Everything Flows
On , 579 words, 3 min read

You cannot step into the same river twice - Heraclitus

This quote from the ancient and obscure Greek philosopher Heraclitus, highlights one of the most fundamental properties of Nature, that the only constant is change. Everything changes, we change, the river change, nothing stays the same.

The inevitability of change comes from the irreversability of time. If time was symmetric, change would be an ilusion. Our models of reality have time symmetry in them, but they are just models. Everywhere we look, time only goes one way. Entropy grows, coffee gets cold, flowers die... The reality of change is directly connected to the growing of entropy which is the growing of uncertainty.

This creates an existential problem to the human condition, because Humans (and every life form) survives on certainty. In fact, survival is by definition the fight against change. Survival is the ability to identify some degree of certainty in a sea of change that allows to predict the future, and come up with an action plan. Run from probable predators, engage with probable mates, to persist, to exist...

So, it's only natural that humans resist change in all its forms. This resistance is so natural that we strive continously to reach the ultimate certainty. The One thing that is immutable and absolute that will never change and help us in our quest for survival. This is the origin source for all religions.

Perhaps the most important teaching of the Buddha, is that there is no such thing as an ultimate certainty. There is an emptiness at the heart of reality. Even the fundamental blocks of Nature decay into nothingness. We are condemned to suffering if we cling to impermanent things, and the only path to enlightnement is to stop clinging to certainty and embrace change.

These ideas are 25 centuries old, but they have not yet fully percolate into the modern scientific view. There is still a tendency to look at entities as "static things" instead of actual dynamical processes of change. Whitehead in his book "Process and Reality", tries to make the distinction between this different views, arguing that, what we see as a permanent Self is an abstraction of the underlying materialistic dynamical proccess, of a baby becoming a child becoming an adult. The Self as an entity has no physical meaning. I think that Prigogine said it better, when he said that we should go from a "physics of being" to a "physics of becoming"

Recently I've read the book Everything Flows and it is another shot to expose this worldview. The book argues, that we should stop to look at organisms as complex machines but instead as flowing streams. Streams that diverge and combine to form the river of life, where little vortexes are born by change and constantly fight it to exist and persist.

To understand flows, I implemented a basic fluid simulator in WebGPU. I used the classic paper by Jos Stam, and Karl Sims has a nice visual tutorial on how everthing works.