I’m really looking forward to it! The chaos of the past year and a half didn’t leave me with much time or energy for travel or events, so it’ll be fun to get out and meet people again. I’m also looking forward to seeing the campus, which I hear has changed substantially since I left.

The talk isn’t limited to CNU students, so if you live nearby, you’re welcome to come! Admission is free, but since space is limited, you’ll need to reserve tickets here.

Hope to see you there!

I wanted to make an algorithm that anyone could implement, which didn’t rely on a central authority or ongoing support from any one maintainer. I also wanted to make it impossible to know the locations more than a day or so in advance, so that if geohashing became popular in an area, no one could publish a list of future locations that woud give property owners, park rangers, or local police time to prepare. So each day’s coordinates are randomized using the most recent Dow Jones opening price, which isn’t known until the morning of that day—or, in the case of weekends, a day or two in advance, which helps with planning larger weekend trips.

In the days after I posted the comic, there was a flurry of geohashing activity, which quieted down as the initial novelty wore off. But it didn’t die, and for the past several years there’s been a small but vibrant community building around the Geohashing Wiki. There are numerous daily expeditions, and they’ve taken some beautiful pictures and come up with a lot of neat tools, games, and achievements.

One of the many things they did was use a tweaked version of the algorithm to come up with a globalhash, a single coordinate for the day somewhere on the planet (biased toward the areas near the poles). They’re usually over the ocean, but a few of the land ones have been reached.

Yesterday’s globalhash fell less than a kilometer from the South Pole. User Carl-Johan got in touch with the Scott-Amundsen research station, and later that day, the hash was reached by Katie Hess, Dale Mole, and Joselyn Fenstermacher of the US, Robert Schwarz of Germany, and Sven Lidström of Sweden.

Wow. Just wow. Congratulations.

If you want to look up today’s geohash for your location, you can use this online tool, or one of the others listed on the Coordinate Calculators page.

When I was a kid, I was had an irrationally powerful fear of tsunamis (Etymology-Man would suggest “cymophobia”). I swam in the ocean a lot when I was very young, so waves were a big part of my world.  I would fret about tsunamis whenever I was near the coast, and to this day I have occasional nightmares about a wave coming out of nowhere and sweeping me away.

Looking back, part of what made tsunamis frightening was was that I didn’t know what they looked like, and my imagination ran wild filling in the gaps. I read what I could find about them. In particular, I remember being just old enough to work my way through this book, and carrying it around with me so I could read the tsunami section over and over. It included a grainy photo of a ship in a Japanese harbor plowing through an unimpressive-looking line of breakers. I think that’s also where I found a photo of some people running away from something (it was this photo, but the reproduction in my book was too grainy to see what they were running from).

Years later, after the rise of the web, I realized maybe I could now find a video of a tsunami, and finally see the thing that had so captivated me as a child. But my searches for videos didn’t turn up much of anything.

Then the 2004 tsunami happened. Shortly after, as YouTube and its various clones proliferated, there was more horrifying footage available than I could handle.

A year or two ago, I read an article somewhere (I have tried to find it again with no luck) which mentioned that before 2004, there hadn’t been much in the way of photographic or video records of tsunamis, and that this had contributed to a lack of understanding of their form. My childhood impression seemingly confirmed, I worked this into a comic.

It turns out I was mistaken. There are several photographs, some of which can be seen here, here, and here. There’s also a video here (sent in by Phil Plait).

I think what confused me as a child was that none of the photos showed the wave I expected—just debris, and occasionally some visible water. Now that I’ve seen horrifying videos like this, I’ve gone back to some of those old photos and realized that they did show a tsunami. It was just so unlike what I was expecting that I didn’t recognize it.

So thank you to everyone who sent in information. It’s really fascinating stuff. Oh, and anyone interested in the history of tsunamis might want to check out a Google Books advanced search for material published before 1850 containing phrases like earthquake wave, earthquake tide, or earthquake water feet. There are some gripping historical accounts buried there, along with some really interesting speculation by 19th-century scientists about the mechanisms behind earthquakes and their associated waves (the consensus seemed to be hot gas moving between subterranean chambers).

I’ve always been a little uneasy about having all my domains with them, since they’ve got a long history of screwing over domain owners, but never got around to doing anything about it. A little while back, as the SOPA thing blew up, I poked davean, the xkcd sysadmin, about whether it was time to make switching to someone more geek-friendly a priority.

