Making History | Building a 2000 Year Old Computer

One of the story lines in the novel The Map of Salt and Stars follows an ancient mapping expedition. The only two surveying tools noted in the text are a notebook and an astrolabe. Naturaly I wondered what's the deal with the astrolabe, and could it realistically power this type of endeavor?

I had some vague notion of what an astrolabe was. In my mind's eye it was a sort of primitive sextant. I was mostly, though not completely, wrong. Here's an excellent TED talk on the subject.

In short, the astrolabe is an ancient mechanical computer. Like the slide rule, it consists of various scales that when aligned solve otherwise complex problems. While the slide rule lets you solve math problems, the astrolabe lets you tackle geospatial ones. What direction is North? What time is it? When is sunset? What stars will appear in the sky tonight? What's my latitude? These are just some of the questions the astrolabe can answer; it has a reputation for being quite the information multi-tool.

This explanation suggests that yes, in ancient times an astrolabe may very well have been the primary tool used by map makers and explorers. Consider that it predates the simple magnetic compass by 1,400 years.

Reading about the remarkable prowess of the astrolabe, I naturally decided I had to have one. I figured Amazon would have a cheap knock-off that I could purchase. Alas, that was a dead end. The products that show up when I searched were both pricey and decorative and wouldn't be useful in a field context. Some additional digging, however, turned up another option: I could make my own, for free no less!

I found two projects that allow you to build an impressively detailed and authentic astrolabe:

• In-the-Sky.org's Make your Own Astrolabe
• AstrolabeProject.com's Astrolabe Generator

I found in-the-sky's version first and the assembly process is straightforward. You download the appropriate PDF for your latitude, print it out, cut the pieces out and pin them together to form a rotating disk. The only gotcha is that you need to print one of the pages on a clear sheet of plastic, which you may not having lying around. See below for the supplies I bought to build my own.

The AstrolabeProject is more sophisticated, it requires that you run a Java based program to generate the relevant PostScript files. The reward for putting up with this requirement, however, is that you can customize the finished device in novel ways. I built the in-the-sky version because I found it first, but I can already imagine building v2 using the AstrolabeProject's generator. Another feature of the AstrolabeProject: it has two lengthy documents that describe how to use the finished device, including a 47 page class handout and a 44 page manual.

I purchased a few items to make my in-the-sky version of the astrolabe, including:

• C-line transparency film - this transparency material worked well with our Canon Laser printer.
• 1/2" brass paper fasteners - these were ideal for holding the stack of papers that make up the astrolabe.
• Japanese Screw Punch - this makes punching the required holes a breeze and was a worthwhile investment.
• OLFA Rotary Circle Cutter - this simplified cutting out the circular parts of the astrolabe. In hindsight I could have lived without it. Like the paper punch, I figured I was investing in a tool that would be useful for future projects.

With the tools in hand, I was able to print and cut out each piece of the astrolabe. I opted to laminate the various paper components to add some heft to the finished product. I used this BIC lighter hack to bend the sights up on the ruler. That worked OK, but I can already envision a better solution for v2.

If paper isn't your thing, you can check out these instructions for a laser cut plastic version, or go crazy and build one by hand from brass (wow!).

I'm now able to hold in my hand the same tool that helped power explorers, astronomers, astrologers and priests over a thousand years ago. This is humbling. I can't wait to get out in the field put the device to use. Move over map, compass, watch and GPS--there's a new player in town.

Review: The Map of Salt and Stars

I try to learn as a little about a book as possible before I start it. Heck, I'll skip the author's introduction just to start chapter one with a blank slate. And yet, the two words I did catch in the description of The Map of Salt and Stars: A Novel by Zeyn Joukhadar were enough to conjure an entire plot. The two words: Syrian and Refugee.

From these two words I envisioned how the story would go: the main character(s) would be living in Syria, get displaced by war and end up in a refugee camp. He/She/They would toil there while the world ignored them.

I realized part way through the book what helped inspire this notion: ads by Patrick Stewart on YouTube. Apparently those ads made quite the impact on me. Between the ads and other stories I've heard, my vision of being a refugee was all about being passive. You remain in limbo, dependent on others, while the word moves on.

I truly enjoyed The Map, and even more so because I went into the text blind. So I don't want to ruin this book for you. But I will say, the plot I imagined above couldn't have been more wrong. Whereas I imagined a static plot, Joukhadar brought the opposite: plenty of heroic action. What a while ride The Map turned out to be.

