A physicist at FEDSM2026

Every once in a while I blog about some conferences that I attended, such as the 2018 Joint Mathematics Meeting in San Diego, the 2023 American Physical Society (APS) March Meeting in Las Vegas, and the 2024 APS Division of Fluid Dynamics (DFD) Meeting in Salt Lake City.  I'm now adding to this series by discussing my attendance at the American Society of Mechanical Engineers (ASME) Fluids Engineering Division (FED) summer meeting (FEDSM) in Bellevue, WA.  FEDSM2026 also celebrates the centennial of the FED, an anniversary I mentioned earlier this year.  For most of the year I wasn't sure if I would be able to attend, but I finally registered in late June.  The conference ran from July 26-29, 2026, and met concurrently with ASME's Summer Heat Transfer Conference (SHTC) and its Energy and Sustainability (ES) Conference.  Attendees were allowed to cross-attend most events in all three meetings, and the reception and two of the lunches were communal among all three.

Bellevue is on the other side of Lake Washington from Seattle, and I flew into SEA-TAC airport on Sunday July 26.  I had been to Bellevue once before, to visit Bellevue Square for dinner with friends.  Bellevue Square was within walking distance of the conference venue.  I had a chance to take a walk through Bellevue's Downtown Park, and nearby Meydenbauer Bay Park that afternoon, before returning to the conference venue (the Hyatt Regency) for the evening reception.  Tragically there was a mass shooting over in Seattle that occurred during the Bite of Seattle event at Seattle Center that very evening.  Those of us at the reception were blissfully unaware of the tragic events that unfolded that evening.

The first regular day of the meeting, Monday the 27th, was the day I was most looking forward to.  It began with an outstanding plenary talk by Prof. Alfred Soldati (TU Wien), on "Bubble and Drop Breakup in Turbulence."  He was also the recipient of this year's ASME Fluids Engineering Award, the division's highest award.  I'll skip ahead and mention the final plenary talk of the meeting, on Wednesday morning the 29th, on "Particles in Liquids:  Collisions, Stress, and the Legacy of R. A. Bagnold" by Prof. Melany Hunt of CalTech. Both of these talks focused on multiphase flows, and were outstanding.  Not only was the research presented extremely interesting, it was presented very well by both speakers.  Unlike some of the routine technical talks, these plenary talks were well organized and easy to follow -- I would even say riveting.  I could imagine either talk being presented at APS-DFD, as they addressed fundamental issues.  My complements to FED for selecting these plenary speakers.

Returning to the first day, Prof. Soldati's keynote was followed by the FEDSM town hall, a sort of annual report on the division.  As this was my first attendance at FEDSM (and only second at an ASME-only conference), I found it very informative.  FEDSM is an annual event, but every four years (including 2027) instead of co-meeting with SHTC and ES, they co-meet with the Japanese and Korean mechanical engineering societies in Asia, at an event known as AJK.  However, FEDSM does sponsor tracks in the SHTC/ES joint meeting back in the states. Finally FEDSM sponsors tracks at the annual international ASME meeting, called the IMECE (International Mechanical Engineering Congress and Exposition).  I also learned that FED sponsors two journals, the Journal of Fluids Engineering and the Journal of Verification, Validation, and Uncertainty Quantification.  The current lead editor of JFE is D. Keith Walters of the University of Arkansas, and the current lead editor of VVUQ is Aaron Koskelo of Los Alamos National Labs (who could not attend the conference).  There were at least 260 registrants of the conference, though there were certainly a lot more than that number present, due to the co-meeting with SHTC and ES.  Even so, the combined conference still felt smaller than APS-DFD.  Another sign of this is that there were hardly any exhibitors at this meeting, and no separate exhibit hall.  Rather, the large open space in front of the ballrooms served as the exhibit space (I counted only 3-4 exhibitors) as well as the reception area and the registration area.  The above photo looks down the hall through this space.  The photo below shows part of the hotel lobby, with the ballroom area visible on the second floor.

I was eager to attend the two sessions on Fluids Education, one scheduled before lunch, and one after.  They did not disappoint.  One of the speakers, Prof. Ivana Milanovic of U. Hartford, gave an informative talk on the history of fluids education in the U.S., during the afternoon session. There was also a memorable joint presentation by Profs. Aarthi Sekaran (SUNY Poly) and Sarah Beetham (Oakland U.) on a very crafty experimental flow visualization project they incorporated in their classes.  The morning session had a focus on artificial intelligence (AI), a topic that came up in nearly every side-conversation I had, whether at lunch or at the reception.  The morning session keynote by Prof. Ganesh Raman (California State University's assistant vice chancellor for research) described how his university system was implementing AI at university-scale.  The afternoon session ended with a presentation by a very precocious high school student.

Later that afternoon, I attended a memorial session for Frank White, a major figure within the FED (for example, he was once lead editor of JFE), as well as the University of Rhode Island.  He is known worldwide as the author of acclaimed textbooks in fluids and heat transfer.  Finally, I ended the day by attending the Energy and Sustainability Power Hour, which was kind of like a networking/focus group session.  It was quite fun.  Indeed, the networking opportunities here, at the reception, and all three lunches, were an unexpected highlight of the meeting. Because of its smaller size, I interacted with far more attendees on a personal level than I usually do at APS-DFD.

I ended the evening with a very late dinner at Din Tai Fung, which was right across the street from the hotel (shown above), sampling (among other dishes) their famed Xiaolongbao, shown below.

There were so many tempting restaurants in the immediate area, that I felt as if I were missing out on all the places I didn't have the time to try!  This Din Tai Fung was the third I have eaten in, having previously visited the ones in Santa Monica, CA, and Taipei, Taiwan (in the 101 Taipei skyscraper).

I allowed myself to sleep in on the morning of Day 2, having been severely sleep deprived for the previous two nights in a row.  Thus I missed that morning's keynote, which I did not regret, as I observed the speaker take a phone call during someone else's talk later that day.  How rude!  On Day 2, I began flitting in and out of the regular technical sessions, which I continued to do in the late morning of Day 3.  The awards lunch was held on Day 2, and I even got to have a small slice of the FED centennial birthday cake!

Based on the photo of the uncut cake that FED posted on LinkedIn, it appears that my piece captured part of the "E" in ASME, under which was written "Setting the Standard".  So the "AR" is from the end of "Standard".

I attended an afternoon plenary talk by Joseph Katz (Johns Hopkins), like Frank White, a former lead editor of JFE and textbook author.  His talk was titled "Turbulent Boundary Layers over Complex Surfaces" (see below).

I ended Day 2 by attending a panel session at the SHTC on "Modern Insights into Computational Fluid Dynamics".   Unfortunately I could not make much sense of it, as I had missed the panelists' individual presentations because I was at the Katz plenary.  I managed to catch the end of the panel discussion, but it was less useful to me than I had hoped.  That evening I had dinner at Fogo de Chao, the Brazilian steakhouse, within walking distance of the hotel.  On the way there I observed what appeared to be a pro-Ukraine protest on a street corner.  The concierge at my hotel gave me a coupon for a free dessert at Fogo de Chao; here is a shot of my key lime pie:

On Day 3, the day began with a panel session on the "Past, Present, and Future of Fluid Mechanics".  The panelists and their focus were, in order, Professors Ted Heindel (Iowa State University) on experimental fluid mechanics, Zhonquan Zheng (Utah State University) on computational fluid dynamics, and Francine Battaglia (U. of Buffalo) on fluids education.  The moderator was the conference chair, Prof. Ning Zhang (McNeese State U.).

