On teaching (Audio Engineering)

 Recently I came across a description of Nvidia's work environment.  Powerpoint is forbidden --- everything must be described on a whiteboard.  This prompted me to think about teaching together with whiteboards vs. "slides".  But let me begin by describing the Audio Engineering course I teach every spring.

 Audio Engineering is a very interdisciplinary engineering course.  It involves linear systems from EE, electroacoustics from Acoustics (part of physics), hearing (from Psychoacoustics, part biology, psychology and anatomy), circuits (again, part of EE) and then Digital Signal Processing (EE again).

 Because I inherited this course, I can't change the prerequisites without a lot of trouble.  So, the students are both juniors and seniors.  Some have taken the filter design class, others not.  Some have taken DSP, others not.  So my approach to this course is to motivate the students to take more advanced classes after completion of this course.

 For the most part (there are always exceptions...) the students are interested and motivated by music production and listening.  So, I try and harness that interest.  The text is "Acoustics, 2nd Edition" by Beranek and Mellow.  It's a reasonable text but it biases my presentation because of its equation dominant nature --- more on that soon.  It only covers Acoustics, specifically Electroacoustics, which means the rest of the course is without a text.

 Since it's an engineering course, I want them to build stuff.  This past year they built a binaural head (a.k.a. "Dummy head") and a loudspeaker.  I want to expand this further.  They also create simple DSP effects using matlab functions I provide.  Using "canned" matlab functions means they don't get down in the weeds trying to figure out how to implement filtering --- it's not a DSP class and so I don't want to get them bogged down.  But this has its problems since they don't really get an idea of various DSP problems including latency and quantization.  They do learn about using the DFT, but I have to explain equal tempered scales every year.

  So, onto lectures.  I begin every lecture with music.  I take a historical approach starting with the beginning of the 20th century.  So, I like to use Stravinsky as a starting point.  Some students know The Rite, others do not.  But when I introduce Ionization, that's when the ears really begin to notice.  The early tape pieces like Gesang and Les Paul's How High the Moon also make them think.  And then we start doing pop music in the 1960s and they are at home.  So, why have them listen to music?  Two reasons: (1) Many don't know the history of recording (2) To get them to listen for nuance.

 Now, here's where it gets problematic: I like to illustrate many of the devices invented over the years.  A picture of the internals of a microphone says much more than a simplified diagram. So it would seem that showing "slides" would be best.  And that leads into just displaying equations instead of deriving them.  I do have lots to say about each equation, of course, but it's not the same as writing it down a line at a a time.

 I once took a class poll for a different class (computer architecture): Did they prefer slides or whiteboard?  Overwhelmingly whiteboard.  And again, there are very nice pictures of old machines.  Maybe the pictures aren't relevant, or maybe they're best for home appreciation.

 Finally, I am always trying to build intuition.  It's shocking how many students can look at an equation and yet not be able to explain how to manipulate it. 

In conclusion, every time I teach this class, I am redoing the notes, trying to make the arcane bits clearer and emphasizing (and de-emphasizing) different parts.  But maybe this is the year I'll wean myself off the PDF display...

 

 

Post-election

Now seasoned by reading various pieces, I have come to my understanding of this debacle.

First, I think Joe Biden bears a large degree of blame.  He should not have run for a second term.  When he did drop out, he didn't leave enough time for Kamala to separate herself.  And second, she didn't cleave from the administration in sufficiently stronger terms.  But I thought she ran a nearly flawless campaign with the time she had.  And, the sad truth is that the electorate is incapable of electing a female at this point.

But this election was bigger than that.  It has shown that Trump is a unique person in the american historical landscape.  History will not judge either him or the electorate kindly.  But I agree with others, this is the beginning of the eventual collapse of the American Empire.  The state has been rotting  from within for some time and this is the final disease that will cause the collapse.  Maybe not within 4 years, but soon.

And again, this election showed a rightward march across the country.  I believe this is a worldwide trend and the U.S. was not immune.  But the urban-rural divide is so stark it's hard to see how to reconcile these two differing viewpoints (see "rot" above).

Many have remarked that the Democratic message is too "woke".  Like it or not, the commercial that concluded "She's for they/them not us" was very effective.

I fully expect this administration to be as chaotic as the previous one, but with more effectiveness (and ruthlessness).  I anticipate the DoJ will charge Biden with some invented crime.

