Physics and Astronomy Calendar

All future


Tuesday, February 18th 2020
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Prof. Robert Marshall,Department of Aerospace Engineering Sciences University of Colorado Boulder
Subject: Characterization of Radiation Belt Electron Precipitation using Space-based X-ray Observations

Radiation belt electron fluxes can be enhanced during geomagnetic storms by two orders of magnitude or more; subsequently, these fluxes decay back to nominal levels over the course of days to weeks. However, the mechanisms by which this enhancement and decay occurs are not well understood. Precipitation into the upper atmosphere is one of the primary loss mechanisms for radiation belt electrons, particularly during the decay phase. When these particles impact the upper atmosphere, they create new ionization, which leads to a chemical response that increases NOx and HOx and destroys ozone. Quantifying both the loss from the radiation belts and the impact on the atmosphere requires an accurate estimate of the flux, energy spectrum, and spatial and temporal scales of precipitation. However, such assessments are particularly difficult due to limitations of most measurement techniques.
The recently-funded Atmospheric Effects of Precipitation through Energetic X-rays (AEPEX) CubeSat mission is designed to quantify these parameters of radiation belt precipitation by measuring the bremsstrahlung X-rays created during the precipitation process. These X-rays have previously been measured from high-altitude balloons, but never from space. AEPEX will image the X-ray fluxes produced by the atmosphere, providing measurements of spatial scales, along with the X-ray flux and spectrum. A solid-state energetic particle detector will measure the precipitating electron energy spectrum, which is used to constrain the inversion of X-ray fluxes to electron fluxes. Simulation work has been conducted to show that the combined particle and X-ray measurements can be used to accurately measure the precipitating electron flux and the atmospheric ionization response. In this talk, I will provide an overview of the science goals of the AEPEX mission, a description of the inversion process by which we estimate the electron precipitation flux, and a detailed description of the instrument, spacecraft, and mission design.

2:30 pm:
Nuclear Physics Seminar in Tate 301-20
There will be no seminar this week.

Wednesday, February 19th 2020
1:30 pm:
There will be no seminar this week.

Thursday, February 20th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: There will be no seminar this week.
12:10 pm:
Speaker: Ian Lin
3:35 pm:
Speaker: S. R. Kulkarni, Principal Investigator, Zwicky Transient Facility George Ellery Hale Professor of Astronomy & Planetary Science, California Institute of Technology
Subject: The Restless Universe (How the Periodic Table Got Built up)
Refreshments in atrium after the Colloquium.

The Universe began only with hydrogen and helium. It is cosmic
explosions which build up the periodic table. Astronomers have now
identified several classes of cosmic explosions of which supernovae
constitute the largest group. The Palomar Transient Factory was
an innovative 2-telescope experiment, and its successor, the Zwicky
Transient Factory (ZTF), is a high tech project with gigantic CCD
cameras, sophisticated algorithms (employing machine & deep learning)
and robust pipelines, and squarely aimed to systematically find
"blips and booms in the middle of the night". The speaker will
talk about the great returns and surprises from this project:
super-luminous supernovae, new classes of transients, new light on
progenitors of supernovae, detection of gamma-ray bursts by purely
optical techniques and troves of pulsating stars and binary stars.
ZTF is now considered to be the stepping stone for the Large Synoptic
Survey Telescope.

Faculty Host: Liliya L.R. Williams

Friday, February 21st 2020
12:20 pm:
Speaker: Joe Meese
Subject: Impact of disorder on the coupled magnetic-nematic transitions of iron-based superconductors.
Faculty Host: Boris Shklovskii
12:30 pm:
There is no seminar this week.
2:30 pm:
No Colloquium. Physics Colloquium speaker Thurs: Shri Kulkarni, Caltech
Speaker: Kylie Smith, School of Nursing, Emory University
Subject: Jim Crow in the Asylum: Psychiatry and Civil Rights in the American South
Refreshments served at 3:25 p.m.
4:40 pm:
Speaker: Shaul Hanany
Subject: TBA

Monday, February 24th 2020
12:15 pm:
Speaker: Jose Maria Ezquiaga Bravo, NASA Einstein Fellow, University of Chicago
Subject: Testing gravity and dark energy with gravitational waves

Multi‐messenger gravitational wave (GW) astronomy offers exciting new avenues to test Einstein's theory of gravity as well as the Standard Model of Cosmology. In this talk I will summarize what we could learn about gravity at cosmological scales using standard sirens. In particular, I will focus on tests of the propagation speed, the GW luminosity distance and additional polarizations. Moreover, I will present recent results on how to probe additional cosmological fields with GW oscillations. FinalIy, I will discuss the prospects of observing these effects with present and future GW observatories such as LIGO/VIRGO and LISA.

