SETI Institute Weekly Colloquium - Upcoming Speakers

Tuesday, March 31 2015 - 12:00 pm, PDT

Saturn's Rings: An accessible Astrophysical Disk

Matthew Tiscareno
Cornell University

Saturn's ring system is an astrophysical disk that is neither light-years away nor billions of years in the past. We can visit this disk at close range and observe a number of phenomena that also operate in disks of other kinds. As a result, we see small-scale processes that shape ring texture, connect those processes to the bodies and structures that cause them, and watch closely as the disk changes with time.

We will discuss recent Cassini observations that elucidate disk processes including 1) "self-gravity wakes" and "spiral density waves," both of which were originally proposed for galaxies but are observed with exquisite precision in Saturn's rings, 2) "propeller" features caused by 100-meter to km-sized moonlets embedded in the disk; these are the first objects ever to have their orbits tracked while embedded in a disk, rather than orbiting in free space, and hold the potential of deepening our understanding of planetary migration, and 3) irregular edge shapes in the gaps opened up by larger moons (10 km and more), which may hold clues to angular momentum transport.

Eventbrite - Saturn's Rings: An accessible Astrophysical Disk


Tuesday, April 07 2015 - 12:00 pm, PDT

Stardust: analyses of cometary and interstellar dust in the laboratory

Andrew Westphal
UC Berkeley

Stardust was the first spacecraft ever to bring back to Earth extraterrestrial materials from beyond the Moon. It was two missions in one spacecraft. Stardust returned the first samples from a known primitive solar system body, the Jupiter-family comet Wild 2. Stardust also carried a separate collector that was exposed the interstellar dust stream for 200 days before the encounter with the comet. These tiny rocks — a trillion would fit into a teaspoon — were identified in the returned collector by a small army of more than 30,000 citizen scientists, through a project called Stardust@home. Dr. Westphal will present results of laboratory analyses of samples from both collectors, including laboratory analyses of seven particles that are likely the first individual rocks from the local interstellar medium ever identified.

Eventbrite - Stardust:  analyses of cometary and interstellar dust<br />
in the laboratory


Tuesday, April 14 2015 - 12:00 pm, PDT

Viewing Solar System Orbital Architecture through an Extrasolar Lens

Konstantin Batygin
Caltech

Eventbrite - Viewing Solar System Orbital Architecture through an<br />
Extrasolar Lens


Tuesday, April 28 2015 - 12:00 pm, PDT

Shape dynamics: a relational view of the Universe

Henrique Gomes
Perimeter Institute
Shape Dynamics is a new theory of gravity which removes the notion of local relativistic time from the guiding principles of gravity in the universe. It is a very promising approach which has been shown to be equivalent to Einstein's Theory of General Relativity, without being embedded in time. It is inspired by adherence to Mach's Principle, which is violated by Einstein's theory.
 
Shape Dynamics provides new tools in the quest for a theory that describes quantum gravity.
 
In the first part of the talk Dr. Gomes will review some of the Machian motivations for shape dynamics and sketch its construction. 
In the second half, Dr. Gomes will talk about recent developments on black holes in this formulation, and discuss some positive aspects of its ongoing quantization program.

Eventbrite - Shape dynamics: a relational view of the Universe


Tuesday, May 05 2015 - 12:00 pm, PDT

Brown Dwarf Variability and implications for Exoplanets

Tyler Robinson
ARC

Tuesday, May 19 2015 - 12:00 pm, PDT

Ultra Lightweight Probes to Catalyze Interstellar Expansion

John Rather

Tuesday, May 26 2015 - 12:00 pm, PDT

Giant planet interiors studied with ab initio computer simulations

Burkhard Militzer
UCB

Tuesday, June 02 2015 - 12:00 pm, PDT

Atmospheric Tides and the Diurnal Cycle on Earth and other Terrestrial Planets

Curt Covey
LLNL