Lecture 1 – Principles, standards and methods
From the 1981 lecture programme:
The immediate objective of measurement is to convert our observations of some aspect of the natural world into numbers. Given a reference standard, when we have measured something we then have information by which we can duplicate it in another place or at another time. This makes possible mass production, with different components being made in different factories, so that components will fit together when assembled in a third factory; without this capability, modern industrial society could not have evolved. The other main application of measurement, certainly no less important, is in making it much easier for scientists to reason about their observations: for once an observation has been expressed as a number, the full power of mathematics and computation, which in this respect can be regarded as a form of shorthand reasoning, can be brought to bear on it.
We have therefore as a first step to consider number systems, and to remark the great advance made in the decimal system, with its incorporation of the sign for zero. Further, the binary system now has a special significance, since numbers when expressed in the scale-of-two are easily handled by electronic circuits and therefore by computers.
Conversion of observations into numbers is, however, possible only if we agree on some standard by which some property such as length or time is to be measured. We have therefore to consider the qualities required in a standard, and to look at the evolution of standards in the course of history. These are, for example, mentioned in Magna Carta; and a major new system of standards sponsored by the French revolutionaries became the metric system.
Exact measurement can only be achieved at a price; to advance in exactness, we need to pay by taking extra time or trouble or by exerting greater powers of ingenuity and invention. But nature is a fair-minded opponent, who will yield further secrets to intelligently directed effort.
Examples of the value of simple methods of measurement will feature in the lecture.
About the 1981 CHRISTMAS LECTURES
From the 1981 lecture programme:
The Christmas Lectures at the Royal Institution started in 1826, and there have now been more than one hundred and fifty in the series; and yet none has previously been on the theme of this year's lectures, which is measurement. Perhaps this is because the measurement is so much part of human life that we tend to take it for granted; but if we are to understand how our modern world, with all its achievements and its dangers, has evolved, then we need to know what measurement is, the principles by which measurements can be made, and why their applications have been of so much importance in the advance of science and in the development of technology. And we also need not be carried away by the spectacular successes of measurements, such as awakening mankind to the huge store of energy in the atomic nucleus, or the microchip, or the control of space probes as far away as Saturn; for despite Plato's proud claim that 'man is the measure of all things' there are many qualities in life that are very difficult, if not impossible, to measure such as love or courage, and we should therefore be cautious about extending measurement beyond its proper domain. But within that domain, measurement is one of the most challenging, fascinating and rewarding of human activities: this is what the lectures are intended to show.