Physics and the Zen of Motorcycle Maintenance

When I arrived at Berkeley in 1981 to start graduate school in physics, the single action I took that secured my future as a physicist, more than spending scores of sleepless nights studying quantum mechanics by Schiff or electromagnetism by Jackson —was buying a motorcycle!  Why motorcycle maintenance should be the Tao of Physics was beyond me at the time—but Zen is transcendent.

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The Quantum Sadistics

In my first semester of grad school I made two close friends, Keith Swenson and Kent Owen, as we stayed up all night working on impossible problem sets and hand-grading a thousand midterms for an introductory physics class that we were TAs for.  The camaraderie was made tighter when Keith and Kent bought motorcycles and I quickly followed suit, buying my first wheels –– a 1972 Suzuki GT550.    It was an old bike, but in good shape and ready to ride, so the three of us began touring around the San Francisco Bay Area together on weekend rides.  We went out to Mt. Tam, or up to Vallejo, or around the North and South Bay.  Kent thought this was a very cool way for physics grads to spend their time and he came up with a name for our gang –– the “Quantum Sadistics”!  He even made a logo for our “colors” that was an eye shedding a tear drop shaped like the dagger of a quantum raising operator.

At the end of the first year, Keith left the program, not sure he was the right material for a physics degree, and moved to San Diego to head up the software arm of a start-up company that he had founder’s shares in.  Kent and I continued at Berkeley, but soon got too busy to keep up the weekend rides.  My Suzuki was my only set of wheels, so I tooled around with it, keeping it running when it really didn’t want to go any further.  I had to pull its head and dive deep into it to adjust the rockers.  It stayed together enough for a trip all the way down Highway 1 to San Diego to visit Keith and back, and a trip all the way up Highway 1 to Seattle to visit my grandparents and back, having ridden the full length of the Pacific Coast from Tijuana to Vancouver.  Motorcycle maintenance was always part of the process.

Andrew Lange

After a few semesters as a TA for the large lecture courses in physics, it was time to try something real and I noticed a job opening posted on a bulletin board.  It was for a temporary research position in Prof. Paul Richard’s group.  I had TA-ed for him once, but knew nothing of his research, and the interview wasn’t even with him, but with a graduate student named Andrew Lange.  I met with Andrew in a ground-floor lab on the south side of Birge Hall.  He was soft-spoken and congenial, with round architect glasses, fine sandy hair and had about him a hint of something exotic.  He was encouraging in his reactions to my answers.  Then he asked if I had a motorcycle.  I wasn’t sure if he already knew, or whether it was a test of some kind, so I said that I did.  “Do you work on it?”, he asked.  I remember my response.  “Not really,” I said.  In my mind I was no mechanic.  Adjusting the overhead rockers was nothing too difficult.  It wasn’t like I had pulled the pistons.

“It’s important to work on your motorcycle.”

For some reason, he didn’t seem to like my answer.  He probed further.  “Do you change the tires or the oil?”.  I admitted that I did, and on further questioning, he slowly dragged out my story of pulling the head and adjusting the cams.  He seemed to relax, like he had gotten to the bottom of something.  He then gave me some advice, focusing on me with a strange intensity and stressing very carefully, “It’s important to work on your motorcycle.”

I got the job and joined Paul Richards research group.  It was a heady time.  Andrew was designing a rocket-borne far-infrared spectrometer that would launch on a sounding rocket from Nagoya, Japan.  The spectrometer was to make the most detailed measurements ever of the cosmic microwave background (CMB) radiation during a five-minute free fall at the edge of space, before plunging into the Pacific Ocean.  But the spectrometer was missing a set of key optical elements known as far-infrared dichroic beam splitters.  Without these beam splitters, the spectrometer was just a small chunk of machined aluminum.  It became my job to create these beam splitters.  The problem was that no one knew how to do it.  So with Andrew’s help, I scanned the literature, and we settled on a design related to results from the Ulrich group in Germany.

Our spectral range was different than previous cases, so I created a new methodology using small mylar sheets, patterned with photolithography, evaporating thin films of aluminum on both sides of the mylar.  My first photomasks were made using an amazingly archaic technology known as rubylith that had been used in the 70’s to fabricate low-level integrated circuits.  Andrew showed me how to cut the fine strips of red plastic tape at a large scale that was then photo-reduced for contract printing.  I modeled the beam splitters with equivalent circuits to predict the bandpass spectra, and learned about Kramers-Kronig transforms to explain an additional phase shift that appeared in the interferometric tests of the devices.  These were among the first metamaterials ever created (although this was before that word existed), with an engineered magnetic response for millimeter waves.  I fabricated the devices in the silicon fab on the top floor of the electrical engineering building on the Berkeley campus.  It was one of the first university-based VLSI fabs in the country, with high-class clean rooms and us in bunny suits.  But I was doing everything but silicon, modifying all their carefully controlled processes in the photolithography bay.  I made and characterized a full set of 5 of these high-tech beam splitters–right before I was ejected from the lab and banned.  My processes were incompatible with the VLSI activities of the rest of the students.  Fortunately, I had completed the devices, with a little extra material to spare.

