionally, entropy is either constant or increased in the
universe. The way things stay organised is because energy is put to keep it
that way. For instance, the ice cube stayed in its cubic shape because energy
from the fridge made the surrounding cold, therefore freezing it into a cube.
When it melted, as said early, entropy happened where it went from a cube to a
puddle. The energy stored to keep that cube shape melted and was released to
the universe, thus making the entropy of the universe positive.
