Young Workers, Old Workers, and Convergence

The human capital of young and old workers are imperfect substitutes both in production and in on-the-job training. This helps explain why capital does not flow from rich to poor countries, causing instantaneous convergence of per capita output. If each generation chooses its human capital optimally given that of the previous and succeeding generations, human capital follows a unique rational- expectations path. For moderate substitutability, human capital within each sector oscillates relative to that in other sectors, but aggregate human capital converges to the steady state monotonically, at rates consistent with those observed empirically.

A New Foundation for Physics

Modern physics describes the mechanics of the Universe. We have discovered a new foundation for physics, which explains the components of the Universe with precision and depth. We quantify the existence of Aether, subatomic particles, and the force laws. Some aspects of the theory derive from the Standard Model, but much is unique. A key discovery from this new foundation is a mathematically correct Unified Force Theory. Other fundamental discoveries follow, including the origin of the fine structure constant and subatomic particle g-factors, a slight correction of neutron magnetic moment, a geometrical structure for charge, the quantification of electromagnetic charge as separate from electrostatic charge, a more precise meaning of spin, the quantification of space-resonance in five dimensions, and a new system of quantum units. The Aether quantifies as a fabric of quantum rotating magnetic fields with electromagnetic, electrostatic, and gravitational dipole structures. Subatomic particles quantify as angular momentum encapsulated in a quantum, rotating magnetic field. All quantum, atomic, and molecular processes can be precisely modeled, leading to discrete physics with new understandings and insights

A Global Climatological Model of Extreme Geomagnetic Field Fluctuations

This paper presents a multi-parameter global statistical model of extreme horizontal geomagnetic field fluctuations (dBH/dt), which are a useful input to models assessing the risk of geomagnetically induced currents in ground infrastructure. Generalised Pareto (GP) distributions were fitted to 1-minute measurements of |dBH/dt| from 125 magnetometers (with an average of 28 years of data per site) and return levels (RL) predicted for return periods (RP) between 5 and 500 years. Analytical functions characterise the profiles of maximum-likelihood GP model parameters and the derived RLs as a function of corrected geomagnetic latitude, λ. A sharp peak in both the GP shape parameter and the RLs is observed at |λ|=53° in both hemispheres, indicating a sharp equatorward limit of the auroral electrojet region. RLs also increase strongly in the dayside region poleward of the polar cusp (|λ|>75°) for RPs > 100 years. We describe how the GP model may be further refined by modelling the probability of occurrences of |dBH/dt| exceeding the 99.97th percentile as a function of month, magnetic local time, and the direction of the field fluctuation, dBH , and demonstrate that these patterns of occurrence align closely to known patterns of auroral substorm onsets, ULF Pc5 wave activity, and (storm) sudden commencement impacts. Changes in the occurrence probability profiles with the interplanetary magnetic field (IMF) orientation reveal further details of the nature of the ionospheric currents driving extreme |dBH/dt| fluctuations, such as the changing location of the polar cusp and seasonal variations explained by the Russell-McPherron effect

The Rebirth of Airships

Until the outbreak of the Second World War, uncertainty existed whether airships and airplanes would dominate intercontinental passenger transportation. The massive investments in fixed-wing aircraft during these hostilities made airplanes the decisive winner, and relegated airships to a negligible role in transportation. As the 21st Century progresses, airships are making a comeback fueled by the 21st Century progresses, airships are making a comeback fueled by the growing demand for air cargo, the unique environmental and operational characteristics of buoyant flight, and advances in engineering science and materials. This paper examines the market niche for airships that exists between air and marine transport and the inherent advantages and disadvantages of this mode of transportation. The economics of airships are considered in light of their past achievements and current designs. The paper concludes with the discussion of two potential applications. A long haul mission for airships between Hawaii and the U.S. mainland is considered for perishable freight, and a short haul mission for airships in northern Canada is considered for the transport of freight and passengers to remote communities

Frazil ice Growth and Production during Katabatic Wind Events in the Ross Sea, Antarctica

Katabatic winds in coastal polynyas expose the ocean to extreme heat loss, causing intense sea ice production and dense water formation around Antarctica throughout autumn and winter. The advancing sea ice pack, combined with high winds and low temperatures, has limited surface ocean observations of polynyas in winter, thereby impeding new insights into the evolution of these ice factories through the dark austral months. Here, we describe oceanic observations during multiple katabatic wind events during May 2017 in the Terra Nova Bay and Ross Sea polynyas. Wind speeds regularly exceeded 20 m s−1, air temperatures were below −25 ∘C, and the oceanic mixed layer extended to 600 m. During these events, conductivity–temperature–depth (CTD) profiles revealed bulges of warm, salty water directly beneath the ocean surface and extending downwards tens of meters. These profiles reflect latent heat and salt release during unconsolidated frazil ice production, driven by atmospheric heat loss, a process that has rarely if ever been observed outside the laboratory. A simple salt budget suggests these anomalies reflect in situ frazil ice concentration that ranges from 13 to 266×10-3 role= presentation style= box-sizing: border-box; display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3e266×10−3 kg m−3. Contemporaneous estimates of vertical mixing reveal rapid convection in these unstable density profiles and mixing lifetimes from 7 to 12 min. The individual estimates of ice production from the salt budget reveal the intensity of short-term ice production, up to 110 cm d−1 during the windiest events, and a seasonal average of 29 cm d−1. We further found that frazil ice production rates covary with wind speed and with location along the upstream–downstream length of the polynya. These measurements reveal that it is possible to indirectly observe and estimate the process of unconsolidated ice production in polynyas by measuring upper-ocean water column profiles. These vigorous ice production rates suggest frazil ice may be an important component in total polynya ice production