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Posts

April 25, 2015

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5:02 PM | Why Scanlon Left Logic for Political Philosophy
T. M. Scanlon is one of the foremost moral and political philosophers alive. But he started as a logician, working with Benacerraf as an undergraduate at Princeton, Dummett during a Fulbright at Oxford, and Dreben for his Ph.D. at Harvard. His first two papers were: The Consistency of Number Theory Via Herbrand’s Theorem, JSL 38…

April 23, 2015

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9:41 AM | Abraham Ortelius and the 16th century information age.
The sixteenth century saw the evolution of modern cartography emerge out of a renaissance in Ptolemaic cartography. In the second half of the century the Netherlands played a leading role in this process. I have already blogged twice about Gerard … Continue reading →

April 22, 2015

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6:04 PM | Pen Maddy: Is Math Mysterious?
They ask, “Is there something mysterious about mathematics?” Among others, Pen Maddy answers. http://ideas.aeon.co/questions/is-there-something-mysterious-about-math
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4:53 PM | What You May Have Missed
Logic went viral, sad news, good news. All on the new blog site, richardzach.org.  Please update your links and subscriptions.
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4:39 PM | Eight Logicians Elected to the American Academy
The American Academy of Arts & of Sciences has announced its 2015 class of members.  The recipients of this prestigious honor include eight logicians: Sanjeev Arora (Computer Science, Princeton University) works in complexity theory, and is especially known for his work on probabilistically checkable proofs. He previously won the Gödel Prize for his work on…
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3:16 PM | Anita Burdman Feferman, 1927-2015
Anita Burdman Feferman, the noted biographer of Jean van Heijenoort and Alfred Tarski, died on April 9.  She was the author of Politics, Logic, and Love: The Life of Jean van Heijenoort (Jones and Bartlett, 1993, reprinted as From Trotsky to Gödel, CRC Press, 200) and the co-author of Alfred Tarski: Life and Logic (CUP, 2004). …

April 20, 2015

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3:34 PM | Finding Cheryl’s Birthday with DEMO
Following up on the Dynamic Epistemic Logic treatment of Cheryl’s Birthday Puzzle, Malvin Gattinger (ILLC Amsterdam) has formalized the problem in DEMO_S5, a Dynamic Epistemic Logic model checker written in Haskell by Jan van Eijck (CWI Amsterdam and ILLC). The original DEMO system was described in: Jan van Eijck: “DEMO—a demo of epistemic modelling” In: Johan…

April 19, 2015

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11:29 PM | Mancosu on Frege and Direction
Remember the part in Frege’s Grundlagen where he starts to talk about abstraction by talking about the direction of lines?  Two lines have the same direction if and only if they are parallel; this gives an identity criterion for directions of lines.  Ever wondered why Frege starts bringing in geometry? What the historical context and…

April 18, 2015

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3:13 PM | Nuova bicicletta: Dulcinea II
Due settimane fa siamo andati nel paradiso delle biciclette. E dopo un giro veloce di considerazioni, di consigli e di guida sulla pista ho deciso quale sarebbe stata l'erede di Dulcinea. Ed ecco a voi Dulcinea II! In tutta la sua scura bellezza.Come catena scoraggia-ladri mi hanno consigliato questa a metro di muratore. Dice che è una delle più resistenti. Ma ho già trovato un video in cui viene spezzata con un frullino. In quest'altro video però sembra essere davvero una delle […]

April 17, 2015

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5:02 PM | Asterisms and Constellations and how not to confuse them with Tropical Signs.
If you are going to write about something, especially if you intend to lay bare somebody else’s ignorance, it pays to actually know what you are talking about otherwise you could well end up looking like a total idiot, as … Continue reading →
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4:06 AM | Ask Your Librarian to Subscribe to PhilPapers!
PhilPapers now has almost 1.75 million entries.  Like the Stanford Encyclopedia, the project is non-profit and largely run by volunteers.  In order to be sustainable, they do need funding.  And like the Stanford Encyclopedia, they are asking for our help: so ask your library to subscribe! The merger of Philosophy Research Index into PhilPapers has…

April 16, 2015

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10:04 AM | Dodecafonia
Dopo aver considerato la teoria e aver ascoltato Schönberg, Webern e Berg arrivò a una conclusione:la dodecafonia è una cacata pazzesca!Seguirono 92 minuti di applausi.

April 15, 2015

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8:23 PM | New Posts: Please Update Links and Subscriptions
Reminder: there is new content on the new blog site, richardzach.org.  Please update your links and subscriptions.
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8:17 PM | Logicians Yap, Kooi Explain Viral Birthday Logic Puzzle
You’ve probably seen the “birthday logic puzzle” that’s gone viral in the past few days. If you haven’t, you might want to try to solve it yourself. Here it is: Two dynamic epistemic logicians, Audrey Yap (UVic) and Barteld Kooi (Groningen) explained the solution (and how to get it) on facebook.  “Dynamic” here modifies “epistemic”,…
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4:57 PM | The worst history of technology headline of the year?
The Guardian website produced a couple of articles to announce the publication of Sydney Padua’s graphic novel, The Thrilling Adventures of Lovelace and Babbage: The (Mostly) True Story of the First Computer. I strongly suspect that despite Padua’s qualifying ‘mostly’ in … Continue reading →
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4:02 PM | Logic without Borders: Essays in Honor of Jouko Väänänen
A Festschrift for Jouko Väänänen‘s 60th birthday is now out with de Gruyter, edited by Åsa Hirvonen, Juha Kontinen, Roman Kossak, and Andrés Villaveces: In recent years, mathematical logic has developed in many directions, the initial unity of its subject matter giving way to a myriad of seemingly unrelated areas. The articles collected here, which…
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7:25 AM | Carnevale della Matematica #84 - I mestieri dei matematici
L'edizione di aprile del Carnevale della Matematica è ospitato da maddmaths. Il tema è "I mestieri dei matematici".Io ho contribuito con la Cellula Melodica e con il mio articoletto così introdotto:Dioniso Dionisi per Pitagora e dintornici domanda: "Se vi chiedessi qual è il vostro numero preferito che rispondereste? E se vi chiedessi se i numeri hanno un sesso? E lo sapete che esiste una legge matematica per capire se qualcuno vi sta frodando? Ma allora come non […]

