04:15 PM - 05:15 PM
Berkeley, CA 94720
Improving Detection of Gravitational Waves using Condensed Matter Physics: Understanding Entropy and Defects in Amorphous Materials
Gravitational waves are ripples in space-time that produce a time-dependent strain, in which distances are compressed in one direction and stretched in the perpendicular direction. Their detection relies on extraordinary precision measurements of distances, specifically displacements on the order of 10-19m, 10000 times smaller than the diameter of a proton, accomplished through laser interferometry between large mirrors 4 km apart from each other. The absorption of a metallic mirror is far too large, necessitating the use of Bragg reflecting mirrors which are ¼ λ high index/low index insulating amorphous (non-crystalline) materials. The present limit on detection is due to thermal noise associated with mirror surface fluctuations, due to poorly understood motions of atoms in the amorphous structure which dissipate energy, causing mechanical loss and thermal noise. At cryogenic temperature, these losses are associated with tunneling of many atoms between states of similar energy, known as tunneling level states (TLS), which are ubiquitous in amorphous materials. Amorphous materials lack structural order, making them difficult to describe and making it difficult to calculate and predict their properties compared to crystalline materials which consist of spatially repeated atoms. This difficulty, however, does not preclude their importance to both applications and scientific impact. The properties of an amorphous material depend strongly on how it was produced, and there are some well-defined known defects, but it is not clear how to describe the different amorphous structures produced by different methods. Intriguingly, there exists evidence for an "ideal glass", which while remaining disordered, lacks imperfections in that disorder and thus approaches the uniqueness and low entropy and energy of a crystal. Amorphous silicon (a-Si) is to date the single material where the mechanical loss and thermal noise can be nearly eliminated; TLS can be tuned via preparation conditions over several decades, from below detectable limits to high in the range commonly seen in amorphous systems. A strong correlation with atomic density is seen, as well as with other structural parameters, but TLS vary by orders of magnitude while other measures of disorder vary by less than a factor of two. The lowest loss a-Si is grown in thin film form at temperatures slightly below the theoretical glass transition temperature Tg of Si, similar to results on polymer films and suggestive that high surface mobility during growth produces materials close to an ideal glass, with low entropy and energy, high density, and low losses due to few nearby configurations with similarly low energy.
Speaker: Frances Hellman, UC Berkeley
03:30 PM - 04:30 PM
In-person and Livestream
Kavli Auditorium and zoom: https://stanford.zoom.us/j/94405112201?pwd=TkZFdUZqRGFQSXJtMmFMcTA5aGxQQT09
Stanford Linear Accelerator (SLAC) Colloquium Series
2575 Sand Hill Rd, Building 51
Menlo Park, CA 94025
Life and Science in an Absolute Monarchy
What is the day-to-day life like in the Vatican? And how does that compare to the ways that such places are depicted in some of your favorite (and not-so-favorite) fantasy novels? What is it really like to live in a five hundred year old palace, to work in an absolute monarchy, to do science in a structure far older than NASA?
Speaker: Dr Guy Consolmagno, Director, Vatican Observatory
Attend in person or online here.
Tuesday, 03/21/23 6:00 PM
Night Sky Network: https://www.youtube.com/channel/UCIvuYlhXEKxDrqIL5LSj3fw
Astronomical Society of the Pacific
Expanding Our View with NASA’s Nancy Grace Roman Space Telescope - Livestream
NASA’s next flagship astrophysics mission, the Nancy Grace Roman Space Telescope, aims to expand our view of the cosmos. Scheduled to launch by May 2027, the Roman Space Telescope will enable new science thanks to its unique combination of a large field-of-view, Hubble-like resolution at near-infrared wavelengths, and the ability to rapidly survey large portions of the sky. Join me as we explore what makes the Roman Space Telescope so special and the amazing science to come from this unique space-based mission.
