Background Independence, Diffeomorphism Invariance, and the Meaning of Coordinates

Diffeomorphism invariance is sometimes taken to be a criterion of background independence. This claim is commonly accompanied by a second, that the genuine physical magnitudes (the "observables") of background-independent theories and those of background-dependent (non-diffeomorphism-invariant) theories are essentially different in nature. I argue against both claims. Background-dependent theories can be formulated in a diffeomorphism-invariant manner. This suggests that the nature of the physical magnitudes of relevantly analogous theories (one background free, the other background dependent) is essentially the same. The temptation to think otherwise stems from a misunderstanding of the meaning of spacetime coordinates in background-dependent theories.Comment: 42 page

Hawaii's Marine Fisheries: Some History, Long-term Trends, and Recent Developments

This paper provides an overview of Hawaii's marine fisheries from 1948 to the present. After three decades of decline following a brief period of growth at the conclusion to World War lI, Hawaii's commercial fisheries began a decade of sustained development in the 1980's. At the same time, fisheries management issues became more significant as different segments of the fishery came into more direct competition. This paper provides new estimates of commercial landings for the 1977-90 period, and summarizes limited information on recreational and subsistence fisheries in the 1980's. It also provides some historical context which may be useful in evaluating fishery development and management options

Economics and Hawaii's Marine Fisheries

This paper reviews economic research conducted on Hawaii's marine fisheries over the past ten years. The fisheries development and fisheries management context for this research is also considered. The paper finds that new approaches are required for marine fisheries research in Hawaii: A wider scope to include other marine resource and coastal zone issues, and increased and closer collaboration between researchers and the fishing community

Multi-National Patent Litigation: Management of Discovery and Settlement Issues and the Role of the Judiciary

National patent laws protect intellectual property rights. However, these rights can only be enforced in the country that granted the patent. Therefore, a patent owner must pursue infringement or revocation proceedings in each country where his patent rights are challenged even if the defendant is the same party. Patent owners are forced to pursue duplicative litigation on a nation-by-nation basis,incurring significant costs and draining valuable judicial resources. Duplicative litigation may result in conflicting outcomes, the impact of which can be complex and costly.... This article will focus on Germany, Japan, the United Kingdom, and the United States. First, we will provide a broad overview of the procedural landscape of these jurisdictions, paying particular attention to discovery and settlement. Then, we will examine the formal and informal mechanisms involved in cross-border discovery and settlement. Finally, we will propose some mechanisms that judges can use to facilitate an efficient discovery process and the settlement of international patent disputes

The origin of the spacetime metric: Bell's `Lorentzian pedagogy' and its significance in general relativity

The purpose of this paper is to evaluate the `Lorentzian pedagogy' defended by J.S. Bell in his essay ``How to teach special relativity'', and to explore its consistency with Einstein's thinking from 1905 to 1952. Some remarks are also made in this context on Weyl's philosophy of relativity and his 1918 gauge theory. Finally, it is argued that the Lorentzian pedagogy - which stresses the important connection between kinematics and dynamics - clarifies the role of rods and clocks in general relativity.Comment: To be published in ``Physics Meets Philosophy at the Planck Length'', C. Callender and N. Huggett (eds.), Cambridge University Press (1999). 22 pages, no figures, LaTeX, uses harvard.sty; 3 references added, typos corrected and minor changes to conten

Eliminating spurious velocities in the free energy lattice Boltzmann method

Spurious velocities are unphysical currents that appear close to curved interfaces in diffuse interface methods. We analyse the causes of these spurious velocities in the free energy lattice Boltzmann algorithm. By making a suitable choice of the equilibrium distribution, and by finding the best way to numerically calculate derivatives, we show that these velocities may be decreased by an order of magnitude compared to previous models. Furthermore, we propose a momentum conserving forcing method that reduces spurious velocities by another factor of ~5. In three dimensions we find that 19 velocity vectors is the minimum number necessary.Comment: 8 pages, 3 figure

Binary formation within globular clusters : X-ray clues

We have investigated the effect of the number of primordial binaries on the relationship between the total number of detected binaries within globular cluster and its collision rate. We have used simulated populations of binary stars in globular clusters : primordial binaries and binaries formed through gravitational interactions. We show that the initial number of primordial binaries influences the relationship between the number of detected sources and the collision rate, which we find to be a power law. We also show that observing an incomplete sample provides the same results as those obtained with a complete sample. We use observations made by XMM-Newton and Chandra to constrain the formation mechanism of sources with X-ray luminosities larger than 10^{31} erg/s, and show that some of the cataclysmic variables within globular clusters should be primordial objects. We point out a possibly hidden population of neutron stars within high mass globular clusters with a low collision rate.Comment: 6 pages, no figure, accepted for publication in Astronomy & Astrophysic

"Mrs Harvey came home from Norwich ... her pocket picked at the station and all her money stolen”:using life writing to recover the experience of travel in the past

In most societies the ability to move easily from place to place is a taken-for-granted aspect of twenty-first century life, but much less is known about such mobility in the past with a tendency for accounts to focus on the exceptional rather than the routine. In this paper we use two personal diaries written in England in the mid-nineteenth century and early-twentieth centuries to explore the ways in which everyday mobility was accomplished in the past. Attention is focused on the ease with which people could move around, the variety of modes of transport used, the enjoyment that travel generated, and the difficulties that were encountered. It is concluded that frequent everyday mobility was commonplace and mostly unproblematic, and was as closely enmeshed with society and economy as is the case in the twenty-first century. Such mobility also facilitated residential migration by providing knowledge about potential locations