April 14, 2015

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10:27 PM | Ma allora le razze esistono davvero?
L'affermazione che il concetto di razza avrebbe una base scientifica mi ha fatto sobbalzare. Lo stavano dicendo durante una puntata di Radio3 Scienza mica a un comizio di Salvini!Ma come!? - ho pensato. - Non è uno di quelle cose che ci ripetono e ci ripetiamo da anni? Non era già stato archiviato tutto anche grazie al lavoro di Luigi Luca Cavalli-Sforza esposto in parte in Geni, popoli e lingue che ci ha spiegato come il concetto di razza umana sia […]

April 13, 2015

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2:11 PM | There is no such thing as Greek science.
I’m pretty certain that a fair number of people reading the title of this post will be going, ‘what the hell is he talking about? We heard all about Greek science at primary (grade) school, secondary school, high school, college, … Continue reading →

April 01, 2015

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6:09 PM | Emmy the student and Emmy the communist!
Emmy Noether’s birthday on 23 March saw her honoured with a Google Doodle, which of course led to various people posting brief biographies of Erlangen’s most famous science personality or drawing attention to existing posts in the Internet. Almost all … Continue reading →
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5:10 PM | The Hoods o C'era una volta in America
La lettura di The Hoods sta dando una nuova vita e aggiungendo nuovi dettagli a una delle storie cinematografiche che ho più amato: quella di C'era una volta in America. Il libro, a differenza del film che ha ispirato, viene narrato in ordine cronologico. Si apre con una scena in cui Noodles è seduto sui banchi di scuola. Seguito da una scena in cui il direttore della scuola cerca di convincerlo, fornendogli le opportunità, a continuare gli studi. Ma, nonostante l'intelligenza e […]

March 31, 2015

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7:17 PM | Moshe Vardi Elected Fellow of SIAM
SIAM just announced its list of Fellows for 2015, and it includes Moshe Vardi. The citation reads: Moshe Y. Vardi is Karen Ostrum George Distinguished Service Professor in Computational Engineering and Director of the Ken Kennedy Institute for Information Technology at Rice University. He is being recognized for contributions to the development of logic as…
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3:39 AM | Wrote Something New!
I wrote something about Quine's paradox and Gödel's theorem on the new blog. Please update the feed URL in your reader to http://richardzach.org/feed/
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2:55 AM | Quine’s Paradox and Gödel’s Theorem
It’s a commonplace to compare Gödel’s theorem to the liar paradox: The sentence This sentence is not true. is neither true nor false. Switch out “provable” for “true” and you get This sentence is not provable. and, modulo some technical stuff, this sentence is then neither provable nor refutable.  But of course the “modulo some…

March 30, 2015

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8:29 AM | Epitaffio a Dulcinea
Dopo quasi sette anni e qualche migliaio di chilometri di viaggi insieme la mia cara Dulcinea mi ha lasciato.O meglio, se la sono portata via. Al suo posto ho trovato i resti metaforici di una catena spezzata.Nei prossimi giorni, o forse dopo Pasqua, dovrò procurarmi una degna erede. E, visto che  non ho cambiato idea dal 2008, l'erede sarà rigorosamente da donna.Il misfatto è avvenuto nottetempo difronte alla biblioteca universitaria. Avevamo lasciato le bici lì perché, dopo una […]

March 29, 2015

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7:30 AM | Details, Details, Details, ...
March 29th, 2015How long is a year on Neptune?Well a year on Neptune takes 1 […]

March 28, 2015

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7:43 PM | My Sessions at the Pacific
I’m organizing two sessions at the Pacific APA; please join me there! Thursday, April 2, morning, 9-noon: 4A Book Symposium: Greg Frost-Arnold, Carnap, Tarski, and Quine at Harvard: Conversations on Logic, Mathematics, and Science Speakers: Richard Creath (Arizona State University) Gary Ebbs (Indiana University Bloomington) Greg Lavers (Concordia University) Greg Frost-Arnold (Hobart and William Smith…
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7:30 AM | Some Answers to Questions I Asks on March 21st
March 28th, 2015Pi Day was on March 14th, and I waited a week to see if anyone would […]

March 25, 2015

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7:38 PM | Qual è il sesso dei numeri? E il numero preferito? E il numero più comune?
Se vi chiedessi qual è il vostro numero preferito che rispondereste? E se vi chiedessi se i numeri hanno un sesso?Nel mio caso le mie risposte hanno coinciso in ambo i casi con le risposte della maggioranza degli intervistati.Mi direte: ma che senso ha la domanda se i numeri abbiano un sesso? Bene, allora restringiamo il campo. I dispari sono maschili o femminili? Restringiamo ancora. Il numero 1 è maschile o femminile? E il 2?Se volete rispondere senza essere influenzati fatelo ora, nei […]
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1:20 PM | Falso
A computer-verified proof of ⊥: https://github.com/clarus/falso (h/t Byron Cook)
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