Facts and Seeing That

Abstract

I tried in the last chapter slightly to unfix your views about what we ordinarily call the facts. By tinkering with the ordinary language in which we so often make statements of fact, I hoped to suggest that the whole character of what we refer to as facts might alter significantly with each change in the fact-stating language. And, of course, the obvious moral of this applies with equal force to the technical and mathematical languages of systematic science; the logical character of the notation and syntax we use to express ourselves is not an inconsiderable factor in the formation of our conception of the physical world. This point has been sharply made in modern physics—especially in elementary particle theory, where, perhaps, all of the limitations placed on our conceptions of what the microphysical world is like are really limitations arising out of the linguistic features of the formal languages available. This is certainly the case with the infamous and much misunderstood uncertainty relations, for example: Though this feature of quantum theory is very often announced as constituting a limit to the possibility of observation within microphysics, the statement is true in a rather different sense than is often supposed. There have never been any experiments or any observations pertinent to the establishment of the uncertainty relations. Nor could there be such. These relations are a logical consequence of the language of quantum physics, a language the utility of which is now very well established by experiment. Or, to put it another way, the uncertainty relations would result from any attempt to synchronize the symbolic description of a wave process with the symbolic description of a particle’s state. All of the several quantum languages agree in this, though they put it in different ways. Some will treat it as a logical effect of the wave-packet conception of an elementary particle; others will talk of non-commutativity of operators. It all comes to the same thing. There is a logical-linguistic obstacle in the way of our describing with precision the total state of an elementary particle. So, of course, if this is a logical limit to description, it is ipso facto a limit on observation. Observation of the impossible is impossible.