Weird Lightning: Sprites, Elves and Other Strange Things Found in Our Atmosphere
Professor and Peter T. Paul Chair in Space Sciences Joseph R. Dwyer | Space Science Center (EOS) and Department of Physics and Astronomy
University of New Hampshire
April 4, 2023
Lightning strikes our planet about a billion times per year, killing as many people as hurricanes or tornadoes. Surprisingly, despite its familiarity, we still don’t understand many things about lightning, including how it gets started inside thunderstorms and how it travels such large distances through air. In addition, many new and strange phenomena have been discovered in and around thunderstorms, including colossal jellyfish-like structures near the edge of space called Sprites; enormous, expanding rings of light called Elves; bizarre, bluish jets shooting out of cloud tops; powerful flashes of gamma rays emanating from deep inside storms; and large but nearly invisible discharges called Dark Lightning. In this presentation, I will talk about the mysteries of lightning and other weird things that lightning does.
Cultural Evolution, Neutral Drift and Acoustic Adaptation in Bird Songs
Professors Jay Pitocchelli, Adam Albina, and David Guerra | Saint Anselm College
February 21, 2023
Birdsong is a socially transmitted trait that is passed on from generation to generation by learning. The syllables of the songs and their occurrence are subject to change or cultural evolution over time. The physical parameters of the songs (e.g., frequencies and durations) may also change due to selection by ecological characteristics of the breeding habitat (acoustic adaptation). We studied songs of the Mourning Warbler across its breeding range, Canada and the Northern US, over a 36-year period and tested hypotheses about the mechanisms responsible for song divergence. The nature of this research required an interdisciplinary approach: Jay collected the song recordings and performed statistical analyses of song data: Alex and Mason developed the agent based models of cultural evolution; David acquired the Landsat data, developed landcover indexes, and extracted georeferenced data using ArcGIS Pro; Adam employed machine learning algorithms (including Random Forest and K-means) in R to test hypotheses about acoustic adaptation.
Global Ecosystems Dynamics Investigation (GEDI)
Laser Physicist Dr. D. Barry Coyle | Laser and Electro-Optics Branch NASA Goddard Space Flight Center
November 15, 2022
The Global Ecosystems Dynamics Investigation (GEDI) LIDAR leverages three solid-state lasers designed, built, and qualified by NASA Goddard Space Flight Center’s (GSFC) Lasers and Electro-Optics Branch. GEDI is currently installed on the International Space Station’s (ISS) Japanese Experiment Module (JEM) and was installed and commissioned in Dec 2018. The GEDI lidar produces 8 parallel tracks of 25 m footprints on the Earth's surface continuously. GEDI’s mission is to accurately measure global biomass volume by creating a set of systematic global canopy measurements, or to literally “weigh the trees”. A total of 5 GEDI-High Output Maximum Efficiency Resonator (GEDI-HOMER) lasers were built. Discussions of how to develop, qualify, and deliver a laser system for space deployment will be presented, using the GEDI laser as an example. GEDI is important in that we proved and demonstrated an order of magnitude in cost reduction while increasing reliability and lifetime.
Our Universe through Sight, Sound & Touch: A Multi-sensory Approach for Multiwavelength Astrophysics Data Sets
Dr. Kimberly Kowal Arcand | NASA's Chandra X-ray Observatory, Center for Astrophysics at Harvard & Smithsonian
October 18, 2022
Information of our Universe doesn't have to be just a two-dimensional snap shot. We can transform these digital assets to be able to listen, feel, or (virtually) move through cosmic objects. Listen to the debris from an exploded star, walk through the core of our Milky Way in 3D through virtual reality, feel vibrations of a stellar nursery, and experience our universe anew. Learn about some of the innovative ways that experts and non-experts can explore astrophysical data through sonification, 3D printing and extended reality.
The Meaning of “Understanding” in Mathematics and Physics: Cognitive and Motivational Aspects
Distinguished Professor Gerald A. Goldin | Graduate School of Education. Rutgers University
September 20, 2022
In this talk, I will discuss and propose some perspectives on two main topics: (1) What does it mean to “really understand” a concept in mathematics or in physics? What kind of understanding should we consider to have fulfilled our objectives as teachers or as learners? (2) How can the process of learning mathematics and physics fulfill fundamental psychological needs? What does this mean for the teaching of these subjects? These questions are relevant for all levels of education, from kindergarten through graduate school. They are also fundamentally important to society at large.
