Why do we perceive the night sky as beautiful? In fact, we might ask why we perceive anything as beautiful.

Philosophers have pondered the question for thousands of years, but perhaps physics gives the best and truest answer. We perceive the night sky as beautiful partly because of the second law of thermodynamics.

The second law states that “in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state.” In other words, no transfer of energy is perfectly efficient. As energy is exchanged or transformed, some of it is not used to perform the process that the exchange was meant to accomplish. That energy is “wasted” as is pours into the environment surrounding it.

On the largest level, most energy in the universe comes from stars like our sun. As the sun explodes deep in its center, it very efficiently converts its hydrogen into energy. However, the star does not use most of that energy to fuel the explosion. The energy bubbles and boils, and heaves its way to the surface and is thus “wasted” as it erupts into space.

Stars are exceedingly efficient and long-lived energy-producing machines. They last a long time mostly because they have so much hydrogen fuel to work with.

However, eventually the stars will run out of fuel and stop producing energy. The universe will cool down to absolute zero as all of its atomic and subatomic components stop moving. The universe is slowly moving from a state of relatively high orderliness to a more disordered state as energy is wasted into space and the stars eventually stop exploding.

Physicists call that slow decay into disorder entropy. Stars are in a highly entropic state — a state of great disorder despite their efficiency — because they plow so little of their energy back into the energy-producing process.

We experience such conversions of energy every day. The battery running the laptop I’m writing on will power the computer until it receives a new input of energy. But not all the energy is used to power the computer. Some of it is wasted as the heat I feel as I rest my hand on the computer to type. Eventually, the battery will wear out from the constant transfer of energy.

Your body works in much the same way. It converts the carbohydrates in your diet to energy that it uses to fuel your body. The process wears it down, but it has a power that much of the universe doesn’t possess. Like all higher-order living things, it can on a limited basis repair itself and delay the eventual system breakdown, a final stage we call death.

The cells of your body and the system of cells as a whole are in a high state of order compared to the rest of the universe. We might call that a state of low disorder or to put it in the language of physics, a state of low entropy.

To continue functioning, we must absorb energy from our environment and the proteins to do the repair. In effect, we absorb orderliness from the universe, and we must choose the most ordered of the universe’s parts to get our own orderliness.

That’s why as living things, we must eat other forms of life to preserve our orderliness. We are, in effect, anti-entropic devices, and we need to dismantle other highly ordered organisms to survive.

Thus, as we absorb order from the universe, we increase its disorderliness. The universe pays for our orderliness by becoming more chaotic.

Living things are in a constant battle against the disorder that surrounds them and the other highly ordered organisms that want to absorb their orderliness. A chance encounter with a truck might overwhelm your body’s ability to repair itself. The flu bug that is trying to take control of your body will absorb your orderliness until it kills you if your body lets it.

We stand out from the rest of the life on our planet because our central control system, our brain, is more advanced. Our brains make us better than other forms of life at absorbing order from the environment. It is also better at preventing the loss of order, the wasting of energy into the environment.

For example, as warm-blooded creatures, we must maintain a certain temperature for the body’s mechanisms to function.

We should have have been gone from the planet a long time ago as climate change played havoc with local temperatures. Too bad that we unintentionally flushed the waste heat generated by body processes out into the environment.

However, our intelligent brains figured out yet another way to absorb order out of other life forms. We robbed them of their fur and wear it. That process allowed us to take heat that was formerly wasted and use it to support the functioning of our bodies.

In other words, our intelligent brains take us to an even lower state of disorder, a lower entropic state, and we live longer as a result.

We see things as beautiful because we admire most of all their magnificent orderliness, even if we do not completely understand what that order entails on all its complex levels. And that sense of beauty is made even more urgent by our sense that entropy rules and that order cannot last forever.

We realize — both on the universal level and the level of our own bodies — that entropy will always win and that we are in a constant state of resistance against the disorder that will eventually lead to our demise.

In doing so, we recognize that our lives, as fundamentally meaningless and chaotic as they might seem sometimes, are part of a grand process called life and that life, at least temporarily, beats back the chaos.

So, gentle readers, add as best you can to the order of the universe. Make something beautiful. Or find something beautiful and help another humans to see that beauty. For me, it is the night sky. For you, it might be the structure of a leaf, a perfectly thrown football, an orderly set of ideas, or a baby’s first cry.

Realize that life is a temporary, but glorious, bulwark against the disorder that will consume the universe and all of its elements — from the most powerful of stars to you, the most fragile and most intelligent of its creations.


By Tom Burns


Tom Burns is director of the Perkins Observatory in Delaware.