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
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.