Faculty Host: M. Claudia Scarlata

Thursday, February 27th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: TBD
12:10 pm:
Speaker: Alexander Criswell
1:30 pm:
Speaker: Daniil Antonenko, Skoltech / L.D. Landau Institute for Theoretical Physics
Subject: Mesoscopic conductance fluctuations in disordered Majorana wires
Please note the date and time of the seminar

We study disordered superconducting wires (of length L), which exhibit a topological phase with a pair of zero-energy Majorana edge states. Our focus is on a quasiparticle thermal conductance (G) in the critical regime between topological and trivial phases, where the interplay of topological effects and Anderson localization is important. We discuss the average conductance along with its mesoscopic fluctuations. We employ nonlinear supersymmetric sigma-model to find var G at arbitrary lengths, including crossover from the weak-localization regime at L << \xi to the regime of a very broad conductance distribution at L >> \xi, where \xi is localization length. We also account for a possible imbalance of right/left movers, described by the topological Wess-Zumino-Witten action.

Faculty Host: Alex Kamenev
3:35 pm:
Speaker: Xavier Siemens, University of Wisconsin-Milwaukee
Subject:  The NANOGrav search for nanohertz gravitational waves
Refreshments in atrium after the Colloquium.

Supermassive black hole binaries (SMBHBs), and possibly other sources,
generate gravitational waves in the nanohertz part of the spectrum. For over a
decade and a half the North American Nanohertz Observatory for Gravitational Waves
(NANOGrav) has been using the Green Bank Telescope, the Arecibo Observatory,
and, more recently, the Very Large Array to observe millisecond pulsars. Our
goal is to directly detect nanohertz gravitational waves, which cause small
correlated changes to the times of arrival of radio pulses from millisecond
pulsars. We currently monitor almost 80 millesecond pulsars with sub-microsecond
precision and weekly to monthly cadences. A detection of the stochastic
gravitational-wave background produced by all the SMBHBs in the universe is
close at hand. I will present an overview of NANOGrav Physics Frontiers Center
(PFC) activities and summarize our most recent gravitational-wave search
results.

Faculty Host: Vuk Mandic

Friday, February 28th 2020
12:20 pm:
Speaker: MM:12.20  Alex Hamill,  12.35 Fei Chen, 12.50  Saumitran Kasturaringan, 13.15  Lis Stolik 13.30  Wen-Han Kao13.45  Cody Schimming
Faculty Host: Boris Shklovskii
12:30 pm:
Speaker: Reserved
2:30 pm:
Speaker: Lars Hansen, University of Minnesota, Earth Sciences
Subject: TBD
Speaker: Michael O’Rourke, Philosophy & AgBio Research, Michigan State
Subject: Epistemic Integration and Cross-Disciplinary Science
Refreshments served at 3:25 p.m.

Thursday, March 5th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: TBD
12:10 pm:
Speaker: Lauren Laufman, Larry Rudnick
3:35 pm:
Speaker: Roger Blandford, KIPAC, Stanford University
Subject: Black Hole Ergomagnetospheres, Electromagnetic Jets and Ejection Disks
Refreshments in atrium after the Colloquium.

Recent, remarkable images, made by the EHT collaboration of M 87, exhibit a ring of emission, presumably orbiting a six billion solar mass black hole. It is proposed that what is observed is not an ion pressure-supported torus, but an extensive "ergomagnetosphere" that connects mechanically to a much larger ``ejection disk??, through a "magnetic clutch". It is conjectured that this magnetic clutch sustains instabilities that transport energy and angular momentum outward as well as upward. The ejection disk is envisaged to be powered primarily by the spinning hole and not the infalling gas, which is expelled as a jet-confining, hydromagnetic wind. Implications for general active galactic nuclei, other sources of relativistic jets and future observations will be briefly discussed.

Faculty Host: Clement Pryke

Friday, March 6th 2020
12:30 pm:
Speaker: Reserved
2:30 pm:
No Colloquium. Physics Colloquium speaker Thurs: Roger Blandford, Stanford University
4:40 pm:
Speaker: Nancy Sims
Subject: TBA

Wednesday, March 11th 2020
3:35 pm:
No Colloquium this week, spring break.

