Category Archives: Technology Artifacts

Open Pits and Bathtubs

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I had to agree that it was an unusual gas station. 

It looked like an airport control tower with a cantilevered roof that protected the customers at the gas pumps – protection from rain and sun that is common today but in 1978, and certainly 20 years earlier when built, it was novel.  The pumps were fueling the local cars:  a mix of old gas guzzlers and newer more fuel-efficient models that were a response to the oil embargos of the 70s.

We were on the way to our business destination—the US Steel mine near Mountain Iron Minnesota, a town slowly being eaten up by the open pit mine as it followed the deposits of diffuse iron known as taconite.

I was the passenger in Steve Haverberg’s VW microbus.  Steve was familiar with the area and knew I would enjoy seeing a gas station that had been designed by Frank Lloyd Wright.  We needed gas anyway and it was a good time to stop and stretch. 

Another vehicle was also on its way to the mine, but had taken a more direct route.  It was equipped with a 4-foot long cylindrical probe, to be lowered by cable into a drill hole.  A custom-built instrument specialized for detecting iron ore was also in that truck.

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Trapped like Mars Flies in a Klein Bottle*

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A Klein bottle, an object with no volume, being weighed for shipping.

I recently received a Klein bottle as a gift from my life-long friend Rich, who shares the same quirky interests in math and science that I do. We find the same fascination and amusement in mathematical puzzles and their visual incarnations by artists like M C Escher, Buckminster Fuller, and Scott Kim, along with mathematicians John Conway, Roger Penrose, and Benoit Mandelbrot. So it was with tremendous pleasure that I received this gift. I soon discovered that it held not only the novelty of being a mathematical object, but it had been created by a scientist/artist that had inspired me in an earlier time in my life.

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The Vancouver Marine Building

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An art deco overhead lighting fixture featuring shipping and ocean themes.

I am not the only one who enjoys encountering unique examples of architecture. I was accompanied in my quest to find the Harvard Biology Building with its intriguing doors, sculpted façades, and anatomically exact statues of rhinoceroses, by my (newly married) wife Poldi. That was the culmination of a scavenger hunt to locate a novel architectural feature that had been captured in an old photograph my grandfather had taken, soon after the building had been inaugurated. We really enjoyed the experience.

Recently, Poldi, while planning a trip that would take us through Vancouver British Columbia, learned of another unique building, built at about the same time. Our destination was Banff, but we had a day before our train’s departure, to explore this famous port city of western Canada. She encountered references to the “Marine Building”, an art deco monument completed in 1930. At the time, it was the tallest building in the city (22 stories), and it was intended to be a grand statement of the value of Vancouver, especially its importance as a major seaport. They thought of it as their version of the mighty Chrysler building in New York City, completed earlier that same year.

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A Retirement Tribute to Fred Nourbakhsh

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Fred and Fereshteh at the welcome and marriage reception (winter 1997-98)

After a long and productive career, my friend and colleague Fred Nourbakhsh is retiring. 

I’ve known Fred a long time.  I hired him at Management Graphics in 1991 at a time when this small company was growing because it had invented an unexpectedly popular device that was having a major impact in the computer graphics field, including how Hollywood made movies.

I was impressed when I interviewed him because it was clear that he had done his homework.  He somehow knew a lot about the company—its size, its products, revenues, history.  MGI was a privately held company, so how had Fred learned all this when corporate reports were only sent to shareholders?  This was a time long before you could go to the “About” page on a company website; there was no website—there was no web.  However he did it, this depth of research is a strong skill in Fred, and it has served him well. 

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Franconia Aurora

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The moon sets behind an outdoor sculpture while auroras light the sky at Franconia Sculpture Park.

Even if light pollution were not an issue, we’d rarely see the northern lights because our latitude in Minneapolis is outside the normal auroral oval.  But last week, Earth experienced a strong geomagnetic storm and we were suddenly in the middle of it!  Here was a chance to see aurora without traveling to Alaska or Manitoba! And it was the perfect opportunity to photograph them with my wide-angle lenses, one of which I call my “Milky Way/aurora lens”, a 2-1/2-pound monster for just this purpose! But we needed to get away from the city lights.

