Realism, lack

Representativeness can be examined from two aspects statistical and deterministic. Any statistical test of representativeness is lacking becau.se many histories are needed for statistical significance. In the absence of this, PSAs use statistical methods to synthesize data to represent the equipment, operation, and maintenance. How well this represents the plant being modeled is not known. Deterministic representativeness can be answered by full-scale tests on like equipment. Such is the responsibility of the NSSS vendor, but for economic reasons, recourse to simplillcd and scaled models is often necessary. System success criteria for a PSA may be taken from the FSAR which may have a conservative bias for licensing. Realism is more expensive than conservatism. 

The outstanding limitation of observations such as these which are based on field studies is the lack of control of animal exposure. Although laboratory experiments can be criticized for a lack of biological realism, they are more carefully controlled than observations based on animals collected under field conditions where accumulation is via inhalation as well as ingestion. By ratioing the concentrations in the body to soil concentrations, this analysis bypasses the question of whether inhalation or ingestion is the more important route of exposure. 

Pollutant realism Is achieved when the test system Includes sufficient diversity of components and the physical and chemical properties so that the pollutant behaves In the test system as it would In nature. Pollutant realism Is lacking because, In most test protocols, the pollutant does not Interact with any part of the environment, except the organism. A lack of pollutant realism In traditional tests may result In overestimates of risk. As an example, substantial Information Is now available about the toxicity of TCDD to numerous species when they are exposed via Injection, Incubation, diet, or dermal application. At Times Beach, Missouri, the TCDD is In the soli, and because It has apparently been there for some time, It is probably tightly bound to the soil. Little Is published about the toxicity of TCDD bound to soil, for any means of exposure. Intuitively, I suspect the TCDD Is less toxic when bound to soil than In the forms commonly used In toxicity testing. Thus, the risks of TCDD-lnduced toxicity to humans at Times Beach may be much smaller than would be suggested by the results of traditional testing which lacks this aspect of pollutant realism. 

At first sight, this poses a fatal dilemma for internal realism. On the first hom of the dilemma we face organizational metaphysical realism. It claims that there are numerous conceptual schemes and they do not simply copy the structure of reality. Such copying would not even be possible, since we do not have direct access to that inherent structure. Rather, the human mind actively projects structures into reality it introduces distinctions, sets up similarity relations, etc. However, there are external constraints on the construction of conceptual schemes, and these constraints are afforded by the inherent structure of reality. Some schemes cut at the joints more often than the others. Failures to cut at the joints are manifested in bad or inaccurate predictions, lack of explanatory power, repeated failures, etc. This view does provide the external constraints necessary for the objectivity of knowledge, and also makes room for the active organizing role of the intellect. But the price is... 

The simplest experiments are those in which one treatment (factor) is applied at a time to the samples. This approach is likely to give clear-cut answers, but it could be criticized for lacking realism. In particular, it cannot take account of interactions among two or more conditions that are likely to occur in real life. A multifactorial experiment (Fig. 10.4) is an attempt to do this the interactions among treatments can be analysed by specialized forms of analysis of variance. 

However, we should also emphasize at the outset of this chapter that the confined fluid is not suitable for the study of yet another feature of central importance to us, namely confinement-induced phase transitions. This is because one can rigorously prove that, in general, one-diniensional systems cannot undergo dLseontinuous phase changes [16]. However, this apparent lack of realism is outweighed by the analyticity of the current model system and its capability to reproduce other important features of more sophisticated models or even experimental systems sufficiently realistically as we pointed out above. Our analysis in this chapter is based upon the original work by Vanderlick et al. [25] and has in part been adopted from the book of Davis [26]. 

Examination of the two-photon state vector in Eq. (10) or (12) shows that it implies nonlocality and lack of realism. It implies nonlocality since a measurement causes a collapse of, say, )+, Eq. (12a), to either x)i x)2 or ll )il> )2, each possibility occurring with probability one half. Thus, detection of photon 1 to the left with polarization in the x direction ensures that photon 2 to the right behaves as a photon polarized in the x direction also. But, as we have already seen, the choice of x direction is quite arbitrary, so the polarization state measured for photon 2 is, in fact, determined by the measurement we choose to make on photon 1 at a position that may be spatially separated, in the relativistic sense, from the position at which the measurement on photon 2 is carried out. Lack of realism also follows from this argument, since it then is impossible to think of the individual photons possessing properties, in this case polarization, which exist independently of any measurements which may be made on them. 

This nonlocality and lack of realism inherent in quantum mechanics has inspired many attempts through the years to explain the results in terms of a theory that is both local and realistic. Without a specific local realistic theory it is, of course, not possible to predict a value for (a, b) to compare with the quantum mechanical value qm(<>> b) in Eq. (14). However, in 1964 J. S. Bell showed for the first time that such theories place constraints on (o, b), or rather combinations of (a, b), for different values of a and b. 

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