Here are the panelists, conveniently sitting in the order in which they spoke:

The panel session was followed by Prof. Melany Hunt's plenary, which I discussed above.  I then attended a technical session, and joined the third and final lunch.  Unfortunately I had to catch a plane, so I headed back to the airport and missed the Rising Stars plenary session that ended Day 3.  It was perhaps regrettable that I was so busy chatting to folks at my table at the lunches, that I completely missed out on the poster sessions.

Conference papers are already posted on the ASME website, and there is supposed to be a special issue of JFE next August (yes, a year from now) with papers from this year's conference.  However, the division promises to have special centenary articles in forthcoming issues of JFE and Mechanical Engineer magazine later this year.  Finally, unlike with the 2023 APS March Meeting, I used the ASME meeting app without any difficulties at FEDSM2026.  

I would like to add that the meeting hotel, the Hyatt Regency, was very impressive.  Every staff member I interacted with was unfailingly nice and helpful.  They even made special hotel room keys for the conference, which I kept as souvenirs:

This was the first time I've seen a hotel make themed room keys, but I'm sure it won't be the last.  My stay was only marred on the last day by a partial power outage in my tower.

So, what did this physicist think?  I was glad to have attended the once-in-a-lifetime centenary meeting of the FED.  It nourished my soul.  I doubt I will have the means and opportunity to attend either the FEDSM or DFD annual meetings for a very long time, so it was particularly fortunate that I did have the ability to attend this year's centennial FEDSM (being in the western U.S. helps).  As I mentioned in my post on the 2024 DFD, the fluids specialty meetings are probably of lesser interest to me at this stage of my career than a larger meeting like the APS Global Physics Summit (formed form the merger of the March and April meetings).  There was definitely more of a focus on engineering research at FEDSM than I have seen at DFD.  On the other hand, this being a smaller meeting (even accounting for the fact that three different conferences were meeting together) allowed me far more face-to-face networking than I usually do at either APS DFD or the March Meeting.  This, despite that I did not meet a single person that I knew from beforehand.  In summary, I had a great time at FEDSM and in Bellevue, but it's unlikely I'll be able to go to another FEDSM (or DFD) for a very long time.

 

Can't stop blogging about book reviews!

My last post commented further about book reviews in the physics community.  An announcement today that the Mathematical Association of America (MAA) has appointed a new editor for its MAA Reviews has reminded me that the mathematical community is doing relatively better on the book review front than the physics community is.  I don't read MAA Reviews regularly, but I see that it is a professional-society sponsored source of curated book reviews.  They also feature a Basic Library List, a downloadable spreadsheet which includes books they recommend for college and university libraries.  The list is annotated with a star system, with 3 stars for books considered essential, 2 stars for strongly recommended, 1 star for "recommended", and zero stars for "suggested".  I haven't examined the list in detail, but conceptually this seems to be a good idea, and quite useful for students and self-learners as well.

More broadly, I can't speak to the quality of MAA Reviews, as I'm not a regular reader, but the concept seems like exactly what I think is missing in the physics community.  As a bonus, all the content seems to be freely available online.  Unfortunately, using the search feature I was able to find only a single reviewed book in the field of fluid mechanics, and only 3 under physics.  Its coverage of statistics is not at all comprehensive, with only 6 books showing up in the search feature for statistics, 6 more for probability, with 3 more under probability theory, two under "Statistics and Probability", one more under Bayesian statistics, one each under classification and clustering, one more under data visualization, and one more under data analysis.

The Basic Library List has much better coverage, but no reviews are attached to the entries.  Looking at the fluid mechanics sections of the list, I count only 13 titles included, of which only two are rated at 3 stars (essential), both by James Lighthill:  his Waves in Fluids and Informal Introduction to Theoretical Fluid Mechanics.  Both are excellent choices that I would agree with.  There are no 2 star recommendations, but earning a single star are Acheson's Elementary Fluid Mechanics, Lamb's Hydrodynamics, Courant and Friedrichs' Supersonic Flow and Shock Waves, Stoker's Water Waves, and a book I'd not heard of until now, Gary Sod's Numerical Methods in Fluid Dynamics.  Aside from that last one, I would consider the rest as classics.  A 14th book, Batchelor's Introduction to Fluid Dynamics, also a classic, appears under "Mathematical Physics:  Fluid Mechanics".  However there are quite a few other classics that should have been included, many of which were written by physicists or engineers.  So, in execution the list might not live up to my expectations, but I suppose opinions about books are always subjective, so that no such list would make everyone happy.

In addition to MAA, I am a member of SIAM (the Society for Industrial and Applied Mathematics), and their SIAM Review (a journal sent to all members) maintains a healthy book review section.

Anyway, perhaps the physics community needs a source of free, online, curated book reviews in the spirit of MAA Reviews, to replace the fallen books section of Physics Today.  A professional society might be a good central place to host one.

 

 

 

 

 

 

 

Congratulations to the ASME Fluids Engineering Division on their 100th anniversary

Earlier this month, I learned that the Fluids Engineering Division (FED) of the American Society of Mechanical Engineers (ASME) is celebrating its 100th anniversary this summer at their annual summer meeting (FEDSM2026).  They may be the oldest fluid mechanics-specific professional society in the United States...let's take a look at the evidence for this claim.

First, ASME was founded in 1880, and its Hydraulics Division (HYD) was formed in 1926, with Prof. Lewis F. Moody as a prime mover in its creation.  Its first separate division conference was held in 1961.  Prof. Robert C. Dean led the effort to change its name to the Fluids Engineering Division (FED) which succeeded in 1963.  A restructuring occurred in 1989-1990, but the name remained.  There was also a Committee on General Hydraulics which existed between 1938-1940, led by Murrough P. O'Brien, and later a Fluid Mechanics Committee, formed in 1957 by Dean, now called the Fluid Mechanics Technical Committee (FMTC).  The Journal of Fluids Engineering was founded in 1973, also under Dean, its first editor.  I've pulled this information from the article by Cooper et al. (2016).

We must turn now to the American Society of Civil Engineers (ASCE), founded much earlier (1852).  Its Hydraulics Division was formed in 1938, the 12th such division formed.  Fred C. Scobey of USDA was the prime mover of that effort.  Its first specialty conference was held in 1950, and its Journal of the Hydraulics Division began in 1956.  In 1982, the journal was renamed the Journal of Hydraulic Engineering.  A 50th anniversary book for the division was published in 1990, but I have not been able to see a copy.  My information is drawn mainly from Petersen (2002).  It is unclear to me from the society's website whether the Hydraulics Division, or its specialty conference, still exist, but the journal definitely does.

