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Doug Lenat (1950-2023)

When I started studying computer science, one of the initiation rites was to read the Jargon File. I stumbled when I read the entry on the microlenat:

microlenat: The unit of bogosity. Abbreviated μL, named after Douglas Lenat. Like the farad it is considered far too large a unit for practical use, so bogosity is usually expressed in microlenats.

I had not heard of Douglas Lenat then. English being my third language, I wasn’t sure what bogosity is. So I tried to learn a bit more to understand it, and I read a bit about Cyc and Eurisko, but since I just started computer science, my mind wasn’t really ready for things such as knowledge representation and common sense reasoning. I had enough on my plate struggling with resistors, electronegativity, and fourier transformations. Looking back, it is ironic that none of these played a particular role in my future, but knowledge representation sure did.

It took me almost ten years to come back to Cyc and Lenat’s work. I was then studying ontological engineering, a term that according to Wikipedia was coined by Lenat, a fact I wasn’t aware of at that time. I was working with RDF, which was co-developed by Guha, who has worked with Lenat at Cycorp, a fact I wasn’t aware of at that time. I was trying to solve problems that Lenat had tackled decades previously, a fact I wasn’t aware of at that time.

I got to know Cyc through OpenCyc and Cyc Europe, led by Michael Witbrock. I only met Doug Lenat a decade later when I was at Google.

Doug’s aspirations and ambitions had numerous people react with rolling eyes and sneering comments, as can be seen in the entry in the Jargon File. And whereas I might have absorbed similar thoughts as well, they also inspired me. I worked with a few people who told me “consider yourself lucky if you have a dozen people reading your paper, that’s the impact you will likely have”, but I never found that a remotely satisfactory idea. Then there were people like Doug, who shouted out “let’s solve common sense!”, and stormed ahead trying to do so.

His optimism and his bias to action, his can-do attitude, surely influenced me profoundly in choosing my own way forward. Not only once did I feel like I was channeling Lenat when I was talking about knowledge bases that anyone can edit, about libraries of functions anyone can use, or about abstract representations of natural language texts. And as ambitious as these projects have been called, they all carefully avoid the incomparably more ambitious goals Doug had his eyes set on.

And Doug didn’t do it from the comfort of a tenured academic position, but he bet his career and house on it, he founded a company, and kept it running for four decades. I was always saddened that Cyc was kept behind closed doors, and I hope that this will not hinder the impact and legacy it might have, but I understand that this was the magic juice that kept the company running.

One of Doug’s systems, Eurisko, became an inspiration and namesake for an AI system that played the role of the monster of the week in a first season episode of the X-Files, a fact I wasn’t aware of until now. Doug was a founder and advisory member of the TTI/Vanguard series of meetings, to which I was invited to present an early version of Abstract Wikipedia, a fact I wasn’t aware of until now. And I am sure there are more facts about Doug and his work and how it reverberated with mine that I am unaware of still.

Doug was a person ahead of their time, a person who lived, worked on and saw a future about knowledge that is creative, optimistic and inspiring. I do not know if we will ever reach that future, but I do know that Doug Lenat and his work will always be a beacon on our journey forward. Doug Lenat died yesterday in Austin, Texas, two weeks shy of his 73rd birthday, after a battle with cancer.

To state it in CycL, the language Cyc is written in:

 (#$dateOfDeath #$DougLenat "2023-08-31")
 (#$restInPeace #$DougLenat)


So, I went to the store with Little One today, and couldn't find the butter.

I ask the person at the cheese stand, who points me to the burrata. Tasty, but not what I'm looking for. I ask again and he sends me to the bread section.

I can't find it at the bread section, so I ask the person at the pastries stand where the butter is. She points me to the bagels. I say no, butter. She says, ah, there, pointing to the bathrooms. I'm getting exasperated, and I ask again. She points back to the cheeses with the burrata. I try again. She gets a colleague, and soon they both look confused.

Finally my daughter chimes in, asking for the butter. They immediately point her to the right place and we finally get the butter.

