Congratulations to Alvin

Last month, the Deep Submergence Vessel (DSV) Alvin celebrated its 50th anniversary of service to oceanographic research.  As Humphris et al. (2014) note, Alvin is "the world's first deep-diving submarine and the only one dedicated to scientific research in the United States."  Named after geophysicist Allyn Vine, the half-century old submarine is returning to service after a major upgrade this year.  I recommend the article by Humphris et al. (2014) for readers interested in learning about the history of this unique vessel.

Reference

S. E. Humphris, C. R. German, and J. P. Hickey, 2014:  Fifty years of deep ocean exploration with the DSV Alvin.  Eos, Transactions, American Geophysical Union, 95 (22):  181-182.

Nobel laureates and fluid dynamics research

Do Nobel laureates do research in fluid dynamics? As far as I can tell, the Nobel Prize has been awarded specifically for achievements in fluid dynamics exactly once, to Hannes Alfven (Physics, 1970) “for fundamental work and discoveries in magnetohydro-dynamics with fruitful applications in different parts of plasma physics.” An argument could be made for Pierre-Gilles de Gennes (Physics, 1991) who was awarded for his work on liquid crystals, and Ilya Prigogine (Chemistry, 1977) who was awarded for his contributions to non-equilibrium thermodynamics and dissipative structures. These fields are at least adjacent to fluid dynamics, with considerable overlap. However, other Nobel laureates, who won the award for other achievements, have often either dabbled or even made substantial contributions to fluid dynamics research.

Perhaps the most accomplished was Lord Rayleigh (Physics, 1904), who won the prize for studies of the densities of gases, as well as for the discovery of Argon. He made immense contributions to the theories of fluid dynamics and acoustics, particularly in the field of hydrodynamic instabilities. In the latter field we find his name attached to the Rayleigh-Taylor instability, the Plateau-Rayleigh instability, and Rayleigh-Benard convection (not to mention the Rayleigh number). Rayleigh's monograph on the Theory of Sound is a landmark publication in the history of acoustics. Another Nobel laureate, astrophysicist Subramanyan Chandrasekhar (Physics, 1983), also contributed to the theory of hydrodynamic instability, authoring the similarly landmark monograph, Hydrodynamic and Hydromagnetic Stability. As far as I know, Chandraskehar is the only Nobel laureate to have served on the executive committee of the American Physical Society's Division of Fluid Dynamics (1954-1957, as chair in 1955; long before he won the Nobel Prize).

The theory of turbulence is said to concern the greatest unsolved problem of classical physics. Werner Heisenberg (Physics, 1932) and Lars Onsager (Chemistry, 1968), both developed turbulence theories analogous to the famous Kolmogorov-Obukhov -5/3 law. Heisenberg, whose doctoral dissertation was in fluid dynamics, developed his theory while detained at Farm Hall after WWII, with Karl von Weizsacker. Lev Landau (Physics, 1962) had his own theory of turbulence, and his monograph with E. M. Lifshitz on Fluid Mechanics is one of the best known volumes of their Course of Theoretical Physics.

Other Nobel Laureates dabbled in hydrodynamic research. Edward M. Purcell (Physics, 1952) wrote a famous paper, “Life at Low Reynolds Number” (1977), and T. D. Lee (Physics, 1957) wrote “On some statistical properties of hydrodynamical and magneto-hydrodynamical fields” (1952). Albert Einstein proposed a new airfoil design in 1916, although it was not successful. Richard Feynman lectured eloquently about fluid dynamics in two chapters of the Feynman Lectures, but as far as I know he did not pursue research in the field.

The above musings were prompted by an article in last week's issue of Science, co-authored by Ahmed H. Zewail (Chemistry, 1999). The paper (Lorenz and Zewail, 2014) concerns measurements of the motion of molten lead in a single zinc oxide nanotube, using electron microscopy. The work is a contribution to the young and growing field of nanofluidics.

Readers, do you know of other Nobel laureates who have contributed to fluid dynamics or related fields? Please leave your comments if you do.

Reference

Ulrich J. Lorenz and Ahmed H. Zewail, 2014:  Observing liquid flow in nanotubes by 4D electron microscopy.  Science, 344:  1496-1500.

 

Efimov trimers: a discovery in molecular physics

Quanta Magazine has an interesting feature article by Natalie Wolchover about the discovery of Efimov trimers, predicted in 1970 by Vitaly Efimov.  The first reported experimental result was in 2006, but it was not considered definitive.  Evidently three different groups now have posted their results, with the first paper published and the other two currently in peer review.  Take a look at Wolchover's article.