A few predictions:

I expect that the new administration will rapidly introduce rules into the federal budget prohibiting DEI in contracts.  And universities will have to comply if they want federal funding.

Ukraine will be settled by granting Putin what he has now. It's not the whole meal he anticipated, but it's enough to satisfy his government. He can bide his time until he wants the rest.  Right now, he can't invade anything since the Ukrainians have significantly degraded his military.

This will signal to the Chinese that it's OK to take Taiwan.  The US won't do anything about it.

It's unlikely but possible that North Korea could try and invade the south.  They have the largest  standing army in the world.  And because they have nukes, they could tell the US to bug off. Additionally, they have Putin in their corner.  And he owes them.

And I expect the US to withdraw from NATO.  If Putin's your friend, then why fight against him? Europe is his sphere of influence, right?

Climate-wise, it's a disaster.  As with the previous administration, drilling will commence anywhere and everywhere.  The only silver lining is that Elon will convince the administration that electric cars are OK.

Les Earnest and the Stanford AI Lab

The Stanford AI Lab was an extraordinary place.  This was due to its location in the Stanford foothills but also because the administrator, Les Earnest, set the tone for the whole endeavor.  Les recently died at the ripe age of 93, failing to meet his end goal of 113.  I'd like to remember both the AI Lab and Les. Tall and lanky, Les nearly always wore a dashiki.  He had a puckish sense of humor.  And this was fundamental in establishing the lab's "atmosphere".

The saga begins with the recruitment of John McCarthy from MIT to Stanford in 1962.  McCarthy set about creating an AI Lab and eventually hired Les to manage it. Sometime in the 1960s, Sylvania built the "Donald C. Power Laboratory" in the Stanford hills (the fact that the sign said "D.C. Power Lab" was always amusing).  This lab was meant to be a doughnut/torus but they only built a quarter of it.  To reach it, you had to drive (or bicycle) up Page Mill Road (you could use Old Page Mill) and then turn right on Arastradero.  The steep driveway was at the turn to the left that led to Rossati's Beer Garden (known to this day as "Zots").

Probably due to the remote nature of the lab, Sylvania abandoned it and sold it to Stanford for $1.  Somehow (and I don't know the story), McCarthy and Earnest moved the wet-behind-the-ears AI Lab into the building.

I know I first visited the lab when I was in high school, circa 1967.  My buddies Bill Parrish and Hal Samson were approved users of the machines.  We went at night and would ring the front door bell.  A scruffy grad student would answer the door and just let us in (who else would be there at that time?).  We could basically explore the building.

Never a big game player (why play a game when you can write code), I will admit to playing Spacewar on the enormous graphics displays.  One experimental version was looking out the window of a spacecraft --- but I have been told the code has been lost.

I want to emphasize the extraordinary nature of this place.  You could find an empty terminal (they were glass CRTs) and the strange keyboard (designed by Les) had additional control keys labeled Meta and Alt.  The display proclaimed "Take me, I'm yours!".  And you could just log into the machine.  No approval, just type your initials and you were in.  Your files would be deleted, eventually, but it was there for you.  This was Les in action.  He understood the power of interactive computing and made it an open facility.

Les (and McCarthy) also permitted the Computer Music folks to begin experimentation during the night.  It was one minute of compute time for every second of sound.  This is where John Chowning invented the FM synthesis algorithm.

The building was always occupied with grad students and faculty.  It was the only place at Stanford that had interactive computing.  Don Knuth wrote Tex there.

The building had many nooks and crannies and the doors were labelled with places from Middle Earth.  The machine room in particular was labelled "Mordor". There was a large lounge with a television and tables and couches.  Another room held the computer controlled vending machine (another Les device). The vending machine was stocked with "pot stickers" from Louie's, the familiar name for the lab's favorite chinese restaurant. To operate the machine, you typed your initials and password into a nearby teletype and specify a slot.  The door would be opened and your account would be charged and eventually you'd have to pay.

Les was very tolerant of the goings on.  For example, Hans Moravec lived above his office and was on a 26 hour day.  If you wanted to talk to Hans, you asked someone "What phase is Hans on today?". 

The room below the computer room had a few mattresses and a lamp.  It was dark and very cool due to the HVAC.  The whoosing sound in the ducts covered up all external noise.  I slept there after all night programming.  I would occasionally spend all night largely because I wanted to see the sunrise.  I would go outside, watch the sun slowly illuminate the ground.  The scent of dew on the earth would top it off.  And then I would go downstairs to sleep.

