At the heart of our reality lies a state of being where nothing is certain. As we slice and dice our material world, we pass through the physical structures we confront in our daily lives and enter a realm of molecules and atoms from which all things are made. As we probe the atom, we discover its constituent parts: electrons, protons, and quarks, and, as we look further, a whole zoo of subatomic particles.
Our intuition says that if our world is solid and predictable, surely that will also be the case for the particles that make it up. But that is not the case. What we think of as a ‘particle’ reveals itself as nothing of the sort, but a standing wave in a universal field of energy. And each ‘wavypart’ has its own rules of being (properties) and carries an integer number of units (quanta) of energy.
We can never precisely say how a wavypart is moving or where it is. Indeed, when we probe the properties of a wavypart, we discover that it is never in one state or another; it is in all states at once. How do we know this: experiments and a mathematical theory which is so perfect that no departure has been discovered from what the theory predicts and what is observed.
We are in the world of quantum mechanics and the ‘wave equation’: a mathematical formula that is perfect in prediction but has left the greatest minds of the last 120 years pondering what it means.
Superposition is one of the most challenging of quantum properties to comprehend, but one which may be sustained in many natural, living systems, so here is an illustration of this bizarre property of matter at its most fundamental.
On my desk in front of me is a small sandstone dog. He stays in one place, and when I return to the desk, he is always there. He is part of my world, and he obeys all the properties I would expect of a sandstone dog. Now let’s imagine what he would look like if he was in a state of superposition.
As I take his photo, he is looking at me. But imagine what he would look like if he were looking away from me at the same time. He would have two heads and two tails, one of each at either end. But in true superposition, he could be looking in any direction. If constrained to lying flat, his head would be in all places in a circle, and if not constrained by the tabletop or by gravity, his head would be anywhere on the outside layer of a sphere, where his tail would be as well. He would look like a sandstone ball.
But it would also be a fuzzy ball because the wave equation tells us that his position is uncertain, and so this ball of superposed sandstone dog would be a very fuzzy ball. He would simultaneously exist in all states at once. Now, if you think that’s weird. It gets weirder yet.
Imagine that I had put him into the centre of a box in which, by some magic, he could be put into a state of superposition. What would happen if I opened the box and peeked at the superposition? I wouldn’t see a fuzzy sandstone dog.
He would instantly appear just as he does on my desk, but in any one of all the possible positions permitted by the wave function. If constrained by gravity, he could be pointing (lying perhaps upside down) in any direction and close to where I placed him, but not necessarily so. His resulting position will be governed by the laws of probability, with the most likely place being where I had put him. Indeed, he might even appear wholly or partly outside of the box.
All of that is weird and hard to imagine. But here is the weird bit, which appears bafflingly inescapable. The superposition of my sandstone dog only collapses when I open the box and look. It appears that my conscious intervention is required to ‘freeze’ the superposition.
No matter how we dodge around it, and despite the great minds of the twentieth century pondering the matter, we have a strange link between conscious awareness and the reality we perceive around us. Consciousness does not appear to be just an accidental property of our brains. It appears to be fundamental in the transition from the quantum to the ‘classical’ world of everyday experience.
This is a topic we will return to as we explore the depths of the Elven Boots in further blogs.