Welcome indeed, Scientific Data

The Nature journals have recently launched a new journal, Scientific Data, for the publication of data sets with detailed descriptions.  Readers should take a look at the journal's website and an editorial in the main journal, Nature, here.  This is a welcome experiment in improving the infrastructure of science (including providing a new incentive for sharing data) and promoting reproducible research. 

Congratulations to Geophysical Research Letters

The American Geophysical Union (AGU) is celebrating the 40th anniversary of its letters journal, Geophysical Research Letters.  They've posted a collection of 40 papers published in the journal in past decades, a sort of 'greatest hits' list, and made them open access.  You can find it here.

I only recently joined the AGU and have not been an avid reader of this particular journal, yet I congratulate AGU on this milestone.

A review of "Farewell to Reality" by Jim Baggott

Farewell to Reality:  How Modern Physics Has Betrayed the Search for Scientific Truth, by Jim Baggott (Pegasus Books, 2013).

The author has an axe to grind with modern physics.  On television and in books about contemporary physics intended for general audiences, established knowledge is seamlessly presented along with speculation and theories (like string theory) which do not, and possibly cannot, have experimental or observational support.  Baggott makes a distinction between what he calls the “authorized version” (theories of physics with well-established empirical support) and “fairy-tale physics” (theories that lack such support).  Moreover, according to him, some physicists have advocated a “post-empirical” re-defining of the scientific method, which would cut science loose from its empirical grounding.

The book begins with a chapter on some amateur philosophy of science, where Baggott sets out the six principles that he thinks demarcate science from metaphysics.  The first is the “reality principle” which is a statement of metaphysical realism – the real world is “out there” independent of our perception of it – tempered by acknowledging that we only have access to “things as they are measured”, not “things in themselves”.  Moreover, “reality is rational, predictable and accessible to human reason.”  Second is the “fact principle” which states that facts are not theory-neutral:  “Observation and experiment are simply not possible without reference to a supporting theory of some kind.”  Third is the “theory principle” which states that any creative process used to develop a theory is acceptable as long as the resulting theory works.  How we define whether a theory works leads to the fourth principle, the “testability principle”, which states that scientific theories must be empirically testable, and for this to be possible auxiliary assumptions are required.  Moreover, no single test is decisive, since either the theory or an auxiliary assumption may be responsible for any discrepancy.  The fifth principle is the “veracity principle” which states that theories can at best be tentatively accepted, while absolute certainty is beyond reach.  The final principle is the “Copernican principle” which states that we are not privileged observers (discussed in a different context by Adams and Laughlin, 1999).  The rest of the book is divided into two parts.  The first is an exposition of the “authorized version”, and the second is titled “The Grand Delusion”, where he outlines “fairy-tale physics” and his problems with it.

Part One begins with a chapter on quantum theory, including the foundational questions.  This is followed by a chapter on quantum field theory and the standard model of particle physics, up to and including the discovery of the Higgs boson.  The next chapter tackles special and general relativity.  Then follows a chapter on the standard model of big bang cosmology, including the inflation model and the unknown nature of dark matter and dark energy.  The final chapter of Part One is about the gaps and flaws of the authorized version.  These include puzzles about quantum measurement, difficulties with the standard models of particle physics and cosmology, and the lack of a theory of quantum gravity.  Efforts to address these issues, such as dark matter searches, are discussed.  Finally, the “fine-tuning problem” is introduced:  this states that the free parameters of the universe seem unusually fine-tuned to allow for the existence of life forms to observe it.

Part Two begins with a chapter on supersymmetry (SUSY).  Baggott feels that SUSY is at least a testable theory and that we can expect experimental elucidation in the next few years.  On the other hand, he is a skeptic of SUSY because he thinks it creates just as many problems as the ones it solves.  He also points to the lack of experimental or observational evidence for supersymmetry thus far, although in my view this judgment is premature.  The next chapter takes on the numerous flaws of string theory (including superstrings and M-theory), ground previously trodden most famously by Smolin (2006) and Woit (2007).  The next chapter tackles various versions of the multiverse concept, from the “many worlds” interpretation of quantum theory, to the inflationary multiverse.  All of these are dangerous, in Baggott’s view, as they violate the testability principle.  The next chapter, “Source Code of the Cosmos,” tackles a hodge podge of ideas.  The first is Max Tegmark’s claim that the universe is a mathematical structure.  Next, he presents quantum information theory and quantum computing, in a more non-committal way.  (I assume he believes these fields do fall into the legitimate side of science, though not yet part of the authorized version, since much remains to be worked out in those fields.)  He then discusses the “black hole war” (involving ideas from general relativity, quantum theory, thermodynamics, and quantum information) which was resolved by Juan Maldacena’s holographic principle.  The fact that the “black hole war” between Stephen Hawking and Leonard Susskind was finally resolved shows that progress can be made here, but it is not the kind of progress Baggott would prefer.  The resolution of the “war” was based entirely on theoretical developments, without grounding in observational or experimental data.

