Le Tour de France, 2012

June 30, 2012

Every summer, the ultimate cycling race, le Tour de France, takes place on the roads of France and surrounding countries.  The race was first held in 1903, and generally lasts approximately three weeks.   The route goes, very roughly, around the “circumference” of France; the direction is clockwise or counter-clockwise in alternating years.   It always features significant segments in the Pyrenees and the Alps.  Most race days (stages) are point-to-point races involving the whole field; a few days are generally set aside as “time trials”:  riders racing against the clock over a fixed course.  Teams of riders (typically, 8-10 riders in each of ~20 teams) compete for a variety of distinctions.  The overall (general classification, or GC) winner is the rider with the lowest cumulative time.  Recognition is also given to the daily stage winners, and there are special prizes for the best sprinter, and the best climber (“King of the Mountains”).  The current leaders in these categories wear distinctive jerseys, during the Tour as well as at the finish: the yellow jersey (the maillot jaune) for the overall (GC) leader, the green jersey for the best sprinter, and the polka-dot jersey for the King of the Mountains.  In recent years, there has also been a white jersey for the best young (less than 26 years of age) rider in the GC.

This year’s edition of le Tour, the 99th, started today with the 6.4 km prologue in Liege, Belgium, and will end on Sunday, July 22. in Paris.  The race will comprise 20 stages following the prologue, and will cover 3,497 km (2,173 miles).   The stages include:

  • 9 flat stages,
  • 5 mountain stages with 2 summit finishes,
  • 4 medium mountain stages,
  • 2 individual time-trial stages

There are also two rest days included in the program.  This year, there are 22 teams and 198 riders in the Tour.

This year’s route does not have as many mountain stages and summit finishes as some recent Tours.  The mountain stages are often of special interest, since the Tour has frequently been won, or lost, there; it is the most likely place for someone to open up a large time gap.  Less emphasis on climbing means that good all-around riders will have a relative advantage.

Significant climbs on the Tour are ranked in categories, according to difficulty; in order of increasing difficulty, there are Category 4, 3, 2, 1, and HC (Hors Catégorie) ascents.   For example, in the Bagnères-de-Luchon to Peyrogudes stage of this year’s race, there is a Category 2 climb, of 8 km (5 miles) at a 5.2% grade, and an HC climb to the finish of 11.7 km (7.2 miles) at a 7.7% grade.  This year’s Tour includes 25 climbs of Category 2 or higher.

The details of the classification system have often been murky, but a few years ago, all was clarified in this USENET post on fr.rec.sport.cyclisme:

Re: Catégories de cols

Ben, c’est assez simple: Tu prends une 2CV. Si celle-ci monte en 4ème, alors c’est un col de 4ème catégorie. Même chose avec la 3ème, 2ème puis 1ère vitesse. Maintenant, si la 2CV ne monte pas, il s’agit du col “hors catégorie”.

A rough translation for those who don’t know French:

Well, it’s quite simple: you take a [Citroën] 2CV. If it climbs in 4th [gear], it’s a 4th category climb. Same thing with 3rd, 2nd and 1st gear. If the 2CV won’t climb at all, it’s a ‘hors catégorie’ col.

The current race leader, following the prologue today, is the Swiss rider Fabian Cancellara, from Team Radio Shack / Nissan.

Google Chrome Updated

June 29, 2012

Google has released a new version, 20.0.1132.47, of the Chrome browser for Linux, Mac OS X, Windows, and Chrome Frame.    According to Google Release Announcement, this release was made to address a specific problem with graphics acceleration:

This release disables some of Chrome’s GPU acceleration features on Mac hardware containing the Intel HD 4000 graphics chip (e.g. the new Macbook Airs), in order to prevent a resource leak which is causing a kernel panic on that hardware. This is a temporary change while we work on fixing the root cause of the issue.

Although I recommend keeping your software up to date as a general principle, I don’t think there’s any great urgency to apply this update, unless you have one of the affected machines.

Windows and Mac users should get the new version via the built-in update mechanism.  Linux users should get the updated package from their distributions’ repositories, using their standard package maintenance tools.

You can check the version of Chrome that you have by clicking on the tool menu icon (the little wrench), and then selecting “About Google Chrome”.

Google Releases Chrome 20

June 27, 2012

Google has released a new version of its Web browser, Chrome 20·0·1132·43, for all platforms (Linux, Windows, Mac OS X, and Chrome Frame).  The new version fixes 20 security vulnerabilities in Chrome, 11 of which Google rates  as High severity.    More details on the flaws patched are in the Release Announcement.

