Boundaries and Connections in Physics and Perception

Apple MandalaMany people are familiar with the maxim from chaos theory that the fluttering of a butterfly in one part of the world can lead to a hurricane in another. Causes and effects are ubiquitous. Mystics tell us that one of the basic revelations is that everything is connected, there is no you and me, and we are one with the cosmos. Let us shine the spotlight of science onto this concept and play a little.

As we go about our day doing ordinary things, we think in terms of tasks that we need to do and the objects and tools that will be useful. We talk to other people who seem distinct from us. We hold in our hand a pen or a book. We put them down, we type on a thing called a computer. We pack it up and put it in a bag, pull out our keys and get into the car. We drive and we think about people and places and relationships between distinct entities.

It is easy to see yourself as an actor in a world populated by things, toiling through the day along-side other actors who are not you. This mode of thought is surely a human perception which has been shaped by evolution because it provides a rich framework for adaptive behavior. The true picture is more subtle.

The universe is a place of very rich interactions, and these are mediated by forces which transmit information from one region to another. One could argue that forces and information flow are the same thing, and perhaps one day a unified theory of physics may be built on this.

If a distant civilization points a laser beam up into the heavens and modulates it to encode some message, the beam may travel silently for many light years before being received by an excited SETI researcher on earth. The distant planet and our own are then causally connected by photons which descend through the atmosphere and interact via the electromagnetic force with electrons in a suitably sensitive receiver. These forces impart information. A cascade of cause-effect electron flow amplifies and decodes the alien chatter into audio-visual patterns which by sight and sound influence the brain of the observer. She then reacts and by email communication with like-minded scientists sets up a cascade of connections leading to complex changes in the mind state of multiple individuals, a back and forth chatter of human networked patterns, creating mass collective behaviors as headlines appear in the morning paper. Cause and effect can be amplified and distant and tenuously connected spaces can come into strong communion.

When one looks at our natural world, the trees, the soil, the river, and other people, we are looking at things that from a physics point of view are all connected to each other by many kinds of forces and constant patterns of information flow. What differs is how tightly the parts are coupled.

The earth consists of soil and rocks. When digging, we think of the rocks as separate from the soil. Before we brought them to the surface they were collections of atoms intimately coupled with other atoms in adjacent grit or organic matter. We have evolved to use linguistic forms to refer to distinct objects, to draw boundaries around them and ourselves, to count objects and to name them. Our tendency is to group amalgams of particles along functional boundaries because certain collections have a utility to us. They seem distinct because they can be easily separated and re-located by human hands. We can pick up a rock that was buried, dust it off and throw it into a lake. These perceptions of separateness are useful constructs that allow us to communicate and to reason about the importance of items in our quest to control and predict our environment. It is not very important to see everything as homogenous and connected, but it is important to see the cracks between things that we can pry apart with our minds and place into linguistic pigeon holes that provide advantageous communication modes.

Red AppleAn apple sits on the table. We mentally draw a boundary around the apple and think about how heavy it would be if held, the way the waxy surface would feel, how it may taste, and whether we shall keep it to ourself or give it to another.

But let us dive deeply into the flow… Think of a different imaginary boundary: a sphere of radius R which intersects a part of the table and the apple and some of the air in the room; an arbitrary and less human-centric segmentation of the universe.

The apple piece consists of a skin over a central pulp. Microscopically it is made of plant cells, cellulose encapsulated structures of complex living atomic construction. It has one boundary to the air and another to the table. If the table is wood, this wood is formed from aging bundles of cellulose fibers. The apple is held in place on this table by the force of gravity, a peculiar force which is actually a constant upward acceleration of the table pushing on the apple, this being just great enough to prevent the apple from otherwise following its natural space-time path of a falling geodesic. The thrust passed on from the table is transmitted at the boundary by intermolecular forces of electric charges, communicated by a ceaseless interchange of ghostly virtual photons. The atoms of the cellular matrix of the apple skin interpenetrate the atomic structure of the table, creating a thin hybrid boundary. The gravitational resting force elastically deforms the shape of the apple via a network of inter-atomic forces, diffusing gravity’s acceleration to all of its parts and subtly conforming the apple to fit the imperceptibly distorted indentation of the table’s accommodating embrace.