The book’s penultimate chapter takes on the anthropic cosmological principle, which directly contradicts the Copernican principle that Baggott develops at the start of the book.  He also takes a swipe at the John Templeton Foundation in this chapter.  In the concluding chapter, Baggott tries to answer six questions.  First, “If fairy-tale physics isn’t science, what is it?”  Baggott’s answer is that the stuff isn’t even metaphysics, but rather “nothing but sophistry and illusion” (quoting philosopher David Hume).  Second, “But aren’t theoretical physicists supposed to be really smart people?”  He answers affirmative but gives an analogy with the financial crisis of 2008, which was partly the result of very intelligent financial engineers who nonetheless fell under a “grand delusion”.  Third, “Okay, but in the grand scheme of things is there any real harm done?”  Baggott’s answer is that the “integrity of the scientific enterprise” is being harmed.  This is where he trots out Brian Greene and Leonard Susskind apparently defending a post-empirical redefinition of the scientific method.  Fourth, “What do the philosophers have to say about it?”  Baggott cites only a commentary by philosophers Cartwright and Frigg (2007), but otherwise would like to hear more from philosophers.  Baggott states that “the guardianship of science and the scientific method should not be left solely in the hands of scientists, particularly those scientists with intellectual agendas of their own.”  Fifth, “Are we witnessing the end of physics?”  Baggott cites Horgan (1996) but offers that the list of unanswered questions in physics is still quite lengthy.  The real problem is impatience, which Baggott feels is a factor driving the development of fairy-tale physics.  The final question is “So, what do you want me to do about it?”  Baggott’s answer is to maintain a healthy skepticism when reading about contemporary physics.

So, what to make of the book?  Baggott focuses on particle physics, cosmology, and quantum information theory.  He makes no reference at all to the largest field in physics, condensed matter, not to mention all the other subfields of physics.  Smolin (2006) does the same but at least explains that he does; Baggott never explains that there are vast areas of physics untouched by the “fairy tale” issue he rants about.  Baggott also fails to explore the sociological reasons why “fairy tale” physics persists, an issue that Smolin (2006) does address in some detail.  Thus in comparing the two books, Baggott tackles a broader set of issues (whereas Smolin is mainly concerned about string theory) but Smolin gives a much more thorough account of his topic.

Personally I think Baggott is mostly right (though his dismissal of SUSY due to lack of evidence is far too premature).  However I think Smolin does a better job of convincing us that fairy-tale physics is actually damaging—how funding and hiring is being dominated by less than worthy theoretical efforts.  Baggott is clearly ticked off, but is not articulate enough about the damage and why we should care.  I am not as prepared to completely dismiss string theory as Baggott and Smolin are, but I certainly agree that in their current form they offer little in the way of scientific progress.  Nonetheless, it’s about time someone wrote a book like Baggott’s.

References

Fred Adams and Greg Laughlin, 1999:  The Five Ages of the Universe:  Inside the Physics of Eternity.  Free Press.

Nancy Cartwright and Roman Frigg, 2007:  String theory under scrutiny.  Physics World, Sept. 2007, p. 15.

John Horgan, 1997:  The End of Science:  Facing the Limits of Knowledge in the Twilight of the Scientific Age.  Little, Brown.

Lee Smolin, 2006:  The Trouble with Physics:  The Rise of String Theory, the Fall of a Science and What Comes Next.  Penguin.

Peter Woit, 2007:  Not Even Wrong:  The Failure of String Theory and the Continuing Challenge to Unify the Laws of Physics.  Vintage.

Surface tension and biology

This blog has tended to focus on methodological issues in science and medicine, but occasionally I do want to lavish praise for substantive work.  Here I'd like to call readers' attention to the delightful article in Science a couple weeks ago by Elizabeth Pennisi, "Water's Tough Skin."  It is a feature article describing a number of ways that surface tension is important in biology, including for plants, animals, and microbes.  A number of scientists, engineers, and mathematicians are interviewed about their work.  This is the kind of article that reminds us of why we became interested in science, engineering, and medicine in the first place.  I won't review the content here, but I commend it to readers to enjoy for themselves.

Reference

Elizabeth Pennisi, 2014:  Water's tough skin.  Surface tension is a force to be reckoned with, especially if you are small.  Science, 343:  1194-1197.