I rode my motorcycle with Andrew and his friends around the Bay Area and up to Napa and the wine country.  One memorable weekend Paul had all his grad students come up to his property in Mendocino County to log trees.  Of course, we rode up on our bikes.  Paul’s land was high on a coastal mountain next to the small winery owned by Charles Kittel (the famous Kittel of “Solid State Physics”).  The weekend was rustic.  The long-abandoned hippie-shack on the property was uninhabitable so we roughed it.  After two days of hauling and stacking logs, I took a long way home riding along dark roads under tall redwoods.

Andrew moved his operation to the University of Nagoya, Japan, six months before the launch date.  The spectrometer checked out perfectly.  As launch day approached, it was mounted into the nose cone of the sounding rocket, continuing to pass all calibration tests.  On the day of launch, we held our breath back in Berkeley.  There was a 12 hour time difference, then we received the report.  The launch was textbook perfect, but at the critical moment when the explosive nose-cone bolts were supposed to blow, they failed.  The cone stayed firmly in place, and the spectrometer telemetered back perfect measurements of the inside of the rocket all the way down until it crashed into the Pacific, and the last 9 months of my life sank into the depths of the Marianas Trench.  I read the writing on the thin aluminum wall, and the following week I was interviewing for a new job up at Lawrence Berkeley Laboratory, the DOE national lab high on the hill overlooking the Berkeley campus.

Eugene Haller

The  instrument I used in Paul Richard’s lab to characterize my state-of-the-art dichroic beamsplitters was a far-infrared Fourier-transform spectrometer that Paul had built using a section of 1-foot-diameter glass sewer pipe.  Bob McMurray, a graduate student working with Prof. Eugene Haller on the hill, was a routine user of this makeshift spectrometer, and I had been looking over Bob’s shoulder at the interesting data he was taking on shallow defect centers in semiconductors.   The work sounded fascinating, and as Andrew’s Japanese sounding rocket settled deeper into the ocean floor, I arranged to meet with Eugene Haller in his office at LBL.

I was always clueless about interviews.  I never thought about them ahead of time, and never knew what I needed to say.  On the other hand, I always had a clear idea of what I wanted to accomplish.  I think this gave me a certain solid confidence that may have come through.  So I had no idea what Eugene was getting at as we began the discussion.  He asked me some questions about my project with Paul, which I am sure I answered with lots of details about Kramers-Kronig and the like.  Then came the question strangely reminiscent of when I first met Andrew Lange:  Did I work on my car?  Actually, I didn’t have a car, I had a motorcycle, and said so.  Well then, did I work on my motorcycle?  He had that same strange intensity that Andrew had when he asked me roughly the same question.  He looked like a prosecuting attorney waiting for the suspect to incriminate himself.  Once again, I described pulling the head and adjusting the rockers and cams.

Eugene leaned back in his chair and relaxed.  He began talking in the future tense about the project I would be working on.  It was a new project for the new Center for Advanced Materials at LBL, for which he was the new director.  The science revolved around semiconductors and especially a promising new material known as GaAs.  He never actually said I had the job … all of a sudden it just seemed to be assumed.  When the interview was over, he simply asked me to give him an answer in a few days if I would come up and join his group.

I didn’t know it at the time, by Eugene had a beautiful vintage Talbot roadster that was his baby.  One of his loves was working on his car.  He was a real motor head and knew everything about the mechanics.  He was also an avid short-wave radio enthusiast and knew as much about vacuum tubes as he did about transistors.  Working on cars (or motorcycles) was a guaranteed ticket into his group.  At a recent gathering of his former students and colleagues for his memorial, similar stories circulated about that question:  Did you work on your car?  The answer to this one question mattered more than any answer you gave about physics.

I joined Eugene Haller’s research group at LBL in March of 1984 and received my PhD on topics of semiconductor physics in 1988.  My association with his group opened the door to a post-doc position at AT&T Bell Labs and then to a faculty position at Purdue University where I currently work on the physics of oncology in medicine and have launched two biotech companies—all triggered by the simple purchase of a motorcycle.

