在美国的导师前两年退休了，最近一位师兄整理了他的退休演讲词和发表的论文，记录一下。希望George退休生活愉快了。

原文链接是：
http://ezcad.org/2020/05/15/george-mcmechans-retire-talk/
http://ezcad.org/2020/05/10/a-complete-list-of-george-mcmechan-publications/

作为学生，我说几点自己的体会吧：
1、George基本上一年到头只有圣诞节休息，从早上8点到晚上7、8点都在实验室工作，基本上是个彻头彻尾的工作狂人了。但是，也是因为他在自己的research里找到了常人无法体会到的乐趣–the magic。这种长时间的付出和投入令人敬佩。但是，代价也是很大，George没有自己的孩子。我想能为了自己的科研有这种付出的真属罕见。
2、我比较认同George的一项，也是我自己常年学习中的感想：
Learning by doing！
3、成功= 努力 + 一个好一些的方向 + 坚持 + 一点点运气吧
也许这也就是为什么George本人没有Geophysics的PhD学位却最终成为一位成功的Geophysics Scientist。

退休演讲原文如下：

George McMechan’s retire talk

This post was last updated on May 15th, 2020 at 06:43 pm

On September 29, 2018, we gathered at UTD to celebrate George’s retirement from a fruitful and glorious career. It was a Saturday and the alumni center was quiet and empty. I felt a bit lost in the familiar and strange Fall campus. We were immersed in memories of the student times we left here. At dinner, the colleague professors and alumni shared touching stories they had with him. What a memorable evening! George gave this talk below. We appreciate his permission for posting here.

Thank you all for coming. It’s great to see so many geophysics alumni who graduated as members of the UT-Dallas Geophysical Consortium family, and consortium sponsors, and those from all the UTD units that provided administrative support. The fact that this group has been so productive and achieved an internationally competitive reputation over its 36 year life has been the result of all of you working together as a community to make it happen. The underlying activity is of course the research program. Like life itself, research is a process, which exists independent of the particular people who arrive and contribute their part for a while, and then move on.

Remember that PhD means Dr. of Philosophy. In science, this Philosophy refers to a world view based on science, and applied, not only in a work context, but in all aspects of life and our participation in it, including critical evaluation of ideas and data, and treating our fellow human beings with respect and in an ethical manner. Science is fundamentally an evolutionary process, in which the best suited solutions survive, and through which the future is built on the accumulated experiences of the past, with occasional leaps at paradigm changes. This structure is extremely effective in producing a constant stream of novel concepts and applications. It also breeds an acceptance, and even an active pleasure in uncertainty as a characteristic of nature, which is a source of discomfort in many non-scientists.

My teaching philosophy has been based on the simple idea that effective learning occurs by ‘doing’, rather than  talking or reading ‘about’ a subject. So interacting with the earth by using equipment to make measurements, or writing software to solve problems and understand physical concepts is a part of all my courses. I see the main value of graduate courses is to provide an efficient mechanism to get up to speed on the current state-of-the-art, and to get conversations going, on the most exciting questions to investigate,  through hands-on research to answer those questions. Thus, the goal of higher education in science is not the learning of various facts, but rather the development of skills and expertise in scientifically-based investigation.

My greatest satisfaction as a teacher is to see ‘the light come on’ when a student finally breaks through and produces the key innovation of his/her dissertation, and thereby crosses the threshold from being a student to becoming a collaborator and an independent scientist. When I start learning from them, I know the process has been successful.  So, creating an educational environment that facilitates that transformation in my students is my main aspiration as a mentor.

This event today is a symbolic transition in a journey. It is, of course, not a solitary journey, for me, or for any of you.  In my case, I have had the good fortune of having a large number of very good graduate students that I have worked with over the past 3 and a half decades; you kept me motivated and have done most of the heavy lifting to realize the transition from initiation of innovative ideas, through to formation of investigative strategies, to the excitement of discovery. The latter is the driving force of science.

So how does this happen?  What is the path that has led to my standing up here today, looking a bit surprised or maybe awed would be more accurate. Yet, there is a pattern. Certainly there have been some decision points that were crucial. I could have easily ended up in social sciences. Some of you may know that one of my degrees is in psychology. My interest in thought processes that support creativity certainly hasn’t hurt me as a teacher, but that did not end up as my main research interest.

My geoscience career began by osmosis when I was very young.  I grew up in the Okanogan Valley in south central British Columbia, in Canada, which has a marvelous assortment of geological environments from metamorphics to volcanics to fluvial and lacustrine sediments, and this exposure provided a predisposition to enjoying the outdoors, and to appreciating the planet that we live on. It also had a local history of small scale mining from placer gold to hard rock copper and silver.  I got my first look at a real operating mine and a 100 ton ore truck at the Brenda porphyry copper mine in a high school field trip.

When I first went to the University of British Columbia, as an undergraduate, I, like many students, was not sure what I wanted to do. I changed my major from electrical engineering to mechanical, but it didn’t yet feel right. In my second summer I got a job stacking lumber in a saw mill on the west slope of the Rockies and spent every weekend hiking in the Canadian National Parks. This was the turning point. Even a snow storm that hit me on a motorcycle in early July did not deter me. That fall I transfered into the Geophysical Engineering Program.  The next summer I got a job with Utah Mining, which was doing the initial exploration of the property that was later to become the Island Copper mine on northern vancouver island which, at the time of its peak production, had the deepest sub sea level open pit bottom on the continent. I was on crews doing soil samples and induced polarization surveys, and learned the joys of the rigours of serious field work.

