By Roland Watson

I described in the last article some of the curiosities in our understanding of physical reality that have been revealed by quantum mechanics. These include that we can never know what, exactly, is going to happen, only the probabilities of different potential events; and, that at the deepest level matter appears to behave both like particles and like waves. What this signifies is that physicists in effect are attempting to describe something that really can't be described, at least in words. This hasn't stopped them from trying, though. For particles and waves, in other words, for our perceptions of reality, they have developed numerous propositions.

What are particles?

- Particles are real.

- Particles are only insubstantial "tendencies to exist," what is called the waveform or wave function of potentialities.

- Actual particles only come into existence when we observe their waveforms. The waveform "collapses" from many potentialities to one actuality, through the interjection of chance.

- As such, we are an inseparable part of this process. Indeed, one can even say that by observing the waveform we cause the collapse, and "make" the particle.

- Particles are "correlations," between the beginning of an experiment and its end - between what are termed "macroscopic observables," such as a light bulb that sends photons on their way and a photographic plate that registers their arrival.

- Particles are also viewed as the points at which different waves come into contact.

- Particles are relationships between other particles. They can only be thought of in terms of these others, as combinations of them, and the others can only be thought of in terms of them. This is called "self-referential," and it is a form of relativity at the quantum level.

- Particles, mathematically, are dimensionless points, or they are vibrating, rotating, one-dimensional "strings."

- And, particles are "reaction channels," through which energy flows. They are "events," blurred and unspecified interactions, the points in space-time at which energy changes state or form.

Now, a lot of this contradicts common sense. Nuclear fusion - which occurs inside stars, and nuclear fission - in reactors and atomic bombs, proves - to us at least - that particles are real. But, to physicists, particles exist only as an extension of us. There are in fact no parts.

The two views of reality

What this reveals is that there are actually two alternative, or competing, basic views of reality. The first is that it is discontinuous, and that this manifests itself in different scales of matter, from particles to galaxies. The second is that it is continuous. The entirety of the universe is in some fundamental way interconnected, even inseparable. It is an indivisible whole. In other words, the jigsaw puzzle exists only as a consequence of our perception of, and interaction with - more precisely, within - this whole. In addition, the first view roughly corresponds to the study of matter-energy and quantum mechanics, and the second to the study of space-time and relativity theory.

But, to continue with the world of "parts," the forces that I described are now understood to be the result of particle interactions. (One model - string theory - provides an alternative explanation.) The strong force is protons and neutrons exchanging virtual particles with each other. This exchange overwhelms the similar virtual particle exchange that is associated with the electromagnetic force. However, if this is the case, and particles can also be viewed as relationships, then forces are actually relationships of relationships.

Particle exchanges are further described as occurring in, or constituting, a force "field." The study of the forces is the subject of quantum field theory, although gravity has yet to be explained using this approach. There is an unresolved paradox in our understanding of gravity. Is it a force, with an associated particle exchange, or is it a consequence of the shape of space? And, if the mathematics that underlies physical theory suggests that it is both, as with particle/wave duality, how can this possibly be the case?

As you might imagine, these perceptual limitations have led to all sorts of difficulties. For example, under quantum mechanics, if an atom is heated - an atom is a collection of particles, or the interaction of waves, interacting with each other: now we have interactions of interactions. Let me start again, if an atom is heated, its electrons absorb the energy of the heat and - one - jump to a greater orbit and distance from the nucleus, or - two - abruptly change to a different, more highly energized state. The question is: how do electrons absorb energy? And, if they do jump, and sometimes this would be really far, such as when they are subjected to the extreme temperatures inside a star, how do they find their way back to "their" nucleus - and what is referred to as their "ground state," such as when they - the nucleus and electrons, and those of many, many other atoms - are expelled by the star into space and cool down?

What about time?

Even more, our difficulties are compounded when we consider time, the view of which under quantum mechanics is confusing and contradictory. (As an aside, this may be because the appraisal of space-time under quantum mechanics is a secondary consideration.)

In some cases, particle interactions take time. They occur at a rate that is subject to the limit set by the speed of light. But in other cases, they appear to occur instantaneously - with no passage or elapsing of time.

For instance, the particle interactions that represent forces require the passage of time, but another type of interaction known as "entanglement" seemingly does not. Two particles with the same spin can become aligned, or entangled, and if they separate this is preserved. Subsequently, if the spin of one is manipulated, the other, no matter how distant, immediately changes as well. This has been demonstrated experimentally.

As another example, if electrons, when energized, actually jump some distance, or merely change state, this is believed to occur instantaneously. There is not actually a transition.

Also, in particle collisions the particles do not collide, and then change into something new. Rather, the old particles are annihilated and new ones created, seemingly into and out of nothing and nowhere. Under quantum mechanics, at least in these circumstances, it appears that there is no time or space. They are only our projections.

To continue the example, if an electron actually jumps some distance away from the atomic nucleus, this is effectively through empty space - the space between subatomic particles. But, the theory of the space-time continuum shows that there is no empty space! It appears that we construct time and space, and matter as well, solely for the purpose of utility, to make sense of the circumstances of our existence.

In this view, we are back to Rene Descartes. Only "I," or my thoughts, really exist. Also, quantum mechanics itself supports the idea that no space is truly empty. All space is continually active with the creation and annihilation of particle and anti-particle pairs.

However, and this is a paradox, once particles do come into existence, they have a life span. They exist for specified - often very, very short - periods of time. Anti-particles may actually have "negative" life spans. They come into existence, and then appear to live backwards in time. For them, time may move in the opposite direction than it does for us.

It is also interesting that the idea that something can come from nothing is similar to a point I made earlier in the articles about religion; specifically, Buddha's view about the creation of a new life out of - but not following on from - the death of another. Indeed, this holds with any parallel act of creation, such as of the universe, or even of thought.

A final perspective on time from quantum mechanics is that particles appear to demonstrate an ability to collect, evaluate and act on information instantaneously, information which common sense would dictate would require the passage of time to accumulate. Indeed, entanglement is an example of this.

As David Peat wrote in his book Superstrings, and the Search for The Theory of Everything: "The idea that information can be collected from many different points all at the same time implies that this information must travel across space at an infinite speed - faster than the speed of light."

Another example of this is given by yet another principle, the Principle of Least Action. According to it, a particle, when it decides to travel from point X to point Y, simultaneously considers all of the possible paths that are available to it, and then chooses the path that minimizes a quantity known as "action." But, to do this, it seemingly must evaluate the totality of all of the different possible paths, without first having traveled them. How is it able to see where it has not yet gone, or, said another way, how can it look into the future?

I should add, this is also known as the "Sum over Paths," and it relates to another idea as well, that of "superposition," where, prior to observation, particles are in many different locations, perhaps infinitely many locations, simultaneously.

To summarize this article, one of the great discoveries of physics - of science, has been the theory known as quantum mechanics. It is based on the idea of quanta of energy, that energy, which underlies all matter, exists in small, discrete chunks. Quantum mechanics has been demonstrated experimentally, again and again. It is further at work in every computer and electrical device that you and I use; literally, in everything that we do. However, looking deeply, quantum mechanics is so strange that no-one is able to understand what is really going on, much less what if anything it might mean. It is clearly a universal level of order, but which is full of contradictions - to us - and paradox.

In the next article, I will consider some other aspects of universal form - what are known as conservation and symmetry.

© Roland Watson 2015