Phase Transitions and superuniversality in the dynamics of a self-driven particle

We study an active random walker model in which a particle's motion is determined by a self-generated field. The field encodes information about the particle's path history. This leads to either self-attractive or self-repelling behavior. For self-repelling behavior, we find a phase transition in the dynamics: when the coupling between the field and the walker exceeds a critical value, the particle's behavior changes from renormalized diffusion to one characterized by a diverging diffusion coefficient. The dynamical behavior for all cases is surprisingly independent of dimension and of the noise amplitude.Comment: 14 pages, 4 figure

Managing soil biodiversity: The New Zealand experience

Species diversity is a very important component of a healthy soil ecosystem, and a necessary condition for long-term sustainable development. However, it is widely recognised that soil degradation and species extinction are on the increase in New Zealand, as land resources come under pressure from urban expansion and modern agribusiness. New Zealand's soils, flora and fauna have evolved many unique elements during their long isolation from other land masses. Habitat destruction and introduced plants and animals have, therefore, had increasingly detrimental effects on indigenous biodiversity. New Zealand must conserve what remains

What's the Big Idea? Intellectual History and the Longue Durée

Historians of all kinds are beginning to return to temporally expansive studies after decades of aversion and neglect. There are even signs that intellectual historians are returning to the longue durée. What are the reasons for this revival of long-range intellectual history? And how might it be rendered methodologically robust as well as historically compelling? This article proposes a model of transtemporal history, proceeding via serial contextualism to create a history in ideas spanning centuries, even millennia: key examples come from work in progress on ideas of civil war from ancient Rome to the present. The article concludes with brief reflections on the potential impact of the digital humanities on the practice of intellectual history.Histor

Historia Intelectual y Longue Durée. La Guerra Civil en Perspectiva Histórica

Resumen: Después de décadas de abandono, historiadores de todo tipo vuelven a ofrecer estudios de gran amplitud temporal. Hay signos de que los historiadores intelectuales están regresando incluso a la longue durée. ¿Cuáles son las razones de este revival de la historia de las ideas desde la larga duración? Este artículo propone un modelo de historia transtemporal, que procede por medio de un contextualismo seriado con el fin de crear una historia en ideas que puede abarcar siglos, incluso milenios: se ofrecen ejemplos clave procedentes de un trabajo en curso sobre las ideas acerca de la guerra civil desde la antigua Roma hasta el presente. El artículo concluye con unas breves reflexiones sobre el potencial impacto de las humanidades digitales en la práctica de la historia intelectual. Abstract: Historians of all kinds are beginning to return to temporally expansive studies after decades of aversion and neglect. There are even signs that intellectual historians are returning to the longue durée. What are the reasons for this revival of long-range intellectual history? And how might it be rendered methodologically robust as well as historically compelling? This article proposes a model of transtemporal history, proceeding via serial contextualism to create a history in ideas spanning centuries, even millennia: key examples come from work in progress on ideas of civil war from ancient Rome to the present. The article concludes with brief reflections on the potential impact of the digital humanities on the practice of intellectual history.Histor

La Primera Crisis Atlántica: La Revolución Americana

El primer ensayo de esta serie analiza aquella protesta provincial —tan frecuente— contra los impuestos de la metrópoli, que se convirtió en guerra civil y, más tarde, en la primera guerra de independencia. David Armitage sitúa este conflicto dentro del Imperio británico atlántico, registrando no sólo a las 13 colonias que se independizaron, sino también a los territorios y pobladores que permanecieron leales a la Corona. Desde esta perspectiva, la experiencia se vuelve comparable con los procesos del Atlántico hispánico, dejando de ser un evento aislado. De esta manera, es posible discutir sobre la influencia global de la gran innovación que fue crear Estados a partir de un Imperio.Histor

Globalizing Jeremy Bentham

Jeremy Bentham's career as a writer spanned almost seventy years, from the Seven Years' War to the early 1830s, a period contemporaries called an age of revolutions and more recent historians have seen as a world crisis. This article traces Bentham's developing universalism in the context of international conflict across his lifetime and in relation to his attempts to create a 'Universal Jurisprudence'. That ambition went unachieved and his successors turned his conception of international law in a more particularist direction. Going back behind Bentham's legacies to his own writings, both published and unpublished, reveals a thinker responsive to specific events but also committed to a universalist vision that helped to make him a precociously global figure in the history of political thought.Histor