Thursday, March 12th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: Spring Break - no seminar this week.
12:10 pm:
There will be no Journal Club today due to Spring Break

Friday, March 13th 2020
12:30 pm:
Subject: SPRING BREAK - No seminar
2:30 pm:
No Colloquium this week due to spring break

Monday, March 16th 2020
12:15 pm:
Speaker: Peter Taylor, Jet Propulsion Laboratory
Faculty Host: M. Claudia Scarlata

Tuesday, March 17th 2020
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Tomohiko Watanabe, Nagoya U
Subject: Theoretical progress in the feedback magnetosphere-ionosphere coupling

Wednesday, March 18th 2020
1:25 pm:
Speaker: Ray Orbach, University of Texas at Austin
Faculty Host: E. Dan Dahlberg

Thursday, March 19th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: Magnus Bauer, Ludwig-Maximilians-Universität, Hermann Gaub's Lab, University of Munich
Faculty Host: Elias Puchner
12:10 pm:
Speaker: Laura Salo, Evan Skillman
3:35 pm:
Speaker: Ray Orbach, University of Texas at Austin
Refreshments in atrium after the Colloquium.
Faculty Host: E. Dan Dahlberg

Friday, March 20th 2020
12:20 pm:
Speaker: Joseph Joe
Subject: Superconducting bismuthates
Faculty Host: Boris Shklovskii
12:30 pm:
Speaker: Alexander Turbiner (ICN-UNAM, Mexico and Stony Brook)
Subject: Phenomenology in atomic physics: Helium (Lithium) atomic case

With contemporary computational efforts the non-relativistic spectra of Helium (Lithium) atomic sequence He,Li + ,Be + + etc can be calculated with practically any accuracy. Today's physics ``limits" the accuracy to 4 figures in non-relativistic QM treatment and to 12-13 figures (when mass, rel and QED effects are included) then {\it terra incognita}: non-QED effects begin to contribute. Does exist a phenomenological description of these two domains?

Take one-, two-, three-electron atomic ions with infinitely-heavy charge Z and focus to the ground state energy. For Z≤20 , 4 figures are described by the Schroedinger equation, then (mass+rel + QED) corrections start to give
contributions. For all three systems,

{\it Observation 1:} the first 4 figures are described by a 2nd degree polynomial in Z in domain Z≤50(20) (for (1e) case this polynomial is known exactly: - Z2 ).

[surprisingly, Ettore Majorana was the first c.1930 who thought in this direction (excerpts from his recently found unpublished notes)]

{\it Observation 2:} Pade approximant (9,5): P9 / Q5 in variable \sqrt{Z-Z_B}, where ZB is the so-called 2nd critical charge, describes ground state energy in domain Z≤50 (for Helium-like) and Z≤20 (for Lithium like) with 13 figures!

{\it Observation 3:} (mass+rel+QED) corrections contribute in ground state energy to the figures 5,6,7 etc. First 3 figures {\it vs} Z are described by 4th degree polynomial in Z (!) for Z≤20 .

2:30 pm:
Speaker: Charlotte Mason, Harvard
Subject: TBD
Speaker: Janet Greenlees, Glasgow Caledonian University
Subject: So few see the importance of antepartum care’: Early efforts to encourage low income women to engage with prenatal care
Refreshments served at 3:25 p.m.

Monday, March 23rd 2020
12:15 pm:
Speaker: Mike Boylan-Kolchin, University of Texas at Austin
Faculty Host: M. Claudia Scarlata

Wednesday, March 25th 2020
Speaker: Igor Mazin, George Mason University
Faculty Host: Rafael Fernandes
Speaker: Igor Mazin, George Mason University
Faculty Host: Rafael Fernandes

Thursday, March 26th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: TBD
12:10 pm:
Speaker: Hayley Williams, Bob Lysak
3:35 pm:
Speaker: Tomasz Skwarnicki, Syracuse University
Subject: Observation of new pentaquark states and other exotic hadrons
Refreshments in atrium after the Colloquium.

The LHCb experiment recently discovered new narrow pentaquark states decaying to J/psi and proton, which shed more light into the nature of such states reported by the LHCb five years ago. We will describe these results in a broader context of experimental evidence for multiquark states with more than minimal quark content. Future experimental prospects will be outlined.

Faculty Host: Mikhail Voloshin

Friday, March 27th 2020
12:20 pm:
Speaker: Hanteng Wang
Subject: Sachdev-Ye-Kitaev Superconductivity.
Faculty Host: Boris Shklovskii
12:30 pm:
2:30 pm:
Speaker: Andrea Dupree, Harvard, Center for Astrophysics
Subject: TBD
Speaker: Sarah Richardson, History of Science & of Studies of Women, Gender, & Sexuality, Harvard
Subject: Cryptic Effects at a Distance: Constructing Causal Claims in Fetal Epigenetic Programming Research
Refreshments served at 3:25 p.m.

