[f-s d] Cetus

Quoting Liz Losh, Jacqueline Wernimont tweeted that behind every visualization is a spreadsheet.

But what, I wondered, is behind every spreadsheet?

Space whales.

Okay, maybe space whales aren’t behind every spreadsheet, but they’re behind this one, dated 1662, notable for the gigantic nail it hammered into the coffin of our belief that heaven above is perfect and unchanging. The following post is the first in my new series full-stack dev (f-s d), where I explore the secret life of data. 1

Hevelius. Mercurius in Sole visus (1662).
Hevelius. Mercurius in Sole visus (1662).

The Princess Bride teaches us a good story involves “fencing, fighting, torture, revenge, giants, monsters, chases, escapes, true love, miracles”. In this story, Cetus, three of those play a prominent role: (red) giants, (sea) monsters, and (cosmic) miracles. Also Greek myths, interstellar explosions, beer-brewing astronomers, meticulous archivists, and top-secret digitization facilities. All together, they reveal how technologies, people, and stars aligned to stick this 350-year-old spreadsheet in your browser today.

The Sea

When Aethiopian queen Cassiopeia claimed herself more beautiful than all the sea nymphs, Poseidon was, let’s say, less than pleased. Mildly miffed. He maybe sent a sea monster named Cetus to destroy Aethiopia.

Because obviously the best way to stop a flood is to drown a princess, Queen Cassiopeia chained her daughter to the rocks as a sacrifice to Cetus. Thankfully the hero Perseus just happened to be passing through Aethiopia, returning home after beheading Medusa, that snake-haired woman whose eyes turned living creatures to stone. Perseus (depicted below as the world’s most boring 2-ball juggler) revealed Medusa’s severed head to Cetus, turning the sea monster to stone and saving the princess. And then they got married because traditional gender roles I guess?

Corinthian vase depicting Perseus, Andromeda and Ketos.
Corinthian vase depicting Perseus, Andromeda and Ketos. [via]
Cetaceans, you may recall from grade school, are those giant carnivorous sea-mammals that Captain Ahab warned you about. Cetaceans, from Cetus. You may also remember we have a thing for naming star constellations and dividing the sky up into sections (see the Zodiac), and that we have a long history of comparing the sky to the ocean (see Carl Sagan or Star Trek IV).

It should come as no surprise, then, that we’ve designated a whole section of space as ‘The Sea‘, home of Cetus (the whale), Aquarius (the God) and Eridanus (the water pouring from Aquarius’ vase, source of river floods), Pisces (two fish tied together by a rope, which makes total sense I promise), Delphinus (the dolphin), and Capricornus (the goat-fish. Listen, I didn’t make these up, okay?).

Jamieson's Celestial Atlas, Plate 21 (1822).
Jamieson’s Celestial Atlas, Plate 21 (1822). [via]
Jamieson's Celestial Atlas, Plate 23 (1822).
Jamieson’s Celestial Atlas, Plate 23 (1822). [via]
Ptolemy listed most of these constellations in his Almagest (ca. 150 A.D.), including Cetus, along with descriptions of over a thousand stars. Ptolemy’s model, with Earth at the center and the constellations just past Saturn, set the course of cosmology for over a thousand years.

Ptolemy's Cosmos [by Robert A. Hatch]
Ptolemy’s Cosmos [by Robert A. Hatch]
In this cosmos, reigning in Western Europe for centuries past Copernicus’ death in 1543, the stars were fixed and motionless. There was no vacuum of space; every planet was embedded in a shell made of aether or quintessence (quint-essence, the fifth element), and each shell sat atop the next until reaching the celestial sphere. This last sphere held the stars, each one fixed to it as with a pushpin. Of course, all of it revolved around the earth.

The domain of heavenly spheres was assumed perfect in all sorts of ways. They slid across each other without friction, and the planets and stars were perfect spheres which could not change and were unmarred by inconsistencies. One reason it was so difficult for even “great thinkers” to believe the earth orbited the sun, rather than vice-versa, was because such a system would be at complete odds with how people knew physics to work. It would break gravity, break motion, and break the outer perfection of the cosmos, which was essential (…heh) 2 to our notions of, well, everything.

Which is why, when astronomers with their telescopes and their spreadsheets started systematically observing imperfections in planets and stars, lots of people didn’t believe them—even other astronomers. Over the course of centuries, though, these imperfections became impossible to ignore, and helped launch the earth in rotation ’round the sun.

This is the story of one such imperfection.