The American Physical Society (APS, founded in 1899) created its Division of Fluid Dynamics (DFD) in 1947, its fourth division.  Raymond J. Seeger was the prime mover of this effort.  The first annual meeting was held in 1949, though sessions were sponsored at the 1948 APS annual meeting, including a joint meeting with the Institute of Aeronautical Sciences (a predecessor to the AIAA, about which more later).  However the APS did not start a special fluid mechanics journal until 2015, Physical Review Fluids.  Prior to that, the DFD collaborated with the American Institute of Physics (AIP) in the publication of Physics of Fluids, founded in 1959 under Francois Frenkiel.  Some historical information on the DFD can be found in this piece by Russell Donnelly.

For the remainder of this post, information is drawn from Wikipedia and/or the websites of the professional societies themselves.

The American Institute of Aeronautics and Astronautics (AIAA) was formed in 1963 from the merger of the Institute of the Aerospace Sciences (founded in 1932 under the name Institute of Aeronautical Sciences, mentioned above), and the American Rocket Society, founded in 1930.  At one time the AIAA sponsored a Fluid Dynamics Conference, but it does not seem to exist anymore.  They do have a Fluid Dynamics Technical Committee, within their Aerospace Sciences Group.  I do not know when it was formed, but it can't be older than AIAA itself.  AIAA does not seem to have a specialty journal for fluids; rather fluids papers appear across the constellation of their journals on other subjects.

The same about the journals can be said about the American Institute for Chemical Engineering (AIChE), founded in 1908.  They don't seem to have a specialty journal, conference, or division or forum dedicated to fluids, as the topic basically pervades much of the discipline, as it does for AIAA.

Indeed, many professional societies in science, mathematics, engineering, and the Earth, environmental, and planetary sciences make use of fluid mechanics, and many of their practitioners carry out fundamental research in fluids.  Fundamental and applied topics in fluids research pervade across multiple technical areas within these professions, so often they do not have a fluids-specific unit, journal, or conference.  Examples include the Society for Industrial and Applied Mathematics (SIAM), the American Geophysical Union (AGU), and the American Meteorological Society (AMS).  However, the AMS does host an annual Atmospheric and Oceanic Fluid Dynamics (AOFD) conference.  It has not always been annual (the most recent, just held earlier this week, was called the 25th, but I coauthored a presentation given at the 13th in 2001), so I'm not sure when it began.  I have seen an announcement for the 2d AMS Atmospheric and Oceanic Waves and Stability conference in 1978, so perhaps this is the same conference under a different historical name?

So to conclude, the major U.S. professional society units that specialize in fluid mechanics appear to be the ASME's FED and the APS's DFD, both of which sponsor annual conferences and journals (JFE and PR Fluids).  The AIAA has a technical committee but no special conference or journal.  The AMS also has their AOFD annual conference, and the ASCE maintains the Journal of Hydraulic Engineering. To these we can add the AIP's Physics of Fluids journal.

The surviving units, ASME FED and APS DFD, were created in 1926 and 1947 respectively, so indeed FED is the oldest that I know of in the United States.  The ASCE has the oldest journal discussed here, however, since JHE dates to 1956, with PoF following in 1959, JFE in 1973, and PR Fluids in 2015.  Finally the oldest surviving conference discussed here is DFD's, starting in 1949, followed by FEDSM in 1961, and AOFD possibly dating to sometime in the 1970s.

References

P. Cooper, C. S. Martin, and T. J. O'Hearn, 2016:  History of the Fluids Engineering Division.  Journal of Fluids Engineering, 138:  100801.

M. S. Petersen, 2002:  Summary of the Hydraulics Division- ASCE (1938-1988).  Environmental and Water Resources History, ed. by J. R. Rogers and A. J. Fredrich, Sessions at ASCE Civil Engineering Conference and Exposition, Nov. 3-7, 2002, Washington, DC., pp. 193-194.

Hydrodynamic Quantum Analogs and nonlocality

Last month's SIAM News featured a front-page, above-the-fold article by Prof. John Bush of MIT, "Shifting the Classical-Quantum Boundary:  Insights from Pilot-wave Hydrodynamics".  Among other things, the article challenges the conventional wisdom that quantum theory is inherently and demonstrably nonlocal.  It does so by championing Hydrodynamic Quantum Analogs (HQAs), which are classical analogs of quantum phenomena, using fluid mechanics.  The author uses HQAs to lend credence to the de Broglie-Bohm pilot wave formulation of quantum mechanics.

I have a passing interest in HQAs, regardless of whether they supports alternate interpretations of quantum mechanics, or challenge nonlocality.  I keep an open mind about Bush's assertions, but am neither a cheerleader nor dogmatic opponent of these ideas.  More importantly, I know almost nothing about the field, except what I've learned from Bush's article, and glimpses of other papers in the area (including his) that I've seen over the years.

However I do think Bush does his readers a disservice in the following passage.

The notion of nonlocality, or action at a distance, should be anathema to any rational scientist. Nevertheless, most physicists have made peace with it; they either remain agnostic on the subject or believe it to be an essential, inescapable feature of quantum physics. Because standard quantum theory describes probabilities but not particle dynamics, nonlocality is perceived to be everywhere — in wavefunction collapse, single-particle interference, the quantum mirage, and interaction-free measurement. Correlation at a distance is taken as evidence of action at a distance. HQAs have demonstrated that if we adopt de Broglie’s physical picture of quantum dynamics, we need not invoke nonlocality for any such effects. In short, HQAs suggest that quantum nonlocality is a misinference that is rooted in the incompleteness of quantum theory. While nonlocality is a feature of quantum theory, it need not be a feature of quantum physics.

I've quoted the whole paragraph to ensure that context is provided, but the main problem I have is with the very first sentence of this paragraph.  Should "action at a distance" be "anathema to any rational scientist"?  I am reminded of Bohr's response to Einstein, who said "God does not play dice."  Bohr replied, "Don't tell God what to do."

Newton's original formulation of his gravitational law was manifestly an action-at-a-distance phenomenon.  Yes, it has been superseded by a local field theory, Einstein's general relativity. But is it fair to accuse Newton of not being a "rational scientist"?  (Perhaps so given his interest in alchemy and biblical chronology, but surely not because of his gravity theory!)  What about the 19th century action-at-a-distance rivals to Maxwell's theory (such as Weber's electrodynamics).  Note how Coulomb's law resembles Newton's.  Again, the rival theories were essentially cast aside as incomplete or even wrong once Maxwell's local field theory was fully understood and accepted, but does that make Coulomb, the Webers, and others failures as rational scientists?

Bush gives no citation nor even an argument as to why action at a distance is unworthy of a "rational scientist".  This is because it is nothing more than an opinion, a preference of the author.  He is just offended by the notion of nonlocality in nature.  Offended!

It's okay to be offended.  Such attitudes drive research on the foundations of quantum theory, in defiance of the "shut up and calculate" mentality.  Such research has led to quantum information science, quantum computing, etc.  This is all good stuff!

