Technological Change and the Environment

Environmental policy discussions increasingly focus on issues related to technological change. This is partly because the environmental consequences of social activity are frequently affected by the rate and direction of technological change, and partly because environmental policy interventions can themselves create constraints and incentives that have significant effects on the path of technological progress. This paper, prepared as a chapter draft for the forthcoming Handbook of Environmental Economics (North-Holland/Elsevier Science), summarizes for environmental economists current thinking on technological change in the broader economics literature, surveys the growing economic literature on the interaction between technology and the environment, and explores the normative implications of these analyses. We begin with a brief overview of the economics of technological change, and then examine three important areas where technology and the environment intersect: the theory and empirical evidence of induced innovation and the related literature on the effects of environmental policy on the creation of new, environmentally friendly technology; the theory and empirics of environmental issues related to technology diffusion; and analyses of the comparative technological impacts of alternative environmental policy instruments. We conclude with suggestions for further research on technological change and the environment.

Casimir interactions of an object inside a spherical metal shell

We investigate the electromagnetic Casimir interactions of an object contained within an otherwise empty, perfectly conducting spherical shell. For a small object we present analytical calculations of the force, which is directed away from the center of the cavity, and the torque, which tends to align the object opposite to the preferred alignment outside the cavity. For a perfectly conducting sphere as the interior object, we compute the corrections to the proximity force approximation (PFA) numerically. In both cases the results for the interior configuration match smoothly onto those for the corresponding exterior configuration.Comment: 4 pages, 3 figure

Casimir potential of a compact object enclosed by a spherical cavity

We study the electromagnetic Casimir interaction of a compact object contained inside a closed cavity of another compact object. We express the interaction energy in terms of the objects' scattering matrices and translation matrices that relate the coordinate systems appropriate to each object. When the enclosing object is an otherwise empty metallic spherical shell, much larger than the internal object, and the two are sufficiently separated, the Casimir force can be expressed in terms of the static electric and magnetic multipole polarizabilities of the internal object, which is analogous to the Casimir-Polder result. Although it is not a simple power law, the dependence of the force on the separation of the object from the containing sphere is a universal function of its displacement from the center of the sphere, independent of other details of the object's electromagnetic response. Furthermore, we compute the exact Casimir force between two metallic spheres contained one inside the other at arbitrary separations. Finally, we combine our results with earlier work on the Casimir force between two spheres to obtain data on the leading order correction to the Proximity Force Approximation for two metallic spheres both outside and within one another.Comment: 12 pages, 6 figure

Testosterone metabolism in target tissues: Hypothalamic and pituitary tissues of the adult rat and human fetus, and the immature rat epiphysis

Rat pituitary, hypothalamic and cerebral cortical minces are demonstrated to effect the conversion of testosterone (T) to 5[alpha]-androstan-17[beta]-o1-3-one (DHT) and [Delta]4-androstene-3,17-dione ([Delta]4A). The pituitary effected the greatest conversion of T to both DHT and [Delta]4A. The hypothalamus converted more T to DHT than did the cerebral cortex; but the conversion of T to [Delta]4A in these two tissues occured to approximately the same extent. Analysis of the time course of the conversion of T to DHT in these tissues demonstrated the conversion to increase in a linear fashion over 180 min., while the maximum conversions in the hypothalamus and cerebral cortex were reached by 120 min.The conversion of T to DHT and [Delta]4A was also demonstrated in the human fetal hypothalamus and pituitary, and in the distal femoral epiphysis of the growing rat. In the femoral epiphysis, 5[alpha]-androstane-3[alpha],17[beta]-diol was also identified.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32875/1/0000253.pd

Ariel - Volume 6 Number 3

Editors Mark Dembert J.D. Kanofsky Frank Chervenak John Lammie Curt Cummings Staff Ken Jaffe Bob Sklaroff Halley Faust Jim Burke Nancy Redfern Hans Weltin Photographer Larry Glazerman Overseas Editor Mike Sinason Humorist Jim McCan

