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NMR pioneers reflect on Silicon Valley: a conversation with Martin Packard and Weston Anderson

2016; Wiley; Volume: 54; Issue: 10 Linguagem: Inglês

10.1002/mrc.4461

1097-458X

Kristin Douty,

Scientific Computing and Data Management

Packard was born in 1921 and raised in the town of Corvallis, Oregon, where his father worked as a paleontologist at the local Oregon State University. It was through his father's workplace that Packard says he felt naturally connected to the scientific community. Although he originally foresaw a future as an archaeologist traipsing through foreign lands, his discovery of a microbiology textbook as a young boy ultimately shifted his course to the hard sciences. Packard was comfortable with his newfound path, describing a career in science as: “just something I wanted to do, so I did it.” One of Packard's first encounters with technology was building crystal radios at the age of 10 years old. The family RCA radio also served as a platform of inspiration with its large four-vacuum tubes and phonograph. Reminiscing on the radios of that time, he says: “In those days, we didn't have all the fancy diodes. We had a galena and what was called a cat's whisker, so you move it around until you had a diode and then you could hear it.” His fascination led to a job at a local radio shop fixing radios, finding bad capacitors, and installing car radios while he was still in high school. Beyond radios, Packard cites Popular Science Magazine as a widespread educational resource for science enthusiasts in the early to mid-20th century. But Popular Science was particularly significant then for its educational approach. It taught young readers to understand the ways that individual parts contribute to an entire invention. Compared with past mainstream technology resources like Popular Science, Packard says that schools these days tend to: “teach kids to program, and that's the central thesis… not to teach them how the computer works or how an LED works, or how does anything work, but can I program them to do something. So, times are different.” Packard stayed in Corvallis after graduating from high school and continued his education at Oregon State University. He completed a bachelor's degree in physics in 1942. When reflecting on his time at Oregon State, Packard joked that he was not necessarily a straight-A student; he confesses to earning a “B” in sociology and psychology. Shortly after graduation, he and four other students were selected to work at Westinghouse Research in Pittsburgh, Pennsylvania. The main goal of his assigned research group was to develop a transmit–receive box that became fundamental to airborne radar. The learning environment at Westinghouse forced Packard, in his words, to “keep peeling the layer off the onion” of whatever technical problem he encountered without seeking assistance from superiors. One particular experience of this sort occurred while tuning a magnetron. When he sought advice from fellow researcher Daniel Alpert, he was curtly instructed to “figure it out!” Straightforward, do-it-yourself replies to enquiries were typical at Westinghouse, but Packard did not mind. He compared the working atmosphere with a doctoral program in the sense that researchers could investigate problems while taking free, extracurricular mathematics courses. The notes of microwave expert and physicist William Hansen – who calculated the radio fields that were necessary to assist with the Varian brothers' development of the Klystron – were the basis of Westinghouse's extracurricular educational opportunities. As Packard said: “It was an ideal environment for somebody just coming out of a normal undergraduate education. Now, I doubt if that happens anymore.” Anderson was born in 1928 in the small town of Kingsburg, California. He says that his mother observed his uncanny inclination for lights and plugs while he was still a crawling infant. While growing up in the California countryside, he fondly recalls the local telephone worker who provided the half-charged batteries with which he built small circuits. Anderson also cites an uncle, who was also a radio amateur and technical enthusiast, as an early source of scientific inspiration. The encouragement fueled his fascination and led him to pursue a HAMM radio amateur license (W6API) while still a high school student. Eventually, his interests led to a radio repair job in the nearby town of Selma. Rather than talking with other HAMM enthusiasts on his radio, as many people do, Anderson enjoyed building beam antennas. These devices could beam radio waves in certain directions depending on how they were turned. He notes: “This was high frequency in those days, two meters, forty-four megahertz. I used to see how far I could go… I was mostly interested in how the beam pattern changed.” Anderson's natural aptitude for science expanded in high school with the guidance of a Stanford University alumnus as well as a chemistry and physics teacher, Gilbert Ewan. Anderson described the teacher's impressive ability to make science more interesting for young students – a feat that is often difficult to achieve as a high school teacher working with restless teenagers. Ewan encouraged a young Anderson to pursue a career in science and to apply to Stanford University. After spending 2 years at Reedley College, Anderson followed Ewan's advice and applied. He transferred to the prestigious university and completed his bachelor's degree 3 years later. Following the completion of his first year of graduate school at Stanford, Anderson travelled to Pittsburgh in order to work at Westinghouse in the summer of 1951. The main research endeavor in his group was to study mercury atoms that were used in lights and lamps at that time. The following summer, he worked for