Andrew Lange’s career was particularly stellar.  He joined the faculty of Cal Tech, and I was amazed to read in Science magazine in 2004 or 2005, in a section called “Nobel Watch”, that he was a candidate for the Nobel Prize for his work on BoomerAng that had launched and monitored a high-altitude balloon as it circled the South Pole taking unprecedented data on the CMB that constrained the amount of dark matter in the universe.  Around that same time I invited Paul Richards to Purdue to give our weekly physics colloquium to talk about his own work on MAXIMA. There was definitely a buzz going around that the BoomerAng and MAXIMA collaborations were being talked about in Nobel circles. The next year, the Nobel Prize of 2006 was indeed awarded for work on the Cosmic Microwave Background, but to Mather and Smoot for their earlier work on the COBE satellite.

Then, in January 2010, I was shocked to read in the New York Times that Andrew, that vibrant sharp-eyed brilliant physicist, was found lifeless in a hotel room, dead from asphyxiation.  The police ruled it a suicide.  Apparently few had known of his life-long struggle with depression, and it had finally overwhelmed him.  Perhaps he had sold his motorcycle by then.  But I wonder—if he had pulled out his wrenches and gotten to work on its engine, whether he might have been enveloped by the zen of motorcycle maintenance and the crisis would have passed him by.  As Andrew had told me so many years ago, and I wish I could have reminded him, “It’s important to work on your motorcycle.”

2018 Nobel Prize in Laser Physics

When I arrived at Bell Labs in 1988 on a postdoctoral appointment to work with Alastair Glass in the Department of Optical materials, the office I shared with Don Olsen was next door to the mysterious office of Art Ashkin.  Art was a legend in the corridors in a place of many legends.  Bell Labs in the late 80’s, even after the famous divestiture of AT&T into the Baby Bells, was a place of mythic proportions.  At the Holmdel site in New Jersey, the home of the laser physics branch of Bell Labs, the lunch table was a who’s who of laser science.  Chuck Shank, Daniel Chemla, Wayne Knox, Linn Mollenauer.  A new idea would be floated at lunchtime, and the resulting Phys Rev Letter would be submitted within the month…that was the speed of research at Bell Labs.  If you needed expertise, or hit a snag in an experiment, the World’s expert on almost anything was just down a hallway to help solve it.

Bell Labs in the late 80’s, even after the famous divestiture of AT&T into the Baby Bells, was a place of mythic proportions.

One of the key differences I have noted about the Bell Labs at that time, that set it apart from any other research organization I have experienced, whether at national labs like Lawrence Berkeley Laboratory, or at universities, was the genuine awe in people’s voices as they spoke about the work of their colleagues.  This was the tone as people talked about Steven Chu, recently departed from Bell Labs for Stanford, and especially Art Ashkin.

Art Ashkin had been at Bell Labs for nearly 40 years when I arrived.  He was a man of many talents, delving into topics as diverse as the photorefractive effect (which I had been hired to pursue in new directions), nonlinear optics in fibers (one of the chief interests of Holmdel in those days of exponential growth of fiber telecom) and second harmonic generation.  But his main scientific impact had been in the field of optical trapping.

Optical trapping uses focused laser fields to generate minute forces on minute targets.  If multiple lasers are directed in opposing directions, a small optical trap is formed.  This could be applied to atoms, which was used by Chu for atom trapping and cooling, and even to small particles like individual biological cells.  In this context, the trapping phenomenon was known as “optical tweezers”, because by moving the laser beams, the small targets could be moved about just as if they were being held by small tweezers.

In the late 80’s Steven Chu was on the rise as one of the leaders in the field of optical physics, receiving many prestigious awards for his applications of optical traps, while many felt that Art was being passed over.  This feeling intensified when Chu received the Nobel Prize in 1997 for optical trapping (shared with Cohen-Tannoudji and Phillips) but Art did not.  Several Nobel Prizes in laser physics later, and most felt that Art’s chances were over … until this morning, Oct. 2, 2018, when it was announced that Art, now age 96, was finally receiving the Nobel Prize.

