I had been to New York City a few times in my life. Each was somewhat accidental: a business trip, a delivery of childhood possessions to children who had grown, and a trip to witness a career accomplishment (a film festival screening) of one of them. Each had a primary purpose, and there was inadequate time to explore the vast experiences that New York City offers. I was not able to be a sightseeing tourist.
This occasion was different. There was no preset agenda or itinerary; we were taking the opportunity to spend a few days with Poldi’s son Shal’s family living in Brooklyn before beginning our travels to Europe. Poldi asked me if there was anything I’d like to do while we were visiting.
Well, I was always curious about the structure and construction of the world’s tallest sculpture (for a hundred years), the Statue of Liberty. Could I climb the spiral staircase inside?
Despite having lived in New York since attending film school twenty years ago, Shal had never visited the famous landmark. This sounded like a great outing to him. Since there were tourist ferries every twenty minutes to it, we could just show up at the dock and tag along.
It turns out that it is not as simple as catching a subway train, and we had to pre-register for a position on the ferry. Security checks were involved before boarding. And if you wanted to go on the tour of its interior, sign up a month ahead. I would not get in this trip (probably for the better, based on the claustrophobia I might suffer).
It was a wonderful experience. Liberty Island is as beautiful as the sculpture it hosts. I have pictures of it in this album of our New York City segment of this trip.
This punch card identifies the parts of a Fortran statement. The first five columns contain the line number, unless column 1 is a “C”, which turns the statement into a comment. Column 6, if marked, usually by an “X”, turns it into an extension of the previous statement. Columns 7-72 hold the Fortran statement itself, and the rest are an optional “sequence field” for use by the programmer as desired.
I wrote my first program at the age of 15 using a coding pad provided by my dad, who was managing an early computer installation for his employer, General Mills. It was 1968, and programs were drafted on these pads, which were basically a grid with 80 columns and maybe two dozen lines. The program statements on the pad would later be transcribed by a keypunch operator onto punch cards, one line per card, and then fed to the computer by a card reader that could sense the holes in the cards and turn them into bits in the computer’s memory.
I didn’t understand the details of how computers worked, but I was able to figure out how to write a series of statements in a programming language (Fortran) to do something I thought was cool: print out the coordinates that I could plot on graph paper (yes, that’s how it was done), to create an Archimedes Spiral; the path traced out by what I imagined to be an insect crawling on a ruler that was rotating around the starting point.
It was an ambitious goal, and I had to think hard about how to do it. I had to learn about loops, conditional IF statements, and distinguish between integers and floating-point numbers. And how to format them and print them out. In the end, I think I was able to do it on one page. I carefully wrote each line on the coding pad and gave it to my dad, who promised to take it to work and run it on the computer (I later learned it was an early Control Data Cyber 6600 model which occupied a large room).
He returned that evening with the result, a line printer output on “computer paper”, large folded pages with detachable tractor feed sprocket edges. I looked at it and saw numbers printed along the left edge. Pairs of numbers, one pair per line on the page. These were the XY Cartesian coordinates I was looking for!
I pulled out my pages of graph paper and started plotting them. I marked a dot at each XY location, and soon I saw that as I connected the dots, a spiral shape was forming! I was quite excited. This was the experience I had of writing my first program.
I later learned that writing a program that ran correctly on the first attempt is a rare thing. And I also heard that my dad teased his staff of professional programmers to try and be as successful as his teenage son.
In 1974, my roommate and classmate Jeff Harvey came home in a highly excited state. He had just purchased the recently published book, “Gravitation”. It was unusual for a reference or textbook —not just because it was a paperback, but also because it was immense. It had large pages and it had a lot of them: over a thousand. And each seemed to have sidebars, notes, and explanatory boxes or illustrations to augment the text, which itself was written in a distinctly non-textbookish, conversational style.
We had both taken courses in special relativity, but general relativity, which explains gravity, was an advanced topic. And Jeff was eager to dive into it. He set himself a goal of digesting some portion of this massive book every day.
The authors of the book were unknown to me at the time but they would become familiar names as I continued my physics education. Charles Misner, Kip Thorne, and John Wheeler, were collectively referred to as “MTW”, which became the moniker to brand this monumental work.
Misner and Thorne were students of legendary physicist John Archibald Wheeler. Wheeler’s distinctive style can be inferred from his coining of popular words and expressions such as “black hole,” “quantum foam,” “wormhole,” and “it from bit” (existence from information).