Because of the security content of the new version, I recommend that you update your systems as soon as you conveniently can.  Windows and Mac users should get the new version via the built-in update mechanism.  Linux users should get the updated package from their distributions’ repositories, using their standard package maintenance tools.

You can check the version of Chrome that you have by clicking on the tool menu icon (the little wrench), and then selecting “About Google Chrome”.

Fuel Cell Power for E-Bay Data Center

June 26, 2012

Back in February, 2010, I posted a note here about a new solid-oxide fuel cell that had been developed by Bloom Energy, a start-up company in Sunnyvale, California.  The company claimed that its technology had several advantages, including lower-cost materials (no platinum or other expensive metals), high electrical efficiency, and fuel flexibility.

Technology Review is now reporting that E-Bay is planning a new data center whose primary power source will be a set of Bloom’s fuel cells; the electric power grid will be used only as a backup power source.

The ecommerce company today said it will install six megawatts worth of Bloom Energy fuel cells to power new portions of its main data center in Utah. eBay said it will seek to run the 30 fuel cells on biogas, which consists of methane and other gases generated by organic waste at landfills or farms.

The company apparently believes that the economics of using fuel cells have improved considerably.

The cost of power from Bloom Energy fuel cells is roughly the same as grid power in places in some areas [sic] and the payback on purchasing the equipment can be three to five years, company executives have said.

Although the company has said that it will seek to use biogas as a fuel, it’s not clear that adequate supplies will be available, especially in the Utah location.  (If you have ever visited Utah, you know that there is a lot of empty space there.)  Coupled with the current low price of natural gas, this may mean that the primary fuel source is natural gas.  Fortunately, the principal constituent of both fuels is methane, so this should not present technical obstacles.

This project should be a useful case study in the viability of fuel cells as a power source for demanding, high-availability applications.

Update Tuesday, 26 June, 21:59 EDT

The New York Times also has an article on this project.

Alan Turing Centenary, Part 3

June 25, 2012

I’ve come across a few more items of interest in connection with the Alan Turing Centenary.  The Official Google Blog has a post marking Turing’s 100th birthday, last Saturday, June 23. In addition to discussing some of Turing’s work, it describes Google’s involvement in the Bletchley Park restoration project, and gives a brief overview of the recently-opened Turing exhibit at the Science Museum.

Google also had a home page “doodle” in honor of Turing’s birthday, which was a small, working Turing machine.  You  can play with it here.

The BBC News site has added a couple of additional essays about Turing.  The first of these includes reminiscences of Turing from two of colleagues.  One, Mike Woodger, served as Turing’s assistant at the National Physical Laboratory after WW II.

Mike Woodger worked as an assistant to Alan Turing in 1946 – the year Turing, fresh from his wartime work code-breaking, joined the National Physical Laboratory, in Teddington. Turing left after a year, but Mr Woodger stayed on to work on the completion of the Pilot Ace Computer, which Turing had helped to design.

The other colleague was Captain Jerry Roberts, a linguist and code-breaker at Bletchley Park from 1941 to 1945.  He remembers the huge importance of Turing’s breaking the German naval Enigma.

Up to the time when he broke it, Britain had been losing tremendous tonnages of shipping, including all our food imports.

If we had gone on losing the same amount of shipping, in another four to six months Britain would have lost the war.

The next BBC essay is by the scriptwriter, Graham Moore, who reviews some of Turing’s appearances in fiction and biography.

If Alan Turing had not existed, would we have had to invent him? The question seems to answer itself: Alan Turing very much did exist, and yet we have persisted in inventing him still.

He mentions the 1986 play, Breaking the Code, by Hugh Whitemore.  I had a chance to see this during its run on Broadway, with Derek Jacobi playing the role of Turing, and enjoyed it very much.  Apparently the BBC has also made a film version. In a slightly different vein, there is Neal Stephenson’s novel, Cryptonomicon.

Stephenson uses historical fiction’s ability to conjure hypothetical, counterfactual realities to play a great game of “what if” with the Turing legend.

I’ve read Cryptonomicon, and recommend it highly.  I’m not familiar with the other works Moore mentions, but they’re now on my list to look into.

Finally, for those readers who may have a DIY itch that needs scratching, it is possible to build a Turing machine out of LEGOs.