All I'm saying is that Bush's dictum, that nonlocality should be anathema to rational scientists, is the least persuasive sentence in this article.  The sentence is itself irrational, as it is based on neither reason nor evidence - it is a purely emotional expression as it stands.  And yes I am also making an emotional expression when I condemn it.  

Perhaps there is a good reason that nonlocality should not be considered rational science, and I'm sure other physicists and philosophers have advanced such reasons.  But Bush fails to do so in this article, nor did he cite those who do.  It's nothing but a cheap shot.  In this, he has not served his readers well.

Finally, I realize that it's quite funny that I wrote an entire blog post about one pesky sentence in an otherwise intriguing and informative article :-)

 

The women cited in Lamb's Hydrodynamics

I was skimming through the index of the sixth (and final) edition of Horace Lamb's Hydrodynamics (Cambridge University Press,1932), when I stumbled upon the name of "Miss Fawcett".  Later was a "Miss Swain".  And I also found Sophie Kowalewski, a famous female mathematician (better known as Sofya Kovalevskaya, 1850-1891).  These were the only obviously female names I could find in the index.

Let's start with Kovalevskaya.  I knew she had worked in mathematical physics, primarily because of her work on rigid body dynamics and the "Kovalevskaya top", well discussed in Roger Cooke's book about her mathematics (Springer, 1984, Ch. 7).  However Cooke also discusses (Ch. 4) her reformulation of Laplace's model of the rings of Saturn, a self-gravitating liquid annulus.  It is this 1885 paper that Lamb cites in his Art. 376.  It was published in the Astronomische Nachrichten, 111 (3):  38-48.  The first page is reproduced here:

  

Now, who are Miss Fawcett and Miss Swain?  Both were British mathematicians.

Philippa Garrett Fawcett  (1868-1948) was the first woman to achieve the top score at Cambridge University's Mathematical Tripos examinations.  In 1893 she published "Note on the motion of solids in a liquid" in the Quarterly Journal of Pure and Applied Mathematics, 26:  231-258.  Here is the first page:

 

This is the paper cited by Lamb in his Art. 130.

Finally Lorna Mary Swain (1891-1936) is another Cambridge grad, who has two papers cited in Lamb's Hydrodynamics.  The first is a 1915  joint paper with Lamb himself, "On a tidal problem", The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, series 6, 29 (174):  737-744.  (Lamb did not insert his own name into his book's name index.)  Here is the first page of the Lamb and Swain paper:

 

The second is a 1923 paper with Arthur Berry, "On the steady motion of a cylinder through infinite viscous fluid", Proceedings of the Royal Society of London, Series A,102 (719):  776-778.  Lamb cites this in his Art. 339.  Here is what the first page looks like.

 

I find it interesting that both Miss Fawcett and Miss Swain are referred to as such in both the journal articles themselves, and Lamb's book.  

Lamb's monograph is probably the oldest of the "classic" fluid mechanics texts that can still be found on researchers' bookshelves today, thanks to a Cambridge Mathematical Library reprint edition. So it is notable that at least 4 papers by at least 3 female authors/coauthors were cited even in the venerable Lamb.  I also found Ben Franklin in the index as well!

 

 

 

Mathematical fluid dynamics, revisited

In April I noted a piece in Scientific American about the work of 3 mathematicians on their work rigorously deriving the links among 3 levels of hierarchy involving the description of fluid dynamics.  Recently a really nice piece by Leila Sloman for Quanta magazine, on the same topic, has been making the rounds.  Again, it's worth checking out.

 

Peter Lax, 1926-2025

As I noted just last month, DTLR does not dwell on mathematics very much, but a second exception seems just as warranted as my earlier post last month.  Today we learn of the passing of Abel Prize laureate Peter D. Lax (1926-2025), a retired professor at the Courant Institute at NYU, last Friday.  He was a highly accomplished pure and applied mathematician, who worked in the field of partial differential equations, and on numerical methods for their solution.  Much of this work has direct relevance to applied physics and engineering, including fluid dynamics.

Prof. Lax is also the only Abel Prize winner I have ever met in person.  It was just a brief meeting during a visit I made to the Courant Institute in the late 2000's on other business.  We did not exchange many words, but I was honored to meet him.

I've attended lectures by at least two other Abel Prize winners, S.R.S. Varadhan and the late John Nash, but did not meet them face to face.

I'll take this chance to mention my encounters with winners of the other major international prizes in mathematics.  As far as I know, I have neither met nor attended lectures by any of the Fields Medalists, except for Shing-Tung Yau.  As for the Wolf Prize in Mathematics, both Lax and Yau are the only ones I've personally encountered as noted.  Well, it must be evident that I don't attend math conferences or math lectures very often.

Mathematical fluid dynamics

I don't often write about mathematics here on DTLR, but this piece by Jack Murtagh in Scientific American is a worthy exception, as it pertains to fluid dynamics.  Namely it reports on the work of 3 mathematicians who claim to have found a way to derive the hierarchy of methods for 3 levels of describing fluid motion, the individual particle level, the statistical description of particle behavior of Maxwell and Boltzmann, and the continuum level of the Euler and Navier-Stokes equations.  The mathematicians posted their work to arXiv, so let the peer review proceed.

 

 

 

My reading in physics biographies

My last post mentioned that I read a biography of C.-S. Wu earlier this year.  This has been part of a larger effort to start reading the biographies of notable physicists, which I began in the summer of 2023, after watching Christopher Nolan's Oppenheimer film.  So far, here are the substantial biographies I've made it through, in chronological order:

• Robert Oppenheimer:  A Life Inside the Center, by Ray Monk (Doubleday, 2012).

• Galileo: Decisive Innovator, by Michael Sharratt (Blackwell, 1994).
  
• Einstein:  His Life and Universe, by Water Isaacson (Simon & Schuster, 2007).
• Jean D'Alembert:  Science and the Enlightenment, by Thomas L. Hankins (Oxford University Press, 1970).
• The Man Who Changed Everything:  The Life of James Clerk Maxwell, by Basil Mahon (Wiley, 2004).
• Madame Wu Chien-Shiung:  The First Lady of Physics Research, by Chiang Tsai-Chien (World Scientific, 2014).

In addition, I read the following short biographies, again in chronological order:

• Isaac Newton, by James Gleick (Pantheon, 2003).
  
• Michael Faraday:  A Very Short Introduction, by Frank James (Oxford University Press, 2010).

• Niels Bohr:  A Very Short Introduction, by J. L. Heilbron (Oxford University Press, 2020).

The Bohr book was the only one so far that I've been disappointed with.

In earlier years, I've read other biographies of physicists; the ones I can remember include:

• Degrees Kelvin:  A Tale of Genius and Invention, by David Lindley (Joseph Henry Press, 2004).
• True Genius:  The Life and Science of John Bardeen, The Only Winner of Two Nobel Prizes in Physics, by Vicki Daitch and Lillian Hoddeson (Joseph Henry Press, 2002). 

I've also read the autobiographies of Max Planck and physicist-turned-quant, Emanuel Derman.