In my last undergraduate year, I did an internship at the Victoria Geophysical Observatory, which was my first practical exposure to seismology. It was earthquake seismology, but seismology nevertheless. This again had a lot of field work in northern BC, Alaska and the McKenzie delta, doing seismic risk analysis for the McKenzie Valley pipeline, which was being constructed at that time.  It’s interesting to see the subject of earthquake location has now appeared in the energy industry in the guise of micro seismic tracking of hydraulic fracturing. So sometimes you can’t predict what knowledge might be useful to you in the future so it’s good to get exposure to a broad range of ideas.

In my graduate studies at the University of Toronto, I worked on crustal and mantle scale seismic inversions, which subsequently led to my employment for 10 years with the Department of Energy, Mines and Resources of the Canadian Federal Government. That department is now called  Natural Resources Canada.  In that job, I began to develop computational skills but outgrew the available budgets for such activity, and so I needed a change of venue. This started with a joint sabbatical at the USGS in Menlo Park, and at Jon Claerbout’s Stanford Exploration Project at Stanford, where my eyes and mind were opened ‘wide’ to the possibilities of a career in exploration seismology. Also that was the time of the beginnings of parallel computing. That was another turning point for me; I knew that was where I needed to be. Everything was new and exciting. It took a couple more years before I was able to make it happen by moving to UT-Dallas, after having resigned from my stable job and working for a couple years doing software and data processing contracts in the Computer Science Department at the University of Victoria.   In 1983 when I arrived in Dallas, UT-Dallas was surrounded by companies like ARCO, Mobil, Sohio and ORYX which provided a wonderfully fertile environment for collaboration and consulting. That was an up cycle in the industry and companies were hiring faculty away from universities, which is what created an opportunity for me to come to UT-Dallas. It was right for me and I took a pay cut to come. That investment has paid off in the subsequent years. That was a while before the great exodus and merging of companies from the mid-continent to the current configuration in Houston.

In 1987, using knowledge I picked up vicariously from Jon Claerbout during my stay at Stanford, I started the UT-Dallas Geophysical Consortium, which now in 2018 is in its 31st consecutive year. During that time there have been a number of industry cycles, which we and our sponsors have weathered together. Our survival has depended on their continued support, so we must have been doing something right. 2018 is the last year of operation of the consortium; the final annual sponsors  meeting will be next spring.

I have been doing a historical ramble, so let me spend a couple minutes for some technical comments. First, the goal of research is not to hang on to your most recent breakthroughs, but rather, to make them obsolete as quickly as possible, by replacing them with something better. That is, to continually be pushing the leading edge. This can be done by addressing the shortcomings in current procedures, or ideally by taking a totally different approach to the problem by viewing it in a new context. Let me give a couple examples of the latter. Although the topic that is most often associated with me is reverse time migration, and this probably has had the most long term economic impact, there are other papers that have been cited almost as often, and they are on quite different geophysical topics. These involved application of tools that were previously developed for the solution of totally different problems. Two of these were published in Geophysics. One is on extracting dispersion curves from surface waves by wavefield transforms. Seeing this solution was one of the most exciting moments in my career. All of the calculations and the writing were done in the space of 3 days, The other paper with more citations was on the application of seismic reflection processing to multi-channel ground-penetrating radar data. These are examples of being at the right place at the right time, but there is also a saying that luck favors those who can capitalize by realizing the significance of the opportunity that is presented. The lesson here is don’t be afraid to take a risk by doing something different if it makes sense. It could change your life. The reverse time paper also illustrates that. The original paper was rejected by the editor of the journal geophysics as it was too far ahead of its time. It took another 20 years for computing capabilities to grow to the point where this approach became cost effective, and now it’s used everywhere. By the way, rather than being discouraged, I resubmitted the paper to Geophysical Prospecting, which is the premier journal in the field in Europe and it was accepted without any changes, and as they say, the rest is history.

In closing, I would like to acknowledge all those that have influenced my career…..that’s probably half the people in this room and many others. I have a major debt to all the editors and reviewers who forced me write better and clearer, and all my students and other collaborators who have challenged me to find new solutions to problems, and who never cease to surprise me with their creativity. I have learned as much from them as they have from me. But let me highlight 3 people who I think have made the largest impact.  First, Jon Claerbout, who provided the opportunity to spend a year at the SEP, where my whole perspective on seismology was changed. Second, Sven Treitel, who was instrumental in getting my first financial support, from Amoco, when I first started at UTD. He made me feel welcome in the exploration community, and has been a friend and a role model ever since. And the third is Peter Annan, who was a graduate student at the University of Toronto at the same time I was there. He was instrumental in my getting me interested in ground penetrating radar research here at UTD, which developed into a very productive second research emphasis for me, in high resolution imaging of reservoir analogs. Peter was one of the people, along with David Strangway, who designed the first GPR system that was sent to the moon in the early 1970s.

Finally, I must express my appreciation to Sharon Edwards who has been the best Administrative Assistant that any Center Director wishes for, and a good friend. She excels at problem solving, and has kept me out of trouble more than once with her knowledge and expertise. She has done all of the arrangements for this event. Let’s give her a hand.

I also need to acknowledge the support of my wife Stella, who over the years, has allowed my career to flourish, by taking responsibility by taking care of the  management of our home. She has also reminded me that now that I’m retired, it’s my turn to do the cooking and cleaning and grocery shopping, and taking care of the yard. So let’s give her a big hand too!

In closing, The best advice I can give to find happiness is to find what you really love to do, and to put in whatever effort is needed to become the best you can at it.

And finally, if you never stop learning, the other aspects of your life will take care of themselves and you will have no regrets. Thank you all for your attendance here today, and now I will turn the podium over to one of my former students, Dr. Xinfa Zhu.