Automata network models of galaxy evolution

Two ideas appear frequently in theories of star formation and galaxy evolution: (1) star formation is nonlocally excitatory, stimulating star formation in neighboring regions by propagation of a dense fragmenting shell or the compression of preexisting clouds; and (2) star formation is nonlocally inhibitory, making H2 regions and explosions which can create low-density and/or high temperature regions and increase the macroscopic velocity dispersion of the cloudy gas. Since it is not possible, given the present state of hydrodynamic modeling, to estimate whether one of these effects greatly dominates the other, it is of interest to investigate the predicted spatial pattern of star formation and its temporal behavior in simple models which incorporate both effects in a controlled manner. The present work presents preliminary results of such a study which is based on lattice galaxy models with various types of nonlocal inhibitory and excitatory couplings of the local SFR to the gas density, temperature, and velocity field meant to model a number of theoretical suggestions

An analysis of the principal media of exchange used in Colonial Virginia

The purpose of this paper is to analyze the principal media of exchange used in Virginia during the Colonial period, showing why these media were used and how adequately or inadequately they performed the function of money. This analysis will be limited primarily to the role played by tobacco money, coin, and paper money in the local economy of Virginia. The role of credit as a medium of exchange will be touched on only briefly, although its importance is recognized

President of the United States, Destroyer of Worlds: Considering Congress\u27s Authority to Enact a Nuclear No-First-Use Law

This article argues that Congress can exercise its constitutional war powers to enact a law restricting the President from using nuclear weapons first. The article contends that using a nuclear weapon is qualitatively different from conventional warfare and that the first use of nuclear weapons marks a decision to enter into war. Therefore, nuclear first use is not a battlefield decision within the President’s commander in chief power but rather a choice to enter the United States into a new type of conflict that could pose a direct, immediate, and existential threat to the U.S. homeland. Regulating that decision falls under Congress’s exclusive war powers. Congress can limit its authorizations of war and prohibit military actions beyond its authorization. Therefore, Congress could stipulate that its war authorizations extend only to conventional hostilities unless Congress expressly authorizes the first use of nuclear weapons. Using its authority to limit authorizations of for the use of military force, Congress can enact a no-first-use law

The Rise and Fall of Section 502B

The first major foreign policy legislation of the human rights revolution of the 1970s,1 Section 502B of the Foreign Assistance Act (FAA) is a latent oversight tool that Congress could use to promote human rights in U.S. security assistance. Section 502B may be the most potent provision of law regarding human rights and security assistance that has never been used. The provision prohibits U.S. security assistance to governments that engage in a consistent pattern of gross violations of human rights, requires the State Department to report on human rights issues, and provides Congress with a mechanism to enforce the statute’s prohibition. This paper traces Section 502B’s history and contends that Congress should incorporate Section 502B into its efforts to promote human rights in U.S. security assistance. Section I discusses how Section 502B functions. Section II then traces the introduction and strengthening of the statute in the context of a rise in congressional oversight and attention to human rights in the 1970s. Section III tracks the decline of Section 502B, pointing to executive resistance to implement the provision’s mandates, judicial tolerance of 502B violations, and legislative reluctance to enforce the statute. Section IV notes a quiet reemergence of interest in Section 502B since 2018. Finally, Section V offers recommendations for how and in which contexts Congress could invoke Section 502B to exercise oversight for U.S. security assistance

The vector algebra war: a historical perspective

There are a wide variety of different vector formalisms currently utilized in engineering and physics. For example, Gibbs' three-vectors, Minkowski four-vectors, complex spinors in quantum mechanics, quaternions used to describe rigid body rotations and vectors defined in Clifford geometric algebra. With such a range of vector formalisms in use, it thus appears that there is as yet no general agreement on a vector formalism suitable for science as a whole. This is surprising, in that, one of the primary goals of nineteenth century science was to suitably describe vectors in three-dimensional space. This situation has also had the unfortunate consequence of fragmenting knowledge across many disciplines, and requiring a significant amount of time and effort in learning the various formalisms. We thus historically review the development of our various vector systems and conclude that Clifford's multivectors best fulfills the goal of describing vectorial quantities in three dimensions and providing a unified vector system for science.Comment: 8 pages, 1 figure, 1 tabl

Aristotle and Augustine on voluntary action and freedom and weakness of the will

Aristotle's remarks on free will suggest, not so much an argument for the existence of free will, as an account of its nature. This account depends on his making no hard distinction between what we call 'free action' and 'voluntary action'. For him, these would be interchangeable terms. The Aristotelian can, then, point out that, if we give up our belief in free will, we must give up many other natural beliefs too. In particular, we must stop believing in voluntary action.There are, in Aristotelian terms, three conditions (not two, as Aristotle himself evidently supposed), which any behaviour must satisfy to count as free/ voluntary action. The behaviour (i) must not be compelled, but must be performed by the agent's own power and desire; (ii) must not be done in ignorance, but must be action on relevant knowledge; and (iii) must not be irrational, but must result from the combination of the agent's own power and desire with the agent's relevant knowledge. (i) leads me to discuss Aristotle's account of what he calls kineseis; (ii) leads me into epistemology; (iii) into an account of Aristotle's theory of proairesis and practical reasoning as the cause of voluntary action.by akrasia, deliberate choice of what I sincerely believe I should not choose. This seems to be voluntary action which is not caused as Aristotle says voluntary action should be. But the three conditions of voluntary action which I say Aristotle should be committed to can be used to show that the existing forms of akrasia make no counter example to Aristotle's theory, but rather an interesting adjunct to it.My study of Augustine's theory of freedom begins with a survey of a crucial text, the de Libero Arbitrio (Ch.5). I then apply an analogous schema to that found in Aristotle. Augustine too depends on the idea that to analyse free action is to analyse voluntary action; he also equates these two types with responsible action. He too believes (i) that ignorance usually makes for involuntariness, and (ii) that there can be no voluntary action which is compelled or which the agent could not have done otherwise. In his later works, these doctrines are often obscured by his interest in original sin and predestination (neither of which topics, be it noted, are focuses of this thesis). But they remain his doctrines. Does Augustine have (iii) any doctrine that voluntary action must be rational? While he does not develop any theory of practical reasoning like Aristotle's, he does develop a theory of practical wisdom. It is an essential feature of all human desire, and hence of all voluntary action, that it aims at happiness, which properly understood is identical with possession of The Good, i.e. of God. From this Augustine draws the conclusion that, to explain any behaviour as a voluntary action or choice, it is necessary and sufficient to specify some good at which it is to be understood as aiming.This sets up for Augustine a problem analogous to Aristotle's problem about akrasia. How is a voluntary choice of evil explicable? Augustine's reply is that human desires have been disordered by the Fall, and so we often choose, not evils per se, but lesser goods than we ought. But this prompts the question: How is a first voluntary choice of evil explicable? Augustine's reply is simply that it is not. Since a voluntary action or choice must be explained by reference to some good at which it aims, a voluntary choice of evil per se cannot be explained at all. This does not mean that there was no voluntary choice of evil; but it does mean that, in principle, that choice is inexplicable- a mystery. Thus Augustine, unlike Aristotle, in this one exceptional case (but in no others) affirms that there can be genuinely voluntary action which is not, in the relevant sense, rational