Future ambitions include tackling substantial biographies of Planck, and more on Galileo, Newton, and Maxwell.   In addition I'd like to add biographies of Leonhard Euler, A.-L. Cauchy, Lord Rayleigh, J. W. Gibbs, Lise Meitner, R.P. Feynman, and P. W. Anderson.  And ultimately I'd like to include 20th century fluid dynamicists; there exist biographies of Ludwig Prandtl, G. I. Taylor, and James Lighthill, and an autobiography of Theodore von Karman, though realistically I may only get to Prandtl and Taylor.  (I have read Iris Chang's Thread of the Silkworm, on H.S. Tsien, which I would strongly recommend.)

 

Fluid Dynamics in Salt Lake City

I have blogged previously about attending the Joint Mathematics Meeting in San Diego (2018) for the first (and so far only) time, and the APS March Meeting in Las Vegas (2023), my fourth time attending that meeting.  I don't typically blog about the conferences I attend, but it behooves me to post today about one more, the APS Division of Fluid Dynamics annual meeting, which took place last week (Nov. 24-26) in Salt Lake City.  This is because fluid dynamics has been a central part of my scientific career, as well as a cornerstone of this blog.  Indeed, the Salt Lake City meeting was my sixth DFD.  My previous five have all been after I left graduate school:

• 2003:  Meadowlands, NJ.
• 2005:  Chicago, IL
• 2009:  Minneapolis, MN
• 2012:  San Diego, CA
• 2014:  San Francisco, CA

As can be seen, I had not attended DFD in exactly a decade.  Partly this is because I decided at the 2014 meeting that the APS March Meeting was probably of greater interest to me than a conference specialized in fluid mechanics, especially since the March Meeting had plenty of fluids sessions itself.  However, the March Meeting tends to be attended by physicists who do fluids; while DFD is dominated by engineers, applied mathematicians, and various Earth & planetary scientists who do fluids -- a much better representative group of this discipline. However I have found in my latter years that my interests in fluid mechanics tends towards historical, pedagogical, and foundational issues, rather than the cutting edge of research, which is what DFD showcases.  Nonetheless, attending DFD once a decade, while attending the March Meeting more often, may be quite appropriate in order to nourish my intellectual interests in physics and fluid mechanics.

Anyhow, this year's DFD was held at the Salt Palace convention center in downtown Salt Lake City.

The West Temple entrance to the Salt Palace Convention Center

I arrived on Saturday evening Nov. 23 to pick up my badge, but through a different entrance where a cheer-leading competition was taking place!  There was glitter all over the carpet, and children practicing their routines in the hallway.  I ran into a colleague in the hallway who must have seen my utterly bewildered expression, and he kindly directed me towards the DFD registration area.  Here is a shot of that part of the convention center at a calmer moment.

The DFD registration area at the Salt Palace Convention Center, as seen from near the West Temple entrance.

The meeting got going promptly at 8am Sunday morning, while the evening reception ran well into the night.  I don't think I headed back to my hotel until around 9pm that night, despite having forgotten that I had been given two free drink tickets for the reception.  (Thus I never used those tickets.)  The second morning session on Sunday featured a new "Interact" poster session, which began with one-minute flash talks by each poster presenter, followed by time for the audience to speak with the poster presenters one-on-one.  I attended the session on Rayleigh-Benard convection, which was graced by two top figures in the field:  Robert Ecke and K. R. Sreenivasan.  Unfortunately the latter's poster consisted of printouts of a recent paper published in the Journal of Fluid Mechanics, and the author did not stay very long, as I'm sure he had other people's posters in other sessions that he wanted to see.  Logistically, the flash talk portion of the session was difficult to execute gracefully, despite everyone's best efforts.  I'm not sure if this was much of an improvement over a regular poster session.

Hall C, where many of the plenary events, including the awards session, took place.

After lunch, the awards session took place in Hall C, presided over by this year's DFD chair, Peko Hosoi of MIT.  The reception, which was not a full scale banquet, took place in the exhibit hall (Hall A) at 7pm.

Entrance to Hall A, the exhibit area.

In the previous 5 DFD meetings, the reception included a real banquet.  Most memorable for me were the receptions for the 2003 and 2012 DFD meetings.  In 2003, the reception was held at Tavern on the Green, in Central Park of New York City.  Buses were provided to take us there.  I recall having conversations with Stephen W. Morris and (more briefly) Troy Shinbrot there.  At dinner I was seated with a professor and his wife, of Eastern European origin, whose names I cannot recall.  I remember the conversation turning toward the professor's son, who had pursued a non-lucrative career in avant-garde film-making.  Alas, the good professor appears to have been incredibly disappointed with his son's career choice.  He seemed to praise my contrasting choice to pursue a scientific career, albeit not one centered in academia, and not even closely related to fluid dynamics.  At the 2012 DFD reception, I befriended a French post-doc, and after dinner we went for a long walk along the marina, almost reaching the U.S.S. Midway, before turning back.  The post-doc had once worked for a technology start up, but their product, while technically quite innovative, provided only a marginal practical improvement over its existing competitors, and customers found it difficult to justify the cost (not just financial, but in requiring specialized training) to use the product.  It was a sound lesson in scientific entrepreneurship.  Eventually I began peppering him with questions about French politics and culture (this was the era of the presidencies of Monsieurs Sarkozy and Hollande).

Alas at this year's reception, I didn't have any interesting conversations at all.  I have also noticed across several conferences that I've attended this year that there are fewer exhibitors, especially book exhibitors.  Here, only SIAM and Cambridge University Press were purveying books (the latter was also promoting the Journal of Fluid Mechanics), while AIP Publishing and APS' Physical Review Fluids were hawking their journals.  I placed an order for two books with SIAM, and picked up a book (60% discount with reservation if picked up on site) from Cambridge, Joseph Powers' Mechanics of Fluids, which look to be very promising.  After returning home I placed an additional order for more Cambridge books, using the meeting 30% discount code.  I've felt for over a decade that they are the lead publisher in fluid mechanics, and I am pleased that they have not yet abandoned the conference circuit, though they may be feeling less and less competition these days.  JFM was celebrating its 1000th volume, and a commemorative brochure was distributed at the conference, which I think will be a lovely keepsake.  However, unlike the previous DFDs I've attended, there was no brochure prepared regarding the Gallery of Fluid Motion entrees.

Monday morning I mainly attended the Education and Outreach session, which featured many talks on in-class lab demos as well as alternatives to traditional textbooks.  I then attended the Fluids Education lunch, which was not clearly described ahead of time.  It turned out to be a panel discussion with lunch provided.  The table I sat at was not very talkative at all, so it wasn't a very social event, unlike the various mixers featured at other conferences I've attended this year.  Monday afternoon featured a poster session.  I zeroed in on one poster that was closely related to my graduate work from over 20 years ago, and while initially the presenters were absent, two of the authors eventually turned up, and I was able to talk to them.  There were also at least two rather controversial posters, which I will not discuss here, as they do not deserve any further attention.  (I am told that an ethics complaint was filed with APS regarding one of them.)

