4, THE PRESIDENTIAL ADDRESS. 
inventions have produced the most astounding changes in our material 
civilisation, but neither in its methods nor in its world-outlook was there 
anything really revolutionary. 
But underneath this placid surface, the seeds of the future were 
germinating. With the coming of the twentieth century, fundamental 
changes began to set in. The new point of departure was reached when 
physical science ceased to confine its attention to the things that are 
observed. It dug down to a deeper level, and below the things that 
appear to the senses, it found, or invented, at the base of the world, so-called 
scientific entities, not capable of direct observation, but which are neces- 
sary to account for the facts of observation. Thus, below molecules and 
atoms still more ultimate entities appeared; radiations, electrons and 
protons emerged as elements which underlie and form our world of matter. 
Matter itself, the time-honoured mother of all, practically disappeared 
into electrical energy. 
“The cloud-capp’d towers, the gorgeous palaces, 
The solemn temples, the great globe itself : ’ 
yea, all the material forms of earth and sky and sea were dissolved and 
spirited away into the blue of energy. Outstanding among the men who 
brought about this transformation are two of my predecessors in this 
Chair: Sir J. J. Thomson and Lord Rutherford. Like Prospero, like 
Shakespeare himself, they must be reckoned among the magicians. 
Great as was this advance, it does not stand alone. Away in the last 
century, Clerk Maxwell, following up Faraday’s theories and experiments, 
had formulated his celebrated equations of the electro-magnetic field, which 
applied to light no less than to electro-magnetism, and the exploration of 
this fruitful subject led Minkowsli to the amazing discovery in 1908 that 
time and space were not separate things, but constituent elements in the 
deeper synthesis of space-time. Thus time is as much of the essence of 
things as space; it enters from the first into their existence as an integral 
element. Time is not something extra and superadded to things in their 
behaviour, but is integral and basic to their constitution. The stuff of 
the world is thus envisaged as events instead of material things. 
This physical concept or insight of space-time is our first revolutionary 
innovation, our first complete break with the old world of commonsense. 
Already it has proved an instrument of amazing power in the newer physics. 
In the hands of an Einstein it has led beyond Euclid and Newton, to the 
recasting of the law and the concept of gravitation, and to the new relativity 
