Model , scientific method

It can be said that science is the art of budding models to explain observations and predict new ones. Chemistry, as the central science, utilizes models ia virtually every aspect of the discipline. From the first week of a first chemistry course, students use the scientific method to develop models which explain the behavior of the elements. Anyone who studies or uses chemistry has, ia fact, practiced some form of molecular modeling. 

Thus literate programming appears ideally suited to the task of publication in computational molecular physics and quantum chemistry, and indeed, in other computational sciences and in engineering. This task must entail placing both the theoretical model and the associated computer code in the public domain, where they can be subjected to the open criticism and constructive use which forms an integral part of the scientific method. 

L. Seijo and Z. Barandiaran. The ab initio model potential method A common strategy for effective core potential and embedded cluster calculations. In J. Leszczynski, (ed), Computational chemistry Reviews of Current Trends, 4, pp. 55-152, World Scientific, Singapore, 1999. 

Leszcynski, Ed., World Scientific, Singapore, Vol. 4,1999, pp. 55-152. The Ab Initio Model Potential Method A Common Strategy for Effective Core Potential and Embedded Cluster... 

In order to clearly explain the possibilities of describing nonequlibrium irreversible processes in terms of equilibrium it is certainly necessary to define quite accurately the notions of equilibrium and reversibility, nonequilibrium and irreversibility. It is clear that their interpretation, as well as the interpretation of other scientific notions, changes with the development of respective theories, models, and methods. Since the work touches upon the issues of interrelations between the competing models in a historical profile it is desirable that the appropriateness of various interpretations of the said notions be assessed in this profile. Making no pretence of the systematic presentation of the issue we will only touch upon some points that are important for understanding the text1 below. 

In the everyday world, people want their lives to be unambiguous with clear-cut answers. Science does not always follow the truth that most citizens set out to find. Scientists use the scientific method as a procedure for developing the knowledge to classify concepts as a law, theory, principle, or model. The scientific method is a framework for the stepwise process to experimentation. The steps are as follows ... 

Matter exists in three distinct physical states gas, liquid, and solid. Of these, the gaseous state is the easiest to describe both experimentally and theoretically. In particular, the study of gases provides an excellent example of the scientific method in action. It illustrates how observations lead to natural laws, which in turn can be accounted for by models. Then, as more accurate measurements become available, the models are modified. 

Before we construct the model, we will briefly review the scientific method. Recall that a law is a way of generalizing behavior that has been observed in many experiments. Laws are very useful, since they allow us to predict the behavior of similar systems. For example, if a chemist prepares a new gaseous compound, a measurement of the gas density at known pressure and temperature can provide a reliable value for the compound s molar mass. 

Important alterations to the global distribution of stratospheric ozone are currently predicted by the best available models which synthesize the chemistry, radiation and dynamics of the middle atmosphere. While these predictions have fluctuated significantly since the first crude estimates were offered in the mid-1970s [31, progress in many fields has brought a growing realization that the stratosphere may well be the first natural system to submit to the scientific method. 

To combine theory and experiment is the ideal scientific method. To model the microscopic world of molecules by computer simulations and directly be able to compare the results with corresponding experimental quantities is therefore a privilege. This chapter covers one such area Molecular Dynamics (MD) simulations, closely combined with Nuclear Magnetic Resonance (NMR) spectroscopy. ... 

One can see why the logic of scientific agriculture would make extension agents the implacable enemies of multiple plots and multiple cultivars. Together they place far too many variables in play for scientific method to model. 

When the above four basic observational facts are combined and considered together, there is no escape from the conclusion that our universe is expanding and cooling. This conclusion is entirely consistent with the Hot Big Bang model. Sometimes, we hear the stronger statement that these observations prove that there was a Hot Big Bang. However, the scientific method does not truly produce proofs in the mathematical sense. 

Much of soil science is empirical rather than theoretical in practice. This fact is a result of the extreme complexity and heterogeneity of soils, which are impossible to fully describe or quantify by simple chemical or physical models. It is not unusual for working solutions to be found for soil chemical problems with little, or even fallacious, understanding at a fundamental level. The simplicity of the empirical approach becomes the seed of its undoing, because the primary advantage of the scientific method, predictive capability, is curtailed or lost. On the other hand, the universality of chemical principles and laws (i.e., theories) permit processes to be described in such a way that soil chemical behavior can be understood and predicted in many situations not yet studied. 

The methodology of impact assessment for some environmental impacts is still under scientific development. This applies especially for the toxicity potential (HTP, AETP, TEPT). The impact models and methods for these and their use in decision making has partly been recalled recently also by developers of the methods... 

This is of course a specific instance of the iterative process we associate with the scientific method. The postulated mechanisms surviving this process can be considered consistent with the experimental data. Kinetics provides a powerful method for eliminating putative reaction mechanisms, but kinetic methods alone can never establish a mechanism unambiguously. Other chemical and physical methods can be of help in this regard, but it must be acknowledged that all our models, at some level, are tentative and subject to revision. In practice, one must accept a certain amount of ambiguity, but for many, if not most, applications this is not crucial. 

Science policy issues and controversies underlie almost every aspect of cancer risk assessment. These policy issues are primarily a function of the scientific uncertainties inherent in risk assessment. As new scientific methods and data begin to fill in some of the data gaps and uncertainties in risk assessment, the role of policy will gradually recede, although there is no prospect of policy issues being mooted entirely in the foreseeable future. Moreover, the extent to which we substitute novel scientific data and models for preexisting policy inferences is itself an ongoing policy debate, as is the appropriate role of precaution and conservatism in risk assessment. 

The last item shows that this method allows the automatic generation of hypotheses along the collection of examples and the evaluation of the Du-quenne/Guigues-basis. Moreover, we note that this is a mathematical model of a popular scientific method Collect examples and do pattern recognition ... 

The qualitative and quantitative theories/models of the electronic structure and chemical reactivity are thus inevitable and necessary ingredients of the scientific method of chemistry only the presence of both marks its harmonious development. The qualitative concepts determine the scientific vocabulary of interpretative chemistry, while the approximate model relations allow for a semi-quantitative prediction of trends implied by changing structural and experimental conditions. 

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