Varian Associates at its original headquarters in San Carlos to conduct research on magnetic resonance. One of his main projects was to work on probes for flux meters. Varian had begun to research magnetic resonance shortly after making improvements in flux meters to measure magnetic fields. Anderson returned for his third year of graduate school at Stanford after working for Varian. Upon his return, Bloch instructed him and a fellow graduate student, James Arnold, to develop a new spectrometer with greater resolution and sensitivity. While Arnold was responsible for making a magnet with improved homogeneity, Anderson was assigned the task of making the radio frequency and switching equipment. His first task, he says, was really to deal with the entire electronic system to ultimately make the instrument more sensitive for resolving spectra. Afterward, he tested chemicals with the spectrometer and analyzed the results using quantum mechanics. The project eventually became Anderson's thesis in 1954, entitled, Nuclear Magnetic Resonance of Some Hydrocarbons. It was not until many years later, he says, that he learned: “… the molecules weren't hydrocarbons in the strict sense of the word. Us physicists, including Bloch, didn't know that.” Although both Anderson and Packard describe a natural inclination for the sciences, their affinities were predominantly nurtured through exposure to radios. Packard describes the progression from radios to later inventions as a straightforward path because their interests: “made it very simple to do the NMR… that required magnets and radio frequency and receivers, so the whole thing was quite normal.” The momentous events that transpired at Stanford, however, were anything but “normal”. Several years before Packard and Anderson's matriculation at Stanford, researcher Felix Bloch worked at a laboratory in Boston where he designed skins for stealth bombers during World War II. His designs were unsuccessful and led him to pursue a new project, but he was not quite sure where to begin. According to Packard's story – which he heard from a friend – Bloch experienced a rush of inspiration in the middle of an orchestra concert in Boston, when he realized the need to explore spin and magnetic moments not only with a molecular beam but also with samples of normal density. He began to hatch a plan to revisit the work of Israel Isaac Rabi, the Nobel Laureate who had worked on deuterium in a molecular beam. Meanwhile, Anderson was an undergraduate student at Stanford at the same time that Packard had finished college and joined the Manhattan Project at the University of California at Berkeley. A recommendation from Daniel Alpert at Westinghouse led Bloch to secure Packard as a researcher. Bloch had previously worked on the moment of the neutron with Nobel Laureate Luis Walter Alvarez at Berkeley, but he decided to explore the concept of nuclear induction. Regarding their first meeting, Packard says: “(Bloch) wanted to see if I knew anything. I remember he asked if I knew why the Earth had two global tides everyday when the moon only went around once. I didn't know the answer to that, but it didn't matter… half an hour later I was a graduate student at Stanford.” Packard's rapid assimilation under Bloch's wing was a remarkable event that would be considered abnormal when compared with the preparation time for present-day academic projects, yet he described the smooth transition to Stanford as commonplace in the mid-20th century. Neither paperwork nor references were required for him to become a graduate student at a research behemoth, a fact that astonishes him now since, as he recalls: “Nobody bothered to look up to see that I had an undergraduate degree.” Bloch went to work to assemble a research team. The first person to join was William Hansen, with whom he had partnered to work on specific aspects of the project, followed by a swift recruiting of Packard. Hansen was primarily responsible for building what the group called the probe and its driving coil with the intention of securing a “sweep” for the signal that they anticipated would reach a width of 10 to 20 Gauss. The apparatus was designed in a way that ensured a high-frequency power to stimulate protons. After observing some compatibility issues with a microvolt signal, Hansen rearranged the transmitter and receiver coils orthogonally so that the spins could process around the magnetic field. Packard busily worked on the third portion of the apparatus that included the radio frequency voltage source and the display. He also brought an oscilloscope that he had used at Westinghouse; the device was a fundamental instrument at the time for displaying traces. The group was ready to perform their initial experiment in a cyclotron laboratory at Stanford shortly before Christmas in 1945. The cyclotron provided a power supply for the little magnet that allowed the group to adjust the magnetic field. Bloch conceived that the long relaxation time required the sample to be placed in the fringing field of the magnet, which would be a few hundred or thousand Gauss. Bloch expected that the sample would be in the fringing field continuously for a day so that the spins would eventually polarize at the magnetic moment. Packard explained: “The idea was to take it and move it over to here and fiddle with the magnetic field, and then we were supposed to see a signal.” Hansen's design functioned quite effectively as a microphone for its ability to record acoustic noise, but it failed to register any NMR signal. Regarding the failed first experiment, Packard described: “… all we saw was nothing but noise.” Hansen returned to the drawing board in order to reconfigure the probe so that it was less sensitive to motion and more rigid. The group took a brief break with the intention to regroup within a few weeks. Packard