Evolution of a drawing

On my CaringBridge blog I mentioned getting back into drawing, and talked a bit about a process. Someone asked to see an example, and I realized this might be a place to show the evolution of one of the pieces I ended up framing for myself.

It started with a pencil sketch that grew out of a few black blobs on the page of a small sketchbook: (Original is about 3" x 4", I think).
I was particularly taken with the blob on the end of the stick -- some kind of seed pod, maybe, with veins -- and decided to see what that was.

That turned into a other-worldly plant scene, also pencil, in the same sketchbook.

Then I tried it as a watercolor, about 8" x 11"

Finally, I turned it into a pen-and-ink drawing about 5"x7" matted.

Ruleset for Debugging?

So, I'm cleaning out my filing cabinet and ran across stuff from grad school, including handwritten notes from a lecture by Gerald Weinberg, I think.

Here's an interesting ruleset, probably related to debugging or at least trying to understand someone else's program:

1. Don't focus in too quickly


2. If you found one problem, keep looking


3. If there's an alibi, there must have been a crime.


4. Why did he do it THAT way?

I must say, rule 3 is one that's had an impact on my own programming.

What Weinberg calls an alibi is one of those comments you've seen where the programmer is either apologizing for something he did  or explaining what she obviously recognizes as bad practice.   You know you've written them.

The impact it had on me was, eventually, that everytime I start to write one I find I can't complete it and/or leave it in.  It forces me to rethink the problem and find a way to avoid the alibi.

The last rule has also been a winner, and I could argue, a major factor in my own success --  I assume the programmer knew what she was doing (until she proves otherwise) and she's done it significantly different than I would have based on what I know, maybe I don't know something she did...The notes say "try to get inside his head -- what was the motive? (though that may refer to the crime for which the alibi exists) -- be skeptical of everything.

Changes

It's late in the year, the music on the radio is rather melancholy, and the times have been changing:  Wonder Woman & I both went on Medicare, my father and another member of our wedding party died, and the kids came and went.

Of course, we had a great year, so I'm not complaining, just musing.

We celebrated WW's birthday along with the arrival of Jesse and Tammy from South Africa in April, with a big party at her sister's home.   Another friend of ours was also turning 65 in early October, and we decided to celebrate along with them with a tour of England and Northern Ireland.  That was a lot of fun.

I've been lusting after my own copy of Mathematica for a number of years, always unable to justify the price, but thinking "Well, maybe one of these days...".   As my birthday approached, they announced a new version with a new, 30% higher, price...  On the other hand Apple stock started going up nicely...   and when I investigated Mathematica Player, I was amazed to find they would offer a 50% discount for home use of the real thing by those as senior as I!    Of course, 50% of too much is still an awful lot.  But then having younger friends with dread diseases heightened my awareness of mortality and I recognized that learning the product wasn't going to get easier as I procrastinated.    So these days I'm entertaining myself by climbing another learning curve (and figuring out how to plot it!).

Then Jesse was recommended for a position in New York City -- I'll let him blog about that -- and just this week he and Tammy moved to Brooklyn!

We had a great Christmas feast with Josh and Tammy -- and Jesse arrived late in the evening.

Tomorrow we entertain Josh and Antonia, and the next day we head to Milwaukee, to see the new year in with friends.

Lisping again

As I mentioned in Lisping, I'm trying to get back to lisp.  I found Successful Lisp and find it's a good way to get going.  I've been using Slime and SBCL and just got my Hyperspec set up so that even when I'm not connected, I have it available.   

I like that as I write code, the argument list shows up in the minibuffer whenever I'm ready for the next argument. If I need more detailed information, a few keystrokes (C-c C-d h) pops up the hyperspec definition in my favorite browser.  Also, I can jump to the definition for a function with the stroke of keys (M-.) and then return at another stroke (M-,). At least some of that was available last time I used Lisp, but I never got it built into my fingers.

Patriarch

I have achieved a position of dubious desirability -- oldest surviving male member of my family -- the Patriarch.

Which is to say, my father died July 28; he was 87, and Parkinson's had been depriving us of him for several years. He had over 80 good years, though, so he did well.   I'll write more about him in a later blog entry, but this one is about how I've been affected

It's been a strange experience for me, making clearer to me the distinction between my intellectual self and the real me.

It started when I returned to cellphone range after a day away. An aunt I was planning to see called and opened with "Jim told be about your father". It wasn't hard to guess what that meant, as he'd been in and out of the hospital several times recently and I'd already gotten two "I think this may be it" calls. We talked for a few minutes and I called other family members and headed back out of cellphone range, to see Susanna. It was all very intellectual -- I'd been expecting it, it had happened...

I told Susanna, she gave me a hug and I started to explain that it wasn't affecting me much, as most of the mourning had already happened. I started -- but I was unable to finish, because I was suddenly in tears and couldn't speak. Then I started to laugh at the same time because the situation was so ridiculous! Mr. Cool discovers his emotions really do exist.

