Human Exploration Technologies for the Second Space Age: Private Development of Space Suits for Earth Orbit and Beyond

A Second Space Age is underway, featuring both private and federal space exploration; to facilitate this, nearly all space-access and -exploration technologies need updates and cost-reduction efforts as they derive from archaic concepts and systems of production of the federally-regulated First Space Age (c.1959-2002).  I describe the efforts of my team, Pacific Spaceflight (which is not a business) to tackle a basic space-access and space-exploration technology,

The Densest Matter in the Observable Universe: Accreting Neutron Stars and the Physics of Dense Matter

Neutron stars are composed of the densest observable matter in nature and occupy the intellectual frontier between astrophysics, nuclear physics, and, now, gravitational physics. Current and planned nuclear experiments on heavy nuclei and observations of neutron stars in both electromagnetic and gravitational waves  will be exploring the nature of dense matter from complimentary approaches.

Between a Rock and A Hard Place: Communicating Contested Geoscience to the Public

Geoscientific knowledge and understanding lies at the heart of many of the most critical societal issues that face us in the 21st century. The pressing human challenges of natural disaster reduction, energy supply and security, and mineral and water resource management, rest on geological foundations. And yet, outside of the academic and industrial geoscience community there is a limited appreciation of Earth Science, especially among policy makers.

Tell Me Why: Interpretable Machine Learning for Space Exploration and Beyond

The growing deployment of machine learning (ML) systems in medicine, finance, advertising, and even space exploration has raised new, urgent questions about how these systems make their decisions and why.  This is especially relevant when ML is used to aid in the discovery of new objects, phenomena, mineralogies, and species.  Interpretable ML methods explicitly acknowledge that there is a human involved in the process, and they seek to provide human-understandable reasons for their decisions.&n

Galaxy Clusters as Cosmological Probes?

Clusters of galaxies are the largest, most massive gravitationally bound objects in the Universe. They are also the most recent of the cosmic objects to form. According to the currently accepted models of cosmic structure formation, the number density distribution of these systems is very sensitive to the parameters describing the large-scale geometry and the expansion history of the universe. For this reason, galaxy clusters are regarded as important cosmological probes.

Characterizing the Diversity of Extrasolar Atmospheres: From Planets to Brown Dwarfs

The spectra of extrasolar objects (both planetary and substellar) offer a window into the physical and chemical processes occurring in their atmospheres.  I will discuss what we have learned about the fundamental properties of the atmospheres of brown dwarfs and extra-solar planets derived from powerful atmospheric retrieval techniques.  A joint understanding of the chemistry and physics in both brown dwarfs and extra-solar planets is required in order to determine the fundamental differ

The Electrochemical Earth

Redox reactions — chemical process capable of generating electrical current — are important in Earth and planets, especially at major interfaces where oxidized and reduced phases may be in contact such as the core/mantle boundary in the deep interior, and mineral-fluid interfaces nearer to the surface. In this seminar, I share the results of some of our experimental and theoretical investigations into geochemical signatures of redox reactions.

The Formation of Planets from the Direct Accretion of Pebbles

In recent years, a radical new scenario has recently been suggested for the formation of planets. This scenario, known as pebble accretion, envisions: 1) Planetesimals form directly from millimeter- to meter-sized objects (the pebbles) that are concentrated by hydrodynamic forces and then gravitationally collapse to form 100 - 1000 km objects. 2) These planetesimals quickly sweep up the remaining pebbles because their capture cross sections are significantly enhanced by aerodynamic drag.

The Habitability of Planets Orbiting M Dwarfs

Recently discovered planets orbiting nearby M dwarfs will provide intriguing near-term targets for the James Webb Space Telescope and ground-based telescopes, and an exciting window into the evolution and nature of terrestrial planets. M dwarfs, although plentiful, undergo strong evolution in stellar brightness when they are young, and have habitable zones that are extremely close to the star.