Entropy
The hidden force that shapes our universe from atoms to galaxies
What is Entropy?
Entropy is a measure of disorder or randomness in a system. It's a fundamental concept in thermodynamics that describes how energy disperses and how systems evolve toward equilibrium.
ΔS = Q/T
The mathematical definition of entropy change (ΔS) is heat transfer (Q) divided by temperature (T)
Entropy in Daily Life
Hot Coffee Cools
Heat disperses from hot coffee to the cooler room until temperatures equalize - increasing the system's entropy.
Puzzle Pieces Scatter
A completed puzzle has low entropy; when pieces scatter, entropy increases as possible arrangements multiply.
Leaves Decompose
Ordered leaf structures break down into simpler compounds, increasing entropy as energy disperses.
The Laws of Thermodynamics
Energy Conservation
Energy cannot be created or destroyed, only transformed from one form to another.
Entropy Always Increases
In any energy transfer, the total entropy of a system and its surroundings always increases over time.
Absolute Zero
As temperature approaches absolute zero, the entropy of a perfect crystal approaches zero.
Entropy and the Universe
The Heat Death Scenario
If entropy keeps increasing, the universe may reach a state of maximum entropy called "heat death" where:
- ✔️ All energy is evenly distributed
- ✔️ No temperature differences exist
- ✔️ No work can be performed
This is the ultimate fate of the universe according to the second law of thermodynamics.
The universe's slow march toward equilibrium
Test Your Understanding
1. When ice melts into water, what happens to entropy?