Mariam’s Choices!

Mariam, please choose one or more paintings and i’ll send or bring them to you as a present. Call and we can discuss details! First is 16×20, second is 9×12, third is 9×12, fourth is 16×12, and the fifth is 9×12.



Comer’s art meanderings

I began painting in October, 2015 when I joined the Sunday morning Art Looking Up class at St. Patrick’s Episcopal church where Anne is quite involved. The group meets for an hour from 9:15-10;15 AM with a group of people interested and practicing art in various forms. We meet, talk about what we are working on, actually do a little art and get valuable takes on what we and others are currently working on.  I have enjoyed the people and the art!

I started painting in oil on canvas and on boards in early October, went to an art retreat in early November and in January 2016 began taking an art class with Charles Young Walls, an excellent representational oil painter from the Atlanta area. Check out some of his excellent works on his I think he is a very good teacher and has helped me a lot!  The classes meet for three hours once a week.  I am painting a different still life each week (not all are finished in the time available). The idea is for me to learn the basics of composition, brush stokes, color composition and mixing. And most importantly to get as much experience painting as I can.  There are many layers to learn and it is going, but slowly.  It is a lot of fun.  I am also painting at home.

I plan to display here some of the paintings, whether they are finished or not…maybe on never really finishes a piece but eventually decides it’s good enough for now.

I wish I had began this process ten years ago!  So much to learn and digest and make my own and so little time to become proficient.  Along the way I plan to bare and share what I have done thus far both as a way to record what I’ve worked on and express whatever musings I feel like stating.

I plan to put this page category on my Facebook page Comer Duncan Art Explorations.

Forward, Yes

Looking backward while looking forward
Is possible but can be confusing
Unless I keep in mind that forward
Is the only really useful direction.
So long as I keep letting the past inform
My adventure into the future.
Getting stuck in the past is both isolating and useless
Since my past is strewn with failures and  successes,
None of which I can now affect,
While the future is open to whatever I can make it.
I must keep the future in my present since if I ever let
My future become my past, I’ll lose track of me.

A few comments on my beginning experience with computing at Brandeis and Bowling Green

This is a follow-up to a post I did a couple of days ago. It was induced by Tom Hern’s email concerning some of his remembrances of how computing and graphics evolution went at Bowling Green.  Today I want to record a few thoughts as to how I got into computing in the first place and perhaps mention a few factors involved in my initialization.

I was a PhD student at Brandeis University in Waltham, Mass from 1966 until I finished in 1970.  While at Brandeis I learned that there was a requirement that each successful PhD candidate would have to pass a test demonstrating a reading knowledge of two foreign languages.  The bad news was that I only had enough German in college to get by reading (not speaking) but I had only taken a year of Spanish in high school. Anyway, those days Spanish was not on the Brandeis list of allowed languages–not that it would  have mattered if it was on the list, since I had forgotten most of the Spanish I learned in high-school.  The allowed languages were French, German, and Russian. There was good reason for this as there was a rather large corpus of scientific journal papers and books in Physics.  So I was quite concerned.  What saved the day for me was a relatively new option at Brandeis:  one could learn and pass a test in a Computer Language!  Alas, I did not know really program in Fortran in 1966 but I figured that leaning Fortran would be a good thing to know in the future.  So, I learned enough Fortran in 1967 to pass the test and also managed to pass the test translating a chapter in one of Arnold Sommerfeld’s much read series of books in various areas of Physics.

I finished at Brandeis in 1970 and took a temporary position in the Physics department at Bowling Green State University.  It was a one year position, which with a lot of help from my colleages in Physics, I managed to obtain a tenure track position and thus became a permanent faculty member with tenure later on. My long-term colleague and good friend Berry Cobb helped me personally and socially.  As did a group of several faculty members in Physics.

Essentially as soon as I arrived Ron Stoner made it clear how excited he was about computing and its utility as an instructional tool.  I distinctly recall seeing in the long hall outside the department office an incredibly long computer print out attached to the wall stretching tens of feet down the hall.  It contained some of Ron’s “graphics” showing the time development of harmonic oscillators, some damped, some not.  There were probably other print outs along there too, but I recall noticing the oscillations.  Pretty cool, I thought. They served as a stimulant to students walking down the hall, showing how the equations they learned could be ‘solved’ using a computer.  The computer which was there was an IBM mainframe existing on the other side of campus locked behind an administrative wall.  Ron would write programs in Fortran, make a stack of cards on which the statements of the program were recorded. Then the card stack was fed into a card reader, translated into machine language and eventually run on the IBM. The output would be pages and pages of Ron’s graphs and those were what he had pasted on the wall.  The reason I am mentioning this is because I credit Ron with stimulating my interest to more immediately begin to explore the characterization of models of physical systems in a computer program and began my real learning of the utility of computational physics.  So thanks Ron.