Volleyball was another Les inspired activity.  In mid-day, a voice was come on over the PA system announcing "Bounce Bounce!" and a bunch of motley students and faculty would head to the outdoor court.

Les also sponsored the "Spring Orgy" with such events as the Felt Lake Cross Country (I took 3rd place one year) as well as the "Slow Bicycle Race" where the last person to cross the line won.  Les was heavy into bicycling and worked with the racing community.  He was prominent in mandating helmets and instigated rule changes.

Eventually, the CS Dept. tired of having this alternative hideout and moved SAIL down to the campus and Margaret Jacks Hall.  The musicians proceeded to take over the building and remained there until Stanford rebuilt the Knoll after the Loma Prieta earthquake.  And then they too were removed.

The building was hardly maintained by Stanford and so developed rot.  Parts of the outdoor walkways were roped off.  After the building was emptied, Stanford razed it and sold the land to a horse stables.  An ignominious end to a glorious place.

Les left Stanford and started up a company, Imagen, to take advantage of the nascent laser printer business.  His memoir tells the story.  Eventually, McCarthy hired Les back in 1980 and Les was part of the Stanford community until he retired.

Les was an amusing and engaging personality.  He enabled the whole facility and made it fun and exciting to be there.  I've worked in other well-known laboratories but I assure you, SAIL was really extraordinary. 

Art lessons

My (limited) understanding of art is a direct consequence of my mother.  I remember her most when I am in a museum confronting a painting.

My mother's art journey began when she (and her brother) were put in a group home by her disturbed mother.  At "The home" she discovered art and also presents at holidays (neither were present at her parents' house).  After she returned from "The home" she was determined to further explore art.  After graduating from Beverly Hills High School (on the other side of the tracks), she worked until she could afford to attend UC Berkeley.  She received a B.F.A. and M.F.A. in painting. Her master's degree work included a neo-cubist painting.

My father's first job after Berkeley architecture school brought him to Italy, where my mother flourished in the Italian culture of arts.  But I was on the way...  My mother abandoned painting whilst she raised 5 children, but was constantly sketching or drawing with pastels.

When I was in junior high school, my father constructed a small studio in the garage and she began to paint again.  I vividly recall the smell of linseed oil and later the smell of acrylic paints.  In one memorable circumstance, I received a note in a Jr. High class that my mother was in the office.  When I went there, she told me that she wanted to take me to a demonstration of Japanese ink painting right there and then (and she did).

My art education really began in high school when she began  teaching Art, particularly painting at the Pacific Art League in Palo Alto. In the evenings she would preview her slides and quiz us about the paintings.  "Who's this?" she would ask.  "No, that's not right because you can see the foreground isn't composed precisely".  Or, "See how ... was influenced by ...". And that was my introduction to Art History.

She also took the kids (as a family outing) to the DeYoung museum in San Francisco (where she would eventually become a docent).  There, she would examine paintings and tell us about the technique: "Look at the use of impasto here" or "See how the red leads the eye".

Whenever I talked with my mother after leaving the house, I would discuss current arts exhibits or a specific painting.  This would fully engage her knowledge of history and technique.  But as her mind was slowly was destroyed by Alzheimers, this became impossible.

So I miss her most when I view a painting but her voice is always in my ear... "Look at the brushwork", "See how he guides your eye" or finally, "Oh how magnificent". 

Gumbo

I'm a fan of gumbo.  But I don't quite make it the way K-Paul describes in his book, so I thought I would describe how to make it.

By far the most important hint is prep: Before actually making the roux, you should prepare the "Holy Trinity": Onions, celery and green pepper.  I don't measure, but make approximately the same amount of each (a half cup, more or less).  The other prep is dealing with the shrimp.  I buy frozen Gulf shrimp, so I defrost and remove the shell and devein them.  The shells go in a pot on the back with water and celery tidbits.  I bring that to a low simmer.  You can also prepare the spices: K-Paul recommends a particular spice blend: 1/2 teaspoon of red, white and black peppers together with oregano and thyme.  You might as well mince garlic too (one or two cloves).  And a few bay leaves.  And lastly, slice the andouille sausage.