A Star is Born (and then dies)

Around 1296 A.D., over the course of half a year, a red dwarf star some 2 quadrillion miles away grew from 300 to 400 times the size of our sun. Over the next half year, the star shrunk back down to its previous size. Light from the star took 300 years to reach earth, eventually striking the retina of German pastor David Fabricius. It was very early Tuesday morning on August 13, 1596, and Pastor Fabricius was looking for Jupiter. 3

At that time of year, Jupiter would have been near the constellation Cetus (remember our sea monster?), but Fabricius noticed a nearby bright star (labeled ‘Mira’ in the below figure) which he did not remember from Ptolemy or Tycho Brahe’s star charts.

Mira Ceti and Jupiter. [via]
Mira Ceti and Jupiter. [via]
Spotting an unrecognized star wasn’t unusual, but one so bright in so common a constellation was certainly worthy of note. He wrote down some observations of the star throughout September and October, after which it seemed to have disappeared as suddenly as it appeared. The disappearance prompted Fabricius to write a letter about it to famed astronomer Tycho Brahe, who had described a similar appearing-then-disappearing star between 1572 and 1574. Brahe jotted Fabricius’ observations down in his journal. This sort of behavior, after all, was a bit shocking for a supposedly fixed and unchanging celestial sphere.

More shocking, however, was what happened 13 years later, on February 15, 1609. Once again searching for Jupiter, pastor Fabricius spotted another new star in the same spot as the last one. Tycho Brahe having recently died, Fabricius wrote a letter to his astronomical successor, Johannes Kepler, describing the miracle. This was unprecedented. No star had ever vanished and returned, and nobody knew what to make of it.

Unfortunately for Fabricius, nobody did make anything of it. His observations were either ignored or, occasionally, dismissed as an error. To add injury to insult, a local goose thief killed Fabricius with a shovel blow, thus ending his place in this star’s story, among other stories.

Mira Ceti

Three decades passed. On the winter solstice, 1638, Johannes Phocylides Holwarda prepared to view a lunar eclipse. He reported with excitement the star’s appearance and, by August 1639, its disappearance. The new star, Holwarda claimed, should be considered of the same class as Brahe, Kepler, and Fabricius’ new stars. As much a surprise to him as Fabricius, Holwarda saw the star again on November 7, 1639. Although he was not aware of it, his new star was the same as the one Fabricius spotted 30 years prior.

Two more decades passed before the new star in the neck of Cetus would be systematically sought and observed, this time by Johannes Hevelius: local politician, astronomer, and brewer of fine beers. By that time many had seen the star, but it was difficult to know whether it was the same celestial body, or even what was going on.

Hevelius brought everything together. He found recorded observations from Holwarda, Fabricius, and others, from today’s Netherlands to Germany to Poland, and realized these disparate observations were of the same star. Befitting its puzzling and seemingly miraculous nature, Hevelius dubbed the star Mira (miraculous) Ceti. The image below, from Hevelius’ Firmamentum Sobiescianum sive Uranographia (1687), depicts Mira Ceti as the bright star in the sea monster’s neck.

Hevelius. Firmamentum Sobiescianum sive Uranographia (1687).
Hevelius. Firmamentum Sobiescianum sive Uranographia (1687).

Going further, from 1659 to 1683, Hevelius observed Mira Ceti in a more consistent fashion than any before. There were eleven recorded observations in the 65 years between Fabricius’ first sighting of the star and Hevelius’ undertaking; in the following three, he had recorded 75 more such observations. Oddly, while Hevelius was a remarkably meticulous observer, he insisted the star was inherently unpredictable, with no regularity in its reappearances or variable brightness.

Beginning shortly after Hevelius, the astronomer Ismaël Boulliau also undertook a thirty year search for Mira Ceti. He even published a prediction, that the star would go through its vanishing cycle every 332 days, which turned out to be incredibly accurate. As today’s astronomers note, Mira Ceti‘s brightness increases and decreases by several orders of magnitude every 331 days, caused by an interplay between radiation pressure and gravity in the star’s gaseous exterior.

Mira Ceti composite taken by NASA's Galaxy Evolution Explorer. [via]
Mira Ceti composite taken by NASA’s Galaxy Evolution Explorer. [via]
While of course Boulliau didn’t arrive at today’s explanation for Mira‘s variability, his solution did require a rethinking of the fixity of stars, and eventually contributed to the notion that maybe the same physical laws that apply on Earth also rule the sun and stars.

Spreadsheet Errors

But we’re not here to talk about Boulliau, or Mira Ceti. We’re here to talk about this spreadsheet:

Hevelius. Mercurius in Sole visus (1662).
Hevelius. Mercurius in Sole visus (1662).

