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As governmental processes and judgments become increasingly digital, the transparency of digital systems that implement the processes of government becomes increasingly important. Open code is a necessary but not sufficient prerequisite for maintaining transparency as democracy becomes digitized, and complete openness of process is not appropriate for every domain. This chapter explores some of the complexities in the relationship between openness of code and democratic government. Computer code controls and enables the actions of users, and for users to have true autonomy they must be able to examine, alter, and redistribute the code. A key issue for transparency is the degree to which this observation applies to the activities of government that are embedded in computer code. Free software creates a fundamentally different market structure than closed code. The philosophy of free software argues that the inability to view code that implements governance suggests totalitarian and Kafkaesque control, a constraining complex network of rules and regulations.

This chapter focuses on time integration schemes, including fourth-order accurate Runge–Kutta and predictor-corrector schemes as well as schemes that allow larger time steps (and therefore fewer steps for a given amount of simulated time) by treating the linear diffusion terms implicitly. The nonlinear terms, however, couple all the modes and so would be extremely expensive to treat implicitly; therefore they are usually treated explicitly. Such “semi-implicit” schemes considerably improve the efficiency of the computer code. The chapter also describes the Crank–Nicolson scheme and concludes by showing how the current numerical model can easily be modified to study mantle convection (also called “geodynamics”) using the vorticity equation in the limit of an infinite Prandtl number.

This chapter focuses on internal gravity waves in a stable thermal stratification. When the amplitude of the fluid velocity is small relative to the amplitude of the phase velocity, a linear analysis, which neglects advection, provides insight to the relation between the wavelength and frequency of internal gravity waves. Furthermore, when thermal and viscous diffusion play relatively minor roles the system can be further simplified by neglecting diffusion. The chapter first describes the linear dispersion relation before discussing the computer code modifications and simulations. In particular, it explains what modifications would be needed to convert one's thermal convection code to a code that simulates internal gravity waves, including the nonlinear and diffusive terms. Finally, it considers the computer analysis of wave energy.

This chapter examines how “social engineering” can be used in computer hacking to gain access to highly secret computer codes and other confidential information, and how to defend yourself against such influence-based attacks. Drawing on Robert Cialdini's principles of influence, the chapter explores the concept of resistance to unwanted persuasion by describing Motorola's experience with a social engineering attack from the perspective of the perpetrator. It also considers the points of vulnerability exploited by the attack and the methods by which individuals and organizations can protect themselves against such attacks and thus avoid the path of least resistance.

This chapter discusses programming as a new way of writing directed toward apparatuses instead of human beings and one that is meant to issue instructions. Children all learn the alphabet, and print has resulted in a comprehensive, democratizing literacy. However, new computer codes makes everybody illiterate again. For most of us, computer programs are suffused with the kind of mystery that surrounded alphabetic writing prior to the invention of print. If a program is to be understood as writing directed not toward human beings but toward apparatuses, then people have been programming since writing was invented—before there were any apparatuses. Because programs instruct apparatuses, the burden of instruction shifts from human beings to inanimate objects, and human beings become free to behave as they like. From this standpoint, the tendency inherent in instructions and culminating in programs is aimed at freedom. Whether programming will render all writing obsolete remains an open question.

In this chapter, the most important quantum-mechanical methods that can be applied to geological materials are described briefly. The approach used follows that of modern quantum-chemistry textbooks rather than being a historical account of the development of quantum theory and the derivation of the Schrödinger equation from the classical wave equation. The latter approach may serve as a better introduction to the field for those readers with a more limited theoretical background and has recently been well presented in a chapter by McMillan and Hess (1988), which such readers are advised to study initially. Computational aspects of quantum chemistry are also well treated by Hinchliffe (1988). In the section that follows this introduction, the fundamentals of the quantum mechanics of molecules are presented first; that is, the ‘localized’ side of Fig. 1.1 is examined, basing the discussion on that of Levine (1983), a standard quantum-chemistry text. Details of the calculation of molecular wave functions using the standard Hartree-Fock methods are then discussed, drawing upon Schaefer (1972), Szabo and Ostlund (1989), and Hehre et al. (1986), particularly in the discussion of the agreement between calculated versus experimental properties as a function of the size of the expansion basis set. Improvements on the Hartree-Fock wave function using configuration-interaction (CI) or many-body perturbation theory (MBPT), evaluation of properties from Hartree-Fock wave functions, and approximate Hartree-Fock methods are then discussed. The focus then shifts to the ‘delocalized’ side of Fig. 1.1, first discussing Hartree-Fock band-structure studies, that is, calculations in which the full translational symmetry of a solid is exploited rather than the point-group symmetry of a molecule. A good general reference for such studies is Ashcroft and Mermin (1976). Density-functional theory is then discussed, based on a review by von Barth (1986), and including both the multiple-scattering self-consistent-field … method (MS-SCF-…) and more accurate basis-function-density-functional approaches. We then describe the success of these methods in calculations on molecules and molecular clusters. Advances in density-functional band theory are then considered, with a presentation based on Srivastava and Weaire (1987). A discussion of the purely theoretical modified electron-gas ionic models is followed by discussion of empirical simulation, and we conclude by mentioning a recent approach incorporating density-functional theory and molecular dynamics (Car and Parrinello, 1985).