What makes a good environment for child AI learning development? Possibly the same as for human child learning development: Minecraft.
Lego is one of the best games to play for impactful learning development for children. The word Lego is based on the words Play and Well in Danish. In the virtual world, Minecraft has of course taken up the mantle. A large part of why they are wonderful games is because they are open-ended and flexible. There are infinite possibilities over what you can build and do. They therefore help encourage not just focussing on something limited to learn as many other games do, but support open-ended creativity and so educational development. Given how positive it can be for children, it shouldn’t be surprising that Minecraft is now being used to help AIs develop too.
Games have long been used to train and test Artificial Intelligence programs. Early programs were developed to play and ultimately beat humans at specific games like Checkers, Chess and then later Go. That mastered they started to learn to play individual arcade games as a way to extend their abilities. A key part of our intelligence is flexibility though, we can learn new games. Aiming to copy this, the AIs were trained to follow suit and so became more flexible, and showed they could learn to play multiple arcade games well.
This is still missing a vital part of our flexibility though. The thing about all these games is that the whole game experience is designed to be part of the game and so the task the player has to complete. Everything is there for a reason. It is all an integral part of the game. There are no pieces at all in a chess game that are just there to look nice and will never, ever play a part in winning or losing. Likewise all the rules matter. When problem solving in real life, though, most of the world, whether objects, the way things behave or whatever, is not there explicitly to help you solve the problem. It is not even there just to be a designed distractor. The real world also doesn’t have just a few distractors, it has lots and lots. Looking round my living room, for example, there are thousands of objects, but only one will help me turn on the tv.
AIs that are trained on games may, therefore, just become good at working in such unreal environments. They may need to be told what matters and what to ignore to solve problems. Real problems are much more messy, so put them in the real world, or even a more realistic virtual world, to problem solve and they may turn out to be not very clever at all. Tests of their skills that are based on such tasks may not really test them at all.
Researchers at the University of Witwatersrand in South Africa decided to tackle this issue, but using yet another game: Minecraft. Because Minecraft is an open-ended virtual world, tackling challenges created in it will involve working in a world that is much more than just about the problem itself. The Witwatersrand team’s resulting MinePlanner system is a collection of 45 challenges, some easy, some harder. They include gathering tasks (like finding and gathering wood) and building tasks (like building a log cabin), as well as tasks that include combinations of these things. Each comes in three versions. In the easy version nothing is irrelevant. The medium version contains a variety of extraneous things that are not at all useful to the task. The hard version is in a full Minecraft world where there are thousands of objects that might be used.
To tackle these challenges an AI (or human) needs to solve not just the complex problem set, but also work out for themselves what in the Minecraft world is relevant to the task they are trying to perform and what isn’t. What matters and what doesn’t?
The team hope that by setting such tests they will help encourage researchers to develop more flexible intelligences, taking us closer to having real artificial intelligence. The problems are proposed as a benchmark for others to test their AIs against. The Witwatersrand team have already put existing state-of-the-art AI planning systems to the test. They weren’t actually that great at solving the problems and even the best could not complete the harder tasks.
So it is back to school for the AIs but hopefully now they will get a much better, flexible and fun education playing games like Minecraft. Let’s just hope the robots get to play with Lego too, so they don’t get left behind educationally.
What makes a good programmer? Is it knowledge, skills or is it the type of person you are? It is actually all three though it’s important to realise that all three can be improved. No one is born a computer scientist. You may not have the knowledge, the skills or be the right kind of person now, but you can improve them all.
To be a good programmer, you need to develop specialist knowledge such as knowing what the available language constructs are, knowing what those constructs do, knowing when to use them over others, and so on. You also need to develop particular technical skills like an ability to decompose problems into sub-problems, to formulate solutions in a particular restricted notation (the programming language), to generalise solutions, and so on. However, you also need to become the right kind of person to do well as a programmer.
Thinking about what kind of person makes a good programmer, to help my students work on them and so become better programers, I made a list of the attributes I associate with good student programmers. My list includes: attention to detail, an ability to think clearly and logically, being creative, having good spatial visualising skills, being a hard worker, being resilient to things going wrong so determined, being organised, being able to meet deadlines, enjoying problem solving, being good at pattern matching, thinking analytically and being open to learning new and different ways of doing things.
More recently, when taking part in a workshop about neurodiversity I was struck by a similar list we were given. Part of the idea behind ‘neurodiversity’ is that everyone is different and everyone has strengths and weaknesses. If you think of ‘disability’ you tend to think of apparent weaknesses. Those ‘weaknesses’ are often there because the world we have created has turned them into weaknesses. For example, being in a wheelchair makes it hard to travel because we have built a world full of steps, kerbs and cobbles, doors that are hard to manipulate, high counters and so on. If we were to remove all those obstacles, a wheelchair would not have to reduce your ability to get around. Thinking about neurodiversity, the suggestion is to think about the strengths that come with it too, not just the difficulties you might encounter because of the way we’ve made the world.
