New Insights into the Obvious

The number of posts I publish here tends to rise around the holidays, when demands on my time temporarily wane, giving me time to think about interesting topics and reflect on life.  I reread a post from a while back, which talked about my frustrations with the hectic nature of my job and my desire to spend more time on deeper thought.  Click here for that post.  My goal was to understand some of the deeper consequences of quantum mechanics and how it underpins thermodynamics/statistical mechanics.

I have approached this goal over the last half decade by rethinking the most basic foundations of quantum mechanics; those topics that students quickly leapfrog to progress to the next stage of solving real research problems.  I find the need to build my intuition by mulling over these basics, perseverating over them until the meaning infuses my brain.  Once it becomes second nature, I can build on these foundations.

In the process skimming through typical textbooks, I found that the connection between quantum mechanics and density operators is not well made.  So, I wrote a simple two-page manuscript with a simple example that illustrates the important facts and submitted it to the American Journal of Physics.  One of the reviewers stated, “Reading this very short and sweet manuscript taught me something about density operators that I did not appreciate before; something that seems vitally important for both students -and- the general interested physicist to understand…

“The main thing I learned by reading this manuscript is that the apparent classical mixture form of the density matrix -always- originates from a purely quantum effect - entanglement with the environment. I almost cannot believe that I did not appreciate that before - interaction with the environment is certainly presented as the main issue to be solved in any open quantum system textbook. But the formalism obscures this, and I think I had come away with the impression that at least in some cases, the density matrix was really just used to represent a classical mixture. The use of the simple example here makes it extremely intuitive and obvious, which I think is just as the authors intended. However, I suggest three changes that I think will make this manuscript even better...”

I find AJP a wonderful journal, authored and read by people who enjoy learning and appreciate new insights or an unexpected twist on a well-worn topic.

At the other extreme, we just had a paper accepted that developed two different models of how light can affect the mechanical properties of matter and used these models to interpret experiments to determine the underlying mechanisms.

This break I plan on continuing my work on a new project related to quantum computing, which is particularly exciting to me because it will require learning a lot of new material.

Stay tuned!

Perseverance trumps intelligence

I have not posted here for almost a year.  Perhaps it's because I have fallen into a bit of depression.  On the bright side, I have been thinking about neat things and trying to build a deeper understanding on topics where everyone else has failed.  So most likely, I will fail too, which is not of great concern to me; rather, I feel that I have not been directing my energies into areas that will most certainly bear fruit, so I might be left in the dust as a result.  I can already see evidence that I am losing connections to my colleagues.

I am concerned that this depression is affecting many aspects of my job.  Reading an article earlier today that was published prior to me presenting the Distinguished Faculty Address in 2005 (click here for the link), I felt that the same narrative would not apply to me now because of this dark undercurrent that draws away energy.

This morning I got a glimmer of hope when I asked my 20-student mechanics class why they chose to major in Physics.  To fill the elongated pause, I offered, "To gain an understanding of how things work?  To use your knowledge to invent things?  To get rich?  To be poor?  You can do all these things with a degree in physics."  This generated a bit of laughter.  I then continued, "for me, I pictured myself being dirt poor, and living in a cave with a blackboard and some physics books.  I sold out and took a lucrative industry job at Bell Labs, which I disliked.  It wasn't that the work was uninteresting --  I ended up doing lots of fun physics, but I disliked the focus on a product."

I then went on, "However, I find it fun to make things and it was very enjoyable being part of a startup that I founded two decades ago.  We did everything from basic research, to making products, and it felt a lot like academics.  There was no boss telling us what to do.  We all did what needed to be done.  That company is now highly successful, but unfortunately, I got out of it years back before it took off."

Though the story brought back fond memories, I quickly got back into the subject matter.

Later in the day, I got an email from a student that said my question resonated with him and he described his passions and how a degree in physics would get him to his ideal career.  However, he admitted that the subject was difficult to him and that he was struggling.

My reply to him (edited to keep anonymity) :


Dear so and so,

A very famous and highly respected colleague of mine (and more senior than I am) once confided in me that he feels like a fraud.  Everything he does seems to take much more effort than it does to others and he feels barely afloat.  The well kept secret is that many people feel this way, especially the successful ones because it drives them to work to exhaustion.  Your approach is spot on; work hard to realize your dream.  And don't be concerned about exam scores; I  consider exams to be a learning experience, so try to redo the problems and learn from your mistakes.  I will include a part of a problem from this exam on the next one to make sure you have learned form the process.

