I received The Quantum Universe: everything that can happen does happen by Brian Cox and Jeff Forshaw for Christmas, and have just got round to reading it. Let me qualify that: I have just got round to reading it in this universe. In an infinite number of other universes I’m probably still trying to do the Times crossword. Be it Schrodinger’s cat, Heisenberg’s uncertainty principle or the small matter to vote Reagan, I have always been fascinated by the incomprehensible.
According to Cox and Forshaw, tiny particles do not appear to follow the rules of behaviour that big stuff follows. This means there is nothing in our experience that compares with things that happen in the subatomic world. As a result, it is almost impossible to explain the quantum universe without resorting to perplexing equations or diagrams.
Or is it? Maybe physicists should spend less time with their heads stuck up their particle accelerators and more time in primary classrooms, because in my experience there is no better way to explain the strange behaviour of the infinitely small than by reference to the even stranger behaviour of the irritably small.
Adults, such as my wife, behave by and large how you would expect them to behave. For example, if I hand my wife a glass of pinot grigio when she staggers in from a busy day at work, I know that she will end up on the sofa watching EastEnders.
Ryan, on the other hand, behaves like an electron. It is impossible to predict where he might be from one second to the next and I can only ever estimate his future location. I could order him to sit in his chair, but the probability of finding him there when I next look involves a decimal point followed by zeros. The reality is that he could be in all possible places at the same time. I call this the Ryan Unpredictability Principle.
Wave-particle duality, on the other hand, is best explained by reference to something I call the Declan Effect. According to quantum mechanics, matter at the tiniest level behaves like a particle and like a wave. This is difficult to comprehend until we consider the fact that Declan does exactly the same. My register tells me there is only one of him, which would appear to make him a particle, whereas my experience of him resembles a wave of Declans surging relentlessly in all directions.
In 1935, Erwin Schrodinger proposed a thought experiment to highlight the problem that the properties of particles cannot be predicted; they can only be directly observed. He suggested that a cat shut inside a box containing a lethal poison activated by the release of a particle from a decaying nucleus could be considered dead and alive at the same time.
The good news is that my own thought experiment, the Kimberley Conundrum, can be used to highlight the same problem.
Imagine Kimberley is listening intently to a set of instructions. At some point I emit a key word that causes her thought processes to switch off. Because her outward expression never changes it is impossible to directly observe this and it is not until she has to carry out the instructions that I discover she stopped listening some time ago. Does this mean that in a cognitive sense she was both dead and alive all the time I was talking?
While you ponder the Kimberley Conundrum, I’ll get on with my crossword. Let’s see. Two down... small matter to vote Reagan... aah, got it! Electron.
Steve Eddison teaches at Arbourthorne Community Primary School in Sheffield. Watch a TES live lesson with Brian Cox at www.tes.co.ukbriancox.
