Category Archives: Projects/Topics

Eclipse Party 2024- name card projections

Posted on by

As co-host of Thor and Poldi’s Excellent Eclipse Party, I wanted to provide something that might augment Poldi’s gourmet camping meals.  I was inspired by a YouTube presentation of how to enjoy the eclipse, including during the partial phases leading up to totality, and how to safely view the sun during this time (over an hour).  One of the techniques was the use of “pinhole projection”  where a small hole in an opaque panel projects an image of the sun onto a flat surface.  It is an embodiment of a pinhole camera, but aimed at the sun.

In 1963 a solar eclipse crossed North America.  I was living where the eclipse would be 80% full and I recall my dad setting up a pinhole projector so we could watch the progress of the eclipse.  The image showed a small crescent, like the moon.  This left an indelible memory on an impressionable 10-year old, but even more so, was seeing the multitude of crescents projected along the street in front of our house.  The cathedral ceiling of elm trees along the avenue had holes in it, formed by the gaps between the leaves.  Each was its own pinhole and cast a crescent image on the pavement.  This is what left the strongest impression on me that day.

Today I understand the physics and optics of what made those images, but it does not diminish the awe and wonder I have for the effect.  I wanted to see it again at this eclipse, and to that end I designed cardstock pages with holes punched in them for our eclipse partiers to project.  The holes spelled out the name of each guest in a dot-matrix font. 

I considered how to punch all these holes and soon realized that doing this by hand would not work.  I did not have the tools or patience for such a task.  I considered acquiring a laser cutter, but this would be a new technology to me, one that I didn’t have the time to learn.  I contacted a local shop, but was not confident in their response to my request (“we’ll have to experiment to see if this will work”), and it would be expensive. 

Fortunately, as I described the situation to my talented and well-equipped friend Odd Dave, he offered to make them on his laser cutter (of course he had one, and he wanted to keep it in condition by using it).  I sent him a test file, he “printed” it with seemingly little effort, and then proceeded to punch the rest of them.  He mailed them to me with plenty of time to pack them with the other eclipse equipment.

The eclipse partiers were thrilled to receive these custom-punched cards and looked forward to making projections of their names during the partial phases of the eclipse.  Sadly, nearly all of that time was overcast.  One needs a full view of the sun for the projection to be effective.  There were a few openings early in the eclipse, and one might be able to make out the solar disk images with a small “bite” taken out, but the more dramatic projections of thin crescents were clouded out.

I hope they save the “name hole projection” cards for their next eclipse.

Pinhole projections of dot-matrix punched names during the brief periods of clear sun.
Name projections during the sunny moments.

Thor and Poldi’s Eclipse Party 2024
previous | beginning | next

Eclipse Party 2024 – preparations

Posted on by
The Rio Frio, beneath Old Baldy, a beautiful spot to await an eclipse.

Two years ago, in anticipation of the 2024 eclipse, I made a reconnaissance trip to Texas, where the historical odds of clear skies were the highest in the US. I located a similar campground to the one we had enjoyed in Idaho, this time along the Frio River in the “Hill Country” of Texas. Zuber’s River Camp was a few hundred meters from the centerline of the eclipse and would yield over four minutes of that bizarre condition we wanted to experience again. I didn’t know two years ago who might want to join us, but I made a guess and put my name on a waiting list for campground shelters.

I sent out an invitation and attracted the attention of several of those who had joined us in 2017. Word spread to relatives, friends, friends of friends, and friends of relatives, and soon we had a full roster. Many in the group had not seen the total eclipse in 2017, or ever.

We secured the campground reservations and plans came together. Poldi, who seems to have a natural desire to feed groups of people, became the camp quartermaster and took on the challenge of planning a menu, pre-cooking and preserving, and the logistics of acquiring fresh provisions on our route to the Texas site. She did reconnaissance and training runs at the local Costco store. She estimated the capacity of coolers and containers and stockpiled all the necessary cooking supplies and staples.

While Poldi was creating and refining her plans for food, I was making other plans. Despite the widespread advice to not spend the precious few minutes of totality fussing with camera settings, I wanted to take pictures. Pictures of the sun’s prominences and corona and maybe even a timelapse of the eclipse. Expert advice or not, it is what I do.

