In Praise of Evolution and Opacity

1.The perspective I bring to questions of creativity in man and machine reflects my background in evolutionary robotics, which I consider an exercise in philosophy of mind, trying to understand the relationship between Behaviour and Mechanism. I have a suitcase full of philosophical premises and assumptions; some of these are common, some will be identifiable as associated with a Dynamical Systems approach to cognitive science, also influenced by Varela; and some will seem plain perverse

A Porosity-Length Formalism for Photon-Tiring-Limited Mass Loss from Stars Above the Eddington Limit

We examine radiatively driven mass loss from stars near and above the Eddington limit (Ledd). We begin by reviewing the instabilities that are expected to form extensive structure near Ledd. We investigate how this "porosity" can reduce the effective coupling between the matter and radiation. Introducing a new "porosity-length'' formalism, we derive a simple scaling for the reduced effective opacity, and use this to derive an associated scaling for the porosity-moderated, continuum-driven mass loss rate from stars that formally exceed Ledd. For a simple super-Eddington model with a single porosity length that is assumed to be on the order of the gravitational scale height, the overall mass loss is similar to that derived in previous porosity work. This is much higher than is typical of line-driven winds, but is still only a few percent of the photon tiring limit--for which the luminosity becomes insufficient to carry the flow out of the gravitational potential. To obtain still stronger mass loss that approaches observationally inferred values near this limit, we introduce a power-law-porosity model in which the associated structure has a broad range of scales. We show that the mass loss rate can be enhanced by a factor that increases with the Eddington parameter Gamma, such that for moderately large Gamma (> 3-4), mass loss rates could approach the photon tiring limit. Together with the ability to drive quite fast outflow speeds, the derived mass loss could explain the large inferred mass loss and flow speeds of giant outbursts in eta Carinae and other LBV stars.Comment: 17 pages, 6 figures, to appear in Ap

Language and Story: An Argument for the Right Reading of Tolkien’s Legendarium

Current views on the translation of Tolkien are that his works are completely translatable and understandable. The Lord of the Rings has been translated into many languages, and has sold millions the world over. While an argument cannot be made for the non-translation of Tolkien’s works, his tales should be experienced in English whenever possible. J.R.R. Tolkien was by profession a philologist, and by hobby a creator of languages and story. His life work was the creation of a unifying legendarium, spanning thousands of years and dozens of languages. These languages and Tolkien’s use of English form the backbone for the intentions and outcomes in the story. Without a proper understanding of the linguistic and cultural journey that takes place, Tolkien’s motives and the narrative thrust of the story are in many ways diminshed. Three options are available for a translator, with necessary but qualified translation being the preferred route for translation of Tolkien’s works

Validating the Universe in a Box

Computer simulations of the formation and evolution of large scale structure in the universe are integral to the enterprise of modern cosmology. Establishing the reliability of these simulations has been extremely challenging, primarily because of epistemic opacity. In this setting, robustness analysis defined by requiring converging outputs from a diverse ensemble of simulations is insufficient to determine simulation validity. Instead, we propose an alternative path of structured code validation that applies eliminative reasoning to isolate and reduce possible sources of error, a potential path that is already being explored by some cosmologists.Comment: 13 pages. Accepted for publication in Philosophy of Science for the PSA2018 symposium proceedings issu

Two Narratives of Platform Capitalism

Mainstream economists tend to pride themselves on the discipline\u27s resem­blance to science. But growing concerns about the reproducibility of economic research are undermining that source of legitimacy. These concerns have fueled renewed interest in another aspect of economic thought: its narrative nature. When presenting or framing their work, neoliberal economists tend to tell sto­ries about supply and demand, unintended consequences, and transaction costs in order to justify certain policy positions. These stories often make sense, and warn policymakers against simplistic solutionism

Status report on the NCRIS eResearch capability summary

Preface The period 2006 to 2014 has seen an approach to the national support of eResearch infrastructure by the Australian Government which is unprecedented. Not only has investment been at a significantly greater scale than previously, but the intent and approach has been highly innovative, shaped by a strategic approach to research support in which the critical element, the catchword, has been collaboration. The innovative directions shaped by this strategy, under the banner of the Australian Government’s National Collaborative Research Infrastructure Strategy (NCRIS), have led to significant and creative initiatives and activity, seminal to new research and fields of discovery. Origin This document is a Technical Report on the Status of the NCRIS eResearch Capability. It was commissioned by the Australian Government Department of Education and Training in the second half of 2014 to examine a range of questions and issues concerning the development of this infrastructure over the period 2006-2014. The infrastructure has been built and implemented over this period following investments made by the Australian Government amounting to over $430 million, under a number of funding initiatives