I always get myself into positions where I am struggling, because being challenged is a sign that you are learning and growing.  So relish the feeling that you are struggling and that you might at times feel stupid;  that's a good thing.  Check out https://www.improbable.com/2011/04/29/the-importance-of-stupidity-2/.  I also wrote on the topic a couple years back.  Take a look at https://unknownphysicist.blogspot.com/2016/11/i-always-feel-stupid-and-confused.html.
Bottom line is that I never worry about students like you.  I can see that you are attentive in class, that you are following the material, and that you participate when I ask questions.  Keep the passion!

Best,

I hope that this letter has sparked the beginning of a return to my previous self.  As I have found, writing this blog has therapeutic value even if it is never read.  So more posts in the future will be a metric of my success in overcoming my malaise.

The next topic for discussion may be my feeling of mental deterioration.  A faculty job requires multitasking at many levels, and I feel that in my older more feeble age, being diverted from actively practicing physics drains creative energy and dulls my senses.  That's something that needs to be reveresed.

I still get excited when I learn something new, and research continues to be stimulating.  The power of physics to explain phenomena, which can be harnessed to the betterment of humanity, is what attracted me to physics, and living with it throughout my lifetime has deepened my love for it.

That's a good starting point to build on...

What I expect of my PhD students

Every graduate student needs to be aware of expectations.  Each adviser is unique and operates on different principles.  A small number view their students as a pair of hands to do the dirty work.  In the old days, some advisers expected their grad students to mow their lawn and do housework. A friend of mine from grad school had an old-school adviser who had him come to his place on the weekend for services.  However, most faculty members by that time had already moved into the modern era and this kind of despicable practice is no longer tolerated.

It is important that each student have an understanding of what they are getting into when they join a research group. Here I will explain what I expect.

My highest principle is thinking of a graduate student as a junior-colleague-to-be.  Even the best students start out incapable of doing real research.  They are clumsy in the lab and need lots of hard work to sharpen their analytical skills.  As such, my first criterion is that they be good students who like to learn.  That doesn't mean that they need to be straight-A students.  In fact, many A students make poor researchers because they lack creativity.

On the topic of classes, I believe that the more the better.  I encourage students who are in the middle of their research phase to take classes.  Ironically, the students themselves resist because they feel it interferes with research.  Even some of my colleagues prefer that their students not take courses that are not of direct help to the research at hand.  I strongly disagree with this premise. The process of learning new things sows new ideas.  I myself enjoy learning because these new nuggets of knowledge invariably get incorporated into my research, which leads to totally new and wonderful directions.

Principle 1.  Always keep learning from classes, reading the literature, and just thinking about crazy ideas.  If you feel yourself to be leaving your comfort zone, you are on the right track.  I expect my students to never stop learning and to be constantly pushing themselves.

An important part of being a PhD scientist is independence.  Grants, which support research activities, expect results.  Many advisers thus give their students a very short leash.  The end result is bad for the student's independence.  I prefer to give the student a specific assignment, and let her and him work on it for a year or so without giving them a detailed map of how to get there.  However, I do give lots of course corrections and teach them things they need to know along the way (or send them to the literature) if their struggles are based on missing information.

I once had a PhD student who complained that I seemed to be giving another student lots of attention while neglecting him.  I treat PhD and masters degrees differently.  The individual with a masters degree needs skills to survive in industry, while a PhD scientist is required to come up with new ideas and find ways to tackle a new problem.  Having said that, some of my best and independent students happened to be masters students who were quite capable of getting a PhD.

Principle 2. Learn to be self reliant early on in your research.  Read the literature and talk to others to gain the skills you need to do your work, but don't wait for someone to tell you what to do with those skills.  Constantly try new things in the lab or with paper and pencil to both sharpen your skills and generate new ideas.  You will make lots of mistakes along the way when not given step-by-step instructions, but making these mistakes and getting through them are the most important part of the experience.

I do not yell at my students, ever.  I may tell them when I am displeased with research performance, but if a student does not perform, (s)he will not get a degree.  Passing the Prelim and being in a research group is no guarantee of success.   I disagree with the idea espoused by the administration that we need to help the students along so that we increase our graduation rate.  Graduating a PhD without the proper skills and talents serves nobody.  A PhD degree is not a ticket to a good job.  It's the skills that the individual has mastered and the ability to think independently that makes him or her valuable to society.  A huge pool of unemployed physicists is not what we want to be generating.