In honor of Alan Turing’s hundredth birthday, Davy Landman, Jereon van den Bos, and Paul Klint built a Turing Machine out of LEGOs. And if you like, you can build one too.

Please enjoy!

Turing Exhibit Opens at Science Museum

June 24, 2012

As part of the Alan Turing Centenary, the Science Museum in London has opened a new exhibit on Turing’s life and work.  The exhibit includes a number of items related to Turing, including a model of the Pilot ACE computer, for which Turing produced the basic design in 1945 at the National Physical Laboratory, and an example of a German Enigma cipher machine.

The “Babbage” blog at The Economist has a review of the exhibit, and the ways in which it relates to Turing’s life, in an attempt to give a rounded picture of the man.

Unlike other Turing tributes, which have tended to focus on one aspect of his work, the Science Museum aims to give a flavour of Turing the individual, and thus the exhibition mixes illustrations of the importance of his academic achievements with exhibits from the personal life of the man himself.

As the article points out, Turing is probably better known to the public for his wartime codebreaking work than for his work in mathematics.  His 1936 paper, On Computable Numbers, with an Application to the Entscheidungsproblem [PDF], in which he described the computing device we now know as a Turing machine, is certainly not light reading.  And computers, especially modern ones, aren’t really all that interesting to look at.  The Pilot ACE is old enough to have a console and visible electronic components.

It sounds like a most interesting exhibit.

Alan Turing Centenary, Part 2

June 23, 2012

As one might expect, the BBC News site has a number of articles related to the Alan Turing Centenary.  In particular, it has been publishing  a series of essays on Turing’s life and work.   I have tried to give a brief overview of these below.  (The essays are set up as separate pages, but there is a set of links to all of them at the top of each article.)

The first essay, on “Turing’s Genius”, is by Google’s Vint Cerf, who I have mentioned before in connection with the ACM’s participation in the Turing Centenary, and who is a recipient of the ACM’s Turing Award.  (As he mentions in his essay, he also, coincidentally, shares a birthday with Turing: June 23.)  He discusses the many ways in which Turing’s original work relates to the technological world we all take for granted today.

The second essay, by Prof. Jack Copeland, University of Canterbury, Christchurch, New Zealand, relates Turing’s involvement in code-breaking at the Government Code and Cypher School at Bletchley Park (also called Station X).  It mentions Turing’s personal contribution to breaking the naval version of the German Enigma encryption system, and the Lorenz cipher.   These mathematical, cryptanalytic contributions would have been impressive; but Turing also made an enormous contribution to the work of turning Station X into what was, in effect, the world’s first code-breaking factory.  He helped develop the bombes, electro-mechanical computers used to break Enigma messages on a production basis, and the Tunny machine, used for the Lorenz cipher.   (A project to reconstruct a Tunny machine is underway.)  As in many aspects of wartime intelligence, time was of the essence.

The faster the messages could be broken, the fresher the intelligence that they contained, and on at least one occasion an intercepted Enigma message’s English translation was being read at the British Admiralty less than 15 minutes after the Germans had transmitted it.

The third essay, “Alan Turing: The Father of Computing?”, is by Prof. Simon Lavington, author of Alan Turing and His Contemporaries: Building the World’s First Computers.   He observes that Turing’s ideas were not always terribly influential in some of the early computer  implementations.

It was not until the late 1960s, at a time when computer scientists had started to consider whether programs could be proved correct, that On Computable Numbers came to be widely regarded as the seminal paper in the theory of computation.

On Computable Numbers, with an Application to the Entscheidungsproblem [PDF], Turing’s paper, proved nonetheless to be of immense importance.  In it, Turing laid out, for the first time as far as I know, the  idea of a theoretical machine that, as demonstrated in his mathematical analysis, could solve any solvable problem.

The fourth essay, by Prof. Noel Sharkey of the University of Sheffield, discusses the Turing Test, proposed by Turing in his 1950 paper, Computing Machinery and Intelligence.  That paper begins with a statement of the fundamental problem:

I propose to consider the question, ‘Can machines think ?’  This should begin with definitions of the meaning of the terms ‘machine ‘ and ‘ think ‘.

Turing’s paper was provocative, in part, because he realized how woolly the question, “Can machines think?”, really is   There are ongoing discussions of whether the test that Turing proposed is the right one, but it does have the considerable virtue of being realizable in practice.

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