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Writings on physics

A variety of writing samples on the subjects of particle physics, astrophysics, cosmology, funding, biography, and bibliography.

Introductory comments about funding for scientific research

Among the recurring topics in the course of discussion with scientists is the real-world problem of funding for theoretical and experimental research. On a popular science program, in a print article, public talk or industry conference, there is usually reference at some point to public or private funding. Very often the comment is about finding additional funding; rarely does someone complain about too much of it.

Usually, the design of the project is carefully gauged to the budget of the available funding. The subject is extensively debated at times when funding is about to run out, the possibility exists for an extension, or it is suddenly withdrawn. In these cases, the decision is sometimes made to re-evaluate the experiment and decide whether to continue taking data or revert to analyzing the data collected to that point. At a finer level, some parts of the data may receive more or less attention than was originally anticipated to make the most of the remaining funds. If a project has to cease temporarily while further funding is sought, some workers in the collaborative teams may lose their job. Those who are university faculty, or at an independent facility, of course, may still have steady income.

The research budget may sometimes be part of a political tug-of-war in which the scientists, and their science, are caught in the middle. A significant problem, if the funding is terminated, is that those very valuable, talented, employable scientists may turn to industry. They may comprise much of the knowledge base in their particular area of expertise, and losing them as a cohesive group can hurt progress in that field.

Scientists are aware of the importance of taking opportunities to point out the need for further funding. They might add a comment about it during a presentation of their research in a conference talk, or perhaps throw in a good-natured joke or two at a public lecture. There has even been a small technological advance along this line.

A physicist once demonstrated for me the customized laser pointer that he uses for talks to potential funders. When he reaches the moment in his presentation when he especially wants a slide to convey the importance of funding, he switches from the traditional red beam to a green one that displays a tiny dollar sign. The data is not in, but perhaps this subliminal approach does cause some potential funders to see the light.

 

The very big and the very small are just right.

 

If she were here today sampling certain areas of research in physics, Goldilocks could have it all.  Studies in particle and quantum physics often intersect the interests of those who observe, think about, or test theories of the large-scale structure of galactic clusters and the early universe, and vice-versa. This makes sense, of course. In common terms, large things are composed of smaller things, later things came from earlier things, and everything, regardless of size, is part of the big picture.


Scientists at either scale (in the sense of physical size or energy) are more frequently referring to the direct relevance of their work at the other scale. Often it is the link itself that initiates new problems to be considered. For example, in big bang theory there is an important question for cosmologists and astrophysicists about the resultant imbalance of particles and antiparticles. But it is particle physicists who design accelerator experiments to probe this interesting problem.


This cooperative merging of work and sharing of information should result in more efficient use of technology, development of new questions, and effective planning and budgeting. It also encourages the casual reader to emulate the new Goldilocks: you can read it all.

Physics Experiments Actually Performed

Two violinists are preparing duet compositions based on elements of particle physics. This may at first sound like an attempt to bring string theory to the stage with real strings. However, the pieces by British composer Edward Cowie, collectively titled “Particle Partitas”, exemplify impact and fragmentation as they occur in a particle accelerator.

The composer and one of the violinists, Brian Foster, who both studied physics, teamed up with violinist Jack Liebeck to create concerts where the audience will witness this musical-physics experiment and learn about particle theory through brief narrations. The performance techniques are not exotic or innovative; rather, it is the combination of note attacks and decays (gradual softening), many ultra-short notes, soft tremolo accompaniments, and occasional use of chromatic scales that give the effect of the collisions and “debris showers”. (A chromatic scale results from playing every note, in order, between any two notes.)

This sort of “scientific impressionism” is not new in music. Since the mid-17th century, composers have imitated natural, mechanical, electrical, and more complex phenomena in compositions for any number of instruments and voices.

The project is partly funded by Oxford University, where Foster is employed. A video excerpt may be found at physicsworld.com.

Scientists at either scale (in the sense of physical size or energy) are more frequently referring to the direct relevance of their work at the other scale. Often it is the link itself that initiates new problems to be considered. For example, in big bang theory there is an important question for cosmologists and astrophysicists about the resultant imbalance of particles and antiparticles. But it is particle physicists who design accelerator experiments to probe this interesting problem.

This cooperative merging of work and sharing of information should result in more efficient use of technology, development of new questions, and effective planning and budgeting. It also encourages the casual reader to emulate the new Goldilocks: you can read it all.

Murray Gell-Mann at TED

A short talk by Murray Gell-Mann on the subject of elegance and simplicity in physical theory was itself delivered with elegance and simplicity. He spoke at a TED Talk event in March 2007. Dr. Gell-Mann outlined his expectations of mathematical beauty and truth in the proposed, so-called “Theory of Everything.”

He began with an example from his own experience. In 1957, he and his colleagues put forward an incomplete theory of the “weak” force, one of the fundamental forces of particle physics. It disagreed with seven existing experiments, but the beauty of their theory convinced them it was correct, which, as it turned out, was the case. He described beauty and elegance as qualities that are inherent in the mathematics, manifested in its simplicity.