There is a sculpture park, Franconia, that Poldi and I have enjoyed and contributed to for many years, and it was less than an hour from home. We arrived before sunset and sought permission to take photos, even after the normal park closing time. As I was scouting for locations and setting up tripods, a trickle of other visitors arrived with the same purpose: to see the predicted northern lights. As twilight faded, the aurora tourists expanded to dozens of vehicles, all of which had headlights that swept across the sculpture park grounds, interfering with my carefully selected compositions.

I have learned not to react to unexpected lighting situations. Oftentimes, they make for interesting photographic results. One of my favorite examples is when I was shooting reflections on a calm alpine lake and a group of partiers arrived and went skinnydipping, breaking up the smooth lake surface. Rather than close the shutter and move on, I kept it open for the duration of my planned exposure. It created a wonderful blend of reflected and scattered light!

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Vacuum Systems-  The Wrong Stuff

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The cost of the learning curve.: hoses and fittings that ended up NOT being helpful in reaching my target vacuum.

My idea of creating a vacuum was terribly simplistic.  Just run a pump until you reach your desired vacuum, right?.  Well… I learned that there is much more to it. 

First, there are different degrees of vacuum, categorized by how difficult it is to attain them.  The easiest can be obtained by a mechanical pump, a piston, or equivalent, pushing air molecules from the chamber to the outside, essentially a reverse bicycle pump.  It is possible to remove 99.9% of the air molecules and a few more, but that still leaves too many for the cool vacuum electron effects like neon signs, nixie tubes, and for audiophiles, amplifier tubes.

The mechanical vacuum pumps can’t reach those levels; more exotic pumps are needed, but they can get close to where radiometers operate, which is my interest.  So following the advice of expert friends, I acquired a pump that, in principle, could reach the level of vacuum I needed:  50 microns (a micron of mercury air pressure is 1/760 thousandth, call it a millionth, of standard atmosphere).  The pump model I bought is commonly used by the HVAC industry, where air conditioning units need to be evacuated before charging them with refrigeration working fluids (Freon, etc.).  They can reach the 50 micron vacuum level internally, but if you connect it to a real world vacuum chamber, there is a myriad of “leaks” that will prevent getting there.

I found this out by trial and error.  I found that the hoses, fittings, and gauges from the HVAC world were not cheap, but there is a market to keep them reasonably affordable to the industry’s practitioners.  Vacuum-rated hoses, gauges, valves, and fittings (the connectors between vacuum elements that minimize leaks), are hard to make.  And they all seem to have their own connection systems.  I learned about “flare” fittings, “nominal pipe thread” and tapered thread, acme threads, o-rings, and a bunch of other methods for connecting things and trying not to leak air molecules.

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Glass Blowing- Getting the Right Stuff

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The “candles” in a neutral flame from my torch.

I decided that to become more skilled, I would need my own torch and materials so I could practice and make as many mistakes as needed to acquire a specific glass-blowing skill.  I found a torch on eBay, some hoses and fittings on Amazon, a tank of propane from my barbeque grill, but then had to figure out an oxygen source.  I also needed an exhaust system so I wouldn’t asphyxiate while heating glass from my propane-burning torch.

The exhaust system was simple in principle, but of course, the actual implementation was not.  I wanted to create a “glass working station” in a corner of my garage/workshop—a recently built structure with a 10-foot high ceiling with no explicit ventilation.  This has already been a limitation when I wanted to work with paints, adhesives, or solvents that required a ventilated area, so I welcomed the excuse to create a ventilation zone for my shop.

Professional paint and chemistry booths are expensive, so I looked for kitchen exhaust hoods.  I discovered that they have an enormous price range which depends almost entirely on the current popular style and appearance of the sheet metal hood, and almost nothing on the exhaust rate of the fan.  The typical kitchen exhaust rate was less than I wanted anyway, so the fan didn’t matter—I would be replacing it.  I really wished I could buy the exhaust hood sans fan motor, but they are rare.  And when you find them, they cost the same or more.  It’s the external visual style you are paying for. 

