The 2nd Law of Thermodynamics says that the entropy of an isolated system increases over time. Simply put, this implies that order transitions into chaos, and everything eventually reaches its end.
Since nothing can contain the universe, we assume it to be a closed system. Instead, it contains everything. Despite the constant increase in chaos, the universe is brimming with complex structures like stars, planets, ecosystems, and life forms.
The reason is that a complex system is essentially a dissipative structure that stays far from thermodynamic equilibrium by constantly taking energy from its environment. Complexity needs energy to come into existence, sustain itself, and propagate further. Maintaining and building complex structures takes work. And it’s the flow of energy that causes work to be done.
In thermodynamic equilibrium, energy is equally distributed, and entropy is at its maximum. There is no energy gradient, and as a result, no energy will flow to get work done. However, all complex systems keep themselves away from thermodynamic equilibrium by doing work: plants do photosynthesis, animals feed, and humans eat. We need energy to keep ourselves alive. Our DNA programs us to continuously search for additional energy to sustain our existence. And this rule applies not just to humans but also to the first living thing that evolved billions of years ago. The entire cycle of evolution by natural selection is a mechanism to keep self-replicating complex structures going.
Organisms take in new energy to keep themselves away from thermodynamic equilibrium, but the overall trend of entropy in the universe is constantly increasing. Why is this so? This is due to the fact that organisms always waste some energy as they consume more and exert themselves to gather more. Thus, energy dissipates and distributes evenly, slowly but surely, throughout the universe. So, complex structures (including living things) are essentially entropy factories.
The 2nd Law of Thermodynamics is akin to the Law of Karma. If we don’t perform the karma, we die. And even if we do perform karma, we still die eventually. That goes to the heart of what it means to be alive. We can extend this concept to encompass our society in its entirety. The vast complexities that sustain our lives and conveniences require us to extract matter and energy from the environment. And even if we use the most eco-friendly way of life, some energy will dissipate and increase the universe's entropy.
This is a fact.
At the core of many issues and problems we have faced and are facing is the need for matter and energy to sustain or increase our complexity. Ultimately, over an extended period, the Second Law will take control. Organisms will die, societies will collapse, and empires will wither away. The universe, too, will march on towards a heat death, finally achieving thermodynamic equilibrium.
When viewed through such a lens, we realize that the woolly mammoth, the cavemen, the mighty empires now ruined, the myths of civilizations, burnt-out stars, and the black holes of deep space all have a commonality. They are all "complexities" in the long-term struggle for existence.
And from this great fundamental strife, all other struggles descend, of which our minuscule struggle for existence is just a small, insignificant footnote.
We can be the best poker players, but eventually, the house wins.