and his wife, Barbara, left for his hometown of Corvallis to visit his parents for the first time since the beginning of the war. After the holidays, Packard rejoined the researchers, ready for a second attempt to record a signal. The group tended to work late into the night at Stanford in order to avoid electric and acoustic interference. For their second attempt, Packard says: “We were all set, everything all tuned up. What did we see? Nothing. Absolutely nothing.” The third attempt led the group to readjust the magnetic field by removing the cyclotron magnet in a way so that it could sweep through the magnetic field. This adjustment did not initially help the experiment. Hansen and Bloch walked to another part of the laboratory to fiddle with the magnet control, while Packard continued to watch for a signal without any expectations. “Then, all of a sudden, what I saw was a signal,” Packard says. He describes the first signal as a line that went up and then inverted and went back down; there was no mistaking such a strange line for acoustic interference. The line was actually what Bloch called a rapid passage adiabatic in a quantum mechanical system. Packard described: “What was happening was that the line widths were rather narrow, and the relaxation time was very short, so it could serve as a signal… so, here we were orders of magnitude off on relaxation time, and orders of magnitude off on line width. But yet, it worked.” Packard recalls that the group anticipated a broad line width; they were not concerned about the homogeneity of the magnetic field. Bloch's theoretical model did not take into account the movement of water molecules in solution. Rather than modeling a water molecule that tumbles relative to a magnetic field, his equations modeled a water molecule that is fixed in space. Sometimes, Packard speculates as to what would have happened had he not watched for the first signal. The approach could have been quite different, he says, because the classical approach at Stanford differed from the spectroscopy approach at Harvard, where scientists working under Edward Mills Purcell placed more emphasis on quantum mechanics and aspects like relaxation times. Bloch had known that using classical physics equations would work for a quantum mechanical system because of the expectation values. But Bloch did not react well when he finally recognized that the Harvard approach was parallel to his undertaking at Stanford. “And it turns out that physicists are fairly human,” Packard reflects: “In many respects (Bloch) was a very easy guy to work with, but in many respects not. He had an ego that was as big as anybody's.” The graduate students working under Bloch did not interact with him at all during the day, while he worked at a blackboard. Regarding the lack of supervision, Packard says: “We just knew what we were doing.” In 1954, on the last night that Anderson was a graduate student, Bloch announced that he accepted an offer to become the first Director of European Organization for Nuclear Research (CERN) in Switzerland. One problem was that neither of his graduate students had submitted nor completed their doctoral theses. Bloch asked Anderson and fellow graduate student, James Arnold, to complete their dissertations within a mere 2 weeks' time in order to accommodate his scheduled move to Switzerland. Anderson's thesis, Nuclear Magnetic Resonance of Some Hydrocarbons, was accepted within that remarkably limited amount of time. But he is not bitter about the arrangement since, he says: “I've always said that it really pays to have a motivated professor. Then, after I got my thesis in and he made me an offer, he said: “Why don't you come to CERN and we can set up some equipment and do some magnetic resonance?” CERN is certainly not an offer that any scientist could refuse. Although the Stanford research group relocated to CERN with the intentions of continuing their experiments, Bloch's new position was more managerial and clerical than he had anticipated. Anderson recalls Bloch's intense dislike for his new position considering, he says: “There was nothing worse than administration as far as Bloch was concerned, he hated administration but he liked theoretical physics.” The new doctoral degree recipients spent their time at CERN setting up a magnet, running some spectra, and publishing papers, but Bloch had had enough by the end of the first year of his 2-year position. He had spent the entire year hiring office workers and determining locations for scientific equipment. Anderson remembers Bloch's refusal to stay for another year when the director said: “I've had it. I can't take anymore of this administration stuff. I'm going back to Stanford.” Although Packard was working at Varian Associates in California throughout the early 1950s, he agrees that the selection of Bloch as the first Director of CERN was an absurd proposition for a devoted theoretical physicist who preferred research and development as opposed to the responsibilities of an office manager. By 1955, Bloch and Anderson returned to California in search of new projects. Anderson accepted a position at Varian Associates and immediately went to work on an anti-submarine warfare project. Later, he became more involved in other projects at the company like improving sensitivity and resolution, and he published many papers on those topics. Other activities included applying for patents and his idea of Fourier transform. Varian Associates developed NMR research using a technique that was pioneered by Russell Varian, a co-founder and director of the company. Varian created a method of polarizing a sample by applying a strong magnetic field and removing it quickly. The magnet precesses the Earth's frequency, or gyromagnetic frequency, which then measures the magnetic field of the Earth. The link between NMR