Physicists on US postage stamps: Robert Goddard

Here I am continuing the series of posts on physicists and astronomers on US postage stamps, including the first, second, and third posts, plus one on chemists.  (I have also covered mathematicians in this series.)

In the very first post I mentioned some aviation pioneers also depicted on US postage stamps; among them was Robert Goddard, who appears on an 8 cent airmail stamp issued in 1964.  I just discovered that his Ph.D. was in physics, so he can officially be considered among the physicists so honored!

 

What about chemists on US postage stamps?

In my last post, I mentioned I couldn't think of any chemists on US postage stamps at the time, though I mentioned discovering a stamp for Harvey Washington Wiley.  This was due to ignorance on my part.  To set the record straight, in addition to Wiley:

• In 1940, Charles W. Eliot appeared on a 3 cent stamp in the Famous Americans series. 
• In 1947, Thomas A. Edison appeared on a 3 cent stamp, on the 100th anniversary of his birth.  (His first lamp had been celebrated earlier, on a 2 cent stamp in 1929.) 
• In 1948, George Washington Carver appeared on a 3 cent stamp, in the same format as the 1940 Famous American Scientists issue (which originally featured no physicists, astronomers, chemists, or mathematicians).  He later appeared on a 32 cent stamp issued in 1998, part of the Celebrate the Century - 1910s series.  I believe this gives him the honor of being the only chemist to have appeared on 2 different US postage stamps.
• In 1954, George Eastman appeared on a 3 cent stamp, celebrating his 100th birthday. 
• In 1983, Joseph Priestley appeared on a 20 cent stamp, celebrating his 250th birthday.
• In 1993, Percy Lavon Julian appeared on a 29 cent stamp, in the Black Heritage series. 
• In 2009, Linus Pauling (Nobel laureate in both chemistry and peace) and biochemist Gerti Cori (Nobel laureate in physiology/medicine) both appeared on 41 cent stamps in the American Scientists issue of that year, its second such issue.
• In 2011, Melvin Calvin and biochemist Severo Ochoa, both Nobel laureates (in chemistry and medicine/phyisology, respectively), appeared on Forever stamps in the third and final American Scientists issue. 

Finally, in 1988 a physicist associated with Xerox, Chester Carlson, appeared on a 21 cent stamp in the Great Americans series. I should have mentioned him earlier.

Once again, I'm grateful to the website of the Mystic Stamp Company, as well as stampworld.com, and finally this article:

L. R. Caswell, 1990:  American chemists and physicists on postage stamps.  Journal of Chemical Education, 67 (10):  842-847.

 

 

Physicists and astronomers honored on US postage stamps: another update.

I previously blogged (2021) about physicists and astronomers honored on U.S. postage stamps, with an update last year here.  It's time for another update, not because any new stamps of interest have been issued, but because I have learned of two other stamps that I should have mentioned in my original post, along with a few other notable finds.

First, in 1973, the 500th anniversary year of his birth, Polish astronomer Copernicus appeared on an 8 cent stamp.  He is a major figure in the history of science, and the only one of those mentioned in this series of posts that did not live in the United States at some point during their life.

Second, in 1988, aviation pioneer Samuel P. Langley (along with his Aerodrome #5) appeared on a 45 cent airmail stamp.  He was an astronomer, mathematician, and physicist.

While I find it odd that I couldn't think of a single chemist honored on a postage stamp (but see below), the American Chemical Society has twice been so honored:  in a 1951 three-cent stamp celebrating the ACS's diamond jubilee, and a 1976 thirteen-cent stamp celebrating their centenary.  Similarly, the American Society of Civil Engineers was honored on the centenary of its founding with a 3-cent stamp in 1952.  This was preceded by another 3-cent stamp in 1950 honoring the Railroad Engineers of America.  This stamp features "Casey" Jones, and was issued on the 50th anniversary of his death. 

"The Sciences" were honored on a 5-cent stamp in 1963, celebrating the centenary of the founding of the National Academy of Sciences, whose first president was a great-grandson of Benjamin Franklin.  In 1983, "Science and Industry" was honored on a 20-cent stamp, issued on the 50th anniversary of Chicago's Museum of Science and Industry.