Spontaneous emission by rotating objects: A scattering approach

We study the quantum electrodynamics (QED) vacuum in the presence of a body rotating along its axis of symmetry and show that the object spontaneously emits energy if it is lossy. The radiated power is expressed as a general trace formula solely in terms of the scattering matrix, making an explicit connection to the conjecture of Zel'dovich [JETP Lett. 14, 180 (1971)] on rotating objects. We further show that a rotating body drags along nearby objects while making them spin parallel to its own rotation axis

Casimir Force at a Knife's Edge

The Casimir force has been computed exactly for only a few simple geometries, such as infinite plates, cylinders, and spheres. We show that a parabolic cylinder, for which analytic solutions to the Helmholtz equation are available, is another case where such a calculation is possible. We compute the interaction energy of a parabolic cylinder and an infinite plate (both perfect mirrors), as a function of their separation and inclination, $H$ and $\theta$, and the cylinder's parabolic radius $R$. As $H/R\to 0$, the proximity force approximation becomes exact. The opposite limit of $R/H\to 0$ corresponds to a semi-infinite plate, where the effects of edge and inclination can be probed.Comment: 5 pages, 3 figures, uses RevTeX; v2: expanded conclusions; v3: fixed missing factor in Eq. (3) and incorrect diagram label (no changes to results); v4: fix similar factor in Eq. (16) (again no changes to results

The Induced Innovation Hypothesis and Energy-Saving Technological Change

It follows from Hicks' induced innovation hypothesis that rising energy prices in the last two decades should have induced energy-saving innovation. We formulate the hypothesis concretely using a product-characteristics model of energy-using consumer durables, augmenting Hicks' hypothesis to allow for the possibility that government efficiency standards also induce innovation. Through estimation of characteristics transformation surfaces, we find that technological change reduced the total capital and operating costs of air air conditioning by half and water heating by about one-fifth. Although the rate of overall innovation in these products appears to be independent of energy prices and regulations, the evidence suggests that the direction of innovation has been responsive to energy price changes. In particular, energy price increases induced innovation in a direction that lowered the capital cost tradeoffs inherent in producing more energy-efficiency products. In addition, energy price changes induced changes in the subset of technically feasible models that were offered for sale. Our estimates indicate that about one-quarter to one-half of the improvements in mean energy-efficiency of the menu of new models for these products over the last two decades were associated with rising energy prices since 1973. We also find that this responsiveness to price changes increased substantially after product labeling requirements came into effect, and that minimum efficiency standards had a significant positive effect on average efficiency levels. Nonetheless, a sizeable portion of efficiency improvements in these technologies appears to have been autonomous.

Quark Masses: An Environmental Impact Statement

We investigate worlds that lie on a slice through the parameter space of the Standard Model over which quark masses vary. We allow as many as three quarks to participate in nuclei, while fixing the mass of the electron and the average mass of the lightest baryon flavor multiplet. We classify as "congenial" worlds that satisfy the environmental constraint that the quark masses allow for stable nuclei with charges one, six, and eight, making organic chemistry possible. Whether a congenial world actually produces observers depends on a multitude of historical contingencies, beginning with primordial nucleosynthesis, which we do not explore. Such constraints may be independently superimposed on our results. Environmental constraints such as the ones we study may be combined with information about the a priori distribution of quark masses over the landscape of possible universes to determine whether the measured values of the quark masses are determined environmentally, but our analysis is independent of such an anthropic approach. We estimate baryon masses as functions of quark masses and nuclear masses as functions of baryon masses. We check for the stability of nuclei against fission, strong particle emission, and weak nucleon emission. For two light quarks with charges 2/3 and -1/3, we find a band of congeniality roughly 29 MeV wide in their mass difference. We also find another, less robust region of congeniality with one light, charge -1/3 quark, and two heavier, approximately degenerate charge -1/3 and 2/3 quarks. No other assignment of light quark charges yields congenial worlds with two baryons participating in nuclei. We identify and discuss the region in quark-mass space where nuclei would be made from three or more baryon species.Comment: 40 pages, 16 figures (in color), 4 tables. See paper for a more detailed abstract. v4: Cleaning up minor typo