That evening, attendees were invited to visit the Leonardo Museum, a few blocks away, which currently has a major exhibit on flight, as well as smaller exhibits on AI, water, and a special exhibit related to the meeting, the Traveling Gallery of Fluid Motion (TGFM).  This is the second year of the TGFM, and this year's exhibit is titled "Spiraling Upwards".  For an additional $15, we could attend a private reception welcoming the TGFM, where the artists (one was a real artist, the others were DFD researchers) each gave a few words about their works.

The Leonardo Museum in Salt Lake City.

The Leonardo Museum was quite an appropriate venue for this event, as Leonardo DaVinci, its namesake, was a keen observer of fluid motion, and he rediscovered what we call the hydraulic continuity equation, a precursor of the mass balance principle in modern fluid dynamics.

I attended additional sessions on Tuesday, though I took a long lunch break to enjoy pho at a busy downtown eatery called Tamarind, which I highly recommend!

I've been away from physics and fluid mechanics for over two decades, so unlike conferences in my current field, where I constantly run into people I know, I am very much an outsider at the March Meeting and DFD conferences.  Indeed, I met only 3 people that I knew from before at this year's DFD, though I intend to reach out to a few others whom I met there and have some professional interests with.

More Earth Science

The June issue of Physics Today featured an interesting article by Gayen and Klocker, "Deep Convection Drives Oceanic Overturning", pointing to the inadequacy of the classical Rayleigh-Benard model of ocean convection.  This reinforces my questioning of the sincerity of those who study small aspect ratio thermal convection, when they make claims that their research is somehow relevant to real convection in planetary or stellar environments.

This month's Eos has a really nice summary of the flaws of the Colorado River Compact, by Ge et al.  Although I don't live in the Colorado River catchment, I am not far away, and this is a case study of the inevitably ugly collision of science and politics.

Speaking of which, this week Nature has a news article by Jeff Tollefson on a whistle-blower at the U.S. Geological Survey.  Unfortunately, any government bureau is necessarily politically accountable, and this leads to unavoidable clashes betweeen scientific "experts" and political authorities.  Formal whistleblower protections codified in federal law have little or no actual value in the real world. though federal employees are forced to take annual trainings on them.  It is a colossal deceit.

Physics Today and fluid mechanics

Back in December, I discussed a couple recent items in Physics Today of great relevance to fluid mechanics.  I remarked that we don't get to see fluid mechanics on the cover of PT very often.  Well, lo and behold, the last couple months have proven me delightfully wrong!  The cover of the April issue featured "Fluid Dynamics of Dry Salt Lakes", referring to a "quick study" article by Beaume, Goehring, and Lasser.  It discusses a theory of groundwater convection as a possible explanation of polygonal patterns on dry lake beds ("salt polygons").  The very next month, the cover features "A Shocking Start to Stars", referring to a piece by Ceccarelli and Codella, on the role of shock waves in the interstallar medium, especially in star formation, and even in synthesizing certain precursor molecules of life itself.

However, I was personally most enthralled by another piece that also appeared in the May issue by meteorologist Tim Palmer, "The real butterfly effect and maggoty applies".  The title seems to have been taken from two earlier efforts, one coauthored by Palmer in 2019 on the real butterfly effect (published in Nonlinearity), and the other a 2002 PT Reference Frame article by Sir Michael Berry on singular limits.  Both these papers seem to have had a strong influence on this article, which mainly deals with weather predictibility, and more generally the predictability of nonlinear systems, including the limits of artificial intelligence-based prediction.  The article is very good, informative, and very readable.  I'd come across the singular limit concept in discussions of aerodynamic lift, where viscosity is the parameter that when taken to exactly zero (and not just a limit approaching zero) results in the impossibility of lift.  Reading Palmer's piece, and then Berry's, has helped me understand that there are other such examples in physics.

Aerodynamic lift

It is natural to expect anyone who claims to be a physicist to be able to give a simple, intuitive explanation of aerodynamic lift, using basic principles of classical mechanics.  Unfortunately, most of the time a physicist's such explanation is misleading, over-simplified, or just plain wrong.  One of the most important reasons for this is that there is no such simple, intuitive explanation.  I recently stumbled upon a reference to this excellent 2020 Scientific American article by Ed Regis, that outlines the two main competing explanations (Bernoulli's theorem vs. Newton's third law).  However, others such as the Coanda effect, have been proposed, and are not mentioned in the article.  Nonetheless Regis' article resonated with me because he seems to give a balanced discussion while debunking some of the clearly incorrect variants of these arguments.  He also spoke with two people whose insights I regard as essential, namely, John D. Anderson and Doug McLean.  Anderson is the author of a number of widely used textbooks on relevant topics, such as Introduction to Flight, Fundamentals of Aerodynamics, Modern Compressible Flow, Computational Fluid Dynamics: The Basics with Applications, and A History of Aerodynamics.  (I own three of these books.)  McLean is a retired Boeing engineer, and author of Understanding Aerodynamics, which I recently acquired.

I became interested in the competing intuitive explanations for aerodynamic lift during my time in graduate school, in the late 1990s.  At the time I was involved in atmospheric science research.  One of the professors I worked with informed the members of his lab that Prof. Anderson had been invited to visit our university; and moreover (knowing of my interest in this topic) my professor had invited Anderson to visit our lab for a discussion on it.  It was certainly an honor, and I and at least one other student in the group asked Prof. Anderson to sign our textbooks during his visit.  At the time, I was very partial to the Newton's third law version of the explanation (and still am, though I recognize it as woefully incomplete).  Anderson struck a more neutral tone, stating that both the Bernoulli principle and Newton's second law were at work in lifting an airfoil.  Neither of them was "wrong" per se.  That discussion over 20 years ago seems compatible with the views he gives in Regis' piece.

I won't discuss the officially accepted explanations, formulated in the early 20th century, given by Kutta and Zhukovsky, for 2-dimensional flow, and by Prandtl, Lanchester, and Prandtl's students (notably Blasius) for 3-dimensional flow, here.  However I note that Falkovich (Fluid Mechanics, 2/e, Cambridge University Press, 2018) points to the importance of viscosity in these formulations.  A purely inviscid flow "produces no lift" (p. 56).  He continues, "Without friction-caused separation [of the boundary layer], birds and planes would not be able to fly."  Neither the Bernoulli principle (which is strictly only true for inviscid flows) nor the Newton's third law explanation makes any reference to boundary layer separation and nonzero circulation around the airfoil.  As Anderson says in the Regis article, there just isn't a "one-liner" explanation of aerodynamic lift.

Galileo's Assayer and Torricelli's barometer

A couple months ago, Science magazine had a retrospective by Alex Gomez-Marin on Galileo's The Assayer, which was published 400 years ago this year.  Part of a series of scientific disputes regarding the nature of comets, this particular piece lays out Galileo's methodological perspective on how science should be done.  I've only read selected excerpts in translation, but I do know that others (e.g., Flemish contemporary Simon Stevin) held similar views.