I got seriously interested in Einstein’s theory of gravitation again in 1974, after the meeting of the Ohio Section of the American Physical Society that Bowling Green Physics hosted in October, 1974.  I had been doing research in Einstein gravity while an undergraduate and then Masters graduate student at North Carolina State University in Raleigh, NC.  When I went to Brandeis, I elected to do a dissertation in Quantum Optics, as I figured a degree in that particular area would make me more employable.  In the big scheme of things, who knows whether it would have made a decisive difference. Anyway, after I got settled in at Bowling Green I decided to return to Einstein gravity as a research focus. In those days there was much excellent research and excitement in Black Holes and in Cosmology, both of which I found (and still do) fascinating. I managed to volunteer to get the program of speakers together for the upcoming Ohio Section meeting. I got Philip Morrison, Robert Geroch, Charles Misner, and Anthony Tyson.  All were central figures in the development of theoretical and experimental efforts in many of the developments in the 1960s and early 1970s, so I was very pleased that they agreed to come.  I had also asked John A Wheeler but he had another engagement.

As a result of that meeting I decided to  get involved in a newly forming effort to devise computational methods to simulate the time evolution of  initial data describing the head-on collision of two Black Holes. The two body problem in classical Newtonian gravity has an exact solution, but due to the complexity of Einstein’s geometric gravity it was impossible to solve the equations analytically.  The new approach was the only way that, with an enormous amount of work, might yield enough information to get closer to the answer as to what would be the end product.  This new area subsequently called Numerical Relativity has been under development ever since and is yielding some answers to these very difficult questions.  Numerical  Relativity has been instrumental in addressing a wide variety of interesting questions of physics in Einstein gravity.  So by the end of 1974 I was immersed in learning to write rather complex computer programs in Numerical Relativity.

Of course, these computer programs spewed out a huge amount of data.  How to understand what the very large (in todays sense, this was a rather small amount of data 🙂 )?  By 1975 I became involved in the necessary visualization of the geometric variables and their time evolution.  Einstein’s theory produces a sequence of data sets characterizing the metric tenor and analogous geometric information, all of which needs to be visualized.  There were two problems, however.  One was the need to write or have someone write computer codes to read the data and display it.  The other was that one needed the devices to do the display.  Both were coupled and both were in scarse supply in the 1970s.  The only places where sufficient visualization could be done were either at research universities or behind the fences at government national labs.  So being at a mid-sized midwestern university did not make this easy to arrange. Collaboration with external colleagues where such visualization could be done was a necessity.  I longed for the day when I could run modest simulations on the IBM at Bowling Green and visualize the results on  ‘my own’ display device.

So, by 1975 I had a great and lasting research focus, but it was not until several years into the 1980s that I had much useful in the way of display devices.  But that is yet another story.

In connecting to the previous post,  I want to mention that I had been working in Numerical Relativity for six years when Tom Hern went to UNC.  I had faced the difficulties of the need for both display equipment and software to massage the numbers into visualizable things.  Tom’s return thus meshed with my six years experience and so I was very ready to find other colleagues interested in graphics at Bowling Green.

So, recalling the early days at Bowling Green and how I survived the paucity of computing facilities and graphics equipment is something I may try to string together in another post sometime…but this is clearly enough for now!


How I got into using graphics at Bowling Green

Today I received email from Tom Hern, one of my Bowling Green State University colleagues.  Tom was in the Mathematics department and was instumental in getting me to begin to realize the utility and intellectual stimulation that graphics/visualization could offer.  Tom’s email chronicled some of the more important stages of the development and evolution of computing and visualization which came about while I was there.  Tom’s remarks were induced in part by the death of a major figure in computing, Dennis Richie.  Richie invented the C language and was instrumental in the development of the Unix operating system.  Unix has mutated to Linux, which is the default workstation computing environment.  I am sorry to hear of Richie’s passing.

I have a few comments about how Tom Hern and others influenced my own development and want to record some of them here.

I recall in the early 1980s Tom Hern disappeared for a couple of years to
UNC on a sabbatical/leave.  I did not hear much from him (email essentially was not available yet between such geographically disparate places such as
Bowling Green and Chapel Hill).  One day at lunch Fred Rickey joined
our table in the university union as he would do from time to time. I
asked him if he had heard from Tom and if so what was he up to.  He
said that you were enjoying being in the CS department at UNC-CH and
were learning a lot.  In particular he said you had concluded that you
would have to learn C.  Well then C was pretty new and there were not
many people in Physics using C.  I went away and looked up C and
searched the book stores in Toledo (for sure the BGSU student book
store would never order anything that could not be used in a specific
course!).  I found a few sources and tried to learn C.  So, I am
saying that you are responsible for opening my eyes to
other-than-fortran languages.  I’ve never looked back since then. Thanks to Tom for that.

I also recall that one summer (either summer of 1980 or 1981) my
family and I went to Roxboro, NC to visit my Mother for a couple of
weeks.  While there I brought my oldest son Sean with me to visit Tom in Chapel Hill on the UNC campus.  What sticks in my mind about that visit is that Tom was working on a Evans and Sutherland workstation (extraordinaire
in that day!).  As a learning project you had written a graphics
application which would demonstrate some of the E&S features in the
guise of constructing  a simple 3D box beginning with a single sheet of paper
laid out in a plane with the outline of the paper already done. While
we watched the E&S graphics screen, the paper started to fold up in just the right order with the  end result being a fully 3D box!  It was neat. Sean and I were impressed. A nice memory.