I found the lyrical nature of the book to be a bit confusing at first, but I'm glad I stuck with it. My suggestion is to go read (or, do as I did and listen to) the book and then come back and read my comments below. They aren't anything Earth shattering, but I can't help but lay out a number of elements of Joukhadar's novel that caught my attention.

Spoilers Below

Joukhadar's use of a 12 year old American girl to serve as the protagonist was inspired. She provided precisely the naive perspective that someone like myself, unfamiliar with Middle East politics and customs, would have. And the decision to give her Synesthesia made not only for a useful poetic device, but was a clever super-power. And the interleaving of modern and historic adventures, that truly made this an outstanding read.

I found myself quite moved by the modern story. The bombing of Nour's family left me stunned. One imagines that residents in a city filled with unrest have a choice; stay or go? And when you do go, you at least have some time to pick which items you'll take with you. But the bombing shows how wrong headed this thinking is. One moment there's a family with a home and possessions, and the next there's nothing but destruction and pain. As I played the scenario over in my head I found myself stuck. What's the right way to respond to this impossible crisis? Nour and her family prove to be inspirational: you take what you can and move towards something better. The situation may be impossible, but giving up is even less of an option.

And that moment on the ferry where time stops; that moment nearly brought me to tears, something I can't recall a book ever doing. Like I said, a wild ride.

Sure, there's a few aspects of the plot I could quibble with. When the family has to separate, why all the secrecy? Wouldn't you want your daughters to know the name of the city and family member they are seeking out? Isn't that everything? The map is clever and full of symbolism, but it seems woefully impractical. And the plot lost a bit of steam at the end when we find Nour busting out of a facility that would let her sister come and go as she pleased. Still, these are minor quirks.

Overall, The Map of Salt and Stars delivers not one, but two epic tales. And while it shows a dark and troubling aspect of our humanity, it also shows  the power hope and moving forward. Perhaps most importantly, the book has inspired me to dig deeper into the subject. Now I'd like to read the true accounts of actual Syrian refugees to see what parts of the story are fanciful and what parts are realistic.

The 3P's of Gear Selection

Over the weekend, this thread was posted over at /r/ultralight:

Calling BS on the 10 essentials (for dayhikes)

I get that they're important, and I get why they are important, but do any of you actually bring all of the 10 essentials on all of your dayhikes and trail runs?
...
Can anyone on this sub, realistically, make a case that I needed a: Paper map and compass. Headlamp with extra batteries. Additional insulating layer (I brought a wind/rain shell). Firestarter. Knife. Emergency shelter.

The top answer is currently:

Hey OP- I’m in search and rescue and while I understand your feelings for sure, a lot of the missions that my search and rescue team get are 100% preventable- day hikers with issues that wouldn’t have been issues if they had the 10 essentials with them (dehydrated, heat exhaustion, injuries, lost, ran out of daylight and had no flashlight, etc). There’s plenty of lightweight versions of the 10 essentials. Even if you are experienced and end up never needing them yourself, it’s nice to have them “just in case” as well as to help anyone else on the trail that might need it.

It's followed up by this terse recap:

This. Because not bringing the ten essentials makes you an asshole. Many SARs are volunteers.

Don’t be an asshole to volunteers.

And while the above is solid reasoning, I'd like to pile on with a bit of my own gear philosophy. Anyone who follows my blog or has spent time with me in person, knows that I often carry a bag, and in that bag is a fairly significant amount of gear  (by /r/ultralight standards, it's massive). Why carry all this gear everywhere? The answer: the Three P's.

P₁ - Prepardness

In the context of a day hike, carrying a bit of extra gear gives you a chance to respond to the unexpected. The original poster imagined taking an 8 mile hike on a popular trail. Does he really need to bring a flashlight, emergency shelter and map and compass for this? While unlikely, it is possible that emergencies can stack up--a servely twisted ankle, as the sun is going down, with a dead cell phone--that may call for emergency gear.

Not moved by this argument? Not to worry, let's talk about the other two P's.

P₂ - Practice

It's not hard to imagine finding yourself finishing the above well known trail in the dark. Depending on the conditions, you may get by on ambient light or your cell phone's flashlight. But this is also a terrific opportuntity to practice with your gear. If you bust out the flashlight that you rely on when backpacking, even though it's overkill for a day hike, you're getting a free opportunity to test it out in a realistic context.

