Over the summer holidays, I decided to become an expert in Quantum Mechanics. This is an idea which has appealed to me ever since reading “that nobody understands quantum mechanics” as suggested by Nobel laureate physicist Richard Feynmann.
If you’re going to be an expert, why not be one in a field that nobody understands?
I was therefore a little puzzled by the subtitle of Carlo Rovelli’s Helgoland, the first book I picked to aid me on my journey to experthood, which is: Making Sense of the Quantum Revolution. But never fear, dear reader, it seemed to me, after reading the book, that ‘making sense’ means accepting that the quantum world fundamentally does not make sense. Which is to say that things on a quantum level do not behave in a way which most of us would regard as making ‘sense’.
Here are just a few examples of this nonsense:
quantum superposition – where an object can be ‘here’ but also ‘there’ at the same time
quantum entanglement – particles behaving as if they have a telepathic connection (Einstein called it ‘spooky action at a distance’)
many worlds interpretation – there are many worlds which exist in parallel at the same space and time as our own (kind of a way of explaining the spookier aspects of quantum phenomena by introducing an even spookier idea)
quantum jumping – electrons seeming to “jump” from one orbit (or energy level) around the nucleus to another, without existing anywhere in between.
As I read more on the subject, what became more apparent was the idea that our common sense notion of ‘reality’ is probably wrong. Or at least what we call our common sense notion of ‘reality’ has changed a lot over the centuries.
Reading about how all these marvellous physicists are investigating the nature of reality, I was reminded of what has been called The Enlightenment Project, in a way which I hope I can explain. I know I have written much on this before, but for the benefit of new readers, here’s a very loose summary…
Flashback to the 18th century, where the Enlightenment is this extremely optimistic framework which believes that after centuries of ignorance, poverty and superstition we human beings have figured out something fundamental; we can observe the world and we can use our faculty of reason to figure out the way the world works. Because the world isn’t just all magic and mystery, it works a certain way and we can take stuff apart and put stuff together in different ways to make things better than they currently are. Reason therefore was championed as the way to decipher and explain Nature. The period saw an explosion in technological and scientific advances as a result. Well done, everyone!
In many ways we still live within the Enlightenment Project. This week marks the return to school and much has already been spoken about, to us as teachers and to new and returning students about the importance of getting a good education. And what ‘a good education’ looks like has, for most people, a distinctly Enlightenment feel to it. Students are in the business of acquiring knowledge and developing the skills which will enable them to critically engage with and manipulate the world around them with the view to making it a better place. And the more you can know with certainty, the better you are equipped to forge your way in this world. Fair enough, you might say.
But there’s a problem. And amongst others, it was our old friend, Kant who pointed this out at the time.
Kant had some interesting things to say about the capacity of human reason to know the world and what the world is, which we might do well to remember at this time of the school year. And other times as well! And I think there’s a link back to the nonsense of the Quantum World. Bear with…
Kant worked for a time on the question of what exactly can reason know and what can reason not know. Now, we would all, I hope, accept there are limits to reason. We can only attend to a limited number of things at any one time. You, of course, are paying full attention to these words as you are reading them and are therefore unable to pay attention to anything else, for example.
Enlightenment thinking suggests that the world means the natural world and the physical world first and foremost. Maybe there is also some Transcendent Dimension to the world but if we’re going to get there we’re not going to get there through simple-minded faith or seeking mystical insights. We’re going to have to adopt some sort of rational scientific method and argue for the existence of a God.
But Kant argues that at a fundamental level reason is not able to know the things that most of us would say are the most important things about the world. And in fact, what we call ‘the world’ is not actually the real world. The world of the senses is a construct made by subconscious or unconscious structural factors, of which we are completely unaware, that create this world for our mind’s attention. Kant calls this the phenomenal world and it is to be very much distinguished from The Real World or the noumenal world.
For Kant, it is impossible for us to get from the sensory phenomenal world to reality as it is. We are cut off from ‘knowing’ reality. He points out that reason is a subjective capacity which knows only a subjectively created reality. It has no objectivity to it and no capacity for knowing real reality.
So on the big questions, like ‘Is there a God?’ Kant is saying as a matter of principle we cannot know.
Which leads me back to the Quantum business. If we take another of the nonsense principles, Heisenberg’s so-called Uncertainty Principle, we might be able to make a point. Firstly, there used to be an idea, suggested most notably by Pierre-Simon Laplace that if we could know (we can’t) all the laws of physics and all the positions and all the momenta of every particle in the universe, we could predict the future. But Quantum Physics shows us that such an idea is categorically wrong. Planck’s constant (ask a physicist) sets a limit up to which we can determine physical variables. Heisenberg took this idea into consideration and came up with his uncertainty principle. As a formula, it’s this:
ΔxΔp≥ℏ/2 (Delta x times Delta P is always greater than or equal to h-bar divided by two), (ask a physicist)
And what it means for this expert is that uncertainty is an absolutely inherent aspect to anything which behaves like a wave. And wouldn’t you know it, subatomic particles behave like waves! Reality is uncertain.
So there it is, dear reader, in triangles and numbers, uncertainty is a property of reality and it applies to everything.
I leave it to Keats and his idea of negative capability to have the last word on this. Let’s try and be comfortable dwelling in “uncertainties, mysteries, doubts, without any irritable reaching after fact and reason.”
(As for whether I am an expert, well, yes I am: expert /ˈɛkspəːt/ x spurt where 𝑥 = an unknown quantity and spurt = a drip under pressure)
Until next time, Happy Reading/Dwelling in Uncertainty