That situation has continued for awhile now -- the split between the unnamed self and the named self being observable.    I became aware, one morning about 3am, that I was telling myself, subvocally,  "my father is dead".  Later that day I became aware that I was doing it again, and that's happened several times since.   This is, to me, a very interesting situation -- the unnamed self, that biological entity that composes the named self, the intellectual construct called "me", is using language to process the event in some way -- usually without bothering to update the construct.    The fact that "I" became aware of it suggests some parallel processing going on in the unnamed -- one process is cogitating about the new fact, "my father is dead", while another process updates the construct -- making "me" "aware" that "I'm talking to myself"...

Maturana and Varela say "Everything said is said by an observer".  

Need to spend some more processing on that.   probably need to look for Hofstadter's new book...

 

Lisping

So, I'm trying to pick up Lisp again -- on yet another different system -- after tripping across this article.

 

   Lisp is an antique language that's more modern than many formerly more popular languages, such as C++.  I first learned to program in Fortran II (actually, FORGO) and IBM 1620 Assembler language back before terminals, screens, and on-line printers were common at universities, in 1964.   I first encountered Lisp via the LISP 1.5 manual when I didn't even have access to a computer!   I loved the mathematical basis for it and played with it on paper for a little while. In 1971 I went back to gradschool and was finally able to run Lisp programs; it was my favorite language.    There seemed then to be basically two groups of users -- the mathematicians, those who appreciated the mathematical underpinning and felt it important to faithful to that vision, and the hackers, those who wanted to do neat things with the language and were perfectly willing to lose the mathematical grounding in order to make programming in the language easier.   I, as you might guess, fall in the former group.

 

   Then I learned C and thought -- "One of these days, I've got to write my own lisp interpreter in C!"  A few years later, I actually did (close to "Portable Standard Lisp") -- not a great one, but I learned a lot about writing portable programs as I moved it from computer system to computer system and memory became cheaper and cheaper.  One of the things I like about that program is it's written in such a way that I can edit one small header file and change the implementation of lisp addresses from offsets into an array to actual machine addresses without needing to modify any other files.  When  I first wrote it, the machines didn't have much memory and I specified how much memory (2K nodes, 4K nodes, ...) I wanted on the command line and used the indexed scheme  Later when it was easy to have a program with lots of memory, I switched over to the pointer version. 

   

    As Lisp evolved -- it became Common Lisp -- my first take was "the hackers won".  That's actually an overstatement -- some of the worst "clevernesses" were eliminated in favor of portability -- for instance, the hackers loved to make zero, the empty list, and the empty string all be equivalent.   As it turned out, preserving the mathematical basis actually made it less machine dependent.   Nowaday, it's actually required that treating NIL as a number be declared an error rather than a clever hack!

 

   I used Harlequin's LispWorks on my job for awhile, and that was an amazing project, but there are some strange tensions between those who want dynamic software that's easy to update and those who want call processing to be as absolutely dammed fast as possible and the true believers didn't really buy the program until the managers had decided to cancel the project ...  so I had to go back to C/C++.

 

   Having been an emacs user for decades, the existence of Slime, an emacs add-on to make interacting with Lisp even easier, lured me back.  Now I'm trying to become familiar with SBCL on my MacBookPro.

The Poincaré Conjecture -- goodish book

I've just finished reading The Poincaré Conjecture, In Search of the Shape of the Universe by Donal O'Shea (at Amazon.com).

     Now, I'm kind of an amateur Math geek, so I'd like it if it had a bit of actual math in it, but I think I'd want to read most of the current version before I hit that math.  That's because O'Shea does an amazing job of describing the basic ideas completely without math, in terms that almost anyone can understand.   

      He starts by considering the shape of the earth, and when we humans developed good ideas about it, and then what was needed to be sure of it.  He shows how, even after Magellen's expedition circumnavigated the earth, in 1522, we couldn't really know it the earth was a sphere -- showing some of the alternative shapes it might have... 

 

   By considering maps and how they relate to the earth and it's shape, he introduces and defines the term "two-dimensional manifold" -- in a completely clear fashion.   He generalizes it to 3 and more dimensions, too.    I've encountered the term "manifold" in mathish contexts before, and had a vague idea about what it was, but have never actually seen as clear a definition.   The nice thing about his definition is that I expect the intuitive understanding it presents will make it easier for me to follow the actual math if I go looking for it.   

 

    Most of the book is actually a history of the mathematics  and mathematicians who worked on problems related to the geometry / shape of surfaces and space right up to about 2006.  As such, you may not be really interested in reading the whole thing and finding out who did what -- but the first few chapters, at least, are worth reading just to understand what the question is about the shape of the earth and/or the universe.

 

    A word of warning -- the Poincaré conjecture and its proof doesn't really tell us what the shape of the universe is, instead the importance of it is impact the search for the proof has had and will have on mathematics and physics.  Like the search for the proof to "Fermat's Last Theorem", and many other difficult math problems, their value is not in the answer, but in the way they stimulate new thinking and new math.