What does the concept of entropy mean?
In: 96
Entropy is NOT disorder, it’s often called that because entropy LEADS to disorder but they are not the same thing. Entropy is simply a statistic that arises because energy is more likely to spread out than to concentrate into a specific state.
For example, imagine you have 100 cups and a pitcher full of water. Now imagine you put drops of that water into the cups at random. What are the chances that *all* of the water ends up in 1 or 2 cups? It’s very slim, definitely possible, but very unlikely, what is more likely is that the water gets spread out between the cups evenly (relatively speaking of course, some cups will have more water than others). Each different way of filling the cups, for example, all the water in 1 cup, the water spread perfectly evenly between the cups, and anything in between, is called a microstate. Some microstates are more likely to occur than others (such as the water spread out evenly is more likely than the water in one cup).
Entropy is essentially just a way to measure which state is more likely. If a state is more likely its said to have high entropy. And that’s why entropy is said to always increase in a closed system, because the system will always evolve to a state that’s more likely.
Now in physics usually when people talk about enteopy they’re talking about energy. So instead of the water used in the previous analogy, it’s energy that gets distributed across the system, and instead of cups, it’s atoms and molecules and other particles and waves where the energy gets distributed in. Now one thing to remember is that there’s nothing in physics that says entropy HAS to increase, it’s just that entropy is extremely (and I can’t stress the extremely enough) likely to increase.
Edit: One example my professor gave that really resonated with me during the talk of entropy is that there is absolutely nothing in physics that is stopping all the air in the room you’re in from suddenly moving to one side and suffocating everyone in the other side. The only thing that keeps the air from doing that is probability. Its just incredibly unlikely that all the trillions of air molecules which have velocities that are more or less random would all randomly start to move in the same direction to the other side of the room, it’s much more likely that they all spread out relatively evenly in the room. That is entropy.
Latest Answers