P₃ - Psychology

Still not moved? Let's say you decide to only carry emergency gear on truly adventerous hikes. Imagine, like Shira and myself that you find yourself turned around in a canyon filled landscape. In our case, we backtracked to the car and all was fine. But let's say you got turned around and backtracking isn't an option. Night and a storm of what-ifs are closing in. What if you miss your flight? What if nobody hikes this trail for weeks? What if you can't get cell signal? What if your cell phone dies? What if the vague message you sent your family isn't detailed enough to have them find you? What if temps drop and the shorts and t-shirt you're wearing leave you hypothermic? Now is precisely the wrong time to bust out an emergency kit you're not familiar with. If you always carry the same gear, you can take a deep breath and realize you have the essentials covered. It's hard to quanitfy this mindset bonus, but when an emergency happens every bit of familiarity with your gear is going to help.

I do agree with the original poster that the traditional 10 Essentials may not be the ideal prescription. Rather, you want to head into the wilderness armed with a kit to deal with emergenices the 10 Essentials were developed for. This includes: getting lost, getting injured, getting stuck in the dark, getting hit by unexpected weather and needing to shelter in place for the night.

The 3P's suggest you want compile a kit to deal with these scenerios (bonus: the kit can even be ultra-lightweight) and carry it religously.

Baby's First Backpacking Trip

At first glance, the Thurston Griggs Trail to Appalachian Trail to Black Rock route hardly looks like a must-do bit of trekking. But this past weekend it served as the setting for an audacious expedition: Baby's First Backpacking Trip.

In a normal year, I'd be itching to take a summer backpacking trip. But this year, with the pandemic keeping us at home, and a 6 month old baby I was eager to share the wonder of nature with, I found the pull of getting out on the trail even stronger. But how to do it?

First off, I'd needed to establish that we could carry the gear to have a proper overnight. I gathered up a tent, a sleeping bag for Shira, inflatable sleeping pads and a few other odds and ends. I shoved them into my 65 liter Gregory Backpack. I eyed the space left over. I'd need to fit in clothes for the Baby and Shira, food for all of us, diapers and plenty of water for making bottles. Yes, I decided it could be done.

But that's not all that needed to be carried. What about the little guy himself? At nearly 25 pounds, we decided that a robust carrier would make all the difference. So we picked up the deluxe Osprey Poco Plus. Like all Osprey packs, this is a thing of beauty. We put the little man it in for a walk through the neighborhood. At first he squirmed, and then got comfortable. We did our walk with him in and it was a success. Hurray, the gear was covered.

Now we needed a route. On one hand, we wanted one close by. On the other, we wanted a location that wouldn't be overrun with people on a weekend. We poured over our options and decided on the Thurston Griggs Trail to Appalachian Trail to Black Rock trip outlined on All Trails. The Thurston Griggs trail was far enough away from the popular Annapolis Rocks trail head, that we hoped it wouldn't be parked up. The trail itself called for an uphill slog that passed by a campsite. That meant that we could hike in, setup camp, and then do some additional hiking on the AT if we felt up to it. On paper, it looked like a solid choice.

The morning of our trip I cataloged the major ways this little project could fail, and possible work-arounds. The weather could take a turn for the worse. The parking lot could be full. The trail could be too technical to safely navigate with a baby in carrier. The campsites could be filled by the time we arrived. And those were just the obvious fail points.

To my amazement and joy, everything went precisely to plan. There was plenty of space to park the car. The schlep up Thurston Griggs trail was relatively steep and rocky, but not at all technical, so we had no problem making our way up the trail. When we arrived at Pogo Memorial Campground we found a couple of campers there. But we also found a half dozen empty sites. We picked one out of the way and setup our tent. Even the weather cooperated, with my Garmin InReach reporting 0% chance of precipitation for the next 24 hours.

After setting up our tent and letting the little guy play around the campsite he started to show signs of being tired. We put him in the carrier and we continued up the trail, this time on the official Appalachian Trail, up to Black Rock overlook. The view was spectacular, the kid fell asleep, and I got to relish in the joy of being in the backcountry.

When we returned to the campsite, I made a fire and Shira perfectly roasted hot dogs and marshmallows. Our little one sat in the grass playing. By the time dinner was cleaned up, it was time to put the little one to bed. I did this by putting him in the Moby wrap and taking him on a stroll along the AT. Rather than listen to music, I droned on about the joy of backpacking and he was asleep in no time.

By 8:30pm we were all asleep in the tent, we'd closed out an amazing day.