Sunday, March 29th 2020
2:30 pm:
Speaker: TBD

Thursday, April 2nd 2020
11:15 am:
Speaker: Taekjip Ha, Johns Hopkins University will give the Colloquium
Faculty Host: Elias Puchner
12:10 pm:
Speaker: Sean Bruton, Lindsay Glesener
3:35 pm:
Speaker: Taekjip Ha, Johns Hopkins University
Refreshments in atrium after the Colloquium.
Faculty Host: Elias Puchner

Friday, April 3rd 2020
12:20 pm:
Speaker: Aset Khakimzhan
Subject: Statistical mechanics of CRISPR target recognition
Faculty Host: Boris Shklovskii
12:30 pm:
2:30 pm:
Speaker: Phil Kaarat, University of Iowa
Subject: TBD
Speaker: Maria Gonzalez Pendas, Art History and Archaeology, Columbia University
Subject: Holy Modern: Cold War Fascism and the Technoaesthetics of Imperial Imagination
Refreshments served at 3:25 p.m.

Tuesday, April 7th 2020
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Liz McDonald, GSFC
Subject: TBA

Thursday, April 9th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: TBD
12:10 pm:
Speaker: Faculty Intros

Friday, April 10th 2020
12:20 pm:
Speaker: Fei Chen?
Faculty Host: Boris Shklovskii
12:30 pm:
Speaker: Kathryn Zurek (Caltech)
Faculty Host: Maxim Pospelov
2:30 pm:
Speaker: Elizabeth McDonald, NASA Goddard Space Flight Center
Subject: Aurorasaurus.org, bringing together people and science in pursuit of the Northern and Southern Lights

Aurorasaurus is an award-winning, eight-year-old citizen science project that utilizes crowdsourced and citizen science data to produce the first real-time, global map of auroral visibility. The project has demonstrated scientific value in multiple areas, including the efficacy of social media in detecting large natural events; the success of crowdsourced verification of citizen science data; and the increased accuracy of space weather alerts when integrated with citizen science data. The Aurorasaurus team in collaboration with citizen scientists and the scientific community published the first scientific study of STEVE (Strong Thermal Emission Velocity Enhancement), an aurora-like phenomenon that appears closer to the equator and flows from east to west. In addition to discoveries, Aurorasaurus conducts outreach and education across the globe, often through partnerships with local groups of enthusiasts. Aurorasaurus utilizes a new scientific product inventory approach to evaluation, developing further metrics specific to citizen science that are applicable to other projects, and ensuring high standards for applicable use. We will give an overview of the project, how to participate, and also discuss the rising role of citizen science in the space sciences, particularly NASA's Science Mission Directorate.

Speaker: Jacob Steere-Williams, Department of History, College of Charleston
Subject: Typhoid Cultures: Disease, Medical Science, and Popular Politics in Victorian Britain
Refreshments served at 3:25 p.m.

Tuesday, April 14th 2020
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Sam Badman, SSL UCB
Subject:  Modeling and predictions of the large scale magnetic structure measured during Parker Solar Probe's early encounters.

Parker Solar Probe has completed four perihelia passes of the Sun, probing an unprecedentedly close range of radial distances within the ecliptic plane. We use a Potential Field Source Surface (PFSS) corona + ballistic inner heliosphere model as a simple approach to describing the global large scale magnetic configuration of the solar wind measured in situ by PSP during these intervals. For Encounters 1-3 we utilize the PSP data directly in determining the best possible fit from the model and compare to 1AU measurements. We find the PFSS source surface height, time evolution of the input magnetogram and use of in situ solar wind velocity measurements are all important in achieving this optimization, while solar activity and photospheric dynamics limits the applicability of this modeling approach. We also show how simple ballistic propagation allows easy visual comparison of the stream structure measured by PSP and 1AU. We then use lessons learned from this procedure to make "blind" predictions in the run up to Parker Solar Probe's 4th encounter as part of a larger modeling and observing campaign to predict the solar connectivity of PSP. Finally, we use the PSP measurements made during this interval to assess the quality of our predictions, focusing on FIELDS measurements of magnetic polarity to test whether our predictions were on the correct side of the Heliospheric Current Sheet. We discuss lessons learned for making predictions for future Earth-observable PSP and Solar Orbiter encounters.