Above and around, a violent gas storm rages. The air molecules pummel constantly on the skins of the apple and table. The molecules of oxygen and nitrogen ricochet from the object surfaces in a ceaseless barrage imparting atmospheric pressure. Atmospheric gases diffuse into each structure, and oxygen combines with molecules in the apple and table, slowly producing oxidative decay.

Thermal energy is present everywhere and the whole picture is in motion. The molecules of the apple and table shake and rattle in a dance of complex vibrational modes as the solid lattices ring and oscillate with heat. The trapped water molecules in the cellular structure tumble and spin in every way, endlessly presenting a different face to their neighbors and reconfiguring their hydrogen bonded fluid connections. Heat energy in motion liberates complex hydrocarbon esters outgassing to the atmosphere as a fragrant apple scent.

Half AppleRather than being in thermal equilibrium, subtle differences in heat absorption cause a flow of energy across each boundary. If the table is dark and the apple is more reflective, the infra-red and visible light photons that rain down from the environment may impart more energy to the table and a net flow of kinetic vibrations will course upwards into the cooler apple. Both objects will radiate thermal photons.

Acoustic waves transmitted into our apple/table/air volume through compressions of the air and mechanical energy via low frequency vibrations rising up from the earth impact the structures. These waves bounce around through the apple and table reflecting and refracting at the geometry and density variations of the internal structures. The apple and table will have their own modes of mechanical resonance and vibration. The objects will sing to one another constantly passing sound energy backwards and forwards across the boundary.

Radioactive carbon 14 incorporated in all biological matrices will decay, sending out a zing of beta radiation and anti-neutrinos before converting into nitrogen 14 and perhaps gassing out into the air. Muons from high energy particle collisions showering the earth with upper-atmosphere decay products will pass through our scene, some of them transforming into electrons which may become incorporated into apple molecules.

This grand picture of interactions is almost complete, save for the vast neutrino flux streaming through our imaginary sphere and maybe a whisper from the ghost of dark matter.

Switch to the realm of human form. Do we really know where our physical boundaries are? We are born with brains and hands and have evolved to be tool makers. We can pick up a power tool or a knife and fork and enjoy the innate ability to extend our body image to the tips of our tools to manipulate the world as though we were born with these appendages. We can drive a car and feel a spatial awareness of its bulk and corners and if we drive over something it is as if our body was involved. Our parietal cortex generates a sensation of the body image that defines our kinetic boundary and keeps itself updated via proprioceptive feedback from sensors in our joints. We have a real sixth sense for the configuration of our hands and legs and torso and head and eyes, and the same part of the brain discriminates which things are self and which things are other. If this magic perception fails due to brain damage then people can treat their own body parts as foreign objects and wish to be rid of them.

Apple LogoThe world can be manipulated by our fingers, but fingers can be lost in accidents, and replacement artificial parts become a tolerable proxy. Human industrial progress has arisen from the mind’s ability to project its boundaries along many complex paths of mechanical and electronic control. We can just as much open our email or destroy nations at the touch of a button.

A natural leader can organize and wield an army. Steve Jobs could impress his will and personality onto a multitude of workers who became an extension of his being to bring forth changes in technology that no single individual could attain. He is like some giant Transformer robot which is made of people charging across the landscape leaving a trail of newly minted iPhones and Mac Books.

From cells to people, to ecosystems, to the cosmos, there exists a continuum of places to examine cause and effect and to draw boundaries outside of daily convention, and nothing is disconnected.

All this goes to say in short that there is plenty of ebb and flow between the parts and the whole, and the illusory distinctions that we make to simplify our lives ignore the intimate and resonant connections between every system that nature presents.