I was born in Milford, Massachusetts and graduated from Milford High School in 1989 (Go Scarlet Hawks!). I was fortunate to attend Harvard University (Go Crimson!), from where I earned my B.A. in Physics, Astronomy & Astrophysics, Magna Cum Laude, in 1993. My undergraduate thesis, "Velocity Coherent Structure in the Dense Cores of Dark Molecular Clouds," was done under the guidance of Professor Alyssa A. Goodman. After graduating from Harvard, I worked for two years in the city of Boston as an urban youth worker (assistant director at an after-school tutoring program called Project 21, and a summer day camp called Camp Ozioma; mentor in a gang-intervention program called Gangs Anonymous). In 1995, I started graduate school at the University of California, Berkeley (Go Bears!).  I earned my Ph.D. in Astrophysics in 2004. My Ph.D. thesis, "Theory and Numerical Simulation of Three-Dimensional Vortices in Protoplanetary Disks," was done under the guidance of Professor Philip S. Marcus in the Berkeley Computational Fluid Dynamics Lab. In 2006, my thesis won the Nicholas Metropolis Prize for Outstanding Doctoral Thesis in Computational Physics from the American Physical Society. I also won a National Science Foundation Astronomy & Astrophysics Postdoctoral Fellowship, which I split between the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara (Go Gauchos!) and the Institute for Theory & Computation at the Harvard-Smithsonian Center for Astrophysics (Go Crimson, again!). I joined the Department of Physics & Astronomy at San Francisco State University (Go Gaters... errr, Gators!) in the summer of 2007.

Classes taught at SF State

PHYS 330: Analytic Mechanics -- F08, F09, F10, F11, F12, F13, F14, F15, F16, F17, F18, F19, F20, F24 --  Syllabus from Fall 2020

Classes taught previously:

PHYS 440/740: Computational Physics -- F12, S14, S16, S18, S20, S22, S24 -- Syllabus from Spring 2024

PHYS 701: Classical Mechanics -- F21, F22, F23 -- Syllabus for Fall 2023

PHYS 712: Physics of Plasmas -- S09, S11, S13, S19, S21, S23 -- Syllabus from Spring 2023

ASTR 400/700: Stellar Astrophysics -- S11, S12, S13, F17 -- Syllabus from Fall 2017

PHYS 220: General Physics with Calculus I -- F07, F08, S09, F09, F10, F11, S12, S14, F14, F15, S16, S17 -- Syllabus from Spring 2017

PHYS 722: Theoretical Astrophysics -- S08 -- Syllabus from Spring 2008

My physics YouTube channel -- some videos where I go over problem-solving techniques

"Flipping Calculus-based Introductory Physics I" -- e-portfolio describing my effort in ``flipping'' Physics 220, as part of the California State University's Course Revision with Technology program.

My field of research is computational astrophysical & geophysical fluid dynamics; that is, I study the motion of fluids on the scale of planets, stars, and interstellar clouds.  Such flows tend to be highly chaotic and turbulent, and so practical solutions of the equations of motion (e.g. the Navier-Stokes equations) require supercomputer simulations.  Here at SF State, we have a small cluster called SF-STAR (Supercomputer Facility for Space & Terrestrial Advanced Research).   I also have allocations through NSF's ACCESS (Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support) (previously XSEDE, eXtreme Science & Engineering Design Environment).

My primary research collaborator is Prof. Philip Marcus at the Berkeley Computational Fluid Dynamics Laboratory, U.C. Berkeley College of Engineering.

My collaborators and I have discovered a new hydrodynamic instability that occurs in stratified, rotating shear flow.  We nicknamed it the "Zombie Vortex Instability" because it occurs in the magnetically "dead zones" of protoplanetary disks, the disks of gas and dust in orbit around newly formed protostars.  It is out of these disks that planets form, somehow growing from micron-sized dust into massive planets in only 10 million years (that's really short on cosmological timescales!).  Another reason we called it the Zombie Vortex Instability is that once one "zombie" vortex is created, it triggers (or infects!) a neighboring region of the flow to go unstable to produce another "zombie" vortex, which then goes on to infect other regions, producing a cascade of "zombie" vortices, which ultimately  makes the "dead zones" of protoplanetary disks no longer dead, but "undead!"

