Ancient eruptions of Eta Carinae: A tale written in proper motions

We analyze eight epochs of Hubble Space Telescope H$\alpha$+[N II] imaging of Eta Carinae's outer ejecta. Proper motions of nearly 800 knots reveal that the detected ejecta are divided into three apparent age groups, dating to around 1250 A.D., to around 1550 A.D., and to during or shortly before the Great Eruption of the 1840s. Ejecta from these groups reside in different locations and provide a firm constraint that Eta Car experienced multiple major eruptions prior to the 19th century. The 1250 and 1550 events did not share the same axisymmetry as the Homunculus; the 1250 event was particularly asymmetric, even one-sided. In addition, the ejecta in the S ridge, which have been associated with the Great Eruption, appear to predate the ejection of the Homunculus by several decades. We detect essentially ballistic expansion across multiple epochs. We find no evidence for large-scale deceleration of the observed knots that could power the soft X-ray shell by plowing into surrounding material, suggesting that the observed X-rays arise instead from fast, rarefied ejecta from the 1840s overtaking the older dense knots. Early deceleration and subsequent coasting cannot explain the origin of the older outer ejecta---significant episodic mass loss prior to the 19th century is required. The timescale and geometry of the past eruptions provide important constraints for any theoretical physical mechanisms driving Eta Car's behavior. Non-repeating mechanisms such as the merger of a close binary in a triple system would require additional complexities to explain the observations.Comment: 14 pages, 11 figures, accepted for publication in MNRA

Intellectual Property and Indigenous Peoples: Adapting Copyright Law to the Needs of a Global Community

The definition and scope of intellectual property and associated laws are under intense debate in the emerging discourse surrounding intellectual property and human rights. These debates primarily arise within the context of indigenous peoples\u27 rights to protection and ownership of culturally specific properties. It is true that intellectual property laws are based on Western, developed markets, Western concepts of creation and invention, and Western concepts of ownership. But whatever their origins, those laws have been, and currently are, the primary vehicle for the protection of artistic, literary, and scientific works worldwide. To segregate indigenous interests from this international legal regime, particularly in light of the increasing globalization of markets, is to deny indigenous peoples both a powerful legal shield and a powerful legal sword. This Article argues that copyright laws can, and must, be expanded so as to maintain the vitality of, and protect, the creative artistic and literary works of indigenous cultures. The article proposes three major changes to international copyright law: the incorporation of collective and communal notions of authorship, the expansion of the originality requirement to reflect these forms of authorship, and the application of limits on the duration of copyright protection in a broader community context. The article further proposes that a variety of intellectual property mechanisms be drawn upon to provide special protection for “sacred” cultural works

Will Work\u27: The Role of Intellectual Property in Transitional Economies -- From Coal to Content

The development and exploitation of intellectual property, and participation in the global information economy, are not dependent upon geography. It can take place from anywhere, from the inside of an empty factory in Detroit, to a small country road, nestled between the rhododendron and the river. From the R&D lab at a university, to a barren plain in New Mexico. To move from coal to content, we must foster a dynamic and profitable environment for entrepreneurship, through a supportive and robust university community, through state legislation and institutional support and through effective utilization of intellectual property laws. Intellectual property and technology can be used in transitional economies to create meaningful opportunities for young people to live and to work in their communities, to make efficient use of their own resources. This issue spans art and science, business and industry, culture and environment. Twin-pops and telephones. Intellectual property can help people use traditional resources in the new economy -- the art, the music, the know-how -- and to cultivate human knowledge and creation in a manner that benefits these communities across the country. This is the American story, too - to create wealth from within. To \u27Will Work\u27

To What Degree do Retail Electricity Prices Inform Residential Solar Energy Investment Decisions?

The relationship between electricity price and household solar photovoltaic (PV) adoption has not been thoroughly studied. How much would a carbon tax, and increase in electricity price, spur growth in residential solar? This paper adds to the literature with a utility-level panel analysis. Consumer choice theory provides the framework for the empirical models. I use electricity price and net metered solar PV capacity data from the Energy Information Administration (EIA). Through a variety of specifications, I control for both utility and state-year effects. My findings suggest that electricity price is significantly positively correlated with solar adoption, with an estimated price elasticity of 1.85. These results are limited by endogeneity and omitted variable bias

Contextual Healing: What to Do About Scandalous Trademarks and Lanham Act 2(a)

Offensive trademarks have come to the forefront of trademark policy and practice in recent years. While it was once true that more attention had been paid to Lanham Act section 2(a) in the pages of law reviews than in the courts, recent prominent cases have focused attention on the ban on registration of offensive marks and the widespread impact of this ban on trademark owners. In this Article, I answer the fundamental question: Given the problems that my previous research has identified, what should be done about the 2(a) bar on registration of scandalous trademarks? This Article argues, as a preliminary matter, that the registration bar on scandalous marks should be removed from the Lanham Act because morality is outside the function and purpose of trademark law. Furthermore, removal of the bar would be in line with other forms of intellectual property, which have moved away from regulating morality. Finally, removing the bar would resolve concerns about the constitutionality of section 2(a). However, if the 2(a) bar remains part of the Lanham Act, it should be applied in a way that is fair and effective within in the legal framework of trademark law. Specifically, this Article argues that trademark examiners should evaluate offensiveness in the same way other bars to registration — and content in broadcast media — are evaluated: by considering the context of the marketplace

Proper motions of collimated jets from intermediate-mass protostars in the Carina Nebula

We present proper motion measurements of 37 jets and HH objects in the Carina Nebula measured in two epochs of H$\alpha$ images obtained $\sim 10$ yrs apart with HST/ACS. Transverse velocities in all but one jet are faster than $\gtrsim 25$ km s$^{-1}$, confirming that the jet-like H$\alpha$ features identified by Smith et al. (2010) trace outflowing gas. Proper motions constrain the location of the jet-driving source and provide kinematic confirmation of the intermediate-mass protostars that we identify for 20/37 jets. Jet velocities do not correlate with the estimated protostar mass and embedded driving sources do not have slower jets. Instead, transverse velocities (median $\sim 75$ km s$^{-1}$) are similar to those in jets from low-mass stars. Assuming a constant velocity since launch, we compute jet dynamical ages (median $\sim 10^4$ yr). If continuous emission from inner jets traces the duration of the most recent accretion bursts, then these episodes are sustained longer (median $\sim 700$ yr) than the typical decay time of an FU Orionis outburst. These jets can carry appreciable momentum that may be injected into the surrounding environment. The resulting outflow force, $dP/dt$, lies between that measured in low- and high-mass sources, despite the very different observational tracers used. Smooth scaling of the outflow force argues for a common physical process underlying outflows from protostars of all masses. This latest kinematic result adds to a growing body of evidence that intermediate-mass star formation proceeds like a scaled-up version of the formation of low-mass stars.Comment: accepted to MNRAS, 29 pages, 30 figures, 3 table