and chemistry began with Varian Associates researcher and microwave spectroscopist James Schoolery. Packard cites Schoolery as the man who brought NMR to the chemists because he says: “We were not chemists so we didn't really know anything about what you could do with it. So it was Jim coming in as a chemist that built on the simple experiment… which then led to the application of NMR to chemistry.” Moreover, the integration of NMR and chemistry was the result of the combined efforts that Packard says was the result of: “No one person, no one idea, but just a multitude of active people.” In response to the apparent need to make magnetic resonance more suitable for chemists and their evaluation of large molecules, Varian researchers' objective was to improve sensitivity and resolution. Anderson had the ideal background to accomplish this task. He designed uniform magnetic shields (called current shims in those days) and placed them on the magnet in order to control separate sets of orthogonal currents. Next, he developed an idea to use simultaneous multiple frequencies on nuclei. Rather than going through each individual line, Anderson separated the frequencies to plot the response of the nuclei to all the lines at once. Anderson's experiments with sensitivity and resolution eventually culminated in his major development: the use of Fourier Transform with computers. Using this concept, he says: “One second might be broken into one hundred channels and then repeat the experiment as many times as you needed to and then add the responses together.” Anderson's student, Richard Ernst, developed the computer apparatus using the Cooley 2K algorithm for faster Fourier transform to test nuclei and read the results. Ernst went on to win the Nobel Price in Chemistry for his contribution to the development of the high resolution multidimensional nuclear magnetic resonance in 1991. Packard cites technology and a keen awareness of the digital age as the reasons for Varian Associates' early successes, together with the workplace culture, “Our general philosophy,” Packard explains: “… occurred from Russell and Sigurd (Varian) and William Hansen and Edward Ginzton… they didn't say from the top that this is what we were going to do. The theory was to hire people and to put them in a decent environment, then they would do things that were important. We did a lot of things that maybe were foolish but they were good science. Some of them worked and some didn't.” But often as companies do, Varian Associates encountered many challenges throughout its lifespan. Some of the company's early unrest was apparent when Felix Bloch, who consulted the research and development department, was dismissed without notice during a restructuring phase. A former doctoral student of Bloch was responsible for the decision. The effect was that the estranged Nobel Prize laureate would never speak to any of his former students again. “But by the same token” Packard recounts: “…there was no interaction between the other students. It's too bad. That isn't the way it should have worked.” “… trying to figure out why I was asked to leave the division after I'd already filed about 30 patents and 15 papers, and done a lot and probably more than anyone else to improve the technology, I never could find that out other than my boss, Peter Llewellyn, said that I had to do it.“ Anderson sites this unsettling situation as the first time that he questioned his then employer. The second incident that Varian was in a state of conflict was one that Anderson witnessed over the course of a decade. While working in corporate research in 1991, he was assigned the task of building NMR probe coils that were more sensitive to identifying higher noise signals in conjunction with a local company called Conductus. Varian and Conductus compared their research in high-energy superconducting materials and tested them to see if they worked. Eventually, Varian decided that they were satisfied with Conductus' coils and wanted to purchase more from them. Problems arose when the manager of the Varian NMR group, Ray Shaw, negotiated to purchase coils from Conductus, but the meeting was a complete disaster. Anderson explains: “(Varian) either wanted Conductus to give them the coils or give them the coils for next to nothing.” The negotiations ended when Shaw refused to make any further attempts to communicate with Conductus; Anderson says because “… he just couldn't stand them. He said they had a different kind of chemistry. That was his explanation.” By 1996, Conductus and Varian had parted ways. Shaw then arranged for an alternative contractor to make the coils, which the company promised that they could make for Varian – they ultimately failed to deliver a functioning coil sample despite receiving substantial payments to make them. Eventually, Anderson says that the contractor stopped sending samples, yet the company still required payments from Varian long enough to arrange any other plans. These messy lasted almost 10 years, and by that time, Anderson had found a new source for coils, but Varian would need to improve their technology, which would require more money. When Bruker purchased Conductus in 1997 and inherited the technology to produce coils and probes, Varian began a period of restructure. In 1999, the company split into three separate divisions. Varian Instruments still had the NMR, but there was no marketable product left to sell. The story of Varian is remarkable because of its pioneering roots as the first company to move into Stanford's Technology Park. Varian founded the Silicon Valley culture that currently embodies scientific progress in the United States, yet many people in the research community have been left confused, shaking their heads and asking: “Why would such a groundbreaking company so rapidly meet its demise?” Packard has also asked himself this question, but he eventually found the answer. Regarding the reacquisition and final closing of Varian, he explains: “To me, the ‘why?’ became that to exist in an ecosystem, whether it is you, a bug or whatever, it doesn't matter, the outside world makes the ecosystem change constantly. If you do not adapt to that, or innovate, then you will not survive.” Likewise, many companies have not survived in Silicon Valley as a consequence of their failure to progress within the ecosystem of scientific research. He continues: “We have companies that have not survived. We have animals, dinosaurs, that couldn't survive the meteorite. The little animals could adapt, the mammals like us, but not the dinosaurs. So, what I view is that when a company forgets how to innovate or adapt, it does not survive.” Packard's words resonate as a prophecy for other companies who still have a chance to learn from Varian's mistakes if the reputation of Silicon Valley is to continue as a globally renowned pinnacle of progress. Around the same time in their careers, both Packard and Anderson stopped publishing in academic journals. Packard explains that this is a natural course of events in a researcher's life, and that the crown must be passed down to the next generation. This passage between researcher and student is a result of a simple model in which, he says: “… the ability of all animals to adapt depends on the curiosity of the young ones.” Research at the university level also depends upon the collaboration of professors with young students who have fresh ideas because, he explains: “… the important part is the younger people that are able to have curiosity and will explore and adapt.” Another reason that explains both scientists' cessation of publishing articles is because each man found a somewhat new direction in research. When Anderson was promoted to the Director of Research at Varian, he no longer worked directly on experiments, thereby inevitably causing his publications to drop off. He eventually took a new direction with ultrasound research. Meanwhile, Packard occasionally published in canine journals and took up his wife Barbara's interest in Bernese Mountain Dogs. Perhaps surprisingly, their interest in the Bernese breed was the result of Varian's move toward biological research in large molecules. Together, Packard and his wife's goal was the improvement of genetic research with the support of veterinarians in order to prevent against the Bernese breed's hereditary disorders. Several years have passed since the reacquisition of Varian Associates, and research publications are no longer a major interest of either Packard or Anderson. The veteran researchers are currently enjoying their retirement. With the exception of his interest in gardening vegetables and fruits, Anderson has not strayed far from his scientific roots. He has volunteered for several years at the Museum of American Heritage in Palo Alto where he teaches electronics courses to children and adults. The courses initiate students with simple projects that gradually become more complex over a series of several sessions. At the first meeting, he teaches students about various historical aspects of technology and its origins. The second session is a lab where Anderson brings in devices for students to work on, such as a shaker flashlight that he designed using a magnet on the inside of a plastic cylinder. The purpose of this lab, he says, is for students to connect a coil up to a bridge and rectifier, which are then attached to a capacitor so that when the flashlight shakes, the rectifier changes the alternating current to direct current, which in turn charges the capacitor. Anderson's electronics courses are meant to engage students both young and old through a hands-on, inventive learning process. He makes sure that his students: “learn by doing and… that's the important aspect of it; it's not learning by reading out of a book. They hear about it and then they have to see how it works.” But his dedications to fostering interest in science for future generations do not end with his weekends as a volunteer educator. Since 2006, Anderson and his wife, Jeanette, have awarded 11 Kingsburg High School graduates with a $10 000 scholarship to advance their scientific studies at a major university; the scholarship was recently increased to $15 000 for all future recipients. Anderson presents the award in honor of his first academic mentor, Gilbert Ewan, the high school science teacher who contributed to an enduring scientific legacy through the groundbreaking work of his protégé. Apart from his contributions to canine journals, Packard spends time with his family and keeps up to date on world events and issues. In the past, however, he and his wife, Barbara, shared a lifelong passion for learning about other cultures and exploring foreign lands. Their home is a testament to their travels across several decades of marriage, where artifacts can be seen from every angle within the 50 year-old Morgan Stedman-designed home in Los Altos Hills. Packard's beautiful home truly mesmerizes its visitors, which is why he and Barbara worked for over 4 years to secure a historical landmark designation, which was officially awarded in late 2012. The home is Packard and Barbara's legacy not just to science but also a monument to their family, where their travels and accomplishments are safely enshrined – especially for a certain curious toddler great grandson from the East Coast to explore when he visits. When they are not working on hobbies or spending time with their families, Packard and Anderson still attend Stanford seminars together whenever they can. The opinions expressed in this article are the interviewee and the author's own and do not reflect the view of Magnetic Resonance in Chemistry, or the publisher.