1. Lesur, G., Ercolano, B., Flock, M., Lin, M.-K., Yang, C.-C., Barranco, J.A, Benitez-Llambay, P., Goodman, J., Johansen, A., Klahr, H., Laibe, G., Lyra, W., Marcus, P., Nelson, R., Squire, J., Simon, J., Turner, N., Umurhan, O., Youdin, A., 2023, "Hydro-, Magnetohydro-, and Dust-Gas Dynamics of Protoplanetary Disks," in ``Protostars & Planets VII" (Astronomical Society of the Pacific Conference Series), 534, 465.
2. Barranco, J.A., Pei, S., Marcus, P.S., 2018, “Zombie Vortex Instability. III. Persistence with Nonuniform Stratification and Radiative Damping.” The Astrophysical Journal, 869. arXiv:1810.06588.
3. Marcus, P.S., Pei, S., Jiang, C.H., Barranco, J.A., 2016, “Zombie Vortex Instability. II. Thresholds to Trigger Instability and the Properties of Zombie Turbulence in the Dead Zones of Protoplanetary Disks.” The Astrophysical Journal, 833:148–161. arXiv:1605.07635.
4. Marcus, P.S., Pei, S., Jiang, C.H., Barranco, J.A., Hassanzadeh, P., Lecoanet, D., 2015, “Zombie Vortex Instability. I. A Purely Hydrodynamic Instability to Resurrect the Dead Zones of Protoplanetary Disks.” The Astrophysical Journal, 808:87–102. arXiv:1410.8143.
5. Penev, K., Barranco, J.A., Sasselov, D.D. 2011, “Three-dimensional Spectral Simulations of Anelastic Turbulent Convection.” The Astrophysical Journal, 734:118. arXiv:0810.5151.
6. Lee, A.T., Chiang, E., Asay-Davis, X., Barranco, J.A., 2010, “Forming Planetesimals by Gravitational Instability: II. How Dust Settles to its Marginally Stable State.” The Astrophysical Journal, 725: 1938–1954. arXiv:1010.0250.
7. Lee, A.T., Chiang, E., Asay-Davis, X., Barranco, J.A., 2010, “Forming Planetesimals by Gravitational Instability: I. The Role of the Richardson Number in Triggering the Kelvin-Helmholtz Instability.” The Astrophysical Journal, 718: 1367–1377. arXiv:1010.0248.
8. Penev, K., Barranco, J.A., Sasselov, D.D. 2009, “Direct Calculation of the Turbulent Dissipation Efficiency in Anelastic Convection.” The Astrophysical Journal, 705: 285–297. arXiv:0810.5370.
9. Barranco, J.A. 2009, “Three-Dimensional Simulations of Kelvin-Helmholtz Instability in Settled Dust Layers in Protoplanetary Disks.” The Astrophysical Journal, 691: 907–921. arXiv:0711.4410.
10. Hartman, J. D., Gaudi, B. S., Holman, M. J., McLeod, B. A., Stanek, K. Z., Barranco, J. A., Pinsonneault, M. H., Meibom, S., Kalirai, J. S., 2009, “Deep MMT Transit Survey of the Open Cluster M37. IV. Limit on the Fraction of Stars With Planets as Small as 0.3 RJ .” The Astrophysical Journal, 695:336–356. arXiv:0809.3807.
11. Hartman, J.D., Gaudi, B.S., Pinsonneault, M.H., Stanek, K.Z., Holman, M.J., McLeod, B.A., Meibom, S., Barranco, J.A., Kalirai, J.S., 2009, “Deep MMT Transit Survey of the Open Cluster M37. III. Stellar Rotation at 550 Myr.” The Astrophysical Journal, 691: 342–364. arXiv:0803.1488.
12. Hartman, J.D., Gaudi, B.S., Holman, M.J., McLeod, B.A., Stanek, K.Z., Barranco, J.A., Pinsonneault, M.H., Kalirai, J.S., 2008, “Deep MMT Transit Survey of the Open Cluster M37. II. Variable Stars.” The Astrophysical Journal, 675: 1254–1277. arXiv:0709.3484.
13. Hartman, J.D., Gaudi, B.S., Holman, M.J., McLeod, B.A., Stanek, K.Z., Barranco, J.A., Pinsonneault, M.H., Meibom, S., Kalirai, J.S., 2008, “Deep MMT Transit Survey of the Open Cluster M37. I. Observations and Cluster Parameters.” The Astrophysical Journal, 675: 1233-1254. arXiv:0709.3063.
14. Barranco, J.A. & Marcus, P.S. 2006 “A 3D Spectral Anelastic Hydrodynamic Code for Shearing, Stratified Flows,” Journal of Computational Physics, 219:21–46. arXiv:astro-ph/0509063
15. Barranco, J.A. & Marcus, P.S. 2005, “Three-Dimensional Vortices in Stratified Protoplanetary Disks,” The Astrophysical Journal, 623:1157-1170. arXiv:astro-ph/0501267
16. Barranco, J.A., 2004, "Theory and Numerical Simulation of Three-Dimensional Vortices in Protoplanetary Disks", Ph.D. Thesis, University of California, Berkeley
17. Barranco, J.A., Marcus, P.S., & Umurhan, O.M. 2000, “Scalings and Asymptotics of Coherent Vortices in Protoplanetary Disks,” in Studying Turbulence Using Numerical Simulation Databases – VIII, Proceedings of the 2000 Summer Program, Stanford University/NASA–Ames Center for Turbulence Research, p.85–95.
18. Barranco, J.A. & Marcus, P.S. 2000, “Vortices in Protoplanetary Disks and the Formation of Planetesimals,” in Studying Turbulence Using Numerical Simulation Databases – VIII, Proceedings of the 2000 Summer Program, Stanford University/NASA–Ames Center for Turbulence Research, p.97–108.
19. Barranco, J.A. & Goodman, A.A. 1998, “Coherent Dense Cores. I. NH3 Observations,” The Astrophysical Journal, 504:207-222.
20. Goodman, A.A., Barranco, J.A., Wilner, D.J., & Heyer, M.H. 1998, “Coherence in Dense Cores. II. The Transition to Coherence,” The Astrophysical Journal, 504:223-246.
21. Barranco, J.A. 1993, "Velocity Coherent Structure in the Dense Cores of Dark Molecular Clouds", B.A. Thesis, Harvard University