In 2018, a set of four Forever stamps were issued in honor of STEM education.  They honored Science, Technology, Engineering, and Mathematics.

Since I've spent time in the pharmaceutical industry, I will also note that in 1956, a 3-cent stamp honoring the 50th anniversary of the Pure Food and Drug Act was issued, which features Harvey Washington Wiley, a major driving force in the passage of that law, and an official at the USDA agency that was a predecessor to the modern Food and Drug Administration.  So, I found at least one chemist after all!

At some point, I hope to find and scrutinize a history of every postage stamp issued by the United States Postal Service, to see if I can find any others of note.

Once again I'm grateful to the website of the Mystic Stamp Company.

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.

 

 

 

 

 

 

 

On book reviews

Not long ago, I lamented on this blog about the termination of Physics Today's book reviews section.  I mentioned that book reviews are pretty rate at the American Journal of Physics these days too.  However, I am pleased to see that the March issue of AJP does include a book review, of a recent text on soft matter physics.

The Atlantic recently had an article by Adam Kirsch about the termination of the Washington Post's book review section, the second time it has been terminated.  There is a good discussion there about disaggregation, that is, separating book reviews from other content.  It reflects a rethinking of the role of a general publication and how we no longer expect it to cultivate all areas of our culture.  This may indeed explain the loss of book reviews in Physics Today as well.

There may not be a single place to go to find authoritative reviews of physics books in the English language.  Perhaps a google search will find blogs or "booktok" videos that provide reviews, from actual users of these books.  But somehow this does not seem to me to replace the curated reviews from selected experts that might have been found in Physics Today, and perhaps can still be found at AJP and Contemporary Physics.  There are very few publications read across the community:  Physics Today and Physics World are the main ones I can think of in the English language.  I don't subscribe to Physics World, so I'm not sure if they even have, or have ever had, a book reviews section.

Another note on scientist biography series

Previously I blogged about some biography book series featuring scientists, notably here and here.  The latter post mentioned the Blackwell Science Biographies series that migrated to Cambridge University Press, as well as a more general biography series at Oxford University Press (OUP) called Lives and Legacies, that has featured two physicists, Isaac Newton and Ben Franklin. 

Somehow I neglected to mention in my post on the Cambridge Companions series, that Oxford University Press has an Oxford Handbook of Newton currently in development.  Some of the chapters have been published online, and they look quite promising.

I recently learned of another Blackwell series, Blackwell Great Minds, that currently resides at the publisher Wiley.  Like OUP's Lives and Legacies, it is a very general series not focused on scientists.  However, I know of two scientists who have volumes dedicated to them:  Darwin and Newton.  (There is also a volume on Descartes.)  So it seems among the larger intellectual history culture, Darwin and Newton may be the most consequential scientists.  Both of them are represented in the following series:

• Cambridge Companions.
• Very Short Introductions (OUP).
• Cambridge Science Biographies.
• Oxford Portraits in Science.
• Blackwell Science Biographies (Wiley).

In addition, Newton is represented in the Oxford Handbooks series and the OUP's Lives and Legacies series.  He is even represented in the Cambridge Texts in the History of Philosophy series!  (So are Robert Boyle and Margaret Cavendish.)  However the Bloomsbury Handbooks series features only one scientist I know of, Emilie du Chatelet (forthcoming later this month).

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.

Another refresh of Physics Today

DTLR has been a regular reader of Physics Today, published by the American Institute of Physics, since the early 1990s.  Since then, PT has also gained an online presence with its website, of which I am an occasional (though not regular) user.  The January 2026 issue has a piece from the editor about the magazine's latest refreshed design.  One of its stated goals is to move to "cleaner layouts, fewer distractions, larger and more readable fonts..."  In this, I am very pleased with the results.  For some reason, the subjective experience of browsing through the print edition of this issue was very enjoyable, and the design changes seem to have enticed me to read more of the content than I usually do.  Another positive change is that it appears that much of PT's content is no longer paywalled.  All moving in the right direction!  So let's take a closer look at Physics Today past and present:  I will share with you what I think are the hits and misses with the current PT compared to its former glories.  For comparison, I have in front of me the May 2007 print issue, one I decided to keep almost 20 years ago, as it has two very interesting articles (one on the physics of groundwater, and the other on Millikan's famous oil drop experiment).