The list of strengths of neurodiverse people given at the workshop were: attention to detail, focussed interest, problem-solving, creative, visualising, pattern recognition. Looking further you find both those positives reinforced and new positives. For example, one support website gives the positives of being an autistic person as: attention to detail, deep focus, observation skills, ability to absorb and retain facts, visual skills, expertise, a methodological approach, taking novel approaches, creativity, tenacity and resilience, accepting of difference and integrity. Thinking logically is also often picked out as a trait that neurodiverse people are often good at. The similarity of these lists to my list of what kind of person my students should aim to turn themselves into is very clear. Autistic people can start with a very solid basis to build on. If my list is right, then their personal positives may help neurodiverse people to quickly become good programmers.
Here are a few of those positives others have picked out that neurodiverse people may have and how they relate to programming:
Attention to detail: This is important in programming because a program is all about detail, both in the syntax (not missing brackets or semicolons) but more importantly not missing situations that could occur so cases the program must cover. A program must deal with every possibility that might arise, not just some. The way it deals with them also matters in the detail. Poor programs might just announce a mistake was made and shut down. A good program will explain the mistake and give the user a way to correct it for example. Detail like that matters. Attention to detail is also important in debugging as bugs are just details gone wrong.
Resilience and determination: Programming is like being on an emotional roller coaster. Getting a program right is full of highs and lows. You think it is working and then the last test you run shows a deep flaw. Back to the drawing board. As a novice learning it is even worse. The learning curve is steep as programming is a complex skill. That means there are lots of lows and seemingly insurmountable highs. At the start it can seem impossible to get a program to even compile never mind run. You have to keep going. You have to be determined. You have to be resilient to take all the knocks.
Focussed interest. Writing a program takes time and you have to focus. Stop and come back later and it will be so much harder to continue and to avoid making mistakes. Decomposition is a way to break the overall task into smaller subtasks, so methods to code, and that helps, once you have the skill. However, even then being able to maintain your focus to finish each method, so each subtask, makes the programming job much easier.
Pattern recognition: Human expertise in anything ultimately comes down to pattern matching new situations against old. It is the way our brains work. Expert chess players pattern match situations to tell them what to do, and so do firefighters in a burning building. So do expert programmers. Initially programming is about learning the meaning of programming constructs and how to use them, problem solving every step of the way. That is why the learning curve is so steep. As you gain experience though it becomes more about pattern matching: realising what a particular program needs at this point and how it is similar to something you have seen before then matching it to one of many standard template solutions. Then you just whip out the template and adapt it to fit. Spot something is essentially a search task and you whip out a search algorithm to solve it. Need to process a 2 dimensional array – you just need the rectangular for loop solution. Once you can do that kind of pattern matching, programming becomes much, much simpler.
Creativity and doing things in novel ways: Writing a program is an act of creation, so just like arts and crafts involves creativity. Just writing a program is one kind of creativity, coming up with an idea for a program or spotting a need no one else has noticed so you can write a program that fills that need requires great creativity of a slightly different kind. So does coming up with a novel solution once you have a novel problem. Developing new algorithms is all about thinking up a novel way of solving a problem and that of course takes creativity. Designing interfaces that are aesthetically pleasing but make a task easier to do takes creativity. If you can think about a problem in a different way to everyone else, then likely you will come up with different solutions no one else thought of.
Problem solving and analytical minds: Programming is problem solving on steroids. Being able to think analytically is an important part of problem solving and is especially powerful if combined with creativity (see above). You need to be able to analyse a problem, come up with creative solutions and be able to analyse what is the best way of solving it from those creative solutions. Being analytical helps with solid testing too.
Visual thinking: research suggests those with good visual, spatial thinking skills make good programmers. The reasons are not clear, but good programs are all about clear structure, so it may be that the ability to easily see the structure of programs and manipulate them in your head is part of it. That is part of the idea of block-based programming languages like Scratch and why they are used as a way into programming for young children. The structure of the program is made visual. Some paradigms of programming are also naturally more visual. In particular object-oriented programming sees programs as objects that send messages to each other and that is something that can naturally be visualised. As programs become bigger that ability to still visualise the separate parts and how they work as a whole is a big advantage.
A methodological approach: Novice programmers just tinker and hack programs together. Expert programmers design them. Many people never seem to get beyond the hacking stage, struggling with the idea of following a method to design first, yet it is vital if you are to engineer serious programs that work. That doesn’t mean that programming is just following methods, tinkering can be part of the problem solving and coming up with creative ideas, but it should be used within rigorous methodology not instead of it. More time is also spent by good programming teams testing programs as writing them, and that takes rigorous methods to do well too. Software engineering is all about following rigorous methods precisely because it is the only way to develop real programs that work and are fit for purpose. Vast amounts of software written is never used because it is useless. Rigorous methods give a way to avoid many of the problems.
Logical thinking: Being able to think clearly and logically is core to programming. It combines some of the things above like attention to detail, and thinking clearly and methodologically. Writing programs is essentially the practice of applied logic as logic underpins the semantics (ie meaning) of programming languages and so programs. You have to think logically when writing programs, when testing them