M.S. Students

12.) Kim Long Le: M.S. Physics/Astro, August 2024. Thesis: "Three-Dimensional Quasi-Geostrophic Simulations of Jupiter’s Zonal Winds and Vortices." Now a PhD candidate in Astronomy at Boston University.

11.) Yan Yan Ley: M.S. Physics/Astro, August 2024. Thesis: "Three-dimensional Simulations of Dust-laden Zombie Vortex Instability."

10.) Lenny Lupin-Jiminez: M.S. Physics, December 2023. Project: "Artificial Intelligence for the Simulation of Highly Nonlinear Physical Systems: Emphasis on Fluid and Geophysical Flows." Now a PhD candidate in Applied Mathematics at U.C. Santa Cruz.

9.) Wendy Crumrine: M.S. Physics/Astro, December 2020. Thesis: "Simulating the Birth of Planets: A Spectral Semi-Lagrangian Hydrodynamic Approach." Now: Ph.D. Physics candidate at U. Southern California.

8.) Nicole Rider: M.S. Physics/Astro, August 2020. Now: Ph.D. Physics candidate at U. North Carolina, Chapel Hill.

7.) Richard McWhirter: M.S. Physics/Astro, December 2018. Thesis: "Application of Thermal Wind Equation to the Jovian Troposphere & Stratosphere." Now: Software Engineer with The Boeing Company in St. Louis, MO.

6.) M. Quinn Parkinson: M.S. Physics/Astro, May 2015. Thesis: "Protoplanet-Planetesimal Interactions in Circumbinary Disks." Now: Haskell Developer with Tokhun.io.

5.) Diana Juarez Madera: M.S. Physics, May 2015. Thesis: "Dust Trapping in Protoplanetary Disk Vortices with a Two-Fluid Terminal Velocity Approach." After SF State: Ph.D. Aeronautics & Astronautics, Stanford University, June 2020. Now: Engineer with Lockheed Martin Corporation in Denver, CO.

4.) Colleen Twitty: M.S. Physics, May 2015. Thesis: "Dust Trapping in Protoplanetary Disk Vortices with a Lagrangian Super-Particle Approach." Now: Software Engineer with Peloton Technology.

3.) Andrew Fittingoff: M.S. Physics, August 2011. Thesis: "Light Curves of Kuiper Belt Objects and a Search for Kuiper Belt Binaries." Now: Adjunct Instructor of Physics with the University of San Francisco, College of Alameda & Laney College.

2.) Samy Kamal: M.S. Physics, August 2011. Thesis: "The Dynamics of Three-Dimensional Vortices in Rotating Stratified Shear Flows." After SF State: Ph.D. Aerospace Engineering, Arizona State University, May 2015. Now: Senior Scientific Programming Analyst at RedLine Performance Solutions, LLC.

1.) Michael Ryan: M.S. Physics, August 2010. Thesis: "Faint Moons Orbiting Kuiper Belt Objects." Now: High school teacher with Sacred Heart Cathedral Preparatory School in San Francisco, CA.

