Designing a damper with optimal damping in a specific mode may leave the cable susceptible to vibration in other modes, and it is almost impossible to specify a priori the dominant mode in which optimal performance should be achieved.
This is sometimes known as the "inner potential" or "Galvani potential".[ 39] As argued by both Gibbs[ 9] and Guggenheim,[ 1] the electrostatic potential within the interior of a condensed phase has no operational meaning in the sense that it seems impossible to specify a thermodynamically acceptable experiment that can unambiguously measure its value.
Although this problem has been generalized by philosophers such as Dennett (1984) to a general problem of relevance and salience of properties pertaining to action, the heart of the problem is that in a 'common-sense' setting as one encounters in AI, it is virtually impossible to specify all the effects by the actions of concern, as well as, notably, all non-effects.
Thus, it may be impossible to specify formative variables in a life-course model without reducing the overall structural model to a meaningless accumulation of linear functions.
Electric companies planning utility poles for a ridge top where the wind blows strongest from a single direction, for example, can order poles that are less prone to bend in one direction than another, a characteristic impossible to specify in the usual material for such poles, tree trunks.
Less well known but the subject of considerable reappraisal by philosophers over recent years is the "sorites paradox": beginning with a pile of stones and removing these one stone at a time, one moves from a pile to a non-pile, but it is impossible to specify the individual stone; the removal of which effects the transition.
This was an interesting programme, free of histrionics, but peppered, once more, with sobering statistics: 56% of cycling accidents are caused by a driver, 6% by the cyclist (the remainder are either down to a combination of factors or impossible to specify).
But here again we should consider the argument that the evolution of meiosis involved the implementation of diverse innovations and a special combination of events that currently are impossible to specify.
The fields have widely varying shapes and sizes, and the primary battleground between offense and defense — i.e., the strike zone — is a box of air with dimensions that have proven impossible to specify.
Indeed, it is impossible to specify what the market is in isolation from the rules that define the possibilities and terms of exchange.
As late as 1989, writing in the International Dictionary of Psychology, the British psychologist Stuart Sutherland could irascibly declare of consciousness that "it is impossible to specify what it is, what it does, or why it evolved.