In addition to planning for my photographic goals, I wanted to do something to help bind this group of people, none of whom knew everyone–  even the hosts had not met them all! This inspired two more preparation projects: “name card projections” and the creation of a t-shirt design, to be described next.

Poldi assesses her cooler options.

Thor and Poldi’s Eclipse Party 2024
previous | beginning | next

Thor and Poldi’s Excellent Eclipse Party – 2024

Posted on by
Our observing site on the Snake River, 2017

In 2017 we hosted “Thor & Poldi’s Excellent Eclipse Party” for about a dozen friends and relatives. They recall fondly the time we spent on the banks of the Snake River at Heise Hot Springs campground, and the beautiful clear day at “Stinking Springs”, where we witnessed the sun turn into a hole in the sky. It was three minutes of an otherworldly sensation.

We decided to do it again for the 2024 eclipse. This begins a series of blog posts that describe that experience– the planning, the traveling, and the day of the eclipse. It is not a spoiler to let you know that clouds interfered with our plans, this is now meteorological history. But we were rewarded with all the pleasures and adventures of the journey, and the sharing of it with friends, old and new.

I will be adding bits to the story over the next few days and weeks. If you wish to subscribe and get the posts in your email, there is a signup link somewhere nearby.

Thor and Poldi’s Eclipse Party 2024
previous | beginning | next

Vacuum Systems-  The Wrong Stuff

Posted on by
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.

Continue reading →

Glass Blowing- Getting the Right Stuff

Posted on by
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.

Continue reading →

Toward a Personal Radiometer

Posted on by

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. 

Continue reading →

Zoom me up, Scotty

Posted on by
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.

Continue reading →

16mm Home Movies from Mid-20th Century

Posted on by

As I mentioned in an earlier blog entry, I inherited a collection of 16mm movies made by my two grandfathers, each an enthusiastic amateur and early adopter of photo technology.  I have been struggling with their fate, as they consume a not-inconsiderable amount of space in my archives.  Space that could be used to store other useless artifacts.

They have now been (mostly) digitized. And one can find them summarized at this page.

I have great difficulty getting rid of things.  As someone who respects the historical path that brought us to our current time, place, and relations, it is hard to discard mementos, especially (for me) photographs that captured moments along that path.  As a scientist, I am loathe to delete “data”, that might someday be valuable.

I have to acknowledge the slim likelihood of such artifacts becoming valuable.  I hold no conceit that some biographer will ever be looking for scraps and clues identifying the influences on my own childhood.  I like to think that my contributions to society have been positive, but probably not worth much more than an oblique reference in an obituary (“he was a curious man”).  But maybe there were things in those movies that would be of interest to someone else. I didn’t know how to find that audience.

So the movies, spooled on metal reels of various sizes, lay dormant for years.  When I wondered about their ultimate fate, I realized that eventually, they would have NO meaning to anyone, even if it were possible to view them.  If there was any value to be extracted, it would have to be now, by me. 

I described that initial effort in the previous post on this topic.  Here is what has happened since.

Continue reading →

LEGOs for Life

Posted on by
Grace and Hoan, with mom Poldi, after presenting me with this terrific gift.

I recently received a most unexpected gift, an extravagant thank-you gesture from newlyweds for being part of their marriage (as driver and other small supporting roles).  Somehow, they found something that would appeal to me on many levels, something I would never consider for myself:  a LEGO set!  And not just any LEGO set, a large and elaborate architectural depiction of an A-frame cabin, with thousands of parts.

It had been inspired by a LEGO enthusiast from Italy, who enjoyed creating Lego models of houses in his spare time.  Evidently, there is a large community of LEGO fans, large enough that there is a program for them to submit ideas and models for the pleasure and approval of other fans.  Those with the highest votes are selected to become an actual LEGO product.  How brilliant!  Let fans come up with cool ideas, and then manufacture the most popular, knowing that it has already passed the “will they like it?” test!  The A-Frame Cabin was the most recent of such crowd-sourced concepts, released just days earlier.

