August 08, 2019 2:42 PM

Encountering an Old Idea Three Times in Ten Days

I hope to eventually write up a reflection on my first Dagstuhl seminar, but for now I have a short story about how I encountered a new idea three times in ten days, purely by coincidence. Actually, the idea is over one hundred fifty years old but, as my brother often says, "Hey, it's new to me."

On the second day of Dagstuhl, Mark Guzdial presented a poster showing several inspirations for his current thinking about task-specific programming languages. In addition to displaying screenshots of two cool software tools, the poster included a picture of an old mechanical device that looked both familiar and strange. Telegraphy had been invented in the early 1840s, and telegraph operators needed some way to type messages. But how? The QWERTY keyboard was not created for the typewriter until the early 1870s, and no other such devices were in common use yet. To meet the need, Royal Earl House adapted a portion of a piano keyboard to create the input device for the "printing telegraph", or teleprinter. The photo on Mark's poster looked similar to the one on Wikipedia page for the teleprinter.

There was a need for a keyboard thirty years before anyone designed a standard typing interface, so telegraphers adapted an existing tool to fit their needs. What if we are in that same thirty-year gap in the design of programming languages? This has been one of Mark's inspirations as he works with non-computer scientists on task-specific programming languages. I had never seen an 1870s teleprinter before and thought its keyboard to be a rather ingenious way to solve a very specific problem with a tool borrowed from another domain.

When Dagstuhl ended, my wife and I spent another ten days in Europe on a much-needed vacation. Our first stop was Paris, and on our first full day there we visited the museum of the Conservatoire National des Arts et Métiers. As we moved into the more recent exhibits of the museum, what should I see but...

a Hughes teleprinter with piano-style keyboard, circa 1975, in the CNAM museum, Paris

... a Hughes teleprinter with piano-style keyboard, circa 1975. Déjà vu! I snapped a photo, even though the device was behind glass, and planned to share it with Mark when I got home.

We concluded our vacation with a few days in Martinici, Montenegro, the hometown of a department colleague and his wife. They still have a lot of family in the old country and spend their summers there working and relaxing. On our last day in this beautiful country, we visited its national historical museum, which is part of the National Museum of Montenegro in the royal capital of Cetinje. One of the country's most influential princes was a collector of modern technology, and many of his artifacts are in the museum -- including:

a teleprinter with piano-style keyboard in the Historical Museum of Montenegro, Cetinje

This full-desk teleprinter was close enough to touch and examine up close. (I didn't touch!) The piano keyboard on the device shows the wear of heavy use, which brings to mind each of my laptops' keyboards after a couple of years. Again, I snapped a photo, this time in fading light, and made a note to pass it on.

In ten days, I went from never having heard much about a "printing telegraph" to seeing a photo of one, hearing how it is an inspiration for research in programming language design, and then seeing two such devices that had been used in the 19th-century heyday of telegraphy. It was an unexpected intersection of my professional and personal lives. I must say, though, that having heard Mark's story made the museum pieces leap into my attention in a way that they might not have otherwise. The coincidence added a spark to each encounter.


Posted by Eugene Wallingford | Permalink | Categories: Computing, Personal

August 02, 2019 2:48 PM

Programming is an Infinite Construction Kit

As so often, Marvin Minsky loved to tell us about the beauty of programming. Kids love to play with construction sets like Legos, TinkerToys, and Erector sets. Programming provides an infinite construction kit: you never run out of parts!

In the linked essay, which was published as a preface to a 1986 book about Logo, Minsky tells several stories. One of the stories relates that once, as a small child, he built a large tower out of TinkerToys. The grownups who saw it were "terribly impressed". He inferred from their reaction that:

some adults just can't understand how you can build whatever you want, so long as you don't run out of sticks and spools.

Kids get it, though. Why do so many of us grow out of this simple understanding as we get older? Whatever its cause, this gap between children's imaginations and the imaginations of adults around them creates a new sort of problem when we give the children a programming language such as Logo or Scratch. Many kids take to these languages just as they do to Legos and TinkerToys: they're off to the races making things, limited only by their expansive imaginations. The memory on today's computers is so large that children never run out of raw material for writing programs. But adults often don't possess the vocabulary for talking with the children about their creations!

... many adults just don't have words to talk about such things -- and maybe, no procedures in their heads to help them think of them. They just do not know what to think when little kids converse about "representations" and "simulations" and "recursive procedures". Be tolerant. Adults have enough problems of their own.

Minsky thinks there are a few key ideas that everyone should know about computation. He highlights two:

Computer programs are societies. Making a big computer program is putting together little programs.
Any computer can be programmed to do anything that any other computer can do--or that any other kind of "society of processes" can do.

He explains the second using ideas pioneered by Alan Turing and long championed in the popular sphere by Douglas Hofstadter. Check out this blog post, which reflects on a talk Hofstadter gave at my university celebrating the Turing centennial.

The inability of even educated adults to appreciate computing is a symptom of a more general problem. As Minsky says toward the end of his essay, People who don't appreciate how simple things can grow into entire worlds are missing something important. If you don't understand how simple things can grow into complex systems, it's hard to understand much at all about modern science, including how quantum mechanics accounts for what we see in the world and even how evolution works.

You can usually do well by reading Minsky; this essay is a fine example of that. It comes linked to an afterword written by Alan Kay, another computer scientist with a lot to say about both the beauty of computing and its essential role in a modern understanding of the world. Check both out.


Posted by Eugene Wallingford | Permalink | Categories: Computing, General, Teaching and Learning