He’s also wanted to switch away from GoDaddy for years (and recently met with the reddit folks to chat about SOPA stuff). He’s periodically done surveys of the alternatives, but—strange as it sounds—he’s actually had trouble finding an affordable registrar with the feature set we needed. In particular, he said he had trouble finding any that support IPv6 Glue and DNSSEC via a control system that doesn’t rely on filing and waiting on support tickets, which he says (and I quote) “freaks me out” as a means of handling registrar stuff (he’s very much an xkcd.com/705 style of administrator). The ones that did offer those features tended to be a little too high-priced for our large number of domains.

We’ve had a number of alternatives recommended in the past week or two, but none have quite satisfied davean’s criteria. If you know of any registrars that might work for us, you can email us at contact@xkcd.com and he’ll take a look.

We’re being cautious about how we handle this switch, since GoDaddy has seemingly been obstructing transfers in a way that can leave the sites trapped in limbo. But don’t worry—it’s in the works!

I’ve corrected a bunch of typos and other minor errors, most of which crept into the project during the final 36-hour no-sleep marathon to integrate all the pieces together. (Those corrections, plus a few more that will be added over the next few days, will all be integrated into the printed version).

Now it’s time for me to to spend some time relaxing with family, and trying to break the habit—trained into me by the research I did for the chart—of thinking of everything in economic terms. To those of you in the US (GDP: $15.18 trillion^[1], total net worth: $58.73 trillion^[2]), have a happy Thanksgiving!

We got married!

HURRICANE HUMBERTO DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
500 AM EDT THU SEP 13 2007

THE NATIONAL HURRICANE CENTER HAS DETERMINED...BASED ON RECON
AND MODEL GUIDANCE...THAT "HUMBERTO" IS A RIDICULOUS NAME FOR
A HURRICANE. THIS WILL BE THE LAST ADVISORY ISSUED CONCERNING
THIS STORM...UNTIL A MORE SERIOUS NAME IS CHOSEN.

$$ FORECASTER BLYTHE

HURRICANE FABIAN DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT SUN AUG 31 2003

FORECASTER AVILA CONTINUES TO INSIST...DESPITE ALL RECON
EVIDENCE...THAT IT WAS NOT HE WHO TOOK MY SANDWICH FROM THE
NHC FRIDGE. THIS ASSERTION IS NOT SUPPORTED BY FORECASTER
STEWART OR MY STATISTICAL MODELS...AND BASED ON THE TIGHT
CLUSTERING OF GUIDANCE...I AM ISSUING A WARNING FOR FORECASTER
AVILA...THAT HE HAD BETTER BRING HIS OWN LUNCH TOMORROW. THIS
WILL BE THE LAST WARNING ISSUED FOR FORECASTER AVILA.

$$ FORECASTER JACOBS

HURRICANE JEANNE DISCUSSION NUMBER 5
NATIONAL WEATHER SERVICE MIAMI FL
5 PM EDT TUE SEP 22 1998

THIS IS JUST TO SAY...THAT THE STORM IN THE ATLANTIC...WHICH
WE NAMED JEANNE...IS STRENGTHENING. IT HAS A DISTINCT EYE...
LIKE A WOMAN...AND GOOD PRESENTATION ON RADAR. THIS IS ALSO
TO SAY...THAT ADVISORIES MAY BE ISSUED FOR BERMUDA...WHERE A
DRYING FISH...RESTS ON A BEACH...BESIDE THE COCONUT PALMS.

$$ FORECASTER CARLOS WILLIAMS

TROPICAL DEPRESSION IVAN DISCUSSION NUMBER 59
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT THU SEP 16 2004

THE LOW LEVEL CENTER OF CIRCULATION OF TROPICAL DEPRESSION
IVAN COULD NOT BE LOCATED BY RECON...AND THE PRESENTATION IS
POOR TO ABSENT ON SATELLITE IMAGERY. IT SEEMS SAFE TO ASSUME
THAT...BARRING RENEWED CONVECTION ...THE CYCLONE HAS DISSAP--
...OH GOD...HE IS HERE...IVAN IS HERE IN THE OFFICE...EVERYONE
GET DOWN OH GOD HE IS INTENSIFYLKSDJFLKHHALKJKL...

