Sunday, October 19, 2014


I just linked up this blog with Google+. This is a test to see what the effect of that is. I assume my posts will now be visible from Google+.

Saturday, October 04, 2014

My 1992 FTP site

Don't believe any links, or email addresses. Almost all have disappeared. Notice the strange domain name for mathematics at Sydney.

We did not get to see the web until at least 1993 when Mosaic came out (though we had to use Chimera on the Appollos). I haven't found my first email but I think it was around 1985 when I went to conferences announcing the importance of email, in particular to us in Australia. Hard to remember those times.

ftp site at the University of Sydney


ftp site at the University of Sydney

Date: Thu, 2 Apr 92 13:35:18 +10

      Category theory material
         Available by Anonymous FTP

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The mess we are in with scientific publishing

I am a little out of the Italian academic scene since my retirement, but if I understood the recent rounds of hiring in Italy they occurred in the following way. It was possible to apply for  "abilitazione", that is a judgment was made if you were at an appropriate level to hold a post. This was made in most cases on the grounds of purely numerical indicators, and was supposed to be a threshold. It was not a competition. A deeper analysis, actually looking at the papers or asking experts who had read the papers, was clearly impossible since, for example, in Computer Science a committee of 5 had to judge in a year the qualities of approximately 900 applicants. (There were even complaints when more than numbers were used, since that gave power to the "barons".)
After this judgment a great number of the abilitati were given permanent posts, thus filling up vacancies for some time.

The pressure this type of thing puts on scientific publishing is enormous. Referees, while trying to make judgments on papers, now have to consider that they are deciding the careers of young people, the grants for older people, that the prestige of the journal will affect jobs and grants. The reason the pressure is so enormous is that the job and granting committees don't look at the papers, just the numbers.
The job of a referee has become impossible, at the same time that there is more and more need for referees since scientists are being forced to publish more and more.

Scientific publishing must free itself from these pressures.

Thinking about this situation brought back to mind some thoughts of Bernhard Neumann.
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Arguments for funding

From the blog of Sabine Hossenfelder regarding the argument for funding the next supercollider:

"The next argument I keep hearing is that the worldwide web was invented at CERN which also hosts the LHC right now. If anything, this argument is even more stupid than the war-also-wastes-money argument. Yes, Tim Berners-Lee happened to work at CERN when he developed hypertext. The environment was certainly conductive to his invention, but the standard model of particle physics had otherwise very little to do with it."

I am glad that some physicists are being a bit more honest in their arguments for science funding. (However even this statement is inaccurate since Berners-Lee did not invent hypertext.)


Friday, September 19, 2014

Sleeping beauty problem III

Previous post in this series

I am writing a third post about the sleeping beauty problem partly because I have seen Sean Carmody's post  (26th August) in which he describes the problem and expresses his uncertainty about it, and promises an opinion in a future post. We are waiting, Sean, for your ideas on the matter!

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Opera d'abbaco del reverendo padre don Smiraldo Borghetti

Here are some pages from a book I bought some years ago on arithmetic, published in 1594.
It is interesting to read that without numbers the world would be without order,  and a horrible chaos.
Strangely the current popular view (which I do not share) is that the world is chaos, even to the extent that the laws of physics are the casual effect of which universe of the multiverse we happen to inhabit.


Wednesday, September 17, 2014

Giuseppe Peano

On Saturday I  bought for 2 euros  at the mercatino of Lavello a little book by Giuseppe Peano of numerical tables. It has an interesting preface by Peano.

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Tuesday, September 16, 2014

Ricordo di Aurelio Carboni, Matematico e Filosofo

I have just received a volume of "Il Protagora" in which there is a section devoted to Aurelio's memory.
There are four articles all in
Il Protagora, Volume XL, July-December 2013, sesta serie, n. 20
The articles are
Fabio Minazzi, Un ricordo di Aurelio Carboni, pp. 489-494
F. William Lawvere, Farewell to Aurelio, pp. 495-498
R.F.C. Walters, Working with Aurelio - Tangled Lives, pp. 499-504
George Janelidze, An open letter to Aurelio Carboni and all Mathematicians who remember him, pp. 505-513

Prepublication versions of three of the papers are at the Como Category Archive.


Sunday, September 14, 2014

Lex total categories and Grothendieck toposes IV

Previous post in this series; next post.

The aim of this post is to complete the proof that well-powered lex total categories are elementary toposes, by proving that they have subobject classifiers.

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Thursday, September 04, 2014

Span(Graph) III: Circuits with feedback

Previous post in this series; next post in the series.

The two main operations in $\bf Circ$ are composition and parallel as for straight-line circuits, and there are a variety of constants.

Today we describe the operation of composition of circuits with feedback in $\bf Circ$.

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