In successive experiments, finer structure of an object or process is observed and compared to previous studies. As the experiments proceed, the mathematics looks increasing similar to the previous layer. This is a sign of an approaching fundamental theory.

He concluded his talk with this comment: The history of the universe should be a consequence not only of a fundamental law, but a combination of that law plus the probabilities, or accidents, resulting from quantum interactions.

50th Anniversary of the Laser

On October 8, 2010, MIT hosted a colloquium celebrating 50 years of laser technology. The speakers’ platform and audience were populated by many of the, well, luminaries of laser history. Four key scientists each gave a short talk illustrating their role in its development and applications.

Moderator and science writer Jeff Hecht began with a brief overview, followed by the introduction of Peter Moulton, who spoke about the innovation of early tunable lasers and the use of diodes and titanium. He mentioned a related but lesser-known term that refers to rejected materials, losers. Richard Osgood followed with a history of gas lasers. He pointed out the importance of the key work performed at facilities such as Bell Labs, IBM, GE, and MIT’s Lincoln Laboratory.

Dick Williamson covered the topic of the now widely used semiconductors and other important advances in lasing materials. Erich Ippen continued the program with accounts of his work in femtosecond lasers at Bell Labs. He then finished with mention of a few current applications, including new atomic clocks, 3D imaging, and research now conducted at SLAC.

One accompanying image showed a typical newspaper headline from 1960, announcing Ted Maiman’s original device: “LA Man Builds Death Ray.”

Review of “Neutrinos and Cosmology: an update”

In cosmology, knowledge of particles and their interactions is as important as that of large-scale galactic structures. That is the key idea in this report on neutrino research by Ofelia Pisanti (University of Naples) and Pasquale D. Serpico (Max Planck Institute). Both ends of the size scale are invisible to theoreticians, as neutrinos, though widely abundant, rarely interact with other elements, and the early universe (the first few hundred thousand years) is beyond look-back distances with even the most sensitive telescopes.

Nevertheless, study of chemical elements and reactions in the earliest times, known as the theory of Big Bang Nucleosynthesis (BBN), has led physicists to a greater understanding of the importance of neutrinos. The authors summarize calculations showing newly revised constraints on temperatures, densities, distances and times needed to determine the ultimate theory of the role of neutrinos in the history of the cosmos.

Neutrinos are members of the generally accepted Standard Model of elementary particles, and they are a critical part of the story of the creation and distribution of matter and energy (more precisely the energy density) throughout the universe. The cumulative gravity of neutrinos is one their most important properties, which is why they are included in some theories of that other elusive stuff now being studied, dark matter.

Review of “Modified Entropic Gravity and Cosmology” 

A recent, highly speculative paper incorporates ideas from thermodynamics, quantum mechanics, and cosmic holography to offer conjectures about the nature of gravity.

“Modified Entropic Gravity and Cosmology,” was published in February 2012, by Miguel Zumalacárregui of the University of Barcelona. The idea is that entropy, a measure of the overall increase in disorder in our expanding universe, is partly responsible for the manifestation of gravity and spacetime. He also takes on established concepts of inflation, dark energy and cosmic acceleration.

The paper is based in part on University of Amsterdam physicist Erik Verlinde. Zumalacárregui recognizes that the modifications of standard cosmology required to formulate his theory, derived through simulations, so far don’t agree with current observations and reasonable assumptions about origins. The theory does not easily align with both the cosmological constant and curvature of spacetime.

But he’s not hesitant to attempt modifications to the equations of Newton, Einstein, and Friedmann. In a recent interview, the author stated that his role models include “Georg Cantor and Charles Darin, for determination in developing revolutionary paradigms that were rejected by orthodox views of most of their colleagues.” The results of his work are inconclusive but his approach is consistent with that philosophy.

Spacetime Atoms and the Unity of Physics

Causal set theory and its application to cosmology was the topic presented by Dr. Fay Dowker at Canada’s Perimeter Institute in November 2011. She began by methodically preparing the audience with an introduction to thermodynamics, entropy, and classical gravity. By the end of the hour she had combined natural extensions of these ideas with a theory of black hole surfaces to support the notion that spacetime may be composed of Planck-sized “atoms.” (The Planck length is the tiniest possible unit allowed in quantum physics.) The theory incorporates ideas about quantum gravity, an area of great interest to researchers; thus the “unity of physics” in the title.

Professor Dowker began with the first two laws of thermodynamics: Energy is conserved in a reaction, and, the entropy (or disorder) of an isolated system never decreases. The measure of disorder of molecules, for example, is important in cosmology. It helps explain development and structure in the universe, and it is related to our notions of time. The surface of a black hole (or “event horizon”) is not a physical structure but rather the invisible limit that gravity imposes on anything inside the hole. Some theorists believe that the configuration of spacetime at the horizon is composed of Planck units of area that can be rearranged in any number of ways, thus representing the total entropy of the hole. Overall, any configuration of these “pixels” would look the same to an outside observer, thus exhibiting high entropy.