Here are some elements that seem to have been maintained across almost two decades:

• Feature stories.
• Search and discovery (short reports about research advances).
• Issues and events (news articles, including FYI "science policy briefs").
• Quick study.
• Back scatter.

I've always considered the first three of these to be the heart of PT, serving the core purpose of the magazine, along with letters/opinion (more on that later).   I read two of the three features in the January issue, and I found Johanna Miller's piece on superconducting quantum circuits (subject of last year's Nobel Prize in Physics) to be superb.  I really enjoy articles like this:  an article that takes the reader by the hand into a field they are not an expert in, and in this case relying on just our memory of undergraduate quantum physics, and gives us a gentle explanation of the research, connecting it to broader trends in physics.  The article was enjoyable and instructive, and the writing was of excellent quality.  I would like to see several articles like this per year in Physics Today.  (The groundwater article by Mary Anderson in the May 2007 issue is another in this vein - so good I kept the issue.)  I am also a fan of physics history, and enjoyed several pieces in last year's issues celebrating the international quantum year, such as Ryan Dahn's article on women in the early history of quantum physics.  That piece inspired me to acquire the book from which the article is derived.

I remember when Quick study and Back scatter were first introduced years earlier.  I thought both of those were excellent additions to the magazine's departments.  They're generally easy to consume, and the topics are very diverse.  They make PT a more well rounded product.

Two new departments are "What can physicists do?" (which started last year) and the Crossword.  I glanced at the Crossword and realized I had to stop myself from starting to mentally pencil in the entries, as I was really too busy to commit to it at the time.  So much for getting rid of distractions LOL!  

"What can physicists do?" is, I think, a long overdue addition to PT.  Years ago the British magazine Physics World used to have a similar department, then more recently APS News did too, though I haven't seen it recently there.  The physics profession is going to have a recruitment crisis unless it broadens awareness of what physicists do, outside of traditional physics jobs.  The much-appreciated annual careers issue just isn't sufficient to address the constantly challenging topic of physicist employment.  I hope this new department never goes away.

How about the new logo?  I dislike that the words "Physics Today" are deemphasized on the cover, next to the initials PT, which I think appear on the cover for the first time ever.  I used to enjoy the puzzled looks from innocent members of the public when they see me flipping through a magazine with PHYSICS TODAY emblazoned across the cover.  It is no longer obvious from the cover that this is a physics magazine!

It's unclear whether the Opinion and Letters departments are continuing.  Both appeared in issues as late as the fall of last year.  I think these departments are essential as they give voice to members of the community.  Yes, the back page of APS News is another venue for such discussions, but social media, the blogosphere, podcasts, youtube, and the like have fragmented the media consumption of physicists.  Physics Today may be one of the few common pieces of curated media that reaches across the physics community (beyond even the individual AIP member societies like APS).  I am also a reader of the U.S. Naval Institute Proceedings, and its Comment and Discussion department is perhaps the liveliest I've seen across professional society magazines - it is usually the first part of the magazine I want to read!  PT's letters & opinion section has never been quite so vigorous, but I would like PT to preserve its place there, as I think it really is also part of the heart of the magazine.

Related to opinion, the May 2007 issue reminds me of the long-departed Reference Frame column.  Some of the best and most stimulating writing in PT has appeared there.  Authors such as Frank Wilczek (in that particular issue), Leo Kadanoff, Jerry Gollub, David Mermin, and so many others provoked much thought, reflection, and amusement.  This was one of the most fun parts of the Physics Today of the past, and I really miss it!

The obituaries were moved fully online a number of years ago, and I understand the reasons why.  There was just no room in the print edition to accommodate the departures of numerous colleagues who first joined the profession in the post-Sputnik expansion of American science.  At least PT has continued its commitment to the community by keeping community-sourced obituaries on its website.  I would still appreciate an occasional tabulation of recently posted obituaries in the print edition, something that has sadly been dropped, since I am not a regular visitor to the website.  

Another department that went online was the Job Opportunities.  And this too is understandable.  Job searching is now done fully online.  Print media is just too slow a venue for it.