We'd stay in our little bubble of bliss for all of 4 hours. At around midnight the little guy awoke for a snack. Shira fed him by the red light of her headlamp, which was a bit surreal. I then put him back in the Moby and we roamed the pitch black campground as I put him to sleep. He eventually drifted off to bed. I made my way back to the tent, took him out of the Moby and put him on his sleeping pad. Moments later, he was awake. Ugh. It took us about 3 hours and 3 more attempts to actually get him fully back to sleep.

What I remember most was the look of wonder on his face as he stared up at the night sky. It was dark, but against the pitch black sky you could clearly make out the trees. I could see the little gears in his spinning as he tried to make sense of the scene.

Between attempts to put him sleep, I managed to experiment with some cellphone night-sky photography. While the photos may not appear like much, I'm impressed at how they came out. All told, it was actually quite nice to be up and exploring the area in the middle of the night.

After getting him back to sleep, we all slept in until 7am. We packed up our campsite and slowly trudged down the mountain back to our car. We met some locals on the way who confirmed what we suspected: the nearby Annapolis Rocks parking area fills up by mid-day, but the Thurston Griggs Trail Head always has parking. Keep that little tip in mind if you want to explore the area.

Before I knew it, we were back at the car and within spitting distance of DC. My little backpacking adventure was complete. I couldn't be happier with how it turned out. If anything it went too well. Now I'm itching to get out for two nights!

Review: Middle Passage

I tried to describe Middle Passage by Charles Johnson, the current book I was listening to Shira, but got stuck. Finally I explained, it's the type of book we'd read in English class. That is the subtext of the book seems to be just as important, if not more so, then the actual story. Below are some ramblings on this novel, beware, there are spoilers.

Since I finished Middle Passage I've been trying wrap my head around what I just heard. Yes, the book is a coming of age story of the main character, Rutherford Calhoun. And it's clearly an opportunity to ask the question: who's truly free and who's truly a slave? But it does all of this in a fairly novel way.

As I've thought through the book, I noticed an interesting clue: the sailors on the ship that Calhoun stows away on are too nice. He's a stowaway who impersonated another sailor to get on board, and yet the crew fairly quickly welcomes him. Even the captain who's feared by all and openly declares he "doesn't like negros" befriends Calhoun. This got me thinking of another story where the sailors are too nice, the Book of Jonah. Recall that in the Book of Jonah the sailors do everything they can to avoid throwing Jonah overboard.

As I thought about it, there are other similarities about Calhoun and Jonah. In the midst of the storm that forces the sailors to throw Jonah overboard, Jonah can be initially found sleeping below. When Calhoun stows away on the Republic his first act: going to sleep. Both stories involve vivid scenes where the crew offers sacrifices on deck to try to persuade the power's that be to rescue them. Far less esoteric is the fact that both Calhoun and Jonah are running from responsibility, and both encounter forces that show how powerless they are to do so. And of course, both ultimately find themselves back at where they started, now prepared to complete their missions.

To me, these similarities underscore that Calhoun's journey is meant to be taken, like Jonah's, as an allegory. This isn't meant to be historic fiction, accurate down to the last detail. In this context, Middle Passage makes more sense to me.

With the latest attention given to racism in our country, there's a trend of being cautious of how minorities are represented. Aunt Jemima is out of a job, tech companies are revisiting the terms the use and Arlington County is reconsidering its logo. In this environment, I was curious how Middle Passage would handle its subject matter. The author isn't just writing about a slave ship, he's writing about a slave ship with an African American crew mate, who also happens to be a thief and philanderer.

And while I'm no expert on these matters, I think Johnson manages to cover the material in a racially intelligent way. I say this not because of how he describes the sailors, but because of how he describes the captured slaves. They aren't pitiful, faceless men. They are a proud tribe, named and elevated. This isn't merely the story of moving slaves across the Atlantic, but the kidnapping of a distinct people with distinct personalities.

Incidentally, there is one group that doesn't fair so well in the book: women. Put bluntly, the main female character is fat and therefore ugly. When Calhoun reunites with the leading female character he finds her beautiful. Is this because he's learn to see her for all her positive qualities? No, it's because she's lost weight. Sorry ladies, better lose some weight if you want to be pretty.

My Grandpa Irv used to say: why ruin a good story with the truth? I think that may be one of Johnson's strategies in the Middle Passage. This isn't just a story on a slave ship, this is a story on a slave ship post 1808 when the slave trade was technically outlawed. This is evil on top of evil. And yet, Johnson risks humanizing the crew and their endeavor to give us the space to appreciate Calhoun's journey and ultimate redemption. I think it works.