She showed that new, parallel laws of “black hole mechanics” could be devised that extend the properties of the event horizon to other limits, such as our cosmic horizon, which is the detectable limit of the visible universe. She diagramed the two sets of laws together to show the striking similarity in their form and function. In this scenario, the unnoticeable cause and effect between Planck pixels would eventually be magnified at great distances near the cosmic horizon. This is the origin of the “causal set” approach.

Dr. Dowker, a professor of theoretical physics at Imperial College, London, works on a variety of problems in quantum mechanics.

A bibliography of selected books on cosmology

John C. Mather and John Boslough. The Very First Light. New York: Basic Books, 1996 (revised 2008), 353pp

Fred Adams and Greg Laughlin. The Five Ages of the Universe. New York: The Free Press, 1999, 251pp

Janna Levin. How the Universe Got Its Spots. New York: Anchor Books, 2002, 216pp

Joao Magueijo. Faster Than the Speed of Light. Cambridge: Perseus Publishing, 2003, 277pp

Paul J. Steinhardt and Neil Turok. Endless Universe. New York: Doubleday, 2007, 284pp

Sean Carroll. From Eternity to Here. New York: Dutton, 2010, 438pp

Frank Close. The Infinity Puzzle. New York: Basic Books, 2011, 435pp

The scientific study of the universe seems to be emulating the universe itself: The rate of experimentation and inflow of data are increasing over time. Likewise, there are ever more writers within the physics and journalism communities who are willing and able to report on all this progress. Of these, books about cosmology for the public at large (so-called “popular” books) are certainly a challenge to write, since the subject is, in a sense, everything. Listed chronologically, these seven books in this brief account each illustrate a distinct approach to describing the origin and development of the universe.

The Very First Light refers to one of the most important astrophysical discoveries of the 20th century – the pervasive radiation from the big bang called the cosmic microwave background (CMB). The story is told both by John Mather, a project leader on the COBE satellite mission that confirmed the phenomenon, and John Boslough, a science historian. Another type of background is the underlying give and take, through seemingly endless meetings, among the scientists, engineers, administrators and funders who eventually made the mission an overwhelming success.

Two physicists authored The Five Ages of the Universe, an imaginative projection of the future of the universe through an unimaginable time span. The many conjectures that are necessary for such a story are cohesively presented using present-day knowledge, educated guessing, and generous sprinklings of intuition. This could be the ultimate escapist adventure for those readers who wish to leave the present world behind them.

Columbia University physicist Janna Levin, author of How the Universe Got Its Spots, picks up on her playful title with a personal and touching narrative of research on the early universe. The “spots” refer to irregularities in the aforementioned CMB.  Parts of the book are loosely based on unsent “letters” to her mother, to whom she reports on her work, colleagues, life and reflections on the meaning of it all.

A controversial theory of the birth of the universe and the initial inflationary era comprises the basis for Jaoa Maguiejo’s Faster Than the Speed of Light. Faster than light? Actually, the concept is not outrageous when considering spatial expansion rather than information. But the discussion heated up when Maguiejo, and others, introduced the concept of a varying speed of light (VSL), that light itself was much faster in the early universe. The ideas were formulated in order to answer some of the outstanding questions in cosmology. His writing style and unusually frank and critical assessment of publishing and peer review in science created a small bang of their own within the physics community.

Endless Universe takes us beyond our comfortable home of normal matter, energy and four-dimensional spacetime to the expanded dimensions of a string theory based brane universe.  Steinhardt and Turok are both experienced and highly regarded physicists who build on a recent concept known as the ekpyrotic universe. Dark energy, a subject very much in the spotlight in recent years, plays a central role in this interesting discussion of a cosmos that no longer requires a beginning or end, but rather a continuum of recycling, which is perhaps the greenest approach to cosmology.

The play on words in the title From Eternity to Here represent the confounding problems hidden in the simple question, What is time? Sean Carroll uses a variety of scientific and metaphorical approaches to guide the reader through bewildering and fascinating ideas – the origin, propagation, and meaning of time. Reading this book is, indeed, time well spent. (Insert your pun here.)

Frank Close and his publisher could not possibly have timed the release of The Infinity Puzzle any better. Published late in 2011, it is an account of the theory behind the so-called “Higgs boson”, a proposed particle and associated mechanism that may be responsible for the physical manifestation of matter itself. In fact, the Large Hadron Collider at CERN (where the author used to work) made preliminary announcements about data that may support the theory during the time the Close was on his promotional book tour. A secondary theme conveys the very human side of decades-long research: the missteps, the faulty memories, and the sequence of events that ultimately must take place to arrive at what may be the true picture of nature and reality.



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