Relations Between Units and Relations Between Quantities

The proposed revision to the International System of Units contains two features that are bound to be of special interest to those concerned with foundational questions in philosophy of science. These are that the proposed system of international units ("New SI") can be defined (i) without drawing a distinction between base units and derived units, and (ii) without restricting (or, even, specifying) the means by which the value of the quantities associated with the units are to be established. In this paper, I address the question of the role of base units in light of the New SI: Do the "base units" of the SI play any essential role anymore, if they are neither at the bottom of a hierarchy of definitions themselves, nor the only units that figure in the statements fixing the numerical values of the "defining constants" ? The answer I develop and present (a qualified yes and no) also shows why it is important to retain the distinction between dimensions and quantities. I argue for an appreciation of the role of dimensions in understanding issues related to systems of units

"Pictures, Models, and Measures" A contribution to Invited Symposium: "Wittgenstein's Picture Theory" at the 2015 Pacific APA Meeting

Putting Wittgenstein's writing into an historical context that includes scientific and technological developments as well as cultural and intellectual works can be helpful in understanding some of Wittgenstein's works. I focus on the Tractatus Logico-Philosophicus in particular in this paper, and on topics related to pictures and models: the development of audio recording technologies, the development of miniature scale models that were both aesthetically pleasing and scientifically useful, particularly in the forensics of traffic accidents, and the culmination of a centuries-long effort to articulate the method behind the use of physical modeling, i.e., the formulation of a concept presented in 1914 and dubbed "physically similar systems.

Relations Between Units and Relations Between Quantities

The proposed revision to the International System of Units contains two features that are bound to be of special interest to those concerned with foundational questions in philosophy of science. These are that the proposed system of international units ("New SI") can be defined (i) without drawing a distinction between base units and derived units, and (ii) without restricting (or, even, specifying) the means by which the value of the quantities associated with the units are to be established. In this paper, I address the question of the role of base units in light of the New SI: Do the "base units" of the SI play any essential role anymore, if they are neither at the bottom of a hierarchy of definitions themselves, nor the only units that figure in the statements fixing the numerical values of the "defining constants" ? The answer I develop and present (a qualified yes and no) also shows why it is important to retain the distinction between dimensions and quantities. I argue for an appreciation of the role of dimensions in understanding issues related to systems of units

Scale Modeling (Chapter 32, _Routledge Handbook of Philosophy of Engineering_)

This chapter describes the role of scale modeling in engineering and related sciences. Accounts of scale modeling in philosophy rarely provide a correct description of how the practice is actually employed in engineering. This chapter corrects misconceptions about scale modeling often found in the philosophical literature. It also provides an informal explanation of how and why scale modeling works, when it does, in terms of an analogy between geometric similarity of plane figures and similarity of physically similar systems, which is founded on physics rather than on geometry. The key idea is to identify the relevant ratios responsible for the kind of similarity that is of interest, and then to characterize similarity in terms of a set of ratios that are the same (i.e., identical, or invariant) between the model system and the system it models. References to more extended treatments are provided for further reading

Scale Modeling (Chapter 32, _Routledge Handbook of Philosophy of Engineering_)

This chapter describes the role of scale modeling in engineering and related sciences. Accounts of scale modeling in philosophy rarely provide a correct description of how the practice is actually employed in engineering. This chapter corrects misconceptions about scale modeling often found in the philosophical literature. It also provides an informal explanation of how and why scale modeling works, when it does, in terms of an analogy between geometric similarity of plane figures and similarity of physically similar systems, which is founded on physics rather than on geometry. The key idea is to identify the relevant ratios responsible for the kind of similarity that is of interest, and then to characterize similarity in terms of a set of ratios that are the same (i.e., identical, or invariant) between the model system and the system it models. References to more extended treatments are provided for further reading

Experimentation on Analogue Models

Summary Analogue models are actual physical setups used to model something else. They are especially useful when what we wish to investigate is difficult to observe or experiment upon due to size or distance in space or time: for example, if the thing we wish to investigate is too large, too far away, takes place on a time scale that is too long, does not yet exist or has ceased to exist. The range and variety of analogue models is too extensive to attempt a survey. In this article, I describe and discuss several different analogue model experiments, the results of those model experiments, and the basis for constructing them and interpreting their results. Examples of analogue models for surface waves in lakes, for earthquakes and volcanoes in geophysics, and for black holes in general relativity, are described, with a focus on examining the bases for claims that these analogues are appropriate analogues of what they are used to investigate. A table showing three different kinds of bases for reasoning using analogue models is provided. Finally, it is shown how the examples in this article counter three common misconceptions about the use of analogue models in physics

B814: Performance Evaluations of Potato Clones and Varieties in the Northeastern States - 1985

New potato clones and varieties must be tested against commercially accepted cultivars to determine If they possess advantages over existing varieties. Possible Improvements over the existing varieties could Include greater disease resistance or tolerance, higher yield, more uniform tuber size distribution, Improved storagability, good processing characteristics, etc. Often new cultivars are sought to fill local special-purpose needs. The cooperative potato variety trials reported In this bulletin were conducted to provide Information on the performance, adaptation, and performance stability of new potato clones under a wide range of geographic, climatic, soil, and cultural conditions. These tests are contributions to Regional Project NE-107 entitled, Breeding and Evaluation of New Potato Clones for the Northeast. The objectives of this regional project are: 1). To develop high quality, widely adapted, productive, pest resistant potato varieties for use In the northeast; 2). To determine regional performance, quality, and storage characteristics for promising potato clones and new varieties; 3). To evaluate promising clones and varieties for special-purpose needs such as pest outbreaks, processing, export, specialized market opportunities and/or production situations; 4). To develop management practices such as plant population, fertilizer rate, disease, weed, and Insect control strategies that will I Improve the yield and/or quality of promising clones. Data presented In this report primarily address objectives 2 and 3.https://digitalcommons.library.umaine.edu/aes_bulletin/1118/thumbnail.jp