I haven't been so frustrated about my English pronunciation since I tried to buy a thermometer.

The Jones Brothers

The two Jones brothers never got along, but both were too stubborn to leave the family estate. They built out two entrances to the estate, one from the south, near Jefferson Avenue, and the newer, bigger one, closer to the historic downtown, and each brother chose to use one of the entrances exclusively, in order to avoid the other and their family. To the confusion of the local folk (but to the open enjoyment of the high school's grammar teacher, who was, surprisingly for his role, a descriptivist), they named the western gate the Jones' gate, and the southern one the Jones's gate, and the brothers earnestly thought that that settled it.

It didn't.

The Future of Knowledge Graphs in a World of Large Language Models

The Knowledge Graph Conference 2023 in New York City invited me for a keynote on May 11, 2023. Given that basically all conversations these days are about large language models, I have given a talk about my understanding on how knowledge graphs and large language models go together.

After the conference, I did a recording of the talk, giving it one more time, in order to improve the quality of the recording. The talk had gotten more than 10,000 views on YouTube so far, which, for me, is totally astonishing.

I forgot to link it here, so here we go finally:

Hot Skull

I watched Hot Skull on Netflix, a Turkish Science Fiction dystopic series. I knew there was only one season, and no further seasons were planned, so I was expecting that the story would be resolved - but alas, I was wrong. And the book the show is based on is only available in Turkish, so I wouldn't know of a way to figure out how the story end.

The premise is that there is a "semantic virus", a disease that makes people 'jabber', to talk without meaning (but syntactically correct), and to be unable to convey or process any meaning anymore (not through words, and very limited through acts). They seem also to loose the ability to participate in most parts of society, but they still take care of eating, notice wounds or if their loved ones are in distress, etc. Jabbering is contagious, if you hear someone jabber, you start jabbering as well, jabberers cannot stop talking, and it quickly became a global pandemic. So they are somehow zombieish, but not entirely, raising questions about them still being human, their rights, etc. The hero of the story is a linguist.

Unfortunately, the story revolves around the (global? national?) institution that tries to bring the pandemic under control, and which has taken over a lot of power (which echoes some of the conspiracy theories of the COVID pandemic), and the fact that this institution is not interested in finding a cure (because going back to the former world would require them to give back the power they gained). The world has slid into economic chaos, e.g. getting chocolate becomes really hard, there seems to be only little international cooperation and transportation going on, but there seems to be enough food (at least in Istanbul, where the story is located). Information about what happened in the rest of the world is rare, but everyone seems affected.

I really enjoyed the very few and rare moments where they explored the semantic virus and what it does to people. Some of them are heart-wrenching, some of them are interesting, and in the end we get indications that there is a yet unknown mystery surrounding the disease. I hope the book at least resolves that, as we will probably never learn how the Netflix show was meant to end. The dystopic parts about a failing society, the whole plot about an "organization taking over the world and secretly fighting a cure", and the resistance to that organization, is tired, not particularly well told, standard dystopic fare.

The story is told very slowly and meanders leisurely. I really like the 'turkishness' shining through in the production: Turkish names, characters eating simit, drinking raki, Istanbul as a (underutilized) background, the respect for elders, this is all very well meshed into the sci-fi story.

No clear recommendation to watch, mostly because the story is unfinished, and there is simply not enough payoff for the lengthy and slow eight episodes. I was curious about the premise, and still would like to know how the story ends, what the authors intended, but it is frustrating that I might never learn.

The right to work

20 May 2023

I've been a friend of Universal Basic Income for thirty years, but in the last twenty years, I have growing reservations about it, and many questions. This article about an experiment with a right to work was the first text in a while I read on it that substantially impacted my thinking on this (text is in German). I recommend reading it.

Work is not just a source of money, but for many also a source of meaning, pride, structure, motivation, social connections. Having voluntary access to work seems to be one major component that is necessary on a societal level, in addition to a universal basic income that allows that everyone can live in dignity. Note: I think work should be widely construed. If someone has something that fills that need, that's work. Raising children, taking care of a garden, writing a book, refining piano skills, creating art, taking care of others, taking care of yourself, all these easily count as work in my book.