Meanwhile the December issue of Physics Today features a Backscatter item on Torricelli's barometer, by Karina Cooper.  Torricelli was Galileo's last "student", and his work with the barometer was an important step in the understanding of hydrostatic pressure.  Together with Torricelli's efflux law, this achievement ranks him as a major founder of 17th century fluid mechanics, along with Stevin and Galileo's older student, Benedetto Castelli.

My interest in these matters, and the history of classical physics more generaly, has grown noticeably in the last year or so, particularly in the arena of fluid mechanics, which is an interdisciplinary field involving physics, mathematics, and engineering.  Seeing these items in Science and Physics Today is a great way to wind down the year of 2023.  

 As a bonus I praise Physics Today for featuring a cover story in November on research in contemporary fluid mechanics, namely the piece by Detlef Lohse and Olga Shishkina on "Ultimate turbulent thermal convection".  However, the authors' insistence on the relevance of the reported work for real world situations, such as atmospheric and photospheric convection, seems to me insincere when they focus on results for "classical regime" aspect ratios between 0.5 and 1.0.  The atmospheric and photospheric examples involve large aspect ratios.

Nonetheless, the cover is worth reproducing here.  We don't get to see fluid mechanics featured on the front cover of Physics Today all that often!

If I don't write again this year, may you all have a wonderful holiday season and a blessed new year.  See you in 2024!

Some good stuff in Quanta magazine

I'd like to highlight a couple of excellent physics articles that appeared in Quanta magazine last month.

First, Thomas Lewton profiles Jonathan Oppenheim's work on hybrid classical-quantum theories of quantum gravity.  The idea seems to be that instead of attempting to quantize the gravitational field, let it remain classical.  To reconcile quantum uncertainty with a classical spacetime, gravity must be stochastic; it must be noisy.  

Second, Katie McCormick discusses a topological insulator analogy that has been used to explain atmospheric motions such as Kelvin waves in the Earth's atmosphere.  Taruh Matsuno's successful prediction of equatorial Kelvin waves in the 1960s was, evidently, one of the only times theoretical work in geophysical fluid dynamics was predictive of phenomena later discovered in nature.  The article focuses on Brad Marston and collaborators' theoretical and observational work demonstrating that Matsuno's waves can be understood using a topological insulator analogy (think quantum Hall effect).  Once again, a theoretical prediction (Poincare gravity waves in the stratosphere) was subsequently confirmed observationally.  Finally the article discusses David Tong's quantum field theoretical framing of coastal Kelvin waves.

I had attended a talk by Marston at the APS March Meeting earlier this year (see my earlier post), but did not quite follow it.  I am grateful to Quanta magazine for distilling the story into a form that can be consumed by a wider public (including me).

Physicists descend upon Las Vegas (March 2023)

For the first time since 1986, the American Physical Society (APS) held its annual March Meeting in Las Vegas, Nevada.  Yep, I was there!

The main lobby at Caesar's Forum, March 8, 2023.

I attended in-person, arriving Sunday afternoon, March 5, 2023, and staying through late morning Friday, March 20.  Most of the events took place in and around Caesar's Forum.  (The virtual sessions have been running this week, ending tomorrow March 22.)  I heard there were about 12,000 physicists registered for the event, but I don't know how that breaks down between the in-person and virtual attendees.

Exterior of Caesar's forum, Las Vegas, NV, 9 March 2023.

I'll just mention some of the highlights for me.  First, being such a large event post-COVID, I noticed that some attendees were wearing masks, but I would say the majority were not.  Lanyards were color coded based on the wearer's comfort level:

Lanyard comfort level guide, 6 March 2023.

This would have been difficult to enforce because of the venue.  The regular session rooms were often too small, resulting in packed rooms with standing room only at the back.  (Some of the larger rooms hosted sparsely attended sessions, in contrast.)  The hallways were packed during breaks between sessions, and lines were long and convoluted (with several merging lines) at the food/drink-serving events, like the Monday evening reception, and the Industry Day reception thursday night.  The catered food was not of great quality, and the food-for-purchase at the exhibit hall was exorbitantly priced.   Continuing with complaints about the venue, there were a number of audio/visual technical glitches throughout the week.  I had trouble using the APS Meetings app on my phone (I was able to use it before the meeting, but never got it to work while I was actually there).  Not the organizers' fault, but it was very cold the night of the Monday evening reception, which was an ourdoor event, and all the food I ate was mostly cold by the time I ate it there.

Nonetheless, I had a great time.  This was only the fourth March Meeting I've attended - the first scientific talk I ever gave was at the 1999 Centennial Meeting in Atlanta, and I also spoke at the 2002 Indianapolis March Meeting.  Both of those were during my graduate student days.  Much later, I attended the 2014 March Meeting in Denver at my own expense.  I did so again this year.  I remember taking some time to explore Atlanta and Denver (even spending part of a day at Boulder) during the 1999 and 2014 meetings, but Indianapolis and Las Vegas are cities I know fairly well (though I did do some off-meeting things in Vegas).

The view from my hotel room at the Flamingo, 5 March 2023.  The "High Roller" is an iconic part of the Las Vegas skyline, and I got to ride on it Monday night after the conference reception!

 

The highlight Sunday evening was the Kavli Foundation Symposium, "Frontier Physics from Atomic to Astronomical Scales".  The first speaker was Monika Aidelsburger (Ludwig-Maximilians University) on using optically trapped cold atoms to simulate other quantum systems.  I especially enjoyed learning about "twistronics" from the second speaker, Pablo Jarillo-Herrero (MIT):  placing two or more graphene sheets on top of each other, but at an angle so that their crystal structures were out of alignment.  These types of systems are known as "moire quantum matter".  Next was Brad Marston (Brown University) who spoke about large scale waves in the Earth's atmosphere. The last speaker, Gabriela Gonzalez of Louisiana State University, is always worth going to hear (I've seen her speak elsewhere) talk about gravitational wave astronomy.  The session was followed by a unique, but very Nevada-ish, entertainment, a delightful performance by Le PeTiT CiRqUe (a children's cirque group actually based in the Los Angeles area), titled "Cosmic Tumbles, Quantum Leaps".  Hopefully the troupe can give a repeat performance for other physics events in the southern California/Nevada area in the future.

Monday's highlights include the session "Physics Outside the Lab:  Government, Policy, and Diplomacy, Outreach, Journalism and Entrepreneurship".  I missed the first talk as I was attending another session (a common occurrence throughout the week - there were so many interesting-looking talks that I missed due to conflicts). I enjoyed all of the remaining speakers though.  Joseph Niemela of ICTP spoke about supporting young physicists throughout the developing world.  Amy Flatten of APS outlined a very interesting career crossing over from government, tech companies, and now the APS itself.  The third speaker Surya Raghu, spoke about working in industry and Pasteur's quadrant (a concept introduced by David Stokes), while the last speaker, Matteo Rini, who had spent a year working at the European parliament, is now editor-in-chief of APS' Physics Magazine.