Around the same time that Art and Steve were developing optical traps at Bell Labs using optical gradients to generate forces on atoms and particles, Gerard Mourou and Donna Strickland in the optics department at the University of Rochester discovered that optical gradients in nonlinear crystals could trap focused beams of light inside a laser cavity, causing a stable pulsing effect called Kerr-lens modelocking.  The optical pulses in lasers like the Ti:Sapphire laser had ultrafast durations around 100 femtoseconds with extremely stable repetition rates.  These pulse trains were the time-domain equivalent of optical combs in the frequency domain (for which Hall and Hansch  received the Nobel Prize for physics in 2005).  Before Kerr-lens modelocking, it took great skill with very nasty dye lasers to get femtosecond pulses in a laboratory.  But by the early 90’s, anyone who wanted femtosecond pulses could get them easily just by buying a femtosecond modelocked laser kit from Mourou’s company, Clark-MXR.  These types of lasers moved into ophthalmology and laser eye surgery, becoming one of the most common and most valuable commercial lasers.

Donna Strickland and Gerard Mourou shared the 2018 Nobel Prize with Art Ashkin on laser trapping, complementing the trapping of material particles by light gradients with the trapping of light beams themselves.

Galileo Unbound

In June of 1633 Galileo was found guilty of heresy and sentenced to house arrest for what remained of his life. He was a renaissance Prometheus, bound for giving knowledge to humanity. With little to do, and allowed few visitors, he at last had the uninterrupted time to finish his life’s labor. When Two New Sciences was published in 1638, it contained the seeds of the science of motion that would mature into a grand and abstract vision that permeates all science today. In this way, Galileo was unbound, not by Hercules, but by his own hand as he penned the introduction to his work:

. . . what I consider more important, there have been opened up to this vast and most excellent science, of which my work is merely the beginning, ways and means by which other minds more acute than mine will explore its remote corners.

            Galileo Galilei (1638) Two New Sciences

Welcome to my blog site Galileo Unbound: The History and Physics of Dynamics. This is the Blog where you can find the historical background and the physical concepts behind many of the current trends in the physics of complex systems.

The topics will fall under two headings that mirror my two recent books:  Introduction to Modern Dynamics (Oxford University Press, 2015), a college junior-level physics textbook describing the mathematical details of modern dynamics, and Galileo Unbound (Oxford University Press, 2018), a general-interest book on the historical development of the same ideas.

Galileo Unbound: A Path Across Life, the Universe and Everything

Galileo Unbound explores the continuous thread from Galileo’s discovery of the parabolic trajectory to modern dynamics and complex systems. It is a history of expanding dimension and increasing abstraction, until today we speak of entangled quantum particles moving among many worlds, and we envision our lives as trajectories through spaces of thousands of dimensions. Remarkably, common themes persist that predict the evolution of species as readily as the orbits of planets. Galileo laid the foundation upon which Newton built a theory of dynamics that could capture the trajectory of the moon through space using the same physics that controlled the flight of a cannon ball. Late in the nineteenth-century, concepts of motion expanded into multiple dimensions, and in the 20th century geometry became the cause of motion rather than the result when Einstein envisioned the fabric of space-time warped by mass and energy, causing light rays to bend past the Sun. Possibly more radical was Feynman’s dilemma of quantum particles taking all paths at once—setting the stage for the modern fields of quantum field theory and quantum computing. Yet as concepts of motion have evolved, one thing has remained constant—the need to track ever more complex changes and to capture their essence—to find patterns in the chaos as we try to predict and control our world. Today’s ideas of motion go far beyond the parabolic trajectory, but even Galileo might recognize the common thread that winds through all these motions, drawing them together into a unified view that gives us the power to see, at least a little, through the mists shrouding the future.

Second Edition of Introduction to Modern Dynamics (IMD). Publication date: Fall 2019.

Top 10 Books to Read on the History of Dynamics

Here are my picks for the top 10 books on the history of dynamics. These books have captivated me for years and have been an unending source of inspiration and information as I have pursued my own interests in the history of physics. The emphasis is on dynamics, rather than quantum and particle physics, although these traditional topics of “modern physics” have inherited many of the approaches of classical mechanics.

(1) Diacu, F. and P. Holmes (1996). Celestial encounters: The origins of chaos and stability. Princeton, N.J., Princeton Univ. Press.

Diacu and Holmes have written a clear, accessible and information-rich general history of the role that the solar system played in the development of dynamical theory, especially issues of the stability of the solar system.

(2) Pais, A. (2005) Subtle is the Lord: The Science and the Life of Albert Einstein: Oxford.

Pais has produced a masterpiece with his inside view of the historical development of Einstein’s ideas, for both special and general relativity. Through Pais’ story telling, it is possible to follow each turn in Einstein’s thinking as he proposed some of the most mind-bending ideas of physics.

(3) Thorne, K. S. (1994). Black holes and time warps : Einstein’s outrageous legacy. New York, W.W. Norton.