$$ FORECASTER PRESCOTT

HURRICANE LILI DISCUSSION NUMBER 49
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT THU OCT 03 2002

HEY GUYS...I WAS JUST WONDERING...IF YOU EVER THINK ABOUT
THINGS. LIKE...YOU KNOW...WHETHER IT IS ALL WORTH IT.

$$ FORECASTER FREDERICK

TROPICAL STORM KATRINA DISCUSSION NUMBER 30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT TUE AUG 30 2005

THE WMO HAS DETERMINED THAT...DUE TO THE EXTREME DESTRUCTION
CAUSED BY THIS HURRICANE...THE NAME "NEW ORLEANS" WILL BE
REMOVED FROM THE LIST OF CITY NAMES...AND NOT USED FOR ANY
FUTURE AMERICAN CITY.

$$ FORECASTER SCHOEN

HURRICANE ISIDORE DISCUSSION NUMBER 24
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT SAT SEP 21 2002

HURRICANE ISIDORE CONTINUES TO STRENGTHEN...AND MOVE TOWARD
THE BAY OF CAMPECHE. HOWEVER...THE NHC WOULD LIKE TO REMIND
EVERYONE IN THE AFFECTED AREA THAT THE REAL STORM...IS INSIDE
US ALL.

$$ FORECASTER ANDERSON

http://www.hollywoodreporter.com/news/earthquake-twitter-users-learned-tremors-226481

It’s always nice to see real-life confirmation of your calculations! The quake started in Virginia at 13:51:04 EST, where most of my family lives.  Texts from my brother in Charlottesville (25 miles from the epicenter) were slowed down by the spike in cell traffic, but I got an IRC message from my brother in Newport News, VA at 13:52:09. Based on USArray/EarthScope detector readings posted at Bad Astronomy, his message overtook the seismic waves outside Philadelphia, and reached New England over a minute before the quake was felt there.

I once heard a story (originally told by Kevin Young) about Gerson Goldhaber, who was a physicist at Lawrence Berkeley National Lab. He was talking on the phone with another physicist at SLAC near Stanford University near the end of the day on Tuesday, October 17, 1989. The SLAC physicist suddenly interrupted with, “Gerson, I have to go! There’s a very big earthquake happening!” and then hung up. So Gerson stepped out into a group of people in the hall, made a big show of yawning and checking his watch, then said, “Aren’t we about due for an earthquake?” Before anyone could respond, the Loma Prieta earthquake reached Berkeley, and he became a legend.

My best friend from college is from Mineral, VA, a town of a few hundred people and one stoplight, which was at the epicenter of yesterday’s quake. A few years ago, he moved to Sendai, Japan, where he got an apartment just a few miles from the coast. Fortunately, he survived the March earthquake, tsunami, and nuclear meltdown. Last I heard from him, he was moving back home. He really can’t catch a break. Fortunately, it sounds like there’s not too much damage. (Though from what I remember of Mineral, I can’t help but wonder—if the quake did cause damage, how would you tell?)

I linked to their site last year when I posted my color survey results, but I confess I hadn’t read through their archives, so I think this was just a case of parallel inspiration. Still, I really like their version and I’m sorry for the repetition!

Happy 4th of July, and to those of you spending it with family, enjoy sitting through your parents watching Double Rainbow for the first time!

In October my fiancée was diagnosed with stage III breast cancer. It’s rare for young women to get breast cancer, and she’s otherwise healthy and has no family history, so it was a real bolt from the blue.

She’s been in nonstop treatment for the last eight months, which has been an emotional and physical ordeal that’s hard to describe. We both have all the support we could ask for—including an incredible medical team—and we’ve had some really good moments during these months, but it’s still a terrifying and isolating experience. Treatment is ongoing, and there’s no well-defined end point; things are going to continue to be scary and difficult for a while.

I’m usually pretty private about my personal life, but I wanted to explain why I’ve missed some midnight comic deadlines and have been particularly hard to reach lately. I’ve also spent a lot of these eight months immersed in cancer science, and I want to be free to talk (and draw comics) about stuff I’m learning without the unexplained subject matter leaving everyone worried and guessing.

Thank you so much for your patience, kind words, and all the little flash games you all sent. And all the best to those of you who are also caring for someone with cancer, or who are struggling with cancer yourselves.