SETI Institute Weekly Colloquium - Upcoming Speakers
Postcards from Chelyabinsk
Meteor astronomer Dr. Peter Jenniskens participated in a two-week Russian Academy of Sciences fact-finding mission to Chelyabinsk, just three weeks after the event, to collect data on the February 15 asteroid impact and the extent of the damage caused by its shock wave. Dr. Jenniskens will talk about his trip to Russia and give a report on the first hand accounts of the impact.
Life before genetics: autogenesis, information, and the outer solar system
The investigation of the origins of life has been hindered by what we think we know about current living organisms. This includes three assumptions about necessary conditions: 1) that it emerged entirely on Earth, 2) that it is dependent on the availability of liquid water, and 3) that it is coextensive with the emergence of molecules able to replicate themselves.
In addition, the three most widely explored alternative general models for a molecular process that could serve as a precursor to life also reflect reductionistically-envisioned fragments of current living systems: e.g. container-first, metabolism-first, or information-first scenarios. Finally, we are hindered by a technical concept of information that is fundamentally incomplete in precisely ways that are critical to characterizing living processes.
These all reflect reductionistic "top-down" approaches to the extent that they begin with a reverse-engineering view of what constitutes a living Earth-organism and explore possible re-compositional scenarios. This is a Frankensteinian enterprise that also begins with assumptions that are highly Earth-life specific and therefore unlikely to lead to a general exo-biology.
The approach Dr. Deacon will outline instead begins from an unstated conundrum about the origins of life. The initial transition to a life-like process necessarily exemplified two almost inconceivably incompatible properties: 1) it must have involved exceedingly simple molecular interactions, and 2) it must have embodied a thermodynamic organization with the unprecedented capacity to locally compensate for spontaneous thermodynamic degradation as well as to stabilize one or more intrinsically self-destroying self-organizing processes.
This talk will explore the origins of life problem by attempting to identify the necessary and sufficient molecular relationships able to embody these two properties. From this perspective Dr. Deacon will develop a model system - autogenesis - that redefines biological information and opens the search for life's origin to cosmic and planetary contexts seldom considered.
Convection in ice mantles: effects of texture and anisotropy
The icy mantles of satellites in the outer solar system may transport heat by solid-state convection, which is important because it provides a mechanism for cycling material between a ocean and surface, controls the rate of heat transport, and may produce surface geological features. The style of convection and rate of heat transport depend strongly on ice rheology, which is complex. I will discuss the effect of crystallographic preferred orientation (CPO) on ice rheology and how this phenomenon affects convection. Next, I will present the results from numerical models of ice convection in which we incorporate CPO development and the resulting viscous anisotropy. CPO develops as a result of strain and can potentially be detected using spacecraft radar observations. Hence, if we can detect CPO, we can study not only the present state but also the strain-history of an icy satellite. Our numerical models lead to specific predictions of where CPO is likely to develop and what CPO fabrics are likely to develop in association with specific geologic settings.
Do cyanobacteria use iron for photosynthesis?
Dr. Parenteau will speak about her research into the origins of photosynthesis and how this might relate to ancient banded iron formations formed during the great oxidation event. Banded Iron Formations (BIFs) are widespread Precambrian sedimentary deposits that accumulated in deep ocean basins with inputs of reduced iron and silica from deep ocean hydrothermal vents.
There is a large scientific debate as to whether abiotic or biotic mechanisms were responsible for the oxidation of mineral assemblages in BIFs. Biotic oxidation could have occurred as a result of the photosynthetic production of oxygen by cyanobacteria, or could have been directly formed by anoxygenic phototrophs or chemolithotrophs.
Dr. Parenteau has been searching for modern descendants of such an ancestral "missing link" cyanobacterium in the phototrophic mats at Chocolate Pots, a hot spring in Yellowstone National Park. Dr. Parenteau will explain how her study of the biomats using C-14 carbon uptake experiments have tantalizingly showed that the cyanobacteria grow anoxygenically using reduced iron as an electron donor for photosynthesis in situ.
Finding the Magic in the Machine
Artistic expression that involves technology can be a quite challenging affair. Is building tools just an exhausting necessity or an essential part of the artistic process? What is the relationship between intuition and engineering? How to judge the artistic outcome? Robert Henke, a Berlin based composer and audiovisual artist presents a selection of recent works and talks about his ideas, concepts and struggles. Henke has been involved with Ableton LIVE software development since it's inception. He is currently teaching a course in computer music at Stanford University.
Measuring Atmospheric Boundary Layer Fluxes on Mars: Sonic Anemometer
The atmospheric boundary layer on Mars is where the influence between the surface and atmosphere (and vice versa) takes place on Mars. To better validate and improve mesoscale atmospheric models we suggest that direct observations of the interactions between the surface and atmosphere are needed. Such direct measurements of the forcings (and response) between surface and atmosphere allow much tighter constraints to be placed on the processes that control the behavior of the atmosphere in and well above the atmospheric boundary layer. To achieve these direct measurements, we propose using a sonic anemometer for Mars.