Misner had a distinguished career in general relativity and cosmology, and Thorne, in addition to popularizing black holes and time warps, spearheaded the effort to build gravitational wave detectors, LIGO, for which he received the Nobel Prize in physics in 2017.
I have encountered these names off and on over the years as my interests have followed the remarkable science yielded by space telescopes, particle accelerators, and gravity wave detectors. I marvel at the things we have learned in my lifetime.
My career was initiated and informed by my study of physics, but veered in other directions. My roommate Jeff, on the other hand, completed his goal of reading and understanding the book Gravitation, and went on to become a noted physicist in his own right, making contributions to string theory and teaching relativity to the next generations of physics students at the University of Chicago.
I was motivated to describe this old memory of Jeff’s enthusiasm for a textbook because Kip Thorne will be the featured speaker at the Misel Family Lecture at the University of Minnesota later this month. I will be thrilled to hear from one of my physics heroes as he describes the fascinating things he has explored in his career.
Had I had Jeff’s fortitude to digest Gravitation, perhaps I would not remain puzzled over the twins paradox. Even now, it seems I just keep mulling it over, and making this post caused me to add some more to my commentary. Well, since the book is still in publication, maybe it is not too late!
Hiking through the desert in the morning after an overnight photo session.
“Can I still do it?” and “Will I still enjoy it?”
I find myself asking these two questions about various activities I undertake. Now maybe you are thinking I am making oblique references to sex, but so far, that hasn’t been in the category of activities I am questioning.
I noticed that, after turning 70, my superpowers appeared to be diminishing. This was a surprise to me because so far, at every decade mark, I had felt little difference from the previous one. There were a few things I suppose– certainly my appearance has changed as I have grayed, but for the most part, my capabilities have held.
Until now. I am starting to notice that my flexibility is less; I am stiff in the morning; my strength and stamina are diminished. Something has happened to the sinew and grit that powered my younger self. The analogy I entertain is: “the rubber bands are drying out”.
My limitations became apparent in a recent outing to take pictures of the night sky, an activity I have enjoyed for decades. One of my life highlights was recording pictures of the night sky on Racetrack Playa in Death Valley a few years ago. Currently, it is a similar trip with a hike to a collection of geologic features in the badlands of New Mexico. I treated it like many others I had undertaken, but this time, things felt different.
During my “Nightscape Odyssey” in 2001, I would survey a candidate night sky site during the day, making notes of how to get there, what compositions were promising, and generally getting familiar with the area. I would then return to the site later, as twilight approached, or sometimes even in the dark, and set up my telescopes and cameras. It made for a long day, and a long night, and I was usually exhausted the next morning. Nevertheless, after a morning nap, I would start the process all over again for the next night’s session.
This time, I was prematurely worn down after the initial reconnaissance and had to postpone the nighttime excursion until the next day. I didn’t expect that. Maybe it was the heat, or maybe it was the elevation, but those were factors before, and back then I still had the energy to carry on.
The lure of an image in your mind’s eye is a strong motivation, and I was very excited to see if I could capture the Milky Way behind the Alien Throne, my target for this outing. I described the overall experience previously, but I will now describe some of my other reactions as I undertook it.
I mentioned that my backpack was heavier than I expected. Yes, it had an excess of camera gear, but that was the payload. The rest was support: water, snacks, and protection against the desert night. The total came close to forty pounds, a typical number for a much longer trip. It was well within the range of packs I had carried before, and tonight I only had to go 1-1/2 miles over relatively flat terrain. I put it on, cinched the hip belt, and felt the familiar shift of my center of gravity as I took the first steps down the trail. It felt good to be doing this again.
As I continued, I noticed that I could feel the load in my legs. This was not a daypack. I could also sense some strain on my knees. This reminded me of an incident that happened a previous time I had carried this pack.
It was fifteen years ago. I had been on a weeklong backpacking trip, and on the last day, while climbing a ridge along the Lake Superior Hiking Trail, I experienced a sudden collapse of my right knee. It was truly a surprise; I fell to the ground. It wasn’t painful, my leg was just uselessly limp. My hiking buddies helped me back to my feet, but I couldn’t sustain the weight of the pack and collapsed again. Fortunately, it was only a short distance to our destination, and by distributing most of my load to the others, we were able to get there.
But here I was, hiking solo in a wilderness area as night approached. If the same thing happened, what would I do? I was a mile from my car, but to get there, I would have to abandon my load: $5000 of camera gear. Well, I guess I should factor that into my choice to embark on these excursions!
