The Relationship Between Life, Stars, and Entropy - A funny-looking cartoon sheep standing on Earth (the sheep is disproportionately large compared to the earth), the sun on the right, and curly arrows somehow relating the earth and the sun to the word "entropy"

In my previous essay on a tale of entropy and the big bang, I started investigating the big bang with the lens of entropy. The underlying question in this investigation turned out to be as follows:

How does our universe keep increasing its entropy, whilst consistently creating lower entropy phenomena like stars, planets, life, etc., along the way?

In this essay, I will be continuing to investigate answers to this question, uncovering the relationship between orderly phenomena such as stars, planets, life, etc., and the universally increasing entropy that we observe.

Since this journey originally started out with investigating the big bang, let us begin our discussion right there.

Immediately after the Big Bang

In the moment immediately after the big bang (say, 10^(-30) seconds), repulsive gravity exploded a tiny, tiny piece of space into a vast expanse far beyond what we can observe today with our state-of-the-art equipment.

Immediately after this happened, the inflaton field expanded rapidly too. Too fast to sustain the rate of expansion, the inflaton field collapsed, unleashing a wealth of particles.

Just like the inflaton field, these particles were not distributed uniformly. The quantum “afterglow” ensured that density of these particles varied slightly across the entire space. As it turns out this variation in density was the key that led to the birth of the universe as we know it today.

The Birth of Galaxies, Stars, and Planets

What these minor fluctuations in particle-densities meant is that the slightly denser regions exerted more gravitational pull than the slightly lighter regions. You know how gravity works.

The slightly denser regions attracted more particles than the slightly lighter regions. As enough time went on, the now-not-so-slightly denser regions got denser and denser. This created a snowball effect, where the denser a region was, the more (gravitational) pull it exerted.

After millions and millions of years of this game of gravitational pulling, certain aggregations got so dense that the particles got compressed, thereby triggering nuclear reactions. These nuclear reactions in turn birthed the galaxies, stars, and planets we observe today.

This is awesome, but it still does not explain how nuclear reactions birthed lower entropic phenomena, while the entire universe’s agenda seems to be increasing entropy.

A Journey Back to my Childhood

At this point, I would like to share a silly story from my child. I grew up in a third-world country, where we needed to boil water before consuming it; tap-water was too risky to drink.

One afternoon, after I had just arrived at home from school, I noticed that one of my parents had boiled water and sealed the container with a plate on top. As I displaced the plate on top, I realized that the water was still too hot to drink.

I immediately put my “clever hat” on and went to work. I picked up a smaller metal container with a smaller opening and filled it up carefully with the hot water. Then, I placed this smaller container inside the refrigerator.

After 20 whole minutes of waiting and pacing around, I grew too thirsty to wait any longer and opened the fridge. To my horror, the water was nearly as hot as it was when I had originally placed the small container inside the fridge.

A shocked stick figure labelled "Le Me" on the left. A container with water placed in the center, and a container with water placed inside a fridge on the right. The water inside the fridge is somehow hotter than the water placed at room temperature on the table.
The Childhood Memory — Illustrative art created by the author

On the contrary, the water in the bigger container on top of the kitchen counter, which did not have a plate on top of it by now, was significantly cooler. It was still hot, but significantly cooler than the water in the fridge. To the best of my understanding, I could not explain why.

Years later, I would learn why in thermodynamics. But in this essay, we are not discussing thermodynamics (not explicitly, at least). So, why did I share this story with you? Well, there is a very good reason for it.

Entropy Does Not Increase Linearly

Let us analyse the story that I just shared with the lens of entropy. The tendency of hot water is to cool down. Why is this? Well, when viewed using an entropic lens, you can say that this process leads to a global entropic increase (towards temperature equilibrium, if you will).

Yet, why is it that the container in the fridge lost temperature slower than the one in a warmer environment (mind you it was around 30°C that day)? To answer this, we need consider the insulation of the container I chose, it’s opening-size as compared to the larger container and a whole bunch of other factors.

This essay is supported by Generatebg

Without going into all that, just focusing on the smaller container in the fridge, we could say the following: the global drive to increase entropy will ensure that temperature equilibrium is achieved in that environment. So, the water will eventually cool down. But it doesn’t need to happen immediately. The rate of cooling could be accelerated (by the fridge for instance) or decelerated (by insulation, for instance) by external factors.

And it is this point I wish to focus on when it comes to how dense aggregations of particles lead to galaxies, stars, planets, and life.

The Locked High Entropy States

In many cases, the absolutely highest-possible entropic states are locked behind “requirements”. Consider any carbon-based fossil fuel. Place it in a container, and you will notice that the carbon and hydrogen atoms sustain their bonds with each other even when they are exposed to oxygen atoms.

Light a fire and place it near the fuel (just hypothetically; please don’t do this in real life as there is injury risk), and you will notice immediately that the carbon and hydrogen atoms break their bonds, whilst forming bonds with oxygen atoms, all while releasing (heat) energy as a by-product. 

Notice that this is a higher entropic state. But it was hidden previously. We were able to unlock it only by introducing a catalyst factor (the flame).

Similarly, the processes that lead to higher entropic states as compared to that of galaxies, stars, and life are locked behind catalyst-requirements. Given enough time, those states will also be reached.

At a galactic scale, the most notable of these catalysts are:

1. Gravitational forces

2. Nuclear forces

The strong nuclear forces hold the atomic nuclei together, whereas the weaker nuclear forces are behind the phenomenon of radioactive decay.

Galaxies, stars, planets, and life are all phenomena that make use of these forces to enable the ever increasing entropy of the universe.

I will continue to explore these concepts in connection to the broader topic of entropy in future essays.

For now, I humbly thank you for your interest in this essay!

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Further reading that might interest you: 

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Reference and Credit: Brian Greene

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