Speaker: Professor Robert Lysak, University of Minnesota
Subject: Aurora: Mysteries of the Northern Lights

Thursday, April 16th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: Li-Chun Tu, Ohio State University
Faculty Host: Elias Puchner
12:10 pm:
Speaker: Cody Carr
3:35 pm:
Speaker: Michael Riordan, University of California Santa Cruz
Refreshments in atrium after the Colloquium.
Faculty Host: Michel Janssen

Friday, April 17th 2020
12:20 pm:
Speaker: Xiaojun Fu
Subject:  "Anomalous broken symmetry states in half-filled high Landau levels".
Faculty Host: Boris Shklovskii
12:30 pm:
2:30 pm:
There is no MIFA colloquium this week
Speaker: Ian Burney, Center for History of Science, Technology and Medicine, University of Manchester
Subject: Erle Stanley Gardner’s ‘Court of Last Resort’ and the Pursuit of Wrongful Conviction in Cold War America
Refreshments served at 3:25 p.m.

Wednesday, April 22nd 2020
1:30 pm:
Speaker: Liang Fu, MIT
Faculty Host: Rafael Fernandes

Thursday, April 23rd 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: TBD
12:10 pm:
Speaker: Nathan Eggen, Liliya Williams
3:35 pm:
Speaker: Liang Fu, MIT
Student Award ceremony before colloquium. Refreshments in atrium after the Colloquium.
Faculty Host: Rafael Fernandes

Friday, April 24th 2020
12:20 pm:
Speaker: Virginia Gali
Subject: "Impact of electromagnetic fluctuations on the ground state of p-wave and d-wave superconductors"
Faculty Host: Boris Shklovskii
12:30 pm:
2:30 pm:
Speaker: Samar Safi-Harb, University of Manitoba
Subject: TBD
Speaker: Sigrid Schmalzer, Department of History, University of Massachusetts – Amherst
Subject: Connecting the Dots: A History of Systems Thinking in Chinese Agricultural Science and Politics
Refreshments served at 3:25 p.m.

Thursday, April 30th 2020
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: Matthew D. Lew, Assistant Professor, Preston M. Green Department of Electrical and Systems Engineering, Washington University in St. Louis
Subject: TBA
Faculty Host: Elias Puchner
12:10 pm:
Speaker: Tom Jones
3:35 pm:
TBD in B50 Tate
Speaker: Bob Brown, Case Western University
Faculty Host: Paul Crowell

Friday, May 1st 2020
12:30 pm:
2:30 pm:
Speaker: Daniel Goldstein, CalTech
Subject: TBD
Speaker: Edouard Machery, History and Philosophy of Science, University of Pittsburgh
Subject: What’s a Replication?
Refreshments served at 3:25 p.m.
7:00 pm:
15th Annual Misel Family Lecture in McNamara Alumni Center
Speaker: Professor Klaus von Klitzing, Max Planck Institute for Solid State Research
Subject: How my Nobel Prize contributed to a new kilogram

On World Metrology Day 2019 (20.5.2019) all countries in the world changed the definitions for the following base units of our International System of Units (SI system): the kilogram, the ampere, the kelvin and the mole. In an historic vote on 16.11.2018, the General Conference on Weights and Measures, which represents 98% of the world gross product, decided this change unanimously. This decision means that all SI units will now be defined in terms of constants that describe the natural world. This change was optimized in such a way, that nearly nothing happened in our daily life but in the field of high precision measurements, some adjustments were necessary and more importantly, the new international system of units will be more stable.

The quantized Hall resistance (Nobel Prize 1985) played a crucial role for the realization of this new SI system since this quantum resistance can be used not only for high precision measurements of electrical standards but also for a new realization of a kilogram by comparing electrical and mechanical forces with the Kibble balance.

The talk summarizes the application of the quantum Hall effect in metrology with the focus on the replacement of the kilogram by a fixed value for the Planck constant.

Faculty Host: Alex Kamenev

Saturday, May 2nd 2020

Sunday, May 3rd 2020

Friday, May 8th 2020
2:30 pm:
Speaker: Ryan Terrien, Carleton College
Subject: TBD

Wednesday, May 13th 2020
1:25 pm:
Speaker: Oleg P Sushkov, UNSW Sydney
Subject:  Lifshitz spin liquid
Faculty Host: Andrey Chubukov

Thursday, May 14th 2020

Friday, May 15th 2020

Saturday, May 16th 2020

Wednesday, October 21st 2020
7:00 pm:
Van Vleck Public Lecture in B50 Tate Hall
Speaker: Rai Weiss, MIT
Subject: To be announced

Thursday, October 22nd 2020
3:35 pm:
Speaker: Rai Weiss, MIT.
Refreshments in atrium after the Colloquium.

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