Speaker: Brandon Lawton, Space Telescope Science Institute
12:00 PM - 01:00 PM
SETI Talks: The Origin of Water on Earth: Alien Meteors, Icy Comets, or Solar Wind? - Livestream
Water is necessary for life on Earth, but its origin is still unknown. There are multiple hypotheses about its origin. The most common theory is Earth’s water is alien, crashing down in meteors long ago when Earth was very young. Over the eons, icy asteroids and comets delivered oceans to Earth, depositing the water directly to its surface. Another scenario suggests that most of Earth’s water was already inside the planet and rose to the surface over time. Water’s origin may be more complex, brought to us by the solar wind, for instance.
Two experts in the field, Luke Daly and Ashley King, will discuss their recent research on this topic, moderated by Beth Johnson. Luke Daly is a lecturer at the University of Glasgow’s School of Geographical and Earth Sciences, who has studied the solar wind contributions to Earth’s oceans. Ashley King is a Research Fellow at the Natural History Museum in London, whose recent study of a rare space rock known as the Winchcombe meteorite suggested that this type of asteroid is the primary source of water on Earth.
Register at weblink to receive connection information
11:00 AM - 12:00 PM
In-person and Zoom
Zoom info: https://stanford.zoom.us/j/423773826
Kavli Institute Astrophysics Colloquium
Physics and Astrophysics Building Room 102/103
452 Lomita Mall
Stanford, CA 94305
Searching for Cosmic Dawn and Beyond with Radio Observations
Observations of redshifted 21-cm emission of neutral hydrogen are a rapidly growing area of cosmology research. Measurements of the radio sky at ~200 MHz and below are a promising tool for exploring cosmic dawn, and at the lowest frequencies (tens of MHz), future observations may allow us to one day probe the dark ages. However, observations at these low frequencies are challenging because of Galactic foreground contamination, ionospheric effects, radio-frequency interference, and instrumental systematics. I will discuss the current status of cosmic dawn measurements from ground-based global 21-cm experiments, and I will introduce two projects, MIST and PRIZM. I will also describe ALBATROS, a companion experiment that is designed to image the low-frequency sky using an array of autonomous antenna stations. With the combination of instrumentation advances and new radio-quiet sites, these experiments aim to open observational windows into the early history of our universe.
Speaker: H. Cynthia Chiang, McGill University
Friday, 03/24/23 7PM
Telescope Makers Workshop
Chabot Space and Science Center
10000 Skyline Boulevard
Oakland, CA 94619-245
The Chabot Telescope Maker's workshop reopens! Chabot's TMW is one of only a handful of regularly scheduled telescope making workshops in the U.S., and probably the world; it meets every Friday evening throughout the year, except Memorial Day weekend. It has been in operation since December of 1930, founded by Franklin B. Wright, and is currently run by Eastbay Astronomical Society member Rich Ozer, with help from other EAS members, Dave Barosso, Barry Leska, and others. The price of admission is FREE. All you have to do is show up, buy a mirror blank and a "tool" (typically around $100 - $200 depending on the size of the mirror) and start "pushin' glass!" We supply you with instruction, the various grits you'll need to first grind, and then polish and figure your mirror, and all the testing equipment needed. With a small bit of luck, you could wind up with a telescope that costs 1/3 or 1/4 the cost of a store-bought telescope, that is yet optically superior! It does take time - depending on how much time you put in on it, and other factors, it could take a few months.. But, it's a fun project, great for kids, and at the end you get a great telescope!
Enter from the main loading dock behind the main building.
Please be prepared with proof of vaccination and a mask. These are
Chabot Rules, which we always must adhere to.
If you have a project, bring it with you so we can assess next steps.
You can also bring any other equipment or literature you may have
For more information call or email Richard Ozer at rrichozer1@... or phone (510) 406-1914.
Friday, 03/24/2023 9PM-11PM for night observing and Saturday 03/25/2023
10AM-12 Noon for solar observing
Foothill Observatory is open again!