I wish we were willing and able to experiment with different ways of structuring society as we are willing and able to experiment with technology. We deployed the Internet to the world without worrying about the long term consequences, but we're cautious about giving everyone enough money to not be hungry. That's just broken. I was always disappointed about the fact that sociology and politics as studied and taught by academia were mostly descriptive and not constructive endeavors.

Wikidata - The Making of

19 May 2023

Markus Krötzsch, Lydia Pintscher and I wrote a paper on the history of Wikidata. We published it in the History of the Web track at The Web Conference 2023 in Austin, Texas (what used to be called the WWW conference). This spun out of the Ten years of Wikidata post I published here.

The open access paper is available here as HTML:

Here as a PDF:

Here on Wikisource, thanks to Mike Peel for reformatting: Wikisource: Wikidata - The Making Of

Here is a YouTube trailer for the talk:

And here is the full talk (recreated) on YouTube:

20 years of editing Wikipedia

11 May 2023

Today it's been exactly twenty years since I made my first edit to Wikipedia. It was about the island of Brač, in the German Wikipedia.

Here is the version of the article I have created: Brač (as of May 11, 2003)

How much April 1st?

In my previous post, I was stating that I might miss April 1st entirely this year, and not as a joke, but quite literally. Here I am chronicling how that worked out. We were flying flight NZ7 from San Francisco to Auckland, starting on March 31st and landing on April 2nd, and here we look into far too much detail to see how much time the plane spent in April 1st during that 12 hours 46 minutes flight. There’s a map below to roughly follow the trip.

5:45 UTC / 22:45 31/3 local time / 37.62° N, 122.38° W / PDT / UTC-7

The flight started with taxiing for more than half an hour. We left the gate at 22:14 PDT time (doesn’t bode well), and liftoff was at 22:45 PDT.. So we had only about an hour of March left at local time. We were soon over the Pacific Ocean, as we would stay for basically the whole flight. Our starting point still had 1 hour 15 minutes left of March 31st, whereas our destination at this time was at 18:45 NZDT on April 1st, so still had 5 hours 15 minutes to go until April 2nd. Amusingly this would also be the night New Zealand switches from daylight saving time (NZDT) to standard time (NZST). Not the other way around, because the seasons are opposite in the southern hemisphere.

6:00 UTC / 23:00 31/3 local time / 37° N, 124° W / PDT / UTC-7

We are still well in the PDT / UTC-7 time zone, which, in general, goes to 127.5° W, so the local time is 23:00 PDT. We keep flying southwest.

6:27 UTC / 22:27 31/3 local time? / 34.7° N, 127.5° W / AKDT? / UTC-8?

About half an hour later, we reach the time zone border, moving out of PDT to AKDT, Alaska Daylight Time, but since Alaska is far away it is unclear whether daylight saving applies here. Also, at this point we are 200 miles (320 km) out on the water, and thus well out of the territorial waters of the US, which go for 12 nautical miles (that is, 14 miles or 22 km), so maybe the daylight saving time in Alaska does not apply and we are in international waters? One way or the other, we moved back in local time: it is suddenly either 22:27pm AKDT or even 21:27 UTC-9, depending on whether daylight saving time applies or not. For now, April 1 was pushed further back.

7:00 UTC / 23:00 31/3 local time? / 31.8° N, 131.3 W / AKDT? / UTC-8?

Half an hour later and midnight has reached San Francisco, and April 1st has started there. We were more than 600 miles or 1000 kilometers away from San Francisco, and in local time either at 23:00 AKDT or 22:00 UTC-9. We are still in March, and from here all the way to the Equator and then some, UTC-9 stretched to 142.5° W. We are continuing southwest.

8:00 UTC / 23:00 31/3 local time / 25.2° N, 136.8° W / GAMT / UTC-9

We are halfway between Hawaii and California. If we are indeed in AKDT, it would be midnight - but given that we are so far south, far closer to Hawaii, which does not have daylight saving time, and deep in international waters anyway, it is quite safe to assume that we really are in UTC-9. So local time is 23:00 UTC-9.