The book reviews have vanished entirely.  I really miss them.  Book reviews are also increasingly rare in the American Journal of Physics. It seems that the journal Contemporary Physics may be one of the last bastions of book reviews covering the breadth of physics.  Perhaps AIP should arrange to provide a subscription to Contemporary Physics for its members?  Even more specialized journals like the Journal of Fluid Mechanics, which used to have book reviews, seem to have lost them. 

Back before 2007, PT used to also feature occasional science policy panel discussions, where a group of prominent physicists would be prompted with questions and the ensuing discussion recorded for readers.  When I was thinking about my post-Ph.D. career in the summer of 1997, I read a number of such panel discussions in back issues of PT as part of my research.  They were quite valuable then, and perhaps continue to be of historical value today.  However PT hasn't hosted one in decades.

Another class of article that PT should increase is interviews.  Last year they did have one with Peter Shor.  We've got to have more such interviews!

Finally I appreciate that Physics Today remains committed, for the moment, to having a print edition.  This is not a given.  The American Meteorological Society ended the print run of its Bulletin, BAMS, at the end of 2025.  I still get EOS in print from the American Geophysical Union, and the less durable print copies of APS News and SIAM News from their respective societies.  I don't always want to be looking into a battery-powered screen, so having these print publications is much appreciated.

It seems that I have no complaints about the new Physics Today except for its logo, and the loss of some of the eliminated departments from the past.  I hope that letters & opinions haven't gone away, and I'd love to bring back Reference Frame and Book Reviews, and a list of obituaries posted online.

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 Grand Design" by Hawking and Mlodinow

I have just finished reading The Grand Design, by Stephen Hawking and Leonard Mlodinow (New York:  Random House).  The book was originally published in 2010, and I acquired a glossy-paged edition in 2013, but it sat on my shelf unread, until a few months ago.  I have been meaning to read it for a long time.  Hawking died in 2018, so this book belongs to the final decade of his career, and I regret not getting to it until long after his passing.

Sadly, since the book was published, both authors (as well as many, many top physicists) have been associated with Jeffrey Epstein.  However as far as can be determined at this time, any allegations of improper or illegal conduct by either Hawking or Mlodinow have not been substantiated.  

On to the book itself.  Much of it is science popularization, and though I am conversant in the more familiar parts of physics exposited, the book did clarify a couple things for me, which I appreciated.  For example, I have often been confused by the use of the term "effective theory" in physics, and the book explained it in layman's terms.

The important point made by the book is a strong endorsement of supersymmetry and M-theory.  On the final page, the authors write that "M-theory is the only candidate for a complete theory of the universe"(italics original).  They also advocate the multiverse concept, and the strong anthropic principle.  Along with these, they present a metaphysical principle, "model-dependent realism", which superficially appears to be a hybrid of instrumentalism and realism.  However, I'm not sure if you can really eat your cake and have it too.  The principle appears to be crafted specifically to accommodate M-theory, which is actually an infinite number of theories, each with its own domain of applicability, though where the domains overlap, the theories make the same predictions.  I don't see what is realist about "model-dependent realism"; it appears to me to be a variant of instrumentalism.

A key passage is this (p. 58):

Regarding the laws that govern the universe, what we can say is this:  There seems to be no single mathematical model or theory that can describe every aspect of the universe.  Instead...there seems to be the network of theories called M-theory.  Each theory in the M-theory network is good at describing phenomena within a certain range.  Wherever their ranges overlap, the various theories in the network agree, so they can all be said to be parts of the same theory.  But no single theory within the network can describe every aspect of the universe--all the forces of nature, the particles that feel those forces, and the framework of space and time in which it all plays out.  Though this situation does not fulfill the traditional physicist's dream of a single unified theory, it is acceptable within the framework of model-dependent realism.

Later, they write (p. 143):  "We seem to be at a critical point in the history of science, in which we must alter our conception of goals and of what makes a physical theory acceptable". 

I am glad that I read this book after I read Jim Baggott's Farewell to Reality, which was published in 2013 (by Pegasus Books), and which I acquired less than a year after acquiring The Grand Design.  I read it within a year, and reviewed it on this blog in 2014.  In the decade since, I think it is fair to say that empirical evidence for supersymmetry has not yet been found, though back then, expectations were high that such evidence would be found within a decade.  This has weakened the case for The Grand Design and strengthened the critique given by Baggott.  Indeed, Baggott uses the phrase "Grand Delusion", which sounds like direct mockery of The Grand Design.  