B.S. Students

7.) Arstanbek Tulekeyev: B.S. Physics, May 2021. Project: Simulation of dust trapping in 2D vortices in protoplanetary disks (joint with Collin Richardson). Now: Ph.D. candidate in Applied Math at U.C. Santa Cruz.

6.) Collin Richardson: B.S. Physics/Astro, May 2021. Project: Simulation of dust trapping in 2D vortices in protoplanetary disks (joint with Arstanbek Tulekeyev). Now: Ph.D. candidate in Earth Systems Science at U.C. Irvine.

5.) Michael Shadchin: B.S. Physics/Astro, December 2018. Project: Numerical simulation of orbits of moons of Uranus with time-dependent obliquity. Now: Private tutor.

4.) David Robinson: B.S. Physics/Astro, May 2015. Project: Numerical simulation of gravitational collapse of dust particles with REBOUND. Now: Ph.D. candidate in Computational Science at Florida State University.

3.) Connor Poland: B.S. Physics/Astro, May 2015. Project: Numerical simulation of gravitational collapse of dust particles with REBOUND. Now: M.S. candidate in Computational Science at U.C. San Diego.

2.) Seth Gossage: B.S. Physics/Astro, May 2014. Project: Numerical simulation of protoplanet collisions with Uranus with GADGET2. After SF State: Ph.D. Astronomy, 2021, Harvard University. Now: CIERA Postdoctoral Fellow at Northwestern University.

1.) M. Quinn Parkinson: B.S. Physics/Astro, May 2012. Project: Numerical simulation of dust settling in proto- planetary disks. Enrolled in M.S. program immediately after. M.S. Physics/Astro awarded May 2015 (see above).

I am on the steering committee and am a mentor for Cal-Bridge. The mission of the Cal-Bridge program is to increase the number of California State University (CSU) students completing their bachelor's degree and successfully entering Ph.D. programs to study physics, astronomy, or a closely related field.  The program is open to CSU students of all backgrounds, but we have a focus on students who are from groups historically underrepresented in physics and astronomy, especially Black/African-American, Latinx/Hispanic, Native American/Pacific Islander students and first-generation college students from all backgrounds.

Cal-Bridge Scholars receive up to $10,000 (depending on financial aid) for each of their junior and senior years.  They also meet twice a month with two mentors, one from their local CSU campus and another from a nearby UC campus. Throughout the academic year, the Cal-Bridge Scholars meet for professional development workshops (Python programming, preparing for GRE, writing graduate admissions essays, etc).  Over the summer, they participate in REU programs (many through CAMPARE).  Finally, they receive extensive advice on applying to Ph.D. programs in Physics, Astronomy, or closely related fields.

Campus Service

Sloan Science in Cinema Prize for "Don't Look Up"

On January 7, 2022,  I was on an online Q&A with director Adam McKay & actor Leonardo DiCaprio to discuss the film "Don't Look Up", which won the Sloan Foundation Science in Cinema Prize!  (The event was supposed to be live, but the in-person event was canceled because of COVID-Omicron, so I missed an opportunity to meet  McKay & DiCaprio in person... oh well!) 

Key quote from me: “With public debates over our collective response to crises such as COVID or climate change, I wanted to participate in this panel to highlight the crucial difference between the constructive process of peer review, in which scientists submit their analyses to rigorous scrutiny from peer experts with the goal of improving the quality of the results, versus ‘just asking questions’ of pundits and talking heads whose goal is to intentionally sow distrust and spread misinformation,” said Barranco. “Skepticism can be good and productive when it is entered into with good faith arguments, or it can be destructive when it is used solely to create chaos and hinder consensus toward necessary action.”

https://sffilm.org/event/sloan-presents-dont-look-up/

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08/21/2017 – Was in-studio guest scientist on KTVU (Channel 2 Oakland) for live coverage of Great American Solar Eclipse. Answered questions about the eclipse and eclipse safety from hosts of the morning show “The 9.”

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08/01/2013 -- I appeared on an episode of "Distort" which is "the show that distorts time to show you things your eyes might otherwise miss." "Distort" was a webshow on TestTube, a former education and documentary internet and app channel network under Discovery Digital Networks. Episode was posted online on August 1, 2013.

Me with my partner DeJon and our rambunctious Rottweiler Rza, who was born in June 2014:

In May 2018, DeJon & I attended my 25th Harvard Reunion in Cambridge, MA; here, we are waiting to hear the indomitable Civil Rights pioneer John Lewis speak at the afternoon meeting of the Harvard Alumni Association: