Post a Comment On: Backreaction

I was very pleased and flattered when Sabine asked me to write a guest post on why I became a physicist, and immediately wrote down some rough notes. That was, umm, three months ago. Last week I re-initiated the process, and at least was pleasantly surprised to find some significant overlap between my present thoughts and the words I wrote down back in January (being of a certain age, I had forgotten that I had already made notes on some of these topics three months ago). What has also transpired in those three months is the development of a really excellent set of guest postings under Sabine's "Inspiration" heading. In reading them, I've realized that not only can I not match their depth and insight, but also that my straightforward, mostly linear story may not provide much inspiration to those still seeking to make their way. That's because I've always wanted to be a scientist, really since my earliest coherent memories, and have had the good fortune to be able to realize my dream without too much career drama.

To put those remarks in some context, I was a child of the late 1950's and 1960's. Optimism about science and technology was everywhere (or so it seemed to me), and you couldn't help (or so it seemed to me) to be fascinated with space exploration, nuclear power, 'electronic brains', and so on. It's hard to convey that zeitgeist today. Some sense of it comes through in Homer Hickam's wonderfully evocative Rocket Boys; another avenue is simply to peruse the advertisements in the magazines of the era. It's hard to beat the effect of being led out into your backyard by your father to stare out a satellite tracing its path across the night sky (I am guessing it was an Echo satellite as we could see it without binoculars or telescope.)

In retrospect, I suppose our household would have been classified 'lower' middle-class as well as 'non-intellectual': my father was an auto mechanic, my mother a homemaker and nurse; both worked damn hard to make ends meet, so for this and other reasons no music lessons, foreign languages, philosophical discussions, or great books. But there were books everywhere in the house, more than enough to stimulate my lifelong love of reading and learning. I recall the[Image] excitement each week when my mother brought home a new volume of The Golden Book Encyclopedia, which was being sold as some sort of promotion through the A&P grocery stores. And I can still picture the cover of what I think was Volume 4, with its weird green background (now confirmed through the magic of Google, see photo to the right) and an image of a chemist holding a test tube up to his eye. Right then, in first grade, I knew that's what I wanted to do, and the subsequent childhood variations (pilot, astronaut, engineer, architect) about that path were never very large.

I was careful to put 'non-intellectual' in quotations above. To be sure, my Golden Book Encyclopedia was a far cry from Julian Schwinger systematically working his way through the Encyclopedia Britannica and then the New York Public Library. But I was still very proud when I used my Golden Book knowledge when I was 5 or 6 to explain to my father's friends what the differential was on a car and why you needed it. This tight coupling between "book learning" and understanding the real world around us is precisely the intellectual engagement which so fascinates me and which drove me to experimental physics. I know that I would be a much better experimentalist if I had 1% of my father's (trade school derived) mastery of mechanics, electricity, plumbing, heating and cooling systems, etc., and as a result I have a real antipathy towards those who use a very narrow definition of 'intellectual' to establish some sort of academic hierarchy (see also Chanda's post on the silly genre prejudices about 'fundamental' physics versus more applied studies).

The hard work of my parents meant that we were able to live in solidly middle class suburbs (of Milwaukee, Wisconsin), and therefore take advantage of a fairly good public school system. Given that I was oriented towards science from a very early age, the most likely perturbation would have been away from this state (after all, what fraction of high school graduates become practicing scientists?), but I encountered very few bad teachers along the way. Somehow in first grade I was directed towards a book on how rockets work, which tried to explain action and reaction by what happens when you a squeeze a bar of soap and it squirts out of your hands. Hardly the best explanation, but even in questioning it I was learning something. In second grade I found a wonderful book of science experiments you can do (I recall it was from UNESCO; I bet this is it). I now know it confused air drag with air pressure, so it wasn't perfect, but following its instructions to study evaporation or make a working barometer was fascinating. I think it was this same book that also led to my first safety violation in experimental physics: In describing how sound propagates in dense materials, it noted that American Indians were able to detect oncoming trains many miles (kilometers) away by placing their ears directly on the railroad track. Well, on my walk to school I crossed a railroad track, so I had to do the experiment, and this was duly reported to the teacher by a classmate, who wrote a very concerned note to my parents (my protestations of scientific persecution not withstanding). Her mistake was giving the note to me to bring home; my mistake was throwing it in the ditch... Somehow the subsequent fallout from these cascading bad decisions didn't deter me from continuing my pursuit of science.

Other than this isolated incident, the pattern of encouragement from these 'ordinary' schools continued. A 4th teacher who introduced me to different number systems. A 5th grade teacher who gave me a 'programmed learning' book on rudimentary set theory. A 6th grade teacher who taught me about logarithms and how to use a slide rule. A shop teacher in 9th grade who taught us about phase in AC circuits (really! And I still remember his description of the vectors in the R and L directions as being like horses of different strength, the resultant is the direction the wagon is going to go...).

I know Chanda and others mentioned the role of science fiction (in particular Robert Heinlein) in expanding their horizons; this was also true for me. Heinlein's oft-repeated Calculus Made Easy). I'm sure that it was also through Heinlein that I first became aware of some place called Caltech, which quickly became the place I wanted to go to college. This became even more true after I attended a NSF-sponsored summer institute in nuclear physics at MacMurray College, where I was introduced to the Feynman Lectures on Physics. I was so grateful when my parents let me purchase my own copy from the University of Wisconsin bookstore, especially given the extravagant price at the time ($9.95 for volumes I and II, $8.50 for volume III; these same very tattered hardbound volumes are within an arm's length as I type).

In reading Yidun Wan's post I was struck by his statement "So again, I have to say: 'I simply followed my destiny.'" I often feel that I have done the same, but in the sense that a light ray being bent by a lens is following its 'destiny'. That is, a very definite principal of least action on my part has combined with some extraordinary luck to position me where I am today. I applied to only three undergraduate schools (Caltech, Reed and Wisconsin), only one(!) graduate school, did not have to actively seek my first postdoc, and was asked to apply for the Columbia position I currently hold. At each of the stops along this path I was the beneficiary of some extraordinary mentoring (Caltech- Tom Tombrello, Berkeley- Ken Crowe; Pennsylvania- Sherman Frankel, Columbia- Shoji Nagamiya).

At the same time, it would be unwise for me to minimize the enormous amount of hard work required for a life in science. If you are simply a careerist, then there are far easier ways to make much more money. You have to have sort of personality that 'forces' you to invests the time (sitzfleisch) because you there is something you really want to know about Nature. There is ample evidence that this discovery process must be the most addictive substance around- in a typical career you get only a few 'hits' of the drug, but they are easily enough to keep you going. In my case, I would estimate one or two such hits on my thesis, one as a postdoc and perhaps two as a junior faculty member. The incredible thing about my time on the PHENIX experiment at RHIC is that the hits just keep coming. It's been an honor and a privilege to be associated with such an enterprise, and I can't wait to see what's in our next data set.

The superficial words I've written here perhaps convey a trajectory of extraordinary luck, beginning with a stable childhood located in the sweet spot of the space age. Indeed that's how I think of my career (so far). And of course the very pinnacle of the space age was July 20, 1969, when Neil Armstrong stepped out of the Lunar Module and spoke his immortal words. I vividly recall watching this on a small black-and-white television outdoors on a boat dock in Ontario, and taking immense pride in the praise of our Canadian hosts "You Yanks really did it right". Yet that joy was tempered with enormous grief, as my brother Mike, two years my junior, avid rocketeer and constant companion in tinkering, model building and general boyhood carousing, was not there to share in the moment, having been killed in a traffic accident just a month previous. I am not one for (public) introspection, and initially did not intend to include these remarks. But after some thought I decided that if I was to take advantage of Bee's hospitality and honestly describe those influences that led me to physics, I should avoid selection effects and include all those things that impact on the human condition. While it's clear to me that I had been interested in science and mathematics from my earliest days, it was not until Mike's death that I realized it was time to take this thing called school seriously in order to reach the opportunities that were out there. Only now do I realize (thinking about things as a parent) how difficult is must have been just two years later for my parents to send me off to a school they had never heard of 2000 miles from home. I take some comfort in knowing that the presence of my younger brother Steve at home was a great source of comfort to them as their prodigal son wandered through academia to his current position.

[Image]
I already mentioned taking advantage of Bee's hospitality, and don't wish to further abuse the reader's interest, so I will avoid rambling on about many other thoughts that preoccupy me (that status of heavy ion physics, why I became an experimentalist, working in large collaborations, academic prejudice against alternative career paths, etc.) But no account of why I am who I am today would be complete without acknowledging the tremendous support of my loving wife Mary, and the joy we take from our sons Thomas and Kevin. I am hardly a role model for parent of the year, but I find inspiration from the existence proofs out there of those who combine a life in science with exceptional parenting. It is possible, and it provides a wonderful and essential balance to the intensity of scientific investigation.

Bill Zajc is a physics professor at Columbia University. He received his BS in physics from the California Institute of Technology in 1975, and his PhD in physics from the University of California at Berkeley in 1982. From 1997 to 2006 he was the spokesperson of the PHENIX experiment at RHIC. Since stepping down as spokesperson last December, he has been using his newly-found free time to answer the mail messages he has been neglecting for the previous decade.

See also the previous contributions to the inspiration-series by
Huang MeiYidunStefan S.ChristineAnnePeterKerstinStefan H.TommasoChanda
and my related guest post at Asymptotia 'Sabine Hossenfelder: My Inspiration' (also available as pdf-file).

TAGS: PHYSICS, PHYSICISTS