On balance, reading The Grand Design was not a waste of my time.  It was important for me to know the views of one of the greatest physicists of my lifetime, and I did learn a few things.  However I am doubtful about its main conclusions, though I have a benefit of hindsight -- 15 years of physics progress since the book was published -- to reinforce my doubts.  If you're interested, don't let me stop you from reading The Grand Design, but if you do, do yourself the favor of also reading Baggott's Farewell to Reality in conjunction, to get a more balanced perspective.

 

 

 

Environmental physics in the undergraduate physics curriculum

Earlier this week, the U.K.'s Physics World featured an excellent op-ed by Peter Hughes about environmental physics education.  He noted the importance of the topic, its practical value, and its incredibly wide disciplinary scope.  His definition, for example, is as follows.

Environmental physics is defined as the response of living organisms to their environment within the framework of the physics principles and processes. It examines the interactions within and between the biosphere, the hydrosphere, the cryosphere, the lithosphere, the geosphere and the atmosphere. Stretching from geophysics, meteorology and climate change to renewable energy and remote sensing, it also covers soils and vegetation, the urban and built environment, and the survival of humans and animals in extreme environments. 

He writes mainly from the perspective of the British university system.  One of his conclusions is "I believe a module on environmental physics should be a component of every undergraduate degree as a minimum, ideally having the same weight as quantum or statistical physics or optics."

While the thought is commendable, let's consider some reasons why it might not fly very far in the United States.

First, at many universities there already exist a robust academic ecosystem in the Earth and environmental sciences, with departments spanning soil physics in the school of agriculture, to atmospheric and oceanic sciences, geosciences, hydrology, civil and environmental engineering, and so on.  I live near a university where most of these disciplines have their own departments.  A physics student interested in this topic would be well advised to pick one of these disciplines as a minor or double major.  I personally find the multidiscplinary aspect of these fields to be quite exciting, but the key is to get out of the physics department and work directly with people who are well trained and active in one or more of these fields.

This leads to my second concern, which is that most physics faculty in the United States are ill equipped to teach or do research in any of these fields, with the possible exception of energy-related technologies.  I claim that within academia, environmental physics is primarily carried out by non-physicists (unless geophysicists are included - however, mostly they are found outside academic physics departments). Let's take a basic subject like fluid mechanics, which is essential for meteorology, climatology, and physical oceanography.  Most physicists have never taken a full class in this subject, and would hardly be qualified to teach one, given the outrageous things they teach about fluids in introductory physics classes.  A crowning example of this is the still often taught "explanation" of aerodynamic lift using Bernoulli's equation.  Granted, some physicists do work with fluid mechanics on a daily basis - plasma physicists, some astrophysicists, some condensed matter physicists, for example - but their focus is not necessarily on the aspects of fluids (like rotating frames of reference) relevant to environmental issues.

Third, it is difficult for me to imagine what, from this incredibly wide field of Earth and environmental physics, could be stuffed into a single undergraduate class.  It would end up being highly dependent on the individual professor teaching it.  I don't know if the Brits have managed to create a standardized curriculum for environmental physics.  

I see there are a few U.S. universities that involve their physics departments in environmental physics, but this is still rare here.  Kudos to them.  For the rest, the fastest way to get a program up and running is to partner with the other departments at the university that have been doing environmental physics from their birth.  In the longer run, physics departments would have to start hiring faculty explicitly in environmental physics.  It could take a decade or so to build a strong program, and not all departments would be well positioned to do so, especially given the hostile funding situation for academia currently prevalent in this country.

While I don't foresee environmental physics being on part with quantum physics, statistical physics, and optics, perhaps eventually it could be on par with solid state physics, astrophysics, or other elective physics courses in the undergraduate program.  However it would take a level of effort and commitment that may not be available in this time of shrinking enrollments and disappearing funding.

 

Physicists and astronomers honored on US postage stamps - Update!

