We camp with Newton on a special ledge sliced out of the Matterhorn of reality and our experience of this rugged and unpredictable world around us can be interpreted by this fact. As we have seen, we are specially equipped by our senses to live on this unique level. But can we define the basis from which this uniqueness springs?

The answer lies, I suggest, in the fact that our scale of experience lies within that no man's land of physics where relativity and quantum physics intermingle. And the characteristic of this no man's land, where all men live, is that it is under the dictatorship of time. In other spheres time is often a partner, even a junior partner, but with us he is the boss. We cannot opt out from his edicts, our most homely phrases reflect his dictatorship. We talk of ‘half-time’ and ‘overtime’ and alarm clocks and calendars are unlikely to become extinct. None of us can, as yet, escape from that rugged ruler, the ancient with the scythe.

It is the time element that makes life so complicated, and in particular, often makes our research complicated too. We cannot avoid its domination ourselves, but can we filter it out from our experiments? Yes, we sometimes can and, when we can, we must, for the savings are notable.

There are two possible escape routes from time's imprisoning complexities; we must organize our variables so that they either have no relationship with time at all or else have an identical relationship with it.