This snippet represents Hevelius’ attempt to systematically collected prior observations of Mira Ceti. Unreasonably meticulous readers of this post may note an inconsistency: I wrote that Johannes Phocylides Holwarda observed Mira Ceti on November 7th, 1639, yet Hevelius here shows Holwarda observing the star on December 7th, 1639, an entire month later. The little notes on the side are basically the observers saying: “wtf this star keeps reappearing???”

This mistake was not a simple printer’s error. It reappeared in Hevelius’ printed books three times: 1662, 1668, and 1685. This is an early example of what Raymond Panko and others call a spreadsheet error, which appear in nearly 90% of 21st century spreadsheets. Hand-entry is difficult, and mistakes are bound to happen. In this case, a game of telephone also played a part: Hevelius may have pulled some observations not directly from the original astronomers, but from the notes of Tycho Brahe and Johannes Kepler, to which he had access.

Unfortunately, with so few observations, and many of the early ones so sloppy, mistakes compound themselves. It’s difficult to predict a variable star’s periodicity when you don’t have the right dates of observation, which may have contributed to Hevelius’ continued insistence that Mira Ceti kept no regular schedule. The other contributing factor, of course, is that Hevelius worked without a telescope and under cloudy skies, and stars are hard to measure under even the best circumstances.

To Be Continued

Here ends the first half of Cetus. The second half will cover how Hevelius’ book was preserved, the labor behind its digitization, and a bit about the technologies involved in creating the image you see.

Early modern astronomy is a particularly good pre-digital subject for full-stack dev (f-s d), since it required vast international correspondence networks and distributed labor in order to succeed. Hevelius could not have created this table, compiled from the observations of several others, without access to cutting-edge astronomical instruments and the contemporary scholarly network.

You may ask why I included that whole section on Greek myths and Ptolemy’s constellations. Would as many early modern astronomers have noticed Mira Ceti had it not sat in the center of a familiar constellation, I wonder?

I promised this series will be about the secret life of data, answering the question of what’s behind a spreadsheet. Cetus is only the first story (well, second, I guess), but the idea is to upturn the iceberg underlying seemingly mundane datasets to reveal the complicated stories of their creation and usage. Stay-tuned for future installments.


  1. I’m retroactively adding my blog rant about data underlying an equality visualization to the f-s d series.
  2. this pun is only for historians of science
  3. Most of the historiography in this and the following section are summarized from Robert A. Hatch’s “Discovering Mira Ceti: Celestial Change and Cosmic Continuity

Fixing the irregular

Our word “fix” comes from fixus: unwavering; immovable; constant; fixed/fastened. Well, the scottbot irregular has been slowly breaking for years, finally broke last week, and it was time to fix it.

Broken how?

A combination of human error (my own), accruing chaos, the complexities of WordPress, and the awful-but-cheap hosting solution that is bluehost.com. As many noticed, the site’s been slowing down, interactive elements like my photo gallery stopped working, and by last week, pages would go dark for hours at a time. By this week, bluehost no longer allowed me ftp or cpanel access. So yesterday I took my business to ReclaimHosting.com, the hands-down best (and friendliest) hosting service for personal and small-scale academic websites.

Quoth the Server "404"
Quoth the Server “404”

I still haven’t figured out what finally did it in, but with so many moving parts, it seemed better to start fresh than repair the beast. I’m currently working on a jekyll static website; this new wordpress blog you’re reading now is an interim solution. However, I couldn’t just cut my losses and start over, since I’ve put a lot of my soul into the 100+ blog posts & pages I’ve written here since 2009.

More importantly, my site has been cited in dozens of articles, and appears on the syllabus of hundreds of courses, DH and otherwise. If I delete the content, I’m destroying part of the scholarly record, and potentially ruining the morning of professors who assign my blog posts as reading, only to find out at the last minute that it no longer exists.

Here lies the problem. Because I no longer had back-end access to my website, I could not download my content through the usual channels. Because of the peculiarities of my various WordPress customizations, not worth detailing here, I could not use a plugin to export my site and its contents.

Since I wanted the form of my site preserved for the scholarly record, the only solution I could come up with was to crawl my entire site, externally, and download static html versions of each page on scottbot.net as it used to exist.

the old scottbot irregular
the old scottbot irregular

Fixed how?

This is where the double-meaning of fix, described above, comes into play. I wanted the site functioning again, not broken, but I also wanted to preserve the old website as it existed at the URLs everyone has already linked to. For example, a bunch of syllab(uses|i)  link to http://www.scottbot.net/HIAL/?tag=networks-demystified to direct their students to my networks demystified posts. I wanted to make sure that URL would continue to point to the version of the site they intended to link to, while also migrating the old content into a new system that I’d be able to update more fluidly. Thankfully the old directory for the site, /HIAL/ (the site used to be called History Is A Lab), made that easier: the new version of the irregular would reside on scottbot.net, and the archive would remain on scottbot.net/HIAL/.