My step-son and his new wife did not know of my past LEGO history.  They did not know that I had been a member of the LEGO Builder’s Club with my son in the 1990s.  Or that his LEGO model of the Eiffel Tower had been featured in their newsletter.  They did not know that I had authored a software program, LegoShop, to create models on a computer screen in a time before computer graphics, video games and virtual reality had been fully invented.  They were unaware of how much time I had spent with a micrometer, reverse-engineering the basic LEGO brick and many other parts to make my virtual models.  They did not know, using that program, I had created a Christmas card featuring a LEGO ice castle with Santa and a reindeer.  They did not know that I had insisted on visiting LEGO Land during a visit to Malasia.  They knew none of this personal LEGO history.

Yet they somehow knew that I would fully appreciate this gift. I’m impressed.  

The LEGO Builder’s Club featured my son’s Eiffel Tower as a Member Masterpiece, circa 1992

LegoShop, an application that allowed the creation of LEGO models from a library of virtual parts.  Some older readers may recognize the window format of early Apple computers.

Our 1990 Christmas card, highlighted by virtual LEGOs

In LEGO-Land Malaysia, 2015

I have been a dormant LEGO builder for many years and have not kept up with the latest sets and themes.  But the skills to assemble LEGOs don’t go away, and even if they did, the remarkable instructions provided with the kits can be followed in any language, even by builders who, like some of my grandchildren, cannot yet read (but you DO need to know your numbers).

In the case of an enormous set like this one, the instructions run to 333 steps, requiring two books to contain all of the illustrations.  The thousands of parts are partitioned into 16 bags, opened one at a time while following the next series of steps to assemble them.  The process is much like putting together a jigsaw puzzle, finding the next target pieces, and mating them in correct position with the previous ones.  Eventually, the parts that tumble out of the bag are all in place, and I can take a moment to appreciate the growing model.

A view of the partially built cabin. The front door opens into an area with bookshelves, a guitar, and an umbrella stand. The owner appreciates rocks; a geode is prominently displayed next to the record player.

What a pleasure to receive a gift like this.  Something created by a LEGO fan and endorsed by a global LEGO community of enthusiasts!  I am savoring the construction steps as I go through them, but have recruited the assistance of other LEGO experts.  I plan to post photos of the completed project!

Grandsons Arthur and Teddy, reenacting the extinguishing of a dangerous fire with a LEGO firetruck.

Texas Road Trip: Reconnaissance Resumes

Posted on by

After the eclipse ended, I packed up my equipment again; this time I collapsed the tripod legs—I would need the space to pack up my campsite, which I did the next morning.  I heated the dregs of leftover coffee thinking I would be stopping soon for breakfast on the road, including fresh brewed coffee. 

I made the mistake of not stopping in Fort Davis for that breakfast. I thought it was too soon, it was only ten miles from the campground.  But I should have stopped there anyway, because the next towns were too small, or too run down to support a café.  I went all the way to Del Rio, which was too large to have the local flavor of a small down diner.

I did find one however—a Mexican restaurant operating out of a Victorian style hotel.  The staff spoke Spanish, as did the other guests.  It was now lunchtime and I ordered the Monday special:  chili relleno (stuffed chilis?) which were delicious, and with rice and beans, too much.

I continued on toward Eagle Pass, the next large city, but in between was “Radar Base”, which is an intersection of roads where the 2024 solar eclipse is said to be at or near maximum—4 minutes, 30 seconds.  It is a miserable spot however—hot, dusty, windy, with heavy highway traffic and not much shade.  I’m not sure why it has a town designation—a local airstrip and a radio/cell phone/radar tower?

Radar Base. I’m not sure where the radar is. Click to enlarge.

I had intended to stay in Eagle Pass, but on learning that the room rates were $250+, I continued on to Uvalde, a town larger than I expected, and whose notoriety to the world would be established a week later.  There was some conference/convention going on, so the rates were still high, but I had reached the end of my range and desperately needed a shower, so I sprang for the room.

The shower was great.

More Options
I wasn’t expecting to find an eclipse viewing site as I originally hoped—I was too late, all the prime locations had already been booked—or couldn’t be booked (the State Park reservation system only goes 5 months out).

But I felt obligated to document the candidates that I had looked up, as this was the purpose for traveling here.  I could at least take photos and maybe get contact info in case of cancellations.

I located a few more places along the Rio Frio, and the Lost Maples areas along the eclipse path.  There were various resorts and RV parks along a road east of the river, and I stopped at some and inquired.  Locals would stop and talk with me, just being friendly, and I learned a lot about the area. Here are my notes.

Continue reading →