标签: turing

The concept of the Turing test was first mooted by the legendary Alan Turing in his 1950 paper Computing Machinery and Intelligence . The idea is that a conversation takes place between a human and a machine using a text-only channel like a computer keyboard and screen.   In the classical form of this test, an evaluator observes the conversation and all three participants are separated from each other. If the evaluator cannot reliably tell the machine from the human, then the machine is said to have passed the Turing test.   The reason I'm waffling on about this here is that my chum Rick Curl recently put me in touch with a guy called Charlie Coultas, who is a volunteer at The National Museum Of Computing , in Bletchley Park, England.   Charlie is currently building a system to allow visitors to perform the Turing test for themselves, and to decide if they are communicating with another human or with a machine. When we first started communicating a couple of weeks ago, Charlie said to me in an email:   We get quite a few schools at the museum and the kids are always happy to get some “hands-on” experience. My Turing Test will drive a 1930s Creed teleprinter and keyboard, much like Turing would have used in the 1940s had he had the computing power to do it. The system -- which is based on a PIC 18F26K22 processor with 64K bytes of on-chip memory from Microchip Technology -- has a series of questions along with “intelligent” answers built in. I hope eventually to add idiomatic context, but initially I’ll see how it goes.   A 1930s Creed teleprinter. I have built in a random delay of a few hundred milliseconds between characters in the reply phase, which makes the teleprinter really look as though a human is typing. An external Flash RAM memory stores all the questions that have been asked, so I can download them into my laptop and then reprogram the on-chip Flash memory with the new questions and suitable answers. There will be a few tempting suggestions that a human might be on the other end; for example, a small UHF aerial will be visible near the teleprinter, thereby giving the idea that there is something “out there” (maybe a human?). A 1930s bell push will ring a distant bell to get things rolling. I really have no idea how this will all work out, but it should be fun.   Well, earlier today I heard back from Charlie, and it looks as though things are going swimmingly. In today's communication, Charlie said: Hi Max, the Turing test machine works, and works well. Even though it has only a few hundred question/answer pairs it is fairly convincing. It isn’t live at Bletchley Park yet, but we are working on it. Here's a photo of one of the short tests:     Charlie went on to say that he is looking for help with regards to the sort of questions people might ask so that he can prepare his answers ahead of time. In turn, I suggested that he couldn’t do better than members of our community.   So, imagine that you are sat in front of Charlie's 1930s teleprinter. You are allowed to pose five questions to determine whether you are communicating with a person or a machine (only text characters, not numbers). What five questions would you ask?

I just finished reading George Dyson's Turing's Cathedral: The Origins of the Digital Universe. I was going to write a review on it, but – sad to relate – I really couldn't rouse the enthusiasm... One of the reason's I got Turing's Cathedral in the first place (apart from the fact that I love learning about the history of computing) is that I really enjoyed the biography Einstein: His Life and Universe by Walter Isaacson. (I mistakenly recollected the Einstein book as also being a work of George Dyson's). You can read the reviews of Turing's Cathedral on Amazon. I pretty much agree with all of them – both "for" and "against". This isn't a book about Alan Turing, although he does get a few good mentions. This is more of a description of the pioneering development of computing in America during the decade after World War II. The central character is the Hungarian-American mathematician and polymath John von Neumann, but we also get introduced to a "cast of thousands". The book is replete with interesting details – but it's also jam-packed with boring details. The bottom line is that (a) I'm glad I read it and (b) I won't be reading it again (grin). By comparison, if you are interested in learning more about the life and works of Albert Einstein, then I most heartily recommend Walter Isaacson's biography of the great man. The book is almost completely without equations ( E = mc 2 might creep in there), but by the end you really have a "feel" for what a staggering achievement Einstein's work was and how incredibly difficult it was to get there. But that's not what I wanted to talk about... I also just finished re-reading Shakespeare – The World as Stage by Bill Bryson. I'm much more used to seeing Bryson's humorous accounts of his life and travels around England, Europe, Australia, and America, so I must admit that I was a tad dubious when I first saw that he'd written a book on Shakespeare. Now, I can drop Shakespearian quotes into the conversation as readily as the next man, and I've slogged my way through a fair number of his plays, but – truth to tell – I would be more than happy if I was never exposed to another one of his works during the rest of my stay on this plane of existence (grin). When I was at high school, the thought that I would one day read a book about Shakespeare for my own pleasure would have had me rolling on the floor laughing. Bill Bryson's skill is that he can write a book about the Bard that is incredibly informative ... and still has me rolling on the floor laughing. Now, it's important to note that this is not a biography of Shakespeare per se. As we soon discover in Bill's book, what we really and truly know about Shakespeare as a person would fit on the back of a postcard. Even the spelling of Shakespeare's name is problematical. As Bryson says: We are not sure how best to spell his name – but then neither, it appears, was he, for the name was never spelled the same way twice in the signatures that survive. The curious thing is that the one spelling Shakespeare didn't actually use himself is the one that is now universally attached to his name. Bryson also points out that one of the reason's Shakespeare remained so well-known (when so many of his peers have been lost in the mists of time) is that, seven years after his death, two of his friends published a compendium of his works that is now known as the First Folio . Now, you might think that the First Folio would be the definitive word (pun intended), but as Bryson says: In fact, however, the First Folio was a decidedly erratic piece of work. Even to an inexpert eye its typographical curiosities are striking. The problem was that there was no "master" copy of any of the plays. There was instead a bunch of different copies for each play, where each copy reflected a different state of development as the play was acted out and revisions were made on the fly. So what Shakespeare's friends had to do was to go through all of the versions they had available to them and create a synthesis of what they thought was best. The results sometimes left something to be desired. One of many examples offered by Bryson is as follows: A crucial line of dialog in King Lear is abbreviated by the character name "Cor.," but it is impossible to know whether "Cor." Refers to Cornwall or Cordelia. Either one works, but each gives a different shadow to the play. The issue has troubled directors ever since. Having said all of this, the fact that we know so little about Shakespeare in no way detracts from the fact that this is a very interesting, informative, and amusing book. As one review on Amazon says: What Bryson does is provide an excellent background piece on what little we do know of "the English Language's Greatest Writer" by exploring where he came from, what life was like generally in his time and how the theater and actor/writers worked as they entertained the masses in London and the countryside. I couldn't have said it better myself. The bottom line is that this is a really good book that I would recommend highly. Even if you have no interest whatsoever in reading Shakespeare's plays, or any of his myriad other writings, I am fully confident that you would really enjoy this work on the man himself.  