Continuing the theme of my last post, let me call back a post from 2021, where I blogged about physicists and astronomers depicted on US postage stamps.  Back then I counted about a dozen such, and I conjectured about possible future honorees.  Top of my list among the latter was Nikola Tesla.  Well, this was an oversight on my part, as Tesla was indeed depicted on a 20 cent stamp in the American Inventors series, issued in 1983.  Also depicted on the same stamp is his induction motor.

I am grateful to this list for helping me identify Tesla's stamp. The list has a number of notable foreign stamps as well, but it is incomplete.  For example, according to the National Institute of Standards and Technology, American Nobel laureates in physics, David Wineland and Daniel Schechtman (both affiliated with NIST), are depicted on foreign postage stamps.

 

Physicists honored on US currency and coinage - Update!

Back in 2022, I blogged about physicists depicted on US currency and coinage; at the time I could only identify two (Ben Franklin and Dr. Sally Ride). Further I stated that I knew of no other scientists, engineers, or mathematicians so depicted, unless we count the polymathic Thomas Jefferson.

I am pleased to see that this year (2025), the American Women Quarters series has added a quarter for Dr. Vera Rubin, a central figure in the discovery of the "dark matter" problem.  This now makes a total of 3 physicists, one male on currency, and two female on coinage.  It is noted that Dr. Ride is the first known LGBT+ person, and Dr. Rubin the first Jewish person, depicted on US money.

Regarding engineers, I should have mentioned in my earlier post that President Herbert Hoover ($1 coin issued in 2014) was a mining engineer.  President Jimmy Carter was also an engineer by training (nuclear engineer in the Navy), but no coin for him has yet been issued.  He is presently the only deceased president for whom a $1 coin has not yet been issued).

Am I missing any others?

 

Bad philosophy or just an urge for glory?

I haven't read many of Carlo Rovelli's works, but I did enjoy an essay he published this month in Nature.  "There is a healthy sense of crisis in fundamental physics" he says, but he is dismayed by commonly seen demands for physics "beyond" the standard model, conventional quantum theory, and general relativity.  He thinks this is because of "bad philosophy" or mis-readings of philosophers of science such as Kuhn and Popper, who he claims are understood to endorse radical "overthrows" of existing theories and treating all speculative theories equally seriously until they've been falsified.  He argues that previous "paradigm shifts" are actually more "conservative" than commonly understood, and that despite this, radical new theories are driven primarily by confronting data not currently understood, as well as apparent contradictions among different pieces of knowledge.

It is a good and thought-provoking essay.  I basically agree with his point that the history of science is far more methodologically valuable to study than philosophy of science.  However I surmise that he's overthought the explanation for the craze for "physics beyond the standard model" (such as supersymmetry and string theory).  I think the more radical alternatives just have greater potential for scientific glory than more "conservative" approaches (such as loop quantum gravity, a field he worked in and seems to think is a "proof of concept" for an approach more closely tied to existing quantum theory and gravitational theories, though he points out some of its "radical" features).  Thus, the appeal of following the wilder approaches is the chance to attain heroic status.

I haven't summarized Rovelli's essay very eloquently; he writes very well and I recommend reading it.  Even though his should not be the final word (I'm certainly not convinced that the wilder speculative theories should be completely abandoned) but it's a good counterpoint to much of what we read, especially in accounts of popular physics.

Thoughts on graduate education in physics

The American Journal of Physics this month features an article by Laurie McNeil, who was given a teaching award named after J. D. Jackson.  The article is based on her acceptance speech for the award, in which she mentions never having taken a full grad course based on Jackson's classic (and notorious) electromagnetism textbook.  But the important point about her article is that it offers a perspective on graduate physics education that focuses not on reproducing physics professors, but on providing success skills for its graduates, most of whom do not make permanent careers in academia.  She does something that few physics departments bother to do - she tried to track down the current positions of all her department's alumni since 1981.  Most physicists only keep track of their graduates who go on to research/academic careers, as she notes, and deem the rest "lost to the profession".

I fully agree with the article.  I should note, though, that the article is a high-level, vision type piece, without a lot of nuts and bolts.  For example, I would advocate that graduate education in physics should include an allowance, if not strong encouragement, for students to take a break to do a summer internship or two in industry, government, or the nonprofit sector.  This is something I've previously discussed on this blog.  If I sat down and thought hard about it, I would add additional recommendations.  The currently common form of physics graduate education is in my view ritualistic and inadequate for purpose.