This book is an exuberant journey through the history of general relativity seen through the eyes of the recent Nobel Prize winner Kip Thorne. The book is full of details, many of them personal recollections as GR went from its early days through the “golden age” with John Wheeler located at the center of the motion.

(4) Schweber, S. S. (1994). QED and the men who made it: Dyson, Feynman, Schwinger, and Tomonaga. Princeton, Princeton University Press.

Schweber has produced a master work in the same genre as Pais, describing the development of QED in such moment-by-moment detail that you feel you are living the history itself. The description of Feynman’s stumble into the world of the “grown ups” at the Shelter Island and Pocono Conferences is priceless.

(5) Bacaer, N. (2011). A Short History of Mathematical Population Dynamics, Springer.

This compact little book is one of my favorites in terms of conciseness and completeness. It tracks a history that is little known inside physics, but which has taken on out-sized importance in the new era of complex systems where evolutionary dynamics describes diverse systems from neural networks to genetic algorithms.

(6) Gleick, J. (1987). Chaos: Making a New Science, Viking.

Gleick’s book is an absolute classic. This was one of my first introductions into the history of modern physics when I read it at the end of my post-doc position at Bell Labs in 1989. It has been a role model for my own dive into the history of physics.

(7) Cassidy, David C. (2010). Beyond Uncertainty : Heisenberg, Quantum Physics, and The Bomb. New York, NY, Bellevue Literary Press.

Cassidy’s sequel to his first book on Heisenberg (Uncertainty) is in the same master genre as Pais and Schweber. Reading page by page allows you to live the history yourself as Heisenberg struggled to escape from an overbearing father (and a disastrous doctoral defense) to make his mark on the world of physics.

(8) Jammer, M. (1989), The conceptual development of quantum mechanics. Tomash Publishers Woodbury, N.Y., American Institute of Physics.

Although dry and a dense read, this book is definitive. If you ever want to understand step-by-step how quantum mechanics evolved from the early thinking of Bohr to the advanced transformations of Dirac and Jordan, this is the book you want as a reference. It is endlessly deep and detailed.

(9) Crowe, M. J. (2007), Mechanics from Aristotle to Einstein: Green Lion Press.

This book is filled with lots of myth-busting about the early days of physics. It’s amazing that what we call “Newtonian Physics” was mostly not invented by Newton himself, but by others … even by his nemesis Leibniz!

(10) Coopersmith, J. (2010), Energy, the Subtle Concept: The Discovery of Feynman’s Blocks from Leibniz to Einstein: Oxford, Oxford University Press.

Coopersmith shows how the history of concepts of work and energy is surprisingly obscure. Newton himself made no mention of energy, and it took nearly 100 years for a clear picture of energy to emerge, despite its central role in dynamical systems.

 

There are many wonderful review articles in review journals. A few of my favorites are:

Aubin A. and Dahan Dalmedico, D. (2002). “Writing the History of Dynamical Systems and Chaos: Longue Durée and Revolution, Disciplines and Cultures”. Historia Mathematica, 29, 273-339.

Ginoux, J. M. and C. Letellier (2012). “Van der Pol and the history of relaxation oscillations: Toward the emergence of a concept.” Chaos 22(2).

Gutzwiller, M. (1998), Moon-Earth-Sun: The oldest three-body problem, Reviews of Modern Physics, vol. 70, No. 2

Jenkins, A. (2013). “Self-oscillation.” Physics Reports-Review Section of Physics Letters 525(2): 167-222.

Morgan, G. J. (1998). “Emile Zuckerkandl, Linus Pauling, and the molecular evolutionary clock, 1959-1965.” Journal of the History of Biology 31(2): 155-178.

 

 

Galileo Unbound: The Physics and History of Dynamics

Welcome to Galileo Unbound: The History and Physics of Dynamics. This is the Blog site where you can find the historical background and the physical concepts behind many of the current trends in the physics of complex systems. It is written at the level of college undergraduates in fields of study like science or engineering. Advanced high school students should be able to find little gems here, too.

The topics here will fall under two headings that mirror my two recent books: Introduction to Modern Dyanamics (Oxford University Press, 2015) and Galileo Unbound (Oxford University Press, 2018). The first is a college junior-level physics textbook describing the mathematical details of modern dynamics. The second is a general interest book on the historical development of the same ideas. The physical concepts in both books will be expanded upon in this Blog at a general level of understanding. I hope you enjoy the broad range of topics that will appear here.

Good company in a journey makes the way seem shorter. — Izaak Walton