When we think of God’s creative activity, Christians are sometimes reluctant to think that randomness and disorder may form part of his toolkit. Motivated by an honourable desire to only associate him with the very best and most perfect means, we limit his creative activity to Victorian clockwork. But I disagree. In my laboratory in Cambridge we create tiny magnets. We aim to study the physics of magnets which are only a few atoms in size and to find new ways of incorporating them into technology. One of my current research projects seeks to place the magnets into human brain tumours to act as a new form of chemotherapy with fewer harmful side-effects.
Modern experimental techniques, known as nanoscience or nanotechnology, allow us to design new materials and structures with atomic precision, construct them atom-by-atom and then analyse the result with unprecedented resolution. In many ways, this endeavour, which finds applications in everything from microchips to healthcare, is the ultimate form of engineering.
One might therefore expect that high levels of order, predictability and control of tolerances are the keys for success in nanoscience, just as they are in human-scale engineering. One of the surprises that researchers find is that while order, predictability and control are important, equally important is the controlled use of randomness and disorder. Without randomness and disorder, the perfection which we seek on the nanoscale cannot be achieved. Far from being a failure of perfection, randomness and disorder are actually a powerful tool for adding robustness into a nanoscale design.
To obtain the properties we need in our magnets, they must be extremely flat – more than a couple of atoms of irregularity on the surface of the magnet will prevent it from functioning correctly. This level of flatness is far beyond what even the best mechanical engineer could achieve in the metal-shop and so we must look to other ways of controlling flatness. The technique we use involves the element tantalum. A remarkable property of tantalum is that if one makes a layer of it which is less than a few nanometres (billionths of a metre) thick, the regular order which most atomic lattices adopt vanishes and the atoms arrange themselves randomly. In doing so, all of the ‘sharp edges’ associated with a conventional atomic lattice disappear and the layer becomes the ideal template on which to build other materials where flatness must be guaranteed.
This is the atomic scale equivalent of the way motorways are built: first a layer of aggregate which is strong but rough, followed by a layer of tarmac to smooth off the rough edges of the aggregate. The analogy is even more accurate than one might have imagined; the reason tarmac is so smooth is that its molecules are arranged randomly.
The idea that we can harness irregularity and randomness in order to create something which is better suited to our needs is actually found throughout all of the natural and physical world. Perhaps the most striking example is temperature itself. Atoms and molecules perpetually vibrate, but not in the regular way that a guitar string does, but rather in a random and unpredictable way.
From a physics point of view, the way we define temperature is by the degree of unpredictability or randomness of the energy of something: cold things have a precisely defined energy, hot things have some uncertainty in their energy. A world in which the energy of every atom and molecule is precisely defined (at an instant in time) is one whose temperature is absolute zero (-273.15oC) – and hence is cold and lifeless. Chemistry, and hence life, only become possible when we introduce some uncertainty and randomness into the energy of the molecules. Uncertainty animates the atomic and molecular world.
In fact, engineers have known this for a long time and already make use of it. Nuclear power plants use one of the few truly random phenomena in nature – the radioactive decay of an atomic nucleus – to generate heat and from there electricity. A refrigerator works by changing the phase of a refrigerant from a more ordered molecular state into a less ordered molecular state; as the randomness of the refrigerant molecules increases, they absorb heat and cool our food. A new type of computer memory called Phase Change Memory stores digital data by switching atoms from a highly ordered and regular state (a binary ‘0’) to a highly random and irregular state (a binary ‘1’).
Why do our buildings have a steel frame and our electrical transformers use steel cores instead of iron frames and cores? Steel is iron with a few percent of impurities – randomly arranged carbon or silicon atoms distributed throughout the iron atomic lattice. Their random position adds mechanical strength by catching slipping atomic planes which would otherwise cause the material to break and adds electrical resistance by randomly deflecting waves which would otherwise cause the material to overheat.
Proverbs 16:33 tells us ‘The lot is cast into the lap, but its every decision is from the LORD.’ Part of God’s supremacy over creation is that even random and disordered processes are subject to him, and I believe that he delights to use them, and to see them being used by us, to bring richness, variety and (surprisingly) high-performance, to the creation.