This apparently isn’t trivial. The first step was to use wget (explained and taught by Ian Milligan on the Programming Historian) to download a static version of the entire original irregular. After fiddling with the wget parameters and redownloading my site a few times, I ended up with a mostly-complete mirror of all the old content. Then I uploaded the entire mirror to my new host in the /HIAL/ directory. Yay!


The only catch was that old dynamic page URLs, like scottbot.net/HIAL/?tag=networks-demystified, were saved by wget as static html pages, like scottbot.net/HIAL/index.html@tag=networks-demystified.html. The solution, Dave Lester helped me figure out last night, was to edit the .htaccess file to make people linking to & visiting HIAL/?tag=networks-demystified automatically redirect to HIAL/index.html@tag=networks-demystified.html

The .htaccess file sits on your server, quietly directing traffic to the various places it should go. In my case, I needed to use regular expressions (remember that thing Shawn, Ian, and I taught in The Historian’s Macroscope?) to redirect all traffic pointing to HIAL/?[anything] to HIAL/index.html@[anything]. An hour or so of learning how .htaccess worked resulted in:

RewriteEngine On
RewriteBase /HIAL/
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^$ index.html@%1.html? [L,R=301]

which, after some false starts, seems to work. The old site is now fixed, as in constant; secured; unwavering, at scottbot.net/HIAL/. The new irregular, at scottbot.net, is now fixed, as in functional, dynamic. It will continue to evolve and change.

the scottbot irregular is dead. Long live the scottbot irregular!

Ghosts in the Machine

Musings on materiality and cost after a tour of The Shoah Foundation.

Forgetting The Holocaust

As the only historian in my immediate family, I’m responsible for our genealogy, saved in a massive GEDCOM file. Through the wonders of the web, I now manage quite the sprawling tree: over 100,000 people, hundreds of photos, thousands of census records & historical documents. The majority came from distant relations managing their own trees, with whom I share.

Such a massive well-kept dataset is catnip for a digital humanist. I can analyze my family! The obvious first step is basic stats, like the most common last name (Aber), average number of kids (2), average age at death (56), or most-frequently named location (New York). As an American Jew, I wasn’t shocked to see New York as the most-common place name in the list. But I was unprepared for the second-most-common named location: Auschwitz.

I’m lucky enough to write this because my great grandparents all left Europe before 1915. My grandparents don’t have tattoos on their arms or horror stories about concentration camps, though I’ve met survivors their age. I never felt so connected to The Holocaust, HaShoah, until I took time to see explore the hundreds of branches of my family tree that simply stopped growing in the 1940s.

Aerial photo of Auschwitz-Birkenau. [via wikipedia]
1 of every 16 Jews in the entire world were murdered in Auschwitz, about a million in all. Another 5 million were killed elsewhere. The global Jewish population before the Holocaust was 16.5 million, a number we’re only now approaching again, 70 years later. And yet, somehow, last month a school official and national parliamentary candidate in Canada admitted she “didn’t know what Auschwitz was”.

I grew up hearing “Never Forget” as a mantra to honor the 11 million victims of hate and murder at the hands of Nazis, and to ensure it never happens again. That a Canadian official has forgotten—that we have all forgotten many of the other genocides that haunt human history—suggests how easy it is to forget. And how much work it is to remember.

The material cost of remembering 50,000 Holocaust survivors & witnesses

Yad Vashem (“a place and a name”) represents the attempt to inscribe, preserve, and publicize the names of Jewish Holocaust victims who have no-one to remember them. Over four million names have been collected to date.

The USC Shoah Foundation, founded by Steven Spielberg in 1994 to remember Holocaust survivors and witnesses, is both smaller and larger than Yad Vashem. Smaller because the number of survivors and witnesses still alive in 1994 numbered far fewer than Yad Vashem‘s 4.3 million; larger because the foundation conducted video interviews: 100,000 hours of testimony from 50,000 individuals, plus recent additions of witnesses and survivors of other genocides around the world. Where Yad Vashem remembers those killed, the Shoah Foundation remembers those who survived.  What does it take to preserve the memories of 50,000 people?

I got a taste of the answer to that question at a workshop this week hosted by USC’s Digital Humanities Program, who were kind enough to give us a tour of the Shoah Foundation facilities. Sam Gustman, the foundation’s CTO and Associate Dean of USC’s Libraries, gave the tour.