 

 

The International Year of Quantum Science and Technology

UNESCO has declared that this year, 2025, is the International Year of Quantum Science and Technology. Numerous international and national physics associations have endorsed the theme.  There are a few industry and academic partners as well.  DTLR welcomes the themed year, just as I did for 2015's "International Year of Light and Light-based Technologies". 

2025 is an appropriate year to celebrate all things quantum.  Though quantum physics got its real start in 1900 with Max Planck's blackbody radiation theory, the theoretical developments from then through 1925 are now characterized as the "old quantum theory".  Quantum theory began to assume the form that we now understand it as in 1925, one century ago, with the publication of Schrodinger's wave mechanics, Heisenberg's matrix mechanics, and Pauli's exclusion principle.

Hence let us welcome the new year of 2025 and take this opportunity to celebrate a century of quantum physics.

Quantum uncertainty and wave-particle duality

I have always felt that Heisenberg's Uncertainty Principle was a manifestation of wave-particle duality, rather than a simple consequence of the quantum randomness.  The principle is literally a theorem in Fourier Analysis rather than a theorem in probability theory.  Recent experimental results reported by Tim Wogan in Physics World seem to provide evidence for this interpretation.  The relationship between uncertainty and wave-particle duality is not as simple as I would have thought, but nonetheless seems to be a better way to interpret it than to merely attribute it to the inherently random nature of quantum phenomena.

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.)

 

Chien-Shiung Wu

This month's issue of Physics Today features Chinese-American nuclear physicist Chien-Shiung Wu on its cover:

I was delighted to see this cover.  The article by Kam, Zhang, and Feng inside discusses Wu's "trailblazing experiments in particle physics".  Best known is her experiment confirming parity violation, which earned the theorists who proposed it, C. N. Yang and T. D. Lee, a Nobel Prize in 1957.  Many (including Yang himself) have commented that Wu should have been a co-recipient of that prize.

The authors go on to make the case that Wu's late 1949 experiment, which they say was "the first conclusive verification of photon entanglement", may also have been Nobel-worthy, given the 2022 Nobel Prize awarded to Aspect, Clauser, and Zeilinger for their work on photon entanglement and the violation of Bell's inequalities".  However, during Wu's lifetime (and well beyond, until quantum information science emerged as a viable discipline in the last decade or two) this field of physics was considered peripheral.  It is only now, in retrospect, that the importance of the work of Wu and others is being fully acknowledged.  Perhaps most unjust of all, John Stuart Bell himself should be recognized as a physicist who should have (but didn't) receive a Nobel Prize.

Earlier this year, I read a biography of Wu by Chiang Tsai-Chien, Madame Wu Chien-Shiung:  The First Lady of Physics Research (World Scientific, 2014), so Wu has been on my mind recently.  I previously blogged about her when the US Postal Service issued a stamp in her honor in 2021, and more recently in my post about the APS March Meeting in Las Vegas last year, where I attended a talk by Michelle Frank about Wu.  Frank has called attention to Wu's work on quantum entanglement in a Scientific American article in April of that year.  Wu's granddaughter, Jada Yuan, published a lovely article about her grandma in the Washington Post in 2021.  The online biographies of Frank and Yuan suggest that they are both at work on biographies of C.-S. Wu.  I think both books would be most welcome.  The Chiang biography, despite its many strengths, leaves much to be desired, and Wu deserves a more substantial biography.  She should be considered one of the titans of 20th century experimental physics.

 

The 2024 Nobel Prizes in science

DTLR cannot resist opining on this year's Nobel science prizes laureates, especially when several of the non-physics laureates have physics connections, while one of the physics laureates does not.

One of the two laureates for physiology or medicine is Gary Ruvkun, whose bachelor's and Ph.D. degrees are in biophysics.  One of the three laureates for chemistry, David Baker, had done a postdoc in biophysics.  He currently has an adjunct appointment in the physics department at his university, along with four other departments aside from his home department.  A second chemistry laureate, John Jumper, had done a bachelor's degree in physics and math, and a master's in theoretical condensed matter physics, before earning a second master's and a Ph.D. both in theoretical chemistry.