Start by making the roux: I measure out 1/3c of flour and then use the same cup for the vegetable (not olive) oil.  Heat the oil up and dust in the flour when hot - stir frequently.  The flour will slowly toast.  K-Paul calls this roux "Cajun Napalm".  I have thus far avoided having it on my skin.

When the roux is almost the right color (don't forget, it continues to cook), you add half the trinity and cook.  After just a short while, add the other half.  Don't be alarmed at the sight of globs of roux.  Then add the spices.  Cook a short while and then add the garlic.  After a minute or two, you are ready.  Start ladling in the shrimp stock from the pot in the back.  It will bubble furiously at first, but keep stirring.  Add more stock.  Continue until you reach the right consistency.  The sauce will smooth out.  Remember that a gumbo is more like a soup than a sauce.

Now you're ready for the last bit of ingredients.  Add the andouille.  Let it cook 10-15 minutes or until you see the fat released (and red color).  Now you can add the shrimp, keeping in mind that shrimp only takes 5 minutes or so.  K-Paul recommends oysters and crab.  If you've got 'em, add 'em now.  But trust me when I say it's not required.  If the gumbo is too thick, just add more stock.

You finish by adding fresh chopped parsley.

Place a cup of cooked rice in the center of a bowl.  Ladle the gumbo around it.

In theory, you should drink a bottle of Dixie Beer with the gumbo but that's a low bar. 

Sophocles Orfanidis

My friend (and former colleague) Sophocles Orfanidis died on March 2nd of Covid complications at the age of 76.

When I arrived at Rutgers, Sophocles had the office next to mine.  I didn't see him too often: Sophocles was truly old school: He would arrive to teach his class, hold office hours and then vanish.  I can't remember how we started to talk, but I may have introduced myself.  Sophocles taught all the DSP classes: Both the undergrad introduction, graduate DSP and finally "Optimum DSP".

But I really got to know him when he invited my family (including a toddler) up to his country house in the Hudson Valley.  I remember stopping by my local Italian food store (DiPietro's, now closed) to stock up on ciliegene to go with basil and tomatoes.  The country house looked across the Hudson Valley to the Shawangunk mountains.  There I learned to appreciate Sophocles innate generosity.

Together with his wife and son, they offered a slow pace, if only for a weekend.  Sophocles continued to invite us to the house and it was always a treat.  In fact, he sent me a set of keys to the house so we could use it if he wasn't using it.  This was typical of him. We went to visit him in Greece and he drove 1.5 hours to Athens to pick us up.  His custom house on the Peloponnese peninsula was designed by his best friend (who also built his own house next door).   The daytime was too hot to go outside, but in the evening light, we would swim in the warm sea and the retire to a nearby restaurant.

Sophocles was first, and foremost, a physicist --- an applied mathematician.  His PhD was on particle physics theory.  He used his formidable mathematical skills to analyze whatever was on his plate.  He would then use matlab to model and simulate the equations.  Somewhere along the line, he started to write down all that he was solving and simulating.  The result was his first book on "Optimum Signal Processing".  When the publisher refused to reprint it, he obtained the copyright and proceeded to update it and then released it for public distribution.

He also wrote his book on DSP, published it, and then once again, the publisher didn't want another printing, so he took the copyright back and publicly distributed it again.  But in the past few years, he turned his attention to Electromagnetics and proceeded to write another book... But this time, he just made it public from the get go.

All of his books follow the pattern of his thinking: First equations, then computer models, then simulation.  I learned this from him.

Sophocles was widely acknowledged as the best teacher in the department.  Maybe college.  He told me he only brought in a single sheet of paper with a few reminders on it and the rest of the lecture would spill out.  I deeply regret I never saw him lecture --- I was told he was energized when at the board.  I did see him give a paper on filter design at the Audio Engineering Society, but that isn't quite the same thing.

He was detail oriented, both in his teaching and in his writing.  Every little nuance was correct.  Most amazingly, he didn't grade on a curve.  No, he changed the subsequent exams to shift the distribution.  He knew how the students would perform on the exam!  I can't imagine how he did that.

Sophocles eschewed the modern university's demands by not applying for grants and not having graduate students.    He loved to teach and did so with incredible perspicacity.

Since leaving New Jersey, I saw Sophocles just a few times.  One forgets that intellectually vital people like him can just vanish.  But they do and the world is that much poorer.

