On the VPRO children’s programme, ‘Achterwerk in de kast’, in the 1980s, I remember seeing a boy pull back the curtain of the box and explain that life was getting more and more complicated. Previously, the wind used to simply blow through his hair, but he now knew that it was gases that moved from high to low-pressure areas. The world gets increasingly complicated the more closely you examine it.
And that’s just the world that we experience through our senses. When it comes to extremely small scales or extremely low temperatures, there are totally different laws and spooky characteristics that we have to deal with. An example is the atomic and sub-atomic quantum world exposed by such prominent scientists as Niels Bohr, Erwin Schrödinger, and Albert Einstein, at the start of the last century. Even for big thinkers, that world is difficult to grasp, but it leads to innovations that could turn everything upside down.
Uncertain and entangled
In this ‘bizarre’ world, quantum particles can rotate to the left and to the right simultaneously, for example. For people who like certainty, this does not sit well. An even stranger and fundamental phenomenon in the quantum world is the so-called entanglement of particles. If, in a crystal, you split one light particle into two light particles, then they remain entangled, as far as their characteristics are concerned. This is the case even if they are located at such a great distance apart from each other that even at the speed of light they are no longer able to ‘talk’ to each other. Both particles rotate to the left and to the right simultaneously, until you take a ‘photo’ of each. That reveals that the particles always rotate in opposite directions. Einstein and his colleagues thought of this as early as 1935, but that was only to show that quantum theory was not complete. Nonetheless, TU Delft demonstrated it definitively last year, in an experiment.
“A fresh quantum wind is blowing through our hair!”
Calculating with particles that are 0 and 1 at the same time produces multiple answers at the same time, with which you can build extremely fast quantum computers. We are going to experience this quantum revolution. Impressive results have been achieved in e.g. the Qutech partnership agreement between TU Delft and TNO, with imposing laboratory filling experimental setups to control particles smaller than an atom. This is so promising that the European Commission has proposed making one billion euros available for a Quantum Flagship programme, yet to be set up, for quantum technology. In around ten to fifteen years, we expect to be able to make calculations so quickly that formulas for new superconductive materials can be worked out (a possible revolution in energy storage), new medicines will be conceived, and robots will finally be able to make complex motor movements (cutting our hair, for example). Moreover, quantum bits can be entangled with each other over large distances, as a result of which traditional communications can be quicker and more secure.
Using quantum characteristics also means that gravity sensors come within reach, allowing you to take a 3D photo of the subsoil, and use quantum cameras for light-sensitive applications in the medical sector (one beam of light knows what the other has seen).