Shoah Foundation Digitization Facility
Shoah Foundation Digitization Facility [via my camera]
Digital preservation it a complex process. In this case, it began by digitizing 235,000 analog Betacam SP Videocassettes, on which the original interviews had been recorded, a process which took from 2008-2012. This had to be done quickly (automatically/robotically), given that cassette tapes are prone to become sticky, brittle, and unplayable within a few decades due to hydrolysis. They digitized about 30,000 hours per year. The process eventually produced 8 petabytes (link to more technical details) of  lossless JPEG 2000 videos, roughly the equivalent of 2 million DVDs. Stacked on top of each other, those DVDs would reach three times higher than Burj Khalifa, the world’s tallest tower.

From there, the team spent quite some time correcting errors that existed in the original tapes, and ones that were introduced in the process of digitization. They employed a small army of signal processing students, patented new technologies for automated error detection & processing/cleaning, and wound up cleaning video from about 12,000 tapes. According to our tour guide, cleaning is still happening.

Lest you feel safe knowing that digitization lengthens the preservation time, turns out you’re wrong. Film lasts longer than most electronic storage, but making film copies would have cost the foundation $140,000,000 and made access incredibly difficult. Digital copies would only cost tens of millions of dollars, even though hard-drives couldn’t be trusted to last more than a decade. Their solution was a RAID hard-drive system in an Oracle StorageTek SL8500 (of which they have two), and a nightly process of checking video files for even the slightest of errors. If an error is found, a backup is loaded to a new cartridge, and the old cartridge is destroyed. Their two StorageTeks each fit over 10,000 drive cartridges, have 55 petabytes worth of storage space, weigh about 4,000 lbs, and are about the size of a New York City apartment. If a drive isn’t backed up and replaced within three years, they throw it out and replace it anyway, just in case. And this setup apparently saved the Shoah Foundation $6 million.

Digital StillCamera
StorageTek SL8500 [via CERN]
Oh, and they have another facility a few states away, connected directly via high-bandwidth fiber optic cables, where everything just described is duplicated in case California falls into the ocean.

Not bad for something that costs libraries $15,000 per year, which is about the same the library would pay for one damn chemistry journal.

So how much does it cost to remember 50,000 Holocaust witnesses and survivors for, say, 20 years? I mean, above and beyond the cost of building a cutting edge facility, developing new technologies of preservation, cooling and housing a freight container worth of hard drives, laying fiber optic cables below ground across several states, etc.? I don’t know. But I do know how much the Shoah Foundation would charge you to save 8 petabytes worth of videos for 20 years, if you were a USC Professor. They’d charge you $1,000/TB/20 years.

The Foundation’s videos take up 8,000 terabytes, which at $1,000 each would cost you $8 million per 20 years, or about half a million dollars per year. Combine that with all the physical space it takes up, and never forgetting the Holocaust is sounding rather prohibitive. And what about after 20 years, when modern operating systems forget how to read JPEG 2000 or interface with StorageTek T10000C Tape Drives, and the Shoah Foundation needs to undertake another massive data conversion? I can see why that Canadian official didn’t manage it.

The Reconcentration of Holocaust Survivors

While I appreciated the guided tour of the exhibit, and am thankful for the massive amounts of money, time, and effort scholars and donors are putting into remembering Holocaust survivors, I couldn’t help but be creeped out by the experience.

Our tour began by entering a high security facility. We signed our names on little pieces of paper and were herded through several layers of locked doors and small rooms. Not quite the way one expects to enter the project tasked with remembering and respecting the victims of genocide.

The Nazi’s assembly-line techniques for mass extermination led to starkly regular camps, like Auschwitz pictured above, laid out in efficient grids for the purpose of efficient control and killings. “Concentration camp”, by the way, refers to the concentration of people into small spaces, coming from “reconcentration camps” in Cuba. Now we’re concentrating 50,000 testimonies into a couple of closets with production line efficiency, reconcentrating the stories of people who dispersed across the world, so they’re all in one easy-to-access place.

Server farm [via wikipedia]
We’ve squeezed 100,000 hours of testimony into a server farm that consists of a series of boxes embedded in a series of larger boxes, all aligned to a grid; input, output, and eventual destruction of inferior entities handled by robots. Audits occur nightly.

The Shoah Foundation materials were collected, developed, and preserved with the utmost respect. The goal is just, the cause respectable, and the efforts incredibly important. And by reconcentrating survivors’ stories, they can now be accessed by the world. I don’t blame the Foundation for the parallels which are as much a construct of my mind as they are of the society in which this technology developed. Still, on Halloween, it’s hard to avoid reflecting on the material, monetary, and ultimately dehumanizing costs of processing ghosts into the machine.