One of the most frustrating problems faced by physicists is the fact that the quantum world cannot be observed as it really exists – in its multiple state, called ‘superposition’ – without its being disturbed. Instead of being a billiard ball of certainty, every quantum particle exists as a cloud of probability.
At its most elemental, the smallest units of life actually aren’t an anything yet, but a self in the process of becoming. In fact, in a pure quantum state, this ‘self’ is collection of all possible future selves all at the same time, like an endlessly replicated chain of paper dolls.
The observer effect
The only thing that appears to dissolve this cloud of probability into something solid and measurable is living observation. In this strange twilight world, where everything exists in a gelatinous goo of all possible states, the very act of measuring or observing reduces the quantum particle to one particular state, referred to as ‘collapsing’ the wave function.
Take the tiniest peek at an electron, and you reduce it to a single state. Take the quickest measurement about where it’s heading, and you end up with just one direction.
By noticing or weighing or calculating, you create what we think of as the ‘real’ world – a storehouse full of set somethings - but you also affect what it is you’re observing and so cannot observe the world in its ‘pure’ state without your influence.
The shadow self
Every type of particle has its shadow self in the form of antimatter or an antiparticle, which behaves just like its corresponding ‘positive’ variety except with an opposite charge. So for every quark there is an antiquark, for every electron a positron. Should the two ever meet, and be observed doing so, they simply combine and implode, so that the superficial appearance of an entity reverts to indeterminate, unspecified energy.
The observer effect suggests that our reality is ‘participatory’ – that we are utterly intrinsic to the creation of reality as we know it Nevertheless, our inability to objectively observe the undisturbed quantum state (or ‘pre-world’ of pure potential) has severely limited our understanding of quantum physics - until recently, when Japanese and Canadian researchers were both able to independently confirm something called Hardy’s paradox.
In 1990 an Oxford physicist called Lucien Hardy devised a very strange thought experiment. Through the use of a gadget called an ‘interferometer’, he imagined an electron hitting a mirror, which creates a superposition, causing the particle to travel down two arms of the device at the same time. The two versions of the particle are then reunited and hit another half-silvered mirror, positioned so that, if the electron has been undisturbed during its travels through the interferometer, it will be collected in detector ‘C’. If it has been disturbed it is sent to detector ‘D’.
Hardy thought up a situation where he’d have two such interferometers positioned so that one arm of each would overlap. He then imagined firing a positron (an electron’s antiparticle) in one, and an electron in the other. At one point of their multiple journeys, they should meet in the central overlapping region and annihilate each other. However, according to Hardy, as these particles exist in multiple states, if unobserved, the two particles could meet, so to speak, but fail to wipe each other out.
But as no one is able to observe this state of affairs, it remains unconfirmed, which is why it is usually referred to as ‘Hardy’s paradox’. (Physicists are fond of weird unobservable ‘unequalities’ and ‘paradoxes’.)
A sideways peek
Several years ago, Yakir Aharonov, a prestigious physicist at the Quantum Group at Tel Aviv University, discovered a means to observe this kind of quantum standoff through a thought experiment that would imagine detectors that would measure so weakly (that is, take such a weak sideways glance) at the particles that they would not collapse its superposition state.
The particles would be remain in several places at once – both in the place where they’d meet and annihilate each other and then in other arms at the same time. Because the measurements were so weak, the scientists would not gather enough information about them to be able to pinpoint the electrons to a set state, but by carrying out the experiment multiple times, they could pool the results and produce results that are more or less accurate.
In this week’s issue of the New Journal of Physics, Kazuhiro Yokota of Osaka University in Japan carried out such an experiment with a pair of entangled photons, or particles of light, as did researchers at the University of Toronto (published two months ago in Physical Review Letters).
What both groups discovered about the state of reality is even stranger than the most farsighted quantum physicist could imagine.
No there there
In this case, as Aharonov predicted, certain of the photons recorded were less than zero (or -1). Although that would usually indicate the presence of antiparticles, there are no such things with photons. The photons themselves must have some sort of negative presence.
Yokota and his colleagues called the results “preposterous’. ‘This gives us new insights into the spooky action of quantum mechanics,’ wrote Yokota cautiously.
But in Aharonov’s view, this may mean that the quantum world is a whole lot stranger than we thought, and that parts of particles can exist as a shadow – they can be there, but not be there.
Or, it could be that without us, and our consciousness, life is less than zero.
What lends any electron a final identity is our presence as a co-creator.
The simple fact is that nothing, finally, exists independently. What our subatomic world teaches us is that matter cannot be understood in isolation but only in relationship, a complex web of relationships, forever indivisible.