I carried on. And I carried the hiking poles that Poldi had lent me. I had always considered them a nuisance, getting in the way of my path and interfering with handling a camera, but I was now starting to appreciate them. They bore my weight and guided my traverse across the ruts and ridges in this rugged landscape. What was once an annoyance has now become a dependence.
I made it to the Valley of Dreams, following the route I had traveled the previous day, but the Alien Throne was another half mile through uncharted ridges and eroded gullies. I could see the destination on my GPS, but the terrain was not adequately shown. I found myself blocked by box canyons and cliffs. My strength was waning, the sun was setting, and I wondered how many more of these obstacles I could clamber over. If I became stuck, I would just make the best of things, taking pictures of whatever features were around me, even if they weren’t my prime target. It could still be a wonderful evening.
I was getting close, but a sudden drop-off was in the way. It was too high to scramble down, especially bearing my pack. So I removed the pack, lowered it over the edge, and then eased myself over and dropped down onto it. This was the last obstacle. I rounded the corner and found the Alien Throne! But it was not lost on me that this was an obstacle that in earlier days would not have presented a challenge. Further, had I not had a semi-graceful landing on my pack, what injuries would I have sustained?
It was a small barrier, but I was stranded on the shelf 5-feet above the valley floor I needed to get to. I dropped the pack and eased myself over the edge onto it.
I filed those thoughts away as I looked over the theater containing the Alien Throne. I needed some time to recover my breath after the stress and strain of navigating these eroded features, but I was aware that the light was rapidly changing. I needed to get my cameras set up.
This is a very pleasurable part of the adventure. I am finally at the site and can look for the compositions I have imagined. It is a mix of guidance and guesswork. I have some tools to help with orientation and timing, but it really takes placing an eye to the eyepiece to see how the landscape fits the sky. There are technical issues to resolve as well: exposure times, lens apertures, focus, and shutter intervals. These keep me narrowly focused on my goals and shut out any other concerns (I’m oblivious of the need to worry about scorpions).
But as I placed each camera and tripod in its place, I could not help but notice each difficult position, and each awkward angle I had to assume in doing so. Yes, the terrain is uneven, and the viewpoint requires the right height and angle, whatever it needs to be for the composition, but I don’t remember it being such a physical strain to achieve it.
Kneeling is a particular motion, required for just about any adjustment. I find that it is hard to get back up. And when I drop something, it becomes a major project to recover it. The aches and pains of drying rubber bands were making themselves known in this otherwise pleasurable setting.
But when the cameras are each in place and running, I heave a sigh and settle in for a night of watching the heavens flow across the sky. It will be an hour or more before the cameras need attention. This is another pleasant part of the nightscape adventure. I record the photographic details of my experiments in a notebook and contemplate what the outcomes might be, and what subsequent exposure tests I should undertake. When I am with Poldi, we find spiritual and intimate activities to fill the time under the stars, but on this night I am alone, at least for a while. Soon after my cameras were set up, another night sky photographer arrives. We share our stories while the stars move above us.
We eventually retreat to our refuge against the cold desert night. I am in a sleeping bag tucked into a recess in the rocks. I relax here, watching the sky above and listening. There is a cricket chirping. I am astounded at how loud it is, and then I remember, I now have “bionic ears,” recently acquired hearing aids, another indicator of crossing the seven-decade threshold. They have been tuned to amplify the high frequencies that I was previously missing. This helps me to understand the speech of women and children, but it really helps me to notice the frequency of cricket chirps, which are slowing as the temperature drops. The chirps keep me awake.
But eventually they stop, or maybe I drift off. When my alarm goes off for the next exposure event, I climb out of the sleeping bag and stumble toward the camera that needs attention. The moon has set, and it is now purely starlight that guides me. Plus my flashlight, because starlight is just not enough, at least on this uneven terrain. As I navigate over the rocks toward the camera, I recognize the precariousness of my path. At home, at night, in the dark, I must sometimes navigate to the bathroom. It is much easier with a nightlight– so we have installed them. Here, in the certified dark sky wilderness of New Mexico, I am on my own. I am aware and notice the uncertainty of my steps on the sandstone terrain. Loose gravel and vegetation contribute to the hazard. Once again, I recognized that if I fell and was injured on one of these camera servicing missions, I would no longer be enjoying the night.
But the cameras, with their new exposure settings and refreshed batteries, continue their nighttime schedule. I return to my nook to marvel at the Milky Way, now high in the sky. The cricket reminded me that I have bionic ears, but the sky reminds me that I also have enhanced eyesight.
