SEMANTICS OF THE EINSTEIN THEORY 649
we saw 'simultaneously' the arrival of the train and the pointer of the clock reaching the mark 9.
Our judgement about the results of measurements of 'time' depends on the seen coincidence of events - in this case, of the arrival of the train with the arrival of the pointer of the clock at the mark 9. Similar considerations, which applied to the measurements of 'lengths', apply also to the measurements of 'time'.
We see with Einstein that if we want to make any headway we shall have to investigate the two key terms; namely, 'velocity' and 'simultaneity'.
The newtonians take a particular delight in accusing Einstein of being a 'psychologist' and not a physicist. We have already stressed the physical subjectivity of physical instruments. What is said there applies, not only to the retina of the eye, but also to a photographic camera, or to a microscope or telescope, or any other instrument. Before an energetic packet, be it a light-impulse or a bullet, is able to accomplish any result it must first reach its mark, and so the finite velocity of propagation must be taken into consideration, which is a hard, established, empirical structural fact. So the criticisms of the newtonians are simply shallow and unscientific (1933). They disregard most important empirical physical facts, and so simply defend a semantic disturbance without aiding science (1933).
With the einsteinians, we treat the eye on the same footing as we would treat the camera or any other physical instrument. Even the newtonians must admit that when they photograph some happening on the sun, for example, the happening actually occurred (approximately) eight minutes before the photographic plate was affected. The eight minutes is the 'time' taken by the light to reach the earth from the sun.
Let us analyse the term 'velocity' first. We find ourselves here, as in any other human problem, on two distinct levels of abstraction, and we must discriminate between them.
Let us take up the verbal level first. We see that before we can talk about our terms 'space' or 'time', 'length' or 'seconds', we have to know a great deal about the term 'velocity'. How do we define the term 'velocity'? We define it as 'space divided by time', v=s/t. We see that on the verbal level the situation is perfectly hopeless and no result can be expected from verbal gambling. It may be added that older notions were based on objectification, or confusion between the two levels of abstraction, and the affective belief in the magic of words, identification playing most of the structural havoc.
How about the instrumental level, the silent level of the lower order abstraction? On this level, we find that physicists in their actions, behaviour, operations. , have elaborated a fairly definite technique for finding the data they require. So we see that there is no choice, we must start on this level.
But starting on this level is not all, and not enough. We must somehow talk about these doings and operations. Hence we must select a language which in its structure will reflect the structure of these actions and operations. Therefore we must abandon the 'is' of identity and describe in the asymmetrical