Universe works based on physical law. There’s one law that’s so powerful it cannot be defied by anything in the universe.

The second law of thermodynamics states that the total entropy can never decrease over time for an isolated system.

The universe we are living in is a super massive isolated system. Let’s say there is nothing outside of our universe, so there is no energy and/or matter that can pass through our universe from outside since there is nothing outside of our universe. Thus make our universe an isolated system. I can say, as time goes by, everything inside the universe tend to increase their entropy level until they reach equilibrium.

If the second law of thermodynamics is so powerful it rules how all maters in the universe behave, How do living organism keep their entropy low, without violating the second law of thermodynamics?

For your information, we, humans, and the other living organisms always keep our entropy as low as possible (every living organism has different optimum entropy level). We do this to maintain our “life”.

Do you realize that our body has a love and hate relationship with our surrounding? Sometimes we do good by helping each other, but most of the time, our surrounding are trying to make us reach the equilibrium state with our surrounding. This equilibrium state (although it sounds so cool) means disintegration or we can call it death or vanish.

For many people, maybe they visualize equilibrium state as an order, arrangement, tidiness neatness; but it’s not. Equilibrium state means more disorder, or I could say Chaotic. Low entropy state means highly ordered, high entropy state means high disorder, or chaotic. Again, so, how can “life” maintain such low entropy to keep them alive? How can “life” creating Order out of this Chaotic universe?

There are terms called Global system and local system or in this analogy, I will use the terms: Global entropy and Local entropy. Our super massive universe is analogue to Global system/entropy, and “life” or we, humans are analogue to Local system/entropy. The entropy level of the global system will always increase till it reach the maximum level or equilibrium level over time, because it is an isolated system. But we, humans, the local systems ARE NOT isolated systems.

Life or we humans or I’ll make it simpler, our body is not an isolated system even closed system. Mass and energy transfer happens through our body with it’s surrounding. There are reactions happening inside of our body that keep its entropy level low. All life on earth capture energy from the sun. Plants creating their own food using solar energy to keep them alive. We humans eat plants also to keep us alive. And then after some period of time, living organism dies because it cannot sustain itself. What actually happens from this journey is the sun was releasing it’s energy to earth and also raising the global entropy, then the earth capture the energy, consume it to create order, then after some period of time, the living organism will create chaos (well, because they die).

I’ll quote a sentence from the book:

“life doesn’t really create order from nowhere. Life captures order, ultimately from the sun.”

- Philip Nelson, 2002

So, life is basically creating order from chaos, then turn it back into chaos.

Footnote: Well, this is actually an answer for my Biophysics assignments last semester. I just wanna write it down again using daily life references and make it simpler. The original document was about 5 pages long.

About my biophysics assignment, there are 6 questions that need to be answered by the students each week. The questions are more about cosmic-astronomical-little bit of biology and physics- related questions. But it’s fun tho. I really enjoyed those 6 weeks in last semester answering the questions.

This entry is my answer for question numero dos: How do living organism keep their entropy low, without violating the second law of thermodynamics?