Now let us answer a question submitted by one of our listeners, regarding the particle-wave duality of light discussed in “Episode Seven – Bohr’s Philosophy“. Thank you, Steve, for this question.
“I just listened to your podcast regarding Niels Bohr. I understand your objection to the duality nature of particles as a violation of the Law of Identity. I also understand your discussion of particles being entities while waves are abstractions about the organization of particles.
So, translating this to the nature of light, is it proper to make the following statements?
1. The current scientific understanding of what light ‘is’ is not correct. It is not a wave because it leaves out the ‘thing’ that is waving.
(sub-question: So, a ‘field’ would not qualify as a ‘thing’ that waves.)
2. Science CAN demonstrate different properties of light. These demonstrations allow us to predict behavior and experimental outcomes. BUT this is not the same as saying we know what light is.”
Good question! The short answer is yes, it is accurate and proper to make those statements.
The main point of that part of episode seven was, of course, to demonstrate that whatever light is, it is not a wave and a particle. But, that does not do much to tell us what light actually is.
We can say that whatever light is, it is something. Whatever that something is, it is not both a wave and a particle.
To say that when we look at what we call “light” we observe just a wave, is incorrect. Since, yes, something has to be doing the waving.
But, at the same time, saying that it is just a particle may also be incorrect, not unless you can explain the observation of wave behavior.
Perhaps when we look at light, we are observing particles with wave behavior, or particles and something else exhibiting wave behavior.
What we do know is that when we observe light, sometimes we seem to observe particle behavior such as when we observe the photoelectric effect and sometimes wave behavior such as what we observe when we perform the double slit experiment. We do not dispute these experiments and their outcomes or that they indeed tell us about the properties of light.
What we dispute is that the particle-wave duality explains what light actually is. To explain what light is, you need to explain why it sometimes is observed as a particle and other times a wave.
That certainly could mean that our current understanding of what light is, is in fact incorrect. It certainly seems that our understanding of light is incomplete, that we have failed to properly explain why we observe what we call “light” to sometimes have particle behavior and other times wave behavior.
In fact, deBroglie and others have tried to suggest pilot wave theories, some of which might help to bridge this gap in our grasp of light. They propose the observation of what we call light actually involves a particle accompanied by a wave. What is doing the waving is an interesting question, but we will not go into that here.
These theories tend to be too easily dismissed. But, is this wise? Perhaps one day we shall find out.
That very well may require a very different idea of what light is than most people accept.
And as for whether or not a “field” qualifies as a “thing” that waves:
Well, what is a field? Physicists often define a field as a quantity assigned to various points of space, so basically, a series of numbers.
Now, the problem is that many physicists think that a field itself explains something. For instance, they might assert that the electromagnetic field explains the behavior of charged particles.
But, it doesn’t. The field allows one to calculate the behavior and properties of charged particles, but it does not itself explain why those properties have those values and why the particles behave the way they do.
For that, you need to explain how the field works. You need to explain what it is about the entities involved and their relationships which cause the behavior described by the field.
But, the short version of the answer is that no, since according to this definition, a field is simply a mathematical description of properties and actions, then it can not qualify as a thing that waves.
Now let’s take this definition of a field, that is to say, a field is “a region where each point is affected by a force.”
Well, a region of space clearly cannot wave, since it is just a relationship. Things in that region might wave around and explain how the force manifests, but that is not the same as the field being a wave or the field waving.
Using either definition of a “field”, it is an abstraction dealing with entities and relationships between them. The field still needs a physical explanation in terms of things that exist, not numbers attached to space.
And if you define a field as a region where each point is affected by force, you need to physically explain the force.
I hope that clarifies and answers your question, Steve.
And that was the last question which brings us to the end of this episode. Remember to check out the website and subscribe if you like our podcast, or follow us on Facebook or Twitter to get the updates!
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