I found a low-cost, unattractive but functional, kitchen exhaust hood with a low-power motor that I could replace with one that was more capable.  It seems a huge waste, but these are the tradeoffs in the DIY world.

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Toward a Personal Radiometer

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I was recently struck by an unexplained desire to craft a classic scientific object, a “radiometer”.  It was first created and demonstrated in the 1800s as scientists explored the fundamental elements of nature, especially the behaviors of atoms and molecules.  The periodic table and the ideal gas law that we learned in school were figured out during this time through many careful experiments.

Among the experiments was one performed by William Crookes while trying to isolate and identify his newly discovered element Thallium.  To make high-precision measurements of mass, he avoided the disturbances of air currents on his balance by putting it in a vacuum.  But he found that the readings were still varying, depending on whether the balance was in sunlight or not.  With his laboratory skills, he crafted a device to demonstrate the effect, a device that today is known as a “Crookes radiometer”, or “light mill”.  It is a delicately balanced arrangement of vanes, black on one side, white or silver on the other side, suspended in a glass vacuum tube.  Crookes discovered that when the vanes were illuminated by sunlight, they moved, rotating around the balance point, demonstrating that light induced some force to cause the rotation, and that force was also responsible for the variations in his mass measurements.  See this account for a wonderful history of the radiometer.  There is still some scientific uncertainty about how exactly it works!

My fascination with the Crookes radiometer began as a child when I first saw one spinning in a store window.  My dad was with me and was able to explain it to the satisfaction of his 8-year-old son:  “The light hits the white side and bounces off, but it gets absorbed by the black side and the difference of force makes it move”. 

I immediately set out to make one for myself.  With black and white construction paper I made some vanes and taped them to a pencil.  I found a sunny spot in our backyard and planted the sharp end of the pencil into the ground.  Nothing.  No motion.  It was quite a disappointment. 

When I later explained to Dad that my radiometer didn’t work, he told me that the force of light is very small, and for it to spin required a very delicate balance and removing the air from around the vanes, which was why the radiometer at the store was inside a glass bulb.  It explained why my backyard radiometer had failed, but it didn’t quench my curiosity. 

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Know-How for Whom?

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The QSL postcard sent through the postal service is the mechanism used by ham radio operators to confirm their over-the-air radio contacts. This is my dad’s QSL card for his Idaho station.

As an electrical engineer I learned that “all digital devices comprise analog components”.  This has remained true even as quantum effects are now being utilized in computational logic gates (they are defined by analog wave functions).

Radio waves, especially those used by amateur radio operators, are analog signals transmitted and received by oddly shaped and configured pieces of conducting metal parts known as “antennas”.  And the techniques to couple a useful signal to them are part of the arcane art and science of amateur radio.  The sharing of this knowledge is a big part of the ham radio community ethos. 

So I should not have been surprised to receive an email asking for help with “s-meter calibration” of an antenna.  It was addressed to my dad, who died in 2016, but whose email address has been set to forward everything to me.  I get occasional messages from this account, but with diminishing frequency, and usually from some company or service he had subscribed to, but for which there was no “unsubscribe”.  In this case however, it was from one of his fellow ham radio acquaintances looking for advice.

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Zoom me up, Scotty

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Who are these people, and why are they jumping out of hyperspace?

This is a computed image. It started as a snapshot of a group at a lunchroom table. There was nothing particularly significant about it except as a record of a pleasant reunion of this group of old friends. And like many such shots of a group at a long table, it is hard to get them all in the frame and to represent each member in a photogenic pose. In particular, the persons at the far end of the table are lost in the distance. It is particularly noticeable with wide-angle lenses, the default for phone cameras.

My test image, a scene shot using a wide angle lens of a group at a table.  Photo courtesy Fred Nourbakhsh.

I wondered if I could re-image this scene so that the people are more equally sized, the furthest members are not so small, and the closest not so big.  This is what would naturally occur if the photographer used a longer focal length lens and stood further back. This is an account of what I learned.

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