From Space and Time to Spacetime
Senior Lecturer in Philosophy Dr. James Binkowski | Dartmouth College
April 19, 2022
Students are typically introduced to the concept of spacetime in connection with the special and general theories of relativity. But the concept is equally useful in classical, Newtonian mechanics. In this talk, I’ll introduce the concept of spacetime and describe four different classical spacetime geometries. I’ll show that the spacetime perspective permits solutions to foundational problems in classical mechanics that are otherwise unsolvable. And I’ll discuss the implications of the four-dimensional perspective for questions concerning the nature of time. This talk will be aimed at a general audience. There will be no equations--everything will be done with pictures. (That's the beauty of geometry!). If you're at all curious about space and time, this talk is for you.
The Business and Physics of Renewable Energy
Emeritus President and CEO of General Electric's Offshore Wind Business John Lavelli 82'
March 22, 2022
Physics Professor Smith and Economics and Business Professor Unger will interview John about the business and engineering challenges that face the energy industry today and in the coming decade, and reflect on lessons he’s learned throughout his 38-year career.
Dashing through the Snow: Autonomous Rovers to Enable Polar Science
Myron Tribus Professor of Engineering Innovation Dr. Laura Ray | Dartmouth College
November 16, 2021
Climate modelers rely on both remote sensing and in situ measurements of the dynamics of and properties of Arctic and Antarctic ice sheets in order to predict the impact of climate change on sea-level rise. Remote sensing products managed by NASA and its counterparts worldwide require ground-truth measurements to assure data quality; however, these measurements are difficult to make in Polar regions owing to cost, accessibility of sites, and safety. Dartmouth researchers have been developing robots to support Polar science since 2005. This seminar reviews both the process and outcomes of designing robots for operation in polar regions and the contribution of autonomous robots to Polar science.
An Accessible Introduction to Quantum Gravity Phenomenology
Associate Professor Dr. David Mattingly | University of New Hampshire
October 19, 2021
The search for a mathematically complete, conceptually sound, and well-tested theory of quantum gravity, the merger of quantum mechanics with general relativity, has involved thousands of physicists for almost a hundred years. Despite the amount of effort expended, we still do not know the correct theory. The difficulties are twofold. First, quantum gravity requires us to rethink fundamental conceptual concepts, such as what we mean by space and time, and incorporate those into a comprehensive mathematical framework. Second, putative models are very difficult to test experimentally. In this talk, I give a theoretical introduction to quantum gravity accessible (I promise) to undergraduates in physics and survey how we experimentally test various proposals using everything from kilometer-scale astrophysical laboratories to micron-sized mechanical systems.
Hydrocarbon Seas and Dynamic Climate on Saturn's Moon Titan
Dr. Jason D. Hofgartner | NASA Jet Propulsion Laboratory, California Institute of Technology
April 20, 2021
Saturn’s moon Titan has an active, global methane cycle with clouds, rain, rivers, lakes, and seas; it is the only world known to presently have a volatile cycle akin to Earth’s water cycle. The discovery and characterization of transient features in Titan's hydrocarbon seas by NASA's Cassini spacecraft will be presented. Anomalously specular radar reflections (ASRR) from Titan’s tropical region observed with the Arecibo Observatory in Puerto Rico were initially interpreted as evidence for liquid surfaces but after the Cassini spacecraft did not observe lakes or seas at those locations, they were unsatisfactorily explained for more than a decade. It will be argued that the ASRR likely originate from paleolakes/paleoseas: i.e., basins that used to be liquid-filled but are now dry due to climatic variability. Titan observations provide "ground-truth" in the search for oceans on exoearths and an important lesson: that identifying liquid surfaces by specular reflections requires a stringent definition of specular, will be discussed.
Planet Formation Through Radio Eyes
Associate Professor Dr. A. Meredith Hughes | Wesleyan University
March 16, 2021
When, where, and how do planets form around other stars? While humans have been pondering this question for centuries, a giant radio telescope called the Atacama Large Millimeter/submillimeter Array (ALMA) has recently given us new and exquisitely detailed views of the inside of planet-forming disks of gas and dust around nearby stars. In this colloquium, we will discuss some of these recent discoveries and what they've taught us about the birth of planetary systems.
The Many Hats of Quantum Information Science
Dr. John Donohue | Institute for Quantum Computing Waterloo, Canada
February 16, 2021
While the strange implications of quantum mechanics caused intense debate in the early days of the theory, the theory proved to be incredibly accurate, leading to the development of quantum technologies like the laser and MRI. By revisiting these usefully unintuitive phenomena, such as superposition and entanglement, through the lens of information science, the field of quantum information was born, with applications in computing, communication, sensing, and more. In this talk, we'll give a birds-eye overview of quantum information science, from its fundamentals to lab experiments being run today. We'll see how the measurement disturbance relation can be used to ensure private communications, how quantum measurement leads to a new computing frontier, and how to make quantum bits one by one.