9:00 UTC / 0:00 4/1 local time / 17.7° N, 140.9° W / GAMT / UTC-9

There is no denying it, we are still more than a degree away from the safety of UTC-10, the Hawaiian time zone. It is midnight in our local time zone. We are in April 1st. Our plan has failed. But how long would we stay here?

9:32 UTC / 23:32 31/3 local time / 13.8° N, 142.5° W / HST / UTC-10

We have been in April 1st for 32 minutes. Now we cross from UTC-9 to UTC-10. We jump back from April to March, and it is now 23:32 local time. The 45 minutes of delayed take-off would have easily covered for this half hour of April 1st so far. The next goal is to move from UTC-10, but the border of UTC-10 is a bit irregular between Hawaii, Kiribati, and French Polynesia, looking like a hammerhead. In 1994, Kiribati pushed the Line Islands a day forward, in order to be able to claim to be the first ones into the new millennium.

10:00 UTC / 0:00 4/1 local time / 10° N, 144° W / HST / UTC-10

We are pretty deep in HST / UTC-10. It is again midnight local time, and again April 1st starts. How long will we stay there now? For the next two hours, the world will be in three different dates: in UTC-11, for example American Samoa, it is still March 31st. Here in UTC-10 it is April 1st, as it is in most of the world, from New Zealand to California, from Japan to Chile. But in UTC+14, on the Line Islands, 900 miles southwest, it is already April 2nd.

11:00 UTC / 1:00 4/1 local time / 3° N, 148° W / HST / UTC-10

We are somewhere east of the Line Islands. It is now midnight in New Zealand and April 1st has ended there. Even without the delayed start, we would now be solidly in April 1st local time.

11:24 UTC / 1:24 4/1 local time / 0° N, 150° W / HST / UTC-10

We just crossed the equator.

12:00 UTC / 2:00 4/2 local time / 3.7° S, 152.3° W / LINT / UTC+14

The international date line in this region does not go directly north-south, but goes one an angle, so without further calculation it is difficult to exactly say when we crossed the international date line, but it would be very close to this time. So we just went from 2am local time in HST / UTC-10 on April 1st to 2am local time in LINT / UTC+14 on April 2nd! This time, we have been in April 1st for a full two hours.

(Not for the first time, I wish Wikifunctions would already exist. I am pretty sure that taking a geocoordinate and returning the respective timezone will be a function that will be available there. There are a number of APIs out there, but none of which seem to provide a Web interface, and they all seem to require a key.)

12:44 UTC / 2:44 4/1 local time / 8° S, 156° W / HST / UTC-10

We just crossed the international date line again! Back from Line Island Time we move to French Polynesia, back from UTC+14 to UTC-10 again - which means it switches from 2:44 on April 2nd back to 2:44 on April 1st! For the third time, we go to April 1st - but for the first time we don’t enter it from March 31st, but from April 2nd! We just traveled back in time by a full day.

13:00 UTC / 3:00 4/1 local time / 9.6° S, 157.5° W / HST / UTC-10

We are passing between the Cook Islands and French Polynesia. In New Zealand, daylight saving time ends, and it switches from 3:00 local time in NZDT / UTC+13 to 2:00 local time in NZST / UTC+12. While we keep flying through the time zones, New Zealand declares itself to a different time zone.

14:00 UTC / 4:00 4/1 local time / 15.6° S, 164.5° W / HST / UTC-10

We are now “close” to the Cook Islands, which are associated with New Zealand. Unlike New Zealand, the Cook Islands do not observe daylight saving time, so at least one thing we don’t have to worry about. I find it surprising that the Cook Islands are not in UTC+14 but in UTC-10, considering they are in association with New Zealand. On the other side, making that flip would mean they would literally lose a day. Hmm. That could be one way to avoid an April 1st!

