Gödel’s Vienna: Finding Café Reichsrat

The Café Reichsrat in Vienna is notable as the place where Gödel, on August 26, 1930, first announced the incompleteness theorem to Carnap, Feigl, and Weismann. The members of the Vienna Circle had met there to prepare for the trip to the “Zweite Tagung für Erkenntnislehre der Exakten Wissenschaften,” a satellite meeting to the congress of the German Society of Mathematicians organized by the Vienna Circle. This was where the famous symposium on the foundations of mathematics took place, with Carnap representing logicism, Heyting intuitionism, and von Neumann speaking for Hilbert’s school of formalism — the contributions are reprinted in Benacerraf’s anthology Philosophy of Mathematics. From Carnap’s diary: “6-1/2 9 [6pm to 8:30pm] Cafe Reichsrat … preparations for the trip to Königsberg. Gödel’s discovery: incompleteness of the system of Principia Mathematica … difficulties of the consistency proof.”  In February 1930, Gödel and Tarski discussed logic here during the latter’s first visit to Vienna.

The Reichsrat no longer exists, and the only picture that’s around shows just the top of one of its doors (from Jimmy Schimanovich’s photo gallery).

Sign above side door of Cafe Reichsrat

The window atop the door, columns, and stucco match the entrance to the Konditorei Sluka at Rathausplatz 8, and presumably on the basis of this it’s long been believed that the Reichsrat used to be located where the Sluka is now. But the Sluka has been around since 1891, which led Paul Raymont to speculate that it expanded into the Reichsrat’s space after the latter closed down. In 2010, Karlis Podnieks noticed that on the other side of the main driveway to Rathausplatz 8 there’s another door that also looks like the one in the picture, and conjectured that the Reichsrat might have been located there. But Vienna’s Kaffeehäuser were cavernous establishments and also almost all located at corners. So I asked Karl Sigmund, co-editor of Kurt Gödel: The Album and creator of the Gödel Exhibition, for help, and he suggested to check the phone book!  And indeed, Adolph Lehmann’s allgemeiner Wohnungs-Anzeiger : nebst Handels- u. Gewerbe-Adressbuch für d. k.k. Reichshaupt- u. Residenzstadt Wien u. Umgebung gives the address for the Reichsrat as Stadiongasse 2.

Phone book entry for Cafe Reichrat

The Café Reichsrat was thus located at the north-west corner of Stadiongasse and Reichsratsstraße/Rathauspark, and the archive picture probably shows the mid-block back entrance facing the Rathauspark identified by Podnieks. A bank now occupies the space:

Location of former Cafe Reichsrath

If you go visit, do have a coffee and cake at the Sluka!  I also made a map for all you Gödel pilgrims.

And here is some background reading:

John W. Dawson, Jr., Karl Sigmund, 2006. Gödel’s Vienna. The Mathematical Intelligencer 28(3), 44-55

For an almost complete list of people and places from the time of the Vienna Circle, consult:

Volker Thurm, 2003. Wien und der Wiener Kreis: Orte einer unvollendeten Moderne: Ein Begleitbuch, Vienna: facultas.wuv / maudric

Bleg: Philosophy survey for mathematicians

A group of researchers in philosophy, psychology and mathematics are requesting the assistance of the mathematical community by participating in a survey about mathematicians’ philosophical intuitions. The survey is here: http://goo.gl/Gu5S4E. It would really help them if many mathematicians participated. Thanks.

The Place of Logic in Computer Science Education Followup

The Special Session on “The Place of Logic in Computer Science Education” took place at the Logic Colloquium on Tuesday. It was well attended and, I think, overall a successful session.  The newly-formed ACM Special Interest Group on Logic and Computation (SIGLOG) was represented by its chair Prakash Panangaden. He stressed the importance of logicians (and computer scientists/instructors relying on logic and logical methods) to push for the integration of logical methods in the CS curriculum — the way the SIG on Programming Languages SIGPLAN has successfully managed to give prominence to programming languages and design. In the US, the existence of a standard curriculum makes it difficult for departments that would even want to put a focus on logic and formal methods to introduce dedicated courses, a point made by Phokion Kolaitis in discussion.  That curriculum includes only propositional logic and just the very basics of predicate logic as a requirement for all CS majors. In a previous panel at a SIGCSE meeting, it was argued that a remedy would be to integrate bits of logic in other courses where logical methods are needed.  This resulted in the TeachLogic Project, led by Moshe Vardi at Rice University, which aimed to provide course materials and ideas for where and how to incorporate logic into CS courses.

In Europe, departments seem to have a lot more leeway.  This makes it possible, e.g., for Austrian CS departments to even offer specialized grad programs in logic and computing, as Alex Leitsch reported.  Nicole Schweikardt presented ideas from an introductory course she teaches in Frankfurt.  One of her didactic lessons was that engaging examples are important to draw in students — pure logic courses tend to do a less-than-optimal job at convincing students that this stuff is useful and important.  Her “provocative statement was: “When confronting computer science students with formal logic for the first time, we should dare to be less formal.” This tied in with another topic of discussion: diversity.  In the US, the gender split in CS is even worse than in philosophy: 12% of 2010-11 CS degrees were awarded to women. Byron Cook also mentioned this as an issue, and pointed to Harvey Mudd College as a success story for how to get and keep members of underrepresented groups in(to) CS.  Now Harvey Mudd is an elite college and in many places that kind of institution-wide initiative is sadly not feasible (as Phokion pointed out). 

There are lessons to be learned, not just for how we teach formal methods in CS but also for logic courses in philosophy departments. One may be to make these courses — not: less rigorous — but simply more appealing by focussing more on examples and applications which are familiar and engaging to a broader audience that’s not already familiar with formal methods. In the discussion, Brigitte Pientka pointed out, however, that it would be a mistake to think that we have sacrifice rigor in logic or CS courses to make them appealing to women and enable them to succeed in them.  She referred to the environment at Carnegie Mellon University and the research by Carol Frieze and others who have documented that a more balanced environment allows both men and women to participate, contribute, and be successful, in the CS major, without accommodating presumed gender differences or watering down the curriculum to become “more female friendly”.  Since 2002 the percentage of bachelor‘s degrees granted to women in the CS major at CMU has exceeded and stayed well above the national average. It is currently at 25%.  These and other initiatives are covered in a piece on drawing women to computer science published in the NYT’s TheUpshot blog just yesterday.

SIGLOG is forming an Education Committee, which will carry on the work of the TeachLogic project and hopefully can serve as a clearing house for ideas, materials, and tools.  If you’re interested in being involved, Prakash would like to hear from you!  In addition, this would be a good place to announce that the conference Tools for Teaching Logic is happening again next year!

(Cross-posted at the Vienna Summer of Logic blog.)

Summer of Logic Dance Party

So there will be a student party at the Summer of Logic. Help me crowdsource logic/math/CS/AI tracks, preferably danceable. Ideas?

Pet Shop Boys – He Dreamed of Machines

Turing Machines – Slave to the Algorithm

My Robot Friend – Robot High School

Super Furry Animals – Fuzzy Logic

Daniel Avery – Drone Logic

Scooter – The Logical Song [Supertramp cover]

Squarepusher – Music for Robots

The Illuminator – 4 r square pi (Association for Symbolic Logic)

Or I guess we can just play Logic all night:

Logic – Mind of Logic / The Spotlight / …

or A-Track’s “Infinity + 1” mix and the entire Stills album “Logic will Break your Heart.”