When Tom did return to Bowling Green, he provided impetus of a number
of computing upgrades and several new directions in the use of graphics.  I was interested in using graphics to visualize various physical quantities which I was beginning to obtain with my first steps in an area of computational physics just being invented called Numerical Relativity. I had become really interested in the simulation of black holes obtained by ‘solving’ Einstein’s equations of general relativity and was hungry to see what was unfolding. Our graphics group’s interest and efforts  stimulated me to ask new questions and sometimes to get useful answers…the group of us who interacted in a weekly graphics seminar in the Mathematics department was a
wonderful intellectual  and social experience.  I credit Tom and Cliff Long for
providing input and encouragement for the use of more graphics in
computational physics.  I really enjoyed interacting with Tom and
Cliff  and a few others in those 1980s years.  We all struggled
with getting useful results from the inadequate computing equipment
(both computers and graphics machines) in that decade. And getting the
university to upgrade mainframe machines to ones which were
interactive was a major task.  I believe, if I am not mistaken, that
it only really happened that the DEC 2060, an interactive machine,
came to be when the CS department pushed it.  In any event, I really
felt like I could finally sit at a terminal and write code and compile
and run it without having to submit  a stack of cards!   And when that
machine came we started to use email on a regular basis.  It thus was
an actually useful thing.

I have been a Unix guy since those ‘early’ days. I have been using
Linux since the mid 1990s and have a Debian Linux machine at home in
the Atlanta area.  Now of course I have a MacBook Pro,  iPad (I), and
a iPhone. I write code and test it on my home machine (only 4 cores)
and tune and compute on clusters of linux boxes numbering at least 32
and if needed thousands (at Ranger at UTAustin). And the visualization
tools have been developing in positive directions.  I use VisIt and
Paraview, both with VTK et al  and python underneath.  Being able to
perform visualizations remotely (which requires a fat data pipe!) is
increasingly becoming more practical. Volume visualization is
increasingly important now that the simulations are in 3 spatial
dimensions (plus time).  I shall forever be interested in
visualization because of the start we crafted at Bowling Green.

I’d appreciate it if you would correct any glaring historical errors in the above.

More later…

WordPress on my iPad

Today I discovered the free iPad app WordPress and installed on my iPad. After a couple of configuration steps I can see, edit, comment, and post to this blog. So this post is just a record of having installed the app and testing that posting new blog entries works. Not too exciting but potentially useful.

First Steps on the Path

I have been reading and contemplating some of the basic tenants of what is called Mindfulness in the west.  It takes many but perhaps not all of the components of Buddhism and I am increasingly finding it to be a useful vehicle inside which I can see how to become a more complete person.  I have spent much of my adult life trying to develop and then deepen my conceptual side.  I am appreciative of the benefits of this approach. However, I am now (after all this time?) realizing some of my limitations are probably self-induced and perhaps mindfulness can help me attain a broader view, a deeper understanding of myself and of my relation to other people on this planet and even nature itself.

I have recently come across a poem by Derek Walcott (which was read by Jon Kabat-Zinn at the end of a great interview with Krista Tippet on the APM show On Being:  Here it is:

"Love after Love"
by Derek Walcott

The time will come
when, with elation,
you will greet yourself arriving
at your own door, in your own mirror,
and each will smile at the other's welcome,

and say, sit here.  Eat.
You will love again the stranger who was your self.
Give wine.  Give bread.  Give back your heart
to itself, to the stranger who has loved you

all your life, whom you ignored
for another, who knows you by heart.
Take down the love letters from the bookshelf,

the photographs, the desperate notes,
peel your own image from the mirror.
Sit.  Feast on your life.

There is much too much to say about this poem. Let me just say here that this poem is meaningful for me because I take it to be an encouragement to reach inward to aspects of myself that are seemingly unexplored. That is a good thing. Also, let me say that this poem does not in any way discourage communication with others. In fact it encourages me to try to understand better all those other people in my life for themselves, for they have also experienced many of the same things I have experienced.  I may well never achieve enlightenment but allowing this approach to inform me has certainly left me enlightened!

Well, maybe it’s a start.

A Try with MathJax

This is an example of a display of an equation. I have incorporated MathJax hooks and hope this works ok. For starters I will just display a single equation. This is the continuity equation for the density \( \rho \) with velocity field \( \mathbf{ v} \):

\[ \partial_{t} \rho + \nabla \cdot \left( \rho \mathbf{v} \right) = 0 \]

And the familiar quadratic equation:

When \( a \ne 0 \), there are two solutions to \(ax^2 + bx + c = 0\) and they are

\[ x = {-b \pm \sqrt{b^2 -4ac} \over 2a}.  \]

Not bad.