14:27 UTC / 3:27 4/1 local time / 18° S, 167° W / SST / UTC-11

We move from UTC-10 to UTC-11, from 4:27 back to 3:27am, from Cook Island Time to Samoa Standard Time. Which, by the way, is not the time zone in the independent state of Samoa, as they switched to UTC+13 in 2011. Also, all the maps on the UTC articles in Wikipedia (e.g. UTC-12) are out of date, because their maps are from 2008, not reflecting the change of Samoa.

15:00 UTC / 4:00 4/1 local time / 21.3° S, 170.3° W / SST / UTC-11

We are south of Niue and east of Tonga, still east of the international date line, in UTC-11. It is 4am local time (again, just as it was an hour ago). We will not make it to UTC-12, because there is no UTC-12 on these latitudes. The interesting thing about UTC-12 is that, even though no one lives in it, it is relevant for academics all around the world as it is the latest time zone, also called Anywhere-on-Earth, and thus relevant for paper submission deadlines.

15:23 UTC / 3:23 4/2 local time / 23.5° S, 172.5° W / NZST / UTC+12

We crossed the international date line again, for the third and final time for this trip! Which means we move from 4:23 am on April 1st local time in Samoa Standard Time to 3:23 am on April 2nd local time in NZST (New Zealand Standard Time). We have now reached our destination time zone.

16:34 UTC / 4:34 4/2 local time / 30° S, 180° W / NSZT / UTC+12

We just crossed from the Western into the Eastern Hemisphere. We are about halfway between New Zealand and Fiji.

17:54 UTC / 5:52 4/2 local time / 37° S, 174.8°W / NZST / UTC+12

We arrived in Auckland. It is 5:54 in the morning, on April 2nd. Back in San Francisco, it is 10:54 in the morning, on April 1st.


Green is March 31st, Red April 1st, Blue April 2nd, local times during the flight.

Basemap CC-BY-SA by TimeZonesBoy, based on PD by CIA World Fact Book


Altogether, there was not one April 1st, but three stretches of April 1st: first, for 32 minutes before returning to March 31st, then for 2 hours again, then we switched to April 2nd for 44 minutes and returned to April 1st for a final 2 hours and 39 minutes. If I understand it correctly, and I might well not, as thinking about this causes a knot in my brain, the first stretch would have been avoidable with a timely start, the second could have been much shorter, but the third one would only be avoidable with a different and longer flight route, in order to stay West of the international time line, going south around Samoa.

In total, we spent 5 hours and 11 minutes in April 1st, in three separate stretches. Unless Alaskan daylight saving counts in the Northern Pacific, in which case it would be an hour more.

So, I might not have skipped April 1st entirely this year, but me and the other folks on the plane might well have had the shortest April 1st of anyone on the planet this year.

I totally geeked out on this essay. If you find errors, I would really appreciate corrections. Either in Mastodon,, or on Twitter, @vrandecic. Email is the last resort, (The map though is just a quick sketch)

One thing I was reminded of is, as Douglas Adams correctly stated, that writing about time travel really messes up your grammar.

The source for the flight data is here:

No April Fool's day

This year, I am going to skip April Fool's day.

I am not being glib, but quite literal.

We are taking flight NZ7 starting on the evening of March 31 in San Francisco, flying over the Pacific Ocean, and will arrive on April 2 in the early morning in Auckland, New Zealand.

Even if one actually follows the flight route and overlays it over the timezone map, it looks very much like we are not going to spend more than a few dozen minutes, or at most a few hours, in April 1, if all goes according to plan.

Looking forward to it!

Here's the flight data of a previous NZ7 flight, from Sunday:

Here are the timezones (but it's Northern winter time). Would be nice to overlay the two maps: 1672px-Standard_time_zones_of_the_world_%282012%29_-_Pacific_Centered.svg.png

Where's Wikifunctions when it's needed?

The question seems to be twofold: how often do we cross the dateline, and how close are we to local time midnight while crossing the dateline. For a perfect date miss one would need to cross the dateline exactly once, at a 24 hour difference, as close as possible to local midnight.