12345 El Monte Road
Los Altos Hills, CA 94022
Foothill Observatory now Open EVERY clear Friday night and Saturday morning
The Foothill College Astronomy Department and Peninsula Astronomical Society (PAS) have reopened public viewing programs at Foothill College Observatory on:
· Every clear Friday night from 9 p.m. to 11 p.m. for star gazing
· Every clear Saturday morning from 10 a.m. to noon for solar viewing
Since we are still dealing with COVID, we are adopting the following guidelines to enable safe operation of the Observatory for both our public visitors and our PAS operators. We ask that visitors please agree to complying with these guidelines before visiting the Observatory, and to direct any questions to info@....
1. Full vaccination against COVID-19 is required to visit the Foothill College campus — This is a College requirement detailed on the Foothill College COVID-19 Behavioral Expectations page. So bring your vaccination certificate if possible.
2. Mask usage is required anytime visiting the Foothill College campus — This includes the Observatory, per the same college policy linked above in item 1.
3. The number of visitors allowed inside the Observatory is reduced — To avoid overcrowding within the limited space, please wait outside the observatory until a PAS telescope operator lets you and your group inside. Once your group is done viewing through the telescope, you will exit the Observatory so that a new group may enter.
Friday, 03/24/23 and Saturday, 03/25/23
07:30 PM - 10:00 PM--Free telescope viewings are back!
Chabot Space and Science Center
10000 Skyline Blvd
Oakland, CA 94619
Free Telescope Viewings
Join Chabot astronomers on the Observatory Deck for a free telescope viewing! Weather permitting, this is a chance to explore stars, planets and more through Chabot’s historic telescopes. Chabot’s three large historic telescopes offer a unique way to experience the awe and wonder of the Universe. Our observatory deck offers breathtaking views 1,500 feet above the Bay. Three observatory domes house the Center’s 8-inch (Leah, 1883) and 20-inch (Rachel, 1916) refracting telescopes, along with a 36-inch reflecting telescope (Nellie, 2003).
Are the skies clear for viewing tonight? Viewing can be impacted by rain, clouds, humidity and other weather conditions. Conditions can be unique to Chabot because of its unique location in Joaquin Miller Park. Before your visit, check out the Weather Station to see the current conditions at Chabot.
Saturday, March 25
Sunset: 7:26 PM
San Mateo Co. Astronomical Society
1000 Crestview Drive
San Carlos, CA
Public Star Partiesat Crestview Park in San Carlos
SMCAS and the City of San Carlos Parks Department host a public star party at Crestview Park in San Carlos twice a month when there is a new moon. Members set up telescopes and let the public view and share their knowledge of the night sky all for Free. All ages are welcome. If you have kids interested in space or science, bring them here for a real time view of planets, nebula, star clusters, and galaxies.
If you are a Non-member and own a telescope, bring it to share! Experts are available if you need assistance or have questions about buying a telescope.
Telescope setup begins at sunset and observing starts one hour after sunset. In the event of inclement weather (rain, clouds, fog, or high winds) the star party will be cancelled. Because each astronomer makes his or her own decision about bringing their telescope, there is no official cancellation notice.
Crestview Park is located at 1000 Crestview Drive in San Carlos
Saturday, March 25th, 2023 7:00 PM
East Bay Astronomical Society
Exoplanet Watch: Inviting Citizen Scientists to Observe Transiting Exoplanets
Dr. Rob Zellem, Exoplanet Astronomer, Jet Propulsion Laboratory, NASA
Join exoplanet astronomer Rob Zellem, of NASA’s Jet Propulsion Laboratory, as he discusses how we find and characterize exoplanets, planets outside of our own Solar System, with the ultimate goal of detecting signatures of life. He will also discuss current and near future ground- and space-based missions, such as NASA’s Hubble, TESS, and James Webb space telescopes, and a new citizen science project called Exoplanet Watch, which features amateur astronomers conducting observations of exoplanets to help use these resources more efficiently and to discover new planets. He will also cover near-future missions, such as NASA’s next flagship mission, the Nancy Grace Roman Space Telescope and its Coronagraph Instrument, which will take photographs of exoplanets and will establish the technologies needed for the next generation of NASA missions that will be designed to discover alien life.
EAS Members will get a private Zoom invitation by Email