Of course, if one is going to think about
quantum mechanics in ordinary terms, there is a sense in which failure is inevitable.
It’s probably impossible to stretch everyday experience to cover something this
strange.
At the same time, this shouldn’t
necessarily be discouraging. After all, even the most esoteric mathematical
models of these phenomena are clearly incomplete. There’s a point where they
don’t join up with relativity, Newtonian physics and so on. So we can expect
our own models to run out of steam – probably even more quickly – but that
doesn’t mean they can’t be used as stepping stones towards some sort of
understanding.
Following on, for instance, from the idea
of propagation as a wave / interaction as a particle, is the question of what
the wave is like. We actually know quite a lot about the particle – after all,
that’s what we can measure – but very little seems to have been written about
the wave.
One possibility is that the wave is pure
energy. The particle converts to energy as it travels and then, when it
interacts with something, turns back into its expression as a particle. That’s in
contrast with the idea (courtesy of Schrodinger and Feynman) that we can think
of particles as interchangeable and simply disappearing at one location and
then appearing again instantaneously somewhere else[1]
with the probability of appearing at any specific location being given by the
interaction of probability curves modelled as sine waves.
In the supposition I'm thinking of, the process is like a soap bubble. It radiates outward from its source, expanding as it goes, as long as it doesn’t encounter anything it can interact with. As long as it is in this phase of propagation it exists purely as a wave of energy. This could last a very long time, think of a photon that left a star early in the life of the universe and has travelled for 14 billion years before it’s detected by a telescope. When it interacts with something, it reverts to being a particle.
At that moment, since the particle needs a fixed quantum of energy, the bubble bursts and all the energy becomes concentrated at the point of interaction. The rest of the wave front would necessarily disappear and this could be thought of as having an instantaneous impact elsewhere – possibly a way of accounting for so-called quantum entanglement.
Returning to the two slit experiment, this provides a second question that could be used to check whether this idea has any validity:
- · If a detector is placed to observe particles passing through just one of the slits then particles it detects would be distributed as particles. Entities which are not detected (i.e. the 50% of cases going through the other slit) would continue to show an interference pattern.
Another interesting question is what constitutes interaction. Clearly if a photon (for example) is absorbed by an object of the right colour that constitutes interaction. What about one that is reflected from a mirror? Or one that is refracted through a prism or diffracted by the edges of the slits in the double slit experiment.
This all sounds as if it fits with the facts. Subatomic entities, when they propagate cannot be detected without turning them into particles, that is, they aren’t detected as waves, but they behave as waves when confronted with the double slit. When they interact as particles, their wave-nature disappears and they interact at defined points. Nevertheless, their wave history determines where they are observed. The outcome is, to an extent, random because it is a function of the interaction that transforms energy to particle rather than something inherent in the transmission.
[1] ‘…the particle hops off to anywhere
and everywhere else in an instant.’ The Quantum Universe: Everything that
Can Happen Does Happen p. 46 Brian Cox and Jeff Forshaw.
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