I will miss his insights and warm generosity.   Sophocles' death leaves behind his family and friends.   And thousands of former students.  Literally thousands.

Russia and the Soviets

I grew up the midst of the Cold War.  Although I never had to "duck and cover", we were constantly aware of the Soviet nuclear threat.  I was intrigued by the Soviet state.  What made this nation so culturally, scientifically and mathematically advanced?  And so, when I hit high school, I enrolled in Russian 1.  It was taught by Elena Vasilovna (Baskin) who I remember to this day.  My chosen class name was "Sergei".  And I was a horrible student.

But when I arrived at Revelle College, I had to pass foreign language proficiency.  That meant reading a text and conversing about it with native language speakers.  I thought I knew next to no Russian, so enrolled in Russian 1 again.  This was a mistake I quickly  rectified: I had actually learned something in high school.  It took me two quarters (and a bad grade) to pass the proficiency exam.  To celebrate, my parents took me to a Russian Restaurant in San Francisco where I spent the whole dinner speaking Russian with the staff.

In the intervening years, my Russian was covered over in layers of French, Italian and a bit of Japanese.  I discovered I wasn't so bad in languages, I just had to pay attention and listen. (Not my strong point in high school).

In 1984 I made my first trip behind the "Iron Curtain" by going to a workshop in Budapest.  It was fascinating but mainly because my grandparents were Hungarian Jews.  The stores were stocked with goods and the cafe life was alive.  And everywhere the sound of Hungarian being spoken reminded me of my grandparents.

The real revelation came in 1990 when I went to Latvia to visit my wife's relatives.  First, there were the visa documents in quadruplicate (with carbon paper!).  Second, when we landed, the baggage carousel was clearly hand-built.  And the toilets were, to put it nicely, smelly.  The relatives had to borrow a car to pick us up: While parked, the windshield wipers had to be removed because they might be stolen.  And we came bearing gifts: Cartons of Marlboros to use as barter.

The Latvians referred to the Russians as "The Occupiers".  This indicated to me that perhaps it wasn't as nice as the Russians would like one to believe.  But, as part of this trip we took a trip to Leningrad (Now renamed [again] to St. Petersburg).  Shockingly, my former Russian language skills were useless.  I had forgotten nearly everything.  When I was ticketed outside the Hermitage for jaywalking, I could barely talk with the Policeman.  I did get a chance to visit "Dom Knigi", the "House of Books" -- which was a place mentioned in our Russian language textbooks.  In order to buy a book, I had to deal with 4 people.

Food and other commodities were impossible to buy: At the summer palace I lined up to buy an ice cream but when I got to the front of the line, it was sold out.  The relative was laughing uncontrollably: "Congratulations!" he exclaimed --- "You've had the true Soviet experience!".

Leaving the Soviet Union was also educational.  We thought one could just show up and buy a train ticket.  Not so.  Not when the office issues 1-2 tickets per hour.  Unless, of course, you buy the clerk a blouse from the foreign goods store.  When we reached the Finnish border, Soviet guards came on the train and searched it from stem to stern.  While the locomotives were switched, we could explore the little store on the Finnish side.  Already commodities were available.  And when we arrived in Helsinki, it was if the world had switched from Black and White to Color.

In the intervening years, I have not returned to Russia.  I've never seen Moscow.  But now, it seems I will never see it.  I always wanted to take the Transiberian Express to Vladivostok.  Again, that's out of the question.

With Putin's murderous rage, it seems that Russia has again returned to the Soviet era.  They will try to be an autarky but will fail.  Once again, their citizens will thirst for what will lie on the other side of Iron Curtain (take 2). And the intelligentia will flee --- if they can.

Stephen Kotkin puts his finger on why Russia is always in a fix: "The West is not a geographical place and gives the following syllogism:  Russia is European, but not Western. Japan is Western, but not European."

Kotkin establishes the critical distinction between European and Western.  And to understand Russia better, one must realize why Russia is not Western (as much as the middle-class would like to be).

Russia could be a great nation if only they could free themselves from the notion of total top-down control.  It was so under the tzars, it was the same under the communists and now, once again, it is the same under Putin.  And therein lies part of their problem.

Watching this war, I am witnessing not only incredible carnage intentionally inflected on civilians (Bucha) but also the total conversion of the Russian state into a Stalinist state.

And this makes me depressed and beyond sad.