It is perhaps also notable that David Baker's father was a physicist and his mother was a geophysicist.  One of the physics laureates, John Hopfield, also had two physicist parents.  

Artificial intelligence was the center of this year's physics and chemistry awards.  Two of the three chemistry laureates were awarded for AI-based protein structure prediction, for their work with AlphaFold, which is owned by Google's parent company, Alphabet.  There is little doubt that this achievement belongs to biological chemistry.  I was pleased to see a share of the award go to employees of a private sector company instead of a university, not something that happens often nowadays.

The physics prize, however, has been extremely controversial, in many cases sparking outrage and cynicism, among both physicists and non-physicists.

Let's start with the laureates themselves before discussing their achievements.  A number of commentators, including some who should know better (e.g., Sabine Hossenfelder) falsely claim that the award was not given to physicists, but to computer scientists.  This is only half true.  One of the laureates, Geoffrey Hinton, is not a physicist, by either education or employment.  He is a cognitive scientist and computer scientist.  (Apparently he is also a direct descendent of George Boole!)  The other, John Hopfield, has superb physics bona fides.  His education was in physics, he was a Buckley Prize winner for his contributions to condensed matter physics, and he is probably the greatest living biological physicist today.  It is true that he is also considered a neuroscientist and a molecular biologist.  In fact, his last academic position before retirement was on the Princeton University molecular biology faculty.  He is a titan of both physics and interdisciplinary science, though the Nobel committee focused on his work on Hopfield Networks, a model of associative memory based on statistical physics (specifically, spin glasses).  He has served as President of the APS.

Unlike many, I celebrate Hopfield's Nobel award.  Geoffrey Hinton is really the puzzle here.  The Nobel committee zeroed in on his stochastic versions of Hopfield Networks, which are called Boltzmann machines.  However, his contributions to neural networks go well beyond that:  he introduced the backpropagation algorithm and later was one of the founders of deep learning methodology.  He is just as much a titan in the neural net community as Hopfield is in the biological physics community.

The history of neural networks is long, and boasts key contributions by a number of individuals.  While Hinton in undoubtedly a key figure in this history, others have also been recognized (including by the Turing award).  Perhaps the key point for the Nobel committee was Hinton's use of statistical physics ideas for the Boltzmann machine. 

There is no doubt that neural networks are used in physics, as in so many other fields of science and engineering.  There is also no doubt that ideas from physics have influenced neural network technology, and machine learning more generally.  But are Hopfield Networks and Boltzmann machines worthy of a Nobel Prize in physics?  This is a question that was hotly debated in the days after the awards were announced.  It seems though, the debate has been lopsided, at least in the sources I've read, with few commentators being willing to defend the Nobel commitee's choice this year.  This award was a huge surprise to nearly everyone who follows the Nobel Prize news every October, including me.  I was even more shocked when the host of the Physics World podcast admitted he had never heard of John Hopfield until the announcement of the prize.

The American Physical Society, in its official new release, decided to get behind the award, but notably emphasized Hopfield as a longtime member of the APS community.  This could be read as a veiled critique of Hinton's award; as far as I know, Hinton's one contribution to the physics literature is a co-authored paper that was published in a physics conference proceedings.

In principle there are several APS units that might choose to celebrate the award to either Hopfield or both Hopfield and Hinton:  the Division of Biological Physics, the Division on Computational Physics, the Topical Group on Statistical and Nonlinear Physics, the Topical Group on Data Science, and the Forum on Industrial and Applied Physics.  However, I have seen and heard of few who have actually embraced this year's award.

This is regrettable.  I think Hopfield is deserving of the honor in the sense that James Peebles was in 2019 - a kind of lifetime career recognition.  I'm not ready to render an opinion on Geoffrey Hinton's Nobel Prize in Physics.  We need to take a step back from the knee-jerk, immediate, and highly emotional reactions.  I'm hoping some thoughtful commentators will, in the coming year, weigh in with well considered opinions.  As a physicist who has worked in machine learning (there are now many, many of us), I may choose to view this award as recognition of those working in this interdisciplinary space who actually use physics ideas, regardless of our formal education or employment in physics.