It takes lots of hard work and perseverance to finish a PhD degree.  People often ask me how many hours they should work.  My answer is all the time.  If you are not excited by your work and don't enjoy thinking about physics beyond your area of expertise, then you're in the wrong field.  Academic jobs are tough to get, and real research jobs in industry are rare.  However, PhD physicists have lots of success in engineering jobs, which are more plentiful.  If you like to tinker, then engineering may be an excellent way to earn a good living while having fun.

A PhD degree should not only be a guarantee of skills, but of work effort and perseverance.

Principle 3.  Approach your research with a passion.  The benefit of enjoying your work, aside form the direct rush of endorphins, is that you will put in the time required to do a good job.

One of the most important attributes is perseverance.  Watching Star Trek, or other sci-fi shows/movies gives one the impression that scientists apply skills to very easily solve problems.  This is not the case unless a student is super lucky.  I have a long list of stories on the same theme;  students who would spend months trying to get an experiment to run, only to have to start from scratch to try a different approach.  Aside from being good problem solvers, the PhD degree is an imprimatur of a person that does not give up.

In my PhD work, I had spent quite some time building an experiment on a 5' x 10' table optical table, which was filled with all sorts of laser sources and optics, resembling a Borg city.  Each step in the process often required a step backwards.  After completing the construction of the experiment, it still didn't work.  I then figured out the reason, tore the experiment apart and rebuilt the whole thing on another optical table with another laser.  Luckily, it ended up working.  Only then could I start taking the data that was the topic of my thesis.

Principle 4. Don't give up.  When something doesn't work, don't shy away from the problem.  Work twice as hard.  This will serve you well in all aspects of your lives.  When I was a new faculty member, aware of the importance of getting grants, I would write two new proposals for every one that did not get funded.  After my first two years, I built a healthy portfolio of projects.

Many people do not recognize the creativity behind science.  Creativity is part of choosing a scientific problem to study, helps in problem solving, and leads to interesting new science.

Principle 5.  Be creative.  Always think about neat implications of what you are doing or find new ways of looking at old problems.  This skill is particularity important in the career of young scientists who want to make it to the next level.

Principle 6.  Be meticulously careful in your work. Do not publish sloppy results, which will come back to haunt you, and always apply the highest standards to yourself.  You should be more critical of your own work than I am of you as your  adviser.  On the flip side, do not let this attitude prevent you from finishing a project.  In the end, we can never be sure if we are right, and there will always be a mistake somewhere.  If a paper is perfect, it is not science.  When working in the unknown, there are always huge dark shadows in the areas not exposed by your searchlight.

Principle 7.  Be honest with others, but especially with yourself.  Many very good scientists have fallen into the trap of fooling themselves into believing in something that is false.  Consider cold fusion, N-rays. etc.  Design experiments that are resistant to experimenter bias.  Also, do not try to make data fit your adviser's expectations.  I need to know when an experiment contradicts my viewpoint.  And it goes without saying that you should never fudge data in any way or plagiarize the work of others.

Principle 8. Impress me.  When you graduate, I need to make an honest assessment of your strengths and weaknesses in the letter of recommendation, which will determine your success on the job market.  Follow all of the above principles.  Do not come to my office to ask what you should do next.  Tell me the issues you are having, your line of reasoning, possible explanations, and engage me in debate about the possibilities.  You should act as a junior colleague.  Don't worry about offending me.  I am more interested in getting at the truth than being right.  However, that does not give you the right to be caustic.

What I have posted above mentions nothing of the content of the work, which is of central importance.  A short post cannot cover the nuances.  To zeroth-order approximation, I expect the student to add a new piece of physics to the body of knowledge.  This could be a theory that helps us understand a phenomenon or the discovery of a new phenomena.  Fitting data to a mathematical expression is not enough.  The parameters of the theory must have meaning that is independently testable, be interpretable in terms of fundamental processes, and make predictions well beyond the domain of the original results that generated the theory.  Perhaps I will write more on the topic later.

If you approach everything in life with a passion, it will be a fulfilling one.   When you take a break from physics, make it count.  While I may seem one-dimensional in this post, I do find time for other activities.  Though I am not good at it, I play ice hockey with a passion.  I enjoy playing the piano and writing.  Taking a break from work is, in a sense, work.  During times of alternate activities, things percolate in the brain.  I have had the most profound revelations while driving my car in the middle of nowhere or playing the piano.  So, don't hesitate to take a break with intense activities.

I have to run now.  After I finish packing, I will take a short walk around San Diego, then I have to catch a plane back to Pullman.  Until then, get excited about physics.