Monday afternoon featured a talk by Michelle Frank, a student at CUNY's Biography and Memoir program.  She spoke about the life of physicist Chien-Shiung Wu, particularly the early part of her career.  This was an incredibly good and informative talk.  The speaker incidentally has an article in the April issue of Scientific American, about Wu's involvement in quantum entanglement.  If Ms. Frank has more work on C.-S. Wu on the way, I will be eager to read it.

Another view of the Caesar's Forum, March 9.  The earlier Monday evening reception was held on this patio, but it was really cold that night!

Tuesday was the first day of the Exhibits, and I usually make sure to spend time at the exhibits whenever I attend a conference, usually shopping for books and occasionally speaking with software companies.  This time was no exception, and I ended up hauling back four books in my luggage, and purchasing 9 more after I got home, using the conference discounts. But I began the day attending a very interesting talk on maximum entropy-based statistical inference, a topic I've always wanted to learn more about.  The presentation by Ying-Jen Yang, a post-doc at Stony Brook, based on his graduate work at the U. of Washington under applied mathematician Hong Qian, was titled "Statistical Thermodynamics and Data Ad Infinitum".  There is an ArXiv preprint by the authors available as well.

Another highlight of the day was a talk by Rob Phillips of CalTech, an award-winning teacher.  He was assigned the title "More is Still Different", celebrating 50 (and a half) years since P. W. Anderson's famous and still influential essay, "More is Different".  As a fluid dynamicist, my absolute favorite slide of the whole meeting was this one of Phillips':

An exemplary slide from Rob Phillips' talk "More is Still Different", March 7, 2023.  The lower left corner is titled "Elasticity" and the lower right "Hydrodynamics".

The one time I was able to get food and drink in a reasonable manner was at the Meet the Physical Review Editors reception Tuesday late afternoon, which was also held outdoors.  I spoke with an editor of PRL and one for PRB, but I did not see the editors of Physical Review Fluids there.  I was able to be more social and talk to more new people there than at the actual reception the previous night.  However, DTLR readers should know that I questioned the editors I met about the efficacy of peer review.  I have come to be very sympathetic to the skeptical views of Adam Mastroianni on peer review.

Speaking of editors, throughout the week I popped in and out of the rolling session on Fluids, which began first thing Monday morning and continued until the end of the conference on Friday:

Placard in front of Room 210, where the Fluids sessions ran (March 8, 2023).

The editor of Physics of Fluids, Jeff Giacomin, was often sitting in the front row of the session.  I was able to speak with him very briefly, and noticed him chatting with the AIP Publishing representative at the exhibits at another point during the week.

On Wednesday I hurried to have a quick lunch (this was the one day I used the caterer at the exhibit hall) so that I could make it to the Art Meets Science session.  I was not disappointed.  I was able to attend the first three talks:

• James Kakalios (U. Minnesota) on "The Art and Science of Superheroes";
• Jessamyn Fairfield (U. Galway) on "Comedy as a Tool for Democratization of Knowledge";
• Julia Ruth (physicist turned cirque performer) on "Finding Center:  A Balancing Act Between Circus and Science".
  

I'm not sure I'll ever seen such a fascinating group of physicists in one place and time again.  All of these speakers gave riveting presentations, and ought to be in high demand on the speaking circuit in my opinion!

On thursday, one of the fluids sessions featured this enthralling talk on "Dancing Raisins" by Severio Spagnolie (U. Wisconsin-Madison).  All I can say is get a bottle of sparkling water, open it and pour into a glass, place some raisins in it, and watch what happens!  He said the first 20 minutes after opening the bottle were the best, but you could watch the raisins continuously aquire, then lose, buoyancy by bubble formation and destruction, for about 2 hours.  The roughness of the raisin surface and their rotational motion turn out to be keys to understanding the effect.

The afternoon featured a session on the history and philosophy of physics.  It began with a philosophical talk by Lena Zuchowski (U. Bristol) on the arrow of time, and ways to formulate a concept of entropy and a second law of thermodynamics in order to understand that arrow.  Astronomer Virgnia Trimble (UC Irvine) gave a general talk about physics anniversaries (the theme of the session).  Chad Orzel (Union College) then gave a phenomenal presentation about the 75th anniversary of quantum electrodynamics.  The session ended with Donnell Walton (Corning) who spoke about Willie Hobbs Moore, the first African-American woman to earn a Ph.D. in physics in the U.S.  A surprising aspect of her career is that after doing physics she moved into quality management at the Ford Motor Company.  Three people asked or commented about this aspect of her career during the Q&A.

The day ended with a special session featuring two of last year's three Nobel laureates in physics.  The session was introduced by David Haviland (KTH Royal Institute of Technology), a member of the Nobel committee, who explained the history of the Nobel Prizes.  We then heard from John F. Clauser, followed by Anton Zeilinger (U. Vienna) about their work on quantum entanglement.  These talks were outstanding, and very inspirational!!!   I took the opportunity to take a quick photo before I left the room.

Anton Zeilinger, John F. Clauser, and David Haviland, after the speical Nobel laureate session, 9 March 2023.

I started my Friday with a talk by the son and grandson of Nobel laureates, Tomas Bohr (Technical U. of Denmark), who spoke about "Sap Flow and Sugar Transport in a Pine Needle".  I've been influenced by his work since my undergraduate years, and was delighted to see him speak about a topic related to one I had a chance to think about (circa 2008) for reasons now lost to time.

Tomas Bohr's talk on plant physics, 10 March 2023.

Having pursued a career away from physics for over 20 years, it was soul-nourishing for me to be back in the company of physicsts, attending the world's largest physics conference.  I should try to come back to this conference more often in future years.

The 2022 Nobel Laureates in Science

The first week of October has been an exciting one, as usual, with the announcements of the Nobel Prizes, especially those in science.  DTLR readers know that I have a particular interest in connections between Nobel Laureates and fluid mechanics research, even though the prizes have rarely been awarded for work in classical hydrodynamics.  This year is no different, but at least two of the science laureates have familial connections to hydrodynamicists!

One of this year's physics laureates, John F. Clauser, stated in an oral history interview conducted 20 years ago with Joan Bromberg, that his father was a grad student of Theodore Von Karman's, and later became chair of the aeronautics department at Johns Hopkins.  Clauser states that "But all along the way, he always was trying to understand physics, and there were very strong similarities between the mathematics of fluid flow and the mathematics of quantum mechanics, and he didn't understand quantum mechanics. And he kind of pre-programmed me as the guy who might help try to solve the problem that he couldn't solve."  This appears in the very first paragraph of the transcript!  Further down in the transcript, Clauser returns to fluid mechanics, revealing that he himself is quite knowledgeable about it, discussing solitons, compressible flow, the subsonic-supersonic transition, and shock waves.

One of this year's chemistry laurates, Carolyn Bertozzi, has an older sister Andrea, who is a distinguished math professor at UCLA and works in fluid mechanics.  Andrea Bertozzi is co-author (with her doctoral advisor, Andrew Majda) of Vorticity and Incompressible Flow (Cambridge University Press, 2002). Incidentally, their father was an MIT physics professor.

Congratulations to all the 2022 Nobel Laureates in physiology/medicine, physics, and chemistry!