This instrument, based on the gold standard wind measurement techniques used terrestrially has been in development under PIDDP (now PICASSO) funding for much of the last decade, and is now ready for use on upcoming Mars missions. Dr. Banfield will discuss the advantages such an instrument offers over other wind measurement techniques for Mars, as well as some details of the instrument itself.
Conformal gravity: New light on dark matter and dark energy
Dr. Nesbet will describe (in layman's terms) implications of a theory that differs from standard particle physics and cosmology only by imposing a universal symmetry principle. This theory has been found to explain dark energy and dark galactic halos without invoking dark matter. Subgalactic phenomenology (relevant to our solar system) is retained.
The model postulates that strict conformal symmetry (local Weyl scaling covariance), already satisfied by standard fermion and gauge boson theory, can be extended to all elementary massless fields. This modifies Einstein-Hilbert general relativity and the Higgs scalar field model. No new physical fields are introduced.
Dr. Nesbet will show that conformal gravity and a conformal Higgs model fit empirical data on galactic rotational velocities, galactic halos, and Hubble expansion including dark energy. By implication, dark matter is not needed for an isolated galaxy. This model appears to be a promising tool for understanding both cosmology and elementary particle physics.
Atmospheric Polar Warming at Mars
https://plus.google.com/events/c9qa6oa1gispcnc5iprg42m3fcg
Topographic Investigations of Io and the Saturnian Mid-Sized Icy Satellites
Optics tricks to image and study habitable exoplanets
Directly imaging exoplanets is both scientifically exciting but notoriously challenging. Scientifically, obtaining images of rocky planets in the habitable zones of stars is key to finding if and how life developed outside the solar system. Large-scale biological activity can modify the chemical composition of the planet's atmosphere and its surface properties, both of which can be studied by spectrophotometry. The measurement is however extremely challenging, as the planet light is considerably fainter that the host star's light, and the angular separation between the two objects is about 0.1 arcsecond or less.
Conventional imaging systems cannot overcome the high star to planet contrast, and unusual optics are required for imaging exoplanets. Dr. Guyon will describe such systems (coronagraphs) and the upcoming scientific opportunities associated with their deployment on ground-based telescopes and in space. He will show that ground-based extremely large telescopes (ELTs) will have the ability to directly image and spectroscopically characterize rocky planets in the habitable zones of nearby M-type stars, thus providing scientific evidence for (or against) the presence of life outside our solar system. Space telescopes operating in optical light are well suited to target Earth-like planets around Sun-like stars.
Dr. Guyon will also describe the PANOPTES (Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanet Survey) project, aimed at supporting a world-wide network of small robotic digital cameras built by citizen scientists and schools to identify a large number of transiting exoplanets.
Distribution, Evolution, and Mineralogy of Volatile Ices on Pluto
https://plus.google.com/events/cso1aot883e1l4jtam4h5tc333g
Ocean Surfaces on Snowball Earth
The Next Generation of Radio Telescopes
The past decade has seen an explosion of creativity and progress in radio astronomy telescopes and techniques. In the coming decade, we will harvest the fruit of these innovations with a powerful new generation of radio telescopes that are coming on line. These will open avenues for new science, in areas such as the epoch of reionization, synoptic surveys for radio transients, and exquisitely sensitive observations of the most distant objects in the Universe.
Dramatic improvements in digital instrumentation have been and will continue to be central to the advancement of the field. But there has also been a resurgence of interest in many other areas including receiver technologies, antennas, optimized array configurations, remote site management, software, commensal observing modes, and algorithms. Considerable attention has been paid to manufacturability and array costs in order to address the prospects of optimizing array performance at costs exceeding $1B. Telescope projects have also bifurcated into general facility instruments and targeted experiments, with significance consequences for their design and operation.
I will review the current state of the art for meter and centimeter wavelength telescopes. Among the projects of note, I will discuss the SKA Technology Development Project, the Allen Telescope Array, MeerKAT, the Australian SKA Pathfinder (ASKAP), the Precision Array for Probing the Epoch of Reionization (PAPER), the Mileura Widefield Array (MWA), the LongWavelength Array (LWA), the Low Frequency Array (LOFAR), and SKA Phase 1. I will also explore what telescope parameter space remains unexplored and where new technical developments are required to make scientific progress.
Marine microbial mats and our early biosphere
Exploring Complex, High-Dimensional Data For Hidden Structure
How does one search for a needle in a multi-dimensional haystack not knowing what a needle is and not being sure there is one in the haystack? Solving this sort of problem might seem to be impossible, yet this is exactly what Dynamic Quantum Clustering (DQC) manages to do. Several key features of DQC are: it is unbiased in that it makes no assumptions about the type, structure or number of clusters that might exist; it is data agnostic, in that it uses no domain-specific knowledge; it doesn’t find clusters when presented with random data; it works when other clustering methods fail to work. These advantages mean that DQC works well for data coming from fields as different from one another as biology, physics, medicine, finance and even national security.
Dr. Weinstein's talk will cover examples drawn from many successful applications of DQC. In each of these, conventional clustering methods failed to produce useful results. The examples are real data from a wide variety of disciplines including x-ray absorption spectroscopy, earthquake science, particle physics, condensed matter physics and biology. These vary in size from thousands to millions entries. They convincingly demonstrate DQC’s power and flexibility.
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