The miracles of modern optics can correct for obscure vision conditions, including astigmatism and other aberrations. I put on my progressive prescription glasses so that I could appreciate the full glory of the night sky, beyond my now compromised seventy-year-old built-in lenses. It was a bust. For whatever reason, my glasses made the view worse, not better. I will be investigating this failure, but in the meantime, I enjoyed the night sky without optical assistance.
The pleasures of the night continued; the cameras were serviced despite the risks, and eventually the sky began to lighten. Dawn was approaching.
The exposure schedule ended as the sun rose, and I gathered my equipment, preparing for the hike back. The night before, I had reached my destination just before my strength ran out. Now, after a night to recover, I expected an easy hike. I knew the way. And it started that way, but soon became hard.
It was not a difficult trail, mostly level. And the sun was still low, the temperature moderate. The path was easy, but on encountering the slight banks in and out of a dry creek wash, I was annoyed that I could not just scramble them; I had to take carefully placed steps.
Only a mile and a half back to my car. Yet, I found my feet becoming “heavy”, without the lift to rise ever slightly for the next step. And they were sloppily planted in that next step. It was the closest thing to a stagger, and I realized it.
So I paused for a rest, dropping my pack for a while. Sitting on a rock and taking some water, one of my hiking poles fell to the ground. I cursed. Now I would have to bend over to get it. When did just stooping down become such a pain? I have never enjoyed getting under the desk to plug in computer or power cables, but just bending over to pick up something I dropped? That’s new.
Reaching the point of involuntarily dragging my feet was a new experience, a physical regime I was unfamiliar with. It made me appreciate the limits that people sometimes overcome, not just for recreation, but for survival.
And it added to my list of items to balance against the pleasures of my remote outings. I really enjoyed the hours in the desert monitoring cameras and watching the galaxy cross the sky. But I have become aware of the risks I am taking on, some of which seem to have increased over my years.
I was halfway back. I was aware of the remaining distance, which was more than the physical distance. It included the depletion of my energy reserves. I may have been staggering, but I was not to the point of stopping. I hoisted the pack and continued back to the car.
I can now declare that “I can still do it”, and I will also declare that “I still enjoy it”, but I must temper this last statement by acknowledging that the enjoyment is diminished by the increased risks I take on.
Life is filled with tradeoffs.
It may seem that I am complaining about getting old, and I guess I am, but I am also thrilled that I am still around to do so.
My motivation, an image in my mind’s eye becomes real (click for full resolution).If I look back a little, I might be able to extrapolate how this next decade will go. So far so good. I hope I can be as spry as Dick Van Dyke when I get there!
“Mushroom Row,” at the edge of the sandstone theater that hosts the Alien Throne.
Having performed my reconnaissance by visiting the Alien Throne during the day, I was now ready to consider taking its portrait at night. I had in mind a view that included the Milky Way. And I wondered if I could create a timelapse of our galaxy moving across the sky behind it. It would require planning, equipment, and a bit of luck. A target 1-1/2 hours away from our hotel in Farmington, a further 1-1/2 mile trek across the desert, and an all-night vigil tending cameras, made this one of my most ambitious photo projects.
I had a backpack into which I put my gear: essentials like navigation tools, raingear and first aid, fleece, hat and gloves for overnight temperatures, a sleeping bag for further warmth (and option for sleeping), some snacks, plenty of water, and then the real payload: 20 pounds of camera equipment, which brought the total close to 40. For a single overnight trip, it felt as if I was going out for a week.
My planning [using the PlanitPro app] informed me that sunset would be at 8:20. I wanted to be at the site well before so I could set up and arrange my compositions, and also to capture the scenery in the “beauty light” that precedes sunset.
I got to the trailhead later than expected because I’m not immune from wrong turns, even when I “know” where I’m going. And the desert hike also took longer (was it the heavy pack?). The terrain tricked me into some dead ends. But I arrived at the Alien Throne just before sunset. It was spectacular!
And I was alone. I had feared that I would encounter other photographers with the same idea, but it looked like I would not have to negotiate camera positions, something I had never needed to do. So I went ahead and placed my tripods, aimed my lenses, set the exposure and interval timers, and started the shutters clicking. It takes a bit of time and concentration, but this is the pleasure of the hobby for me. Every outing is a new experiment; I add the details of each to my notebook, which then helps me on the next one.
With the cameras now clicking away on their schedules, I could step back and breathe a little easier. I found a niche among the rock formations to set my pack and recline against it. Twilight was advancing, and as I was recording my notes, I noticed lights splashing against the rock formations. Someone was hiking here in the dark, a headlamp lighting the way!
Rather than have them stumble across me in the dark, I called out, “hello?”
A voice replied, and a lone hiker arrived in the sandstone theater around the Alien Throne that hosted my cameras and my nesting place.
As I mentioned, I prefer to be alone during my nighttime star gazing excursions. If I see headlights approaching, I worry about what that vehicle brings. Often, it is a patrol car whose occupants either want to see your permit, or they want to look at Jupiter through your telescope. Though I am more fearful of wild carnivores than humans, I understand why women might prefer to encounter a bear than a man.
In this case, it was a student, recently graduated from UCLA, exploring the country before returning to his home in China. He had acquired a camera and discovered the cool startrail effects that could be obtained at night in unique settings like the one we were now both immersed in. It was a shared interest.
We exchanged introductions while he found a location for his tripod and camera. We had similar equipment, even identical travel tripods. Because my cameras were already in place and running, he found a location for his that did not interfere. It was an act of respect for the compositional claims that I had already staked, but also, I think, a reflection of his Asian culture of honoring and deferring to elders. I was pleased, perhaps even flattered, at the respect. There are few perks to being a septuagenarian; this was one of them.
My plans involved keeping my cameras in place and running all night. I needed to make some tracking adjustments and periodically replace batteries. His plans were to gather an hour or so of exposure in one place, and then move to a new location with a new subject and new backdrop. It all worked out with little or no interference. Between camera moves, we chatted and exchanged information from across our generations, homes, and cultures.
As the desert cooled down, we took refuge. I climbed into my sleeping bag, and he found enough surface area to pitch a small tent. I faced the open sky and watched the young moon set, the stars drift past, and the Milky Way rise from the east. “Sleeping under the stars” is a romantic notion, and a rare opportunity in modernity’s protected life. It is not easy to do in my midwestern home, where the sky is often cloudy and the air is filled with insects, but here in the desert, it is a wondrous experience.
The night passed pleasantly by, in 90 minute segments, per my alarms to get up and attend the cameras. In this remote location far from city lights, the sky transitioned from one of the darkest possible, to the natural progression of twilight leading toward sunrise. The Milky Way faded into the brightening sky. My startrail and timelapse work was now complete, but I wanted to see the hoodoos in the morning sunlight. I was not disappointed.
As I started packing up my gear for the trek back, my fellow photographer brought out another of his gadgets: a drone, which he sent overhead to capture stunning views of the terrain in which we were immersed. I think this is technically not permitted in a BLM wilderness area, but I couldn’t deny how cool it was, and no one else seemed to be around to complain.
I finally said goodbye to my overnight companion. We exchanged email addresses, and I hope to share photos with him. I then hoisted my pack and headed back. The water weight had diminished, and I admired the morning light on the unique desert features. I was exhausted, making the night’s experience all the more valuable.
Here are some photos from that beautiful night. The first set was taken during daylight, the next from my nighttime exposures. Finally, I offer the timelapse video composited from the frames I acquired. I hope you enjoy them.
As I start out on my hike to the Valley of DreamsTypical of the landscape along the routeThe Alien Throne among its neighbor thrones in this theaterThe moon is a few hours behind the sunMy camera and tripod, trying to emulate a hoodoo and fit in with the crowd.The niche containing my pack and sleeping bag, with Weiheng and his tent behind. The “Giant Mushroom”, surrounded by a ring of similar structuresI encountered this on my hike back the next morning. It is exactly how I felt.Photos of my hike to and from the Alien Throne. Click to enlarge, then scroll through.Alien Throne in moonlightMilky Way to the northMilky Way to the southA mushroom hoodoo and Milky WaySouthern star trails. Look for the celestial equator.Circumpolar star trails, one-hour exposure.Photos from my overnight session in Valley of Dreams.
A link to the timelapse sequence. Enlarge to full screen for the full visual experience.
The American Southwest is an amazing, mysterious, and visually stunning place. I’ve had a fascination with it my whole life, and make excursions whenever an opportunity arises. A few years ago, Poldi and I discovered an area in New Mexico with remarkable geologic features: badlands, hoodoos, and petrified wood! It was the Bisti Wilderness Area, held apart from private and reservation land by the Bureau of Land Management for the benefit of the public. It is only very lightly “managed” by the BLM. There are no visitor centers, no picnic areas or campgrounds, and no trails. There is a small parking area at the end of a difficult dirt road, marked by a signpost and featuring an outhouse.
Despite the lack of trails, we were able to follow the breadcrumb descriptions posted online by a photographer who explores Bisti for its photogenic subjects. We located and visited the Alien Egg hatchery, a 30-foot-long petrified log, and a hoodoo village. In the years since, we have wanted to return and explore more of this fascinating area.
Poldi in the nest of alien eggsPetrified logHoodoo villagePhotos of Bisti Wilderness, November 2022. Click to expand, then scroll
We were able to do so this year. The timing was right—late Spring, before the desert becomes intolerably hot. We both researched and found several more sites with novel features bearing names like “King of Wings”, “Chocolate Penguin King”, and “Alien Throne”. These are not roadside points of interest with explanatory markers; they are deep in wilderness area, accessible to intrepid hikers willing to explore the desert and locate them. Those that are successful bring back stunning photographs.
Those photographs inspired us to consider visiting them. A particularly novel feature, “The Alien Throne”, made me wonder if I could get a picture of it with a night sky backdrop. I read the accounts of others who had made the trip. Maybe it was possible!
I find the news these days to be very distressing; I’m surprised by how many things being enacted by our leaders seem to contradict the values I was raised with. So I retreat to the world of what’s real, which to me is the world of Nature and the physical laws and relationships it embodies.
Science and math are incredibly powerful tools. Despite their unpopularity, their predictive abilities are unrivaled. So I use them to assess the world around me, and recently I have been exploring the limits of our cultural assumption of unlimited growth. Unfortunately, I find that we are reaching those limits, and I suspect that our current political conflicts may be related to them.
I don’t want this blog to become dominated by such heavy material, so I will simply reference the next essay, Defending Malthus, in my “limits” series, for those who find them interesting.
Everyone else can hold tight. I’m on my way to New Mexico, hoping to hike the Bisti Badlands again and take some photos. That is what will keep my attention away from the daily dose of discouraging news.
Many of you follow my eclectic blog posts hoping that one of them might appeal to you. They span a broad range from personal to professional, craft to art, simplistic to technical, worldly to cosmic. I sometimes offer my opinions and back them up with data. In today’s data-challenged world (not from a dearth of data, but rather the challenges from those who don’t like the data), it is hard to make a compelling argument.
Nevertheless, I recently embarked on exploring a topic that has always bothered me: the idea that we can solve our problems by economic growth. I can see how it can solve certain short term problems, like borrowing money to pay back interest on prior loans, but it didn’t seem like a viable long term strategy. We live on a finite planet and so eventually we would end up against practical physical limitations, right?
It is obvious to a physicist, but seemingly not to many others.
Over the last month, while staying warm in our natural gas-heated home, I looked into the future of fossil fuels and their impact on our global economy. I crafted three essays which are more technical than many of my posts, and may not be of interest to many of my followers. So don’t feel compelled to digest them.
But if you are curious, here are brief descriptions, with links.
I still don’t have a reliable setup, but some recent changes I made to my cloud chamber have resulted in this very satisfying display of subatomic contrails. Here are a couple of recordings. The first documents when I was stunned to see multiple concurrent trails and I called for Poldi to witness it.
“Hey Poldi!” (expand to see what we were excited about).
The second video is a sustained view for several minutes, placed to background music, to mesmerize those of us who are susceptible. Think about it. This is a visual representation of the radiation that is all around us! Expand to full screen for best effect.
If you’d like to read about how I got here, the previous post describes the project of building the cloud chamber.
A view looking directly down in my cloud chamber showing a fragment of uranium glass. A small white streak pointing to 11:00 appears above it, which is a track of some subatomic particle, possibly an alpha particle from a radioactive decay within the glass. (Click to enlarge).
Years ago, after watching some YouTube videos on making cloud chambers, I tried my hand. A cloud chamber is one of the earliest techniques to see the paths of subatomic particles. It turns out that there is a natural background radiation of them and I wanted to see if I could watch these particles as they whizz around us. It seemed like a cool experiment.
The analogy I like to use is of a high altitude jet leaving a condensation trail behind it. You can see the contrail, but not the jet making it. In a cloud chamber, similar condensation physics is at work, but instead of engine exhaust, it is the particle’s ionization of gas molecules that triggers the condensation. The original Wilson cloud chambers used water vapor; modern chambers use alcohol, which is more easily managed.
My attempt to make one was less than satisfying. I recall staring at the mist at the bottom of the container and imagining that I was seeing patterns of droplets. Maybe I did, but it was not the thrilling experience of seeing the invisible that I was hoping for. I put the project aside. Until recently.