With regard to my previous blog " Check these out: 1bit processor and an ultra-cool Turing Machine ", I've been bouncing around the Internet discovering all sorts of cool things... But before we hurl ourselves headfirst into the fray with gusto and abandon, let's make sure that we're all tap-dancing to the same drum beat by briefly remind ourselves as to just what a Turing machine is when it's at home. According to the Wikipedia: A Turing machine is a device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a computer. The "Turing" machine was described by Alan Turing in 1936, who called it an "a(utomatic)-machine". The Turing machine is not intended as a practical computing technology, but rather as a hypothetical device representing a computing machine. Turing machines help computer scientists understand the limits of mechanical computation. The bottom line is that a Turing machine is something that uses very, very simple rules to perform computations. As originally conceived, Turing machines are not physical objects but mathematical ones. Having said this, lots of folks have constructed some jolly interesting physical realisations. For example, consider this entry from legoofdoom.blogspot.com . Or how about this offering , which is described as "A mechanical Turing machine built from scrap metal." I must admit that this little rascal does have a certain "agricultural charm" (grin). However, the tastiest one I've seen thus far was created by a guy called Mike Davey. Since Mike could not find the infinitely long tape required for the project (as specified by Alan Turing), his solution was to use 1,000 feet of white 35mm film leader and a dry erase marker. As you will see in this video , the result is absolutely incredible. Although Mike's Turing machine is controlled by a Parallax Propeller microcontroller, this little scamp is emulating the actions of the theoretical Turing engine (sometimes the convolutions involved in all of this really make your head spin). Now, even though I really, REALLY like Mike's solution, I must admit that I'm still drawn to the idea of a physical engine moving back and forth along tracks. We could increase the length of the track by implementing some sort of serpentine arrangement as illustrated below.   Top-down (bird's eye) view of model railway track I'm imagining a mechanical engine something like the Lego implementation shown at the beginning of this column, but maybe moving a bit faster, trundling back and forth along this track reading and writing "something". Based on the fact that I'm always saying "Cool Beans", someone suggested that my Turing machine operates by moving beans around ... I like it! I can really visualise something like one of these this on a table in my office trundling along performing some humongous calculation that will take years to complete... we could chart it's progress against a simulation running on a PC. Alternatively, instead of restricting ourselves to a 1D environment, like a tape or a train track, in which our Turing machine can move only in the Forward and Backward directions, how about a 2D environment like a large chess / checkers board? In this case, our Turing machine could move Forward, Backward, Left, or Right. Or here's another suggestion – imagine a 3D structure formed from miniature scaffolding presented in a cubic arrangement. Now imagine a Turing machine that can climb through the structure and move Forward, Backward, Left, Right, Up, and Down. In addition to clambering around, there would have to be some way for the machine to read / write data into each cube (maybe using coloured beans that it hangs from the scaffolding). My initial thought was that the machine would have to be battery-powered, which would mean it would have to come out of the framework occasionally to recharge itself. But after a moment's reflection I realised that we could use the framework itself to provide power. Just imagine how awesome this would look beavering away in the corner of my office. OK, I've done the hard part conceiving this little beauty. All that is left is to design and build it ... any volunteers (grin)?  

My friend Alvin (my co-author on several books) just showed me a rather interesting website that describes a 1bit processor. Since it's a 1bit processor, this little scamp supports only a single type of instruction. Before you read further, if you were doing this, which instruction would you choose to implement? ...tick tock... tick tock... tock tock... Well, the creator of this little beauty opted for a Copy then Branch-If type of instruction. The idea is that the machine copies the current bit to one address, and if that bit was one, then it branches to a second address. Click Here to read more... But wait, there is more, because someone who was commenting on one of my blogs on MicrocontrollerCentral.com mentioned a really interesting article on the BBC Technology website ( Click Here to see the original BBC article). This article describes the "goings on" at the annual Maker Faire in Newcastle, England. It seems that this year there were a plethora of exhibitions to tempt the curious and the geeky – everything from mushrooms that make music to Steampunk Jewelry. One item that really captured my attention was a mechanical computer that is programmed by the movement of ball bearings.   Students of computer history will recognise this as a Turing Machine , just like the one Alan Turing envisaged and explored in his mathematical paper that kicked off the computer age. I don't know about you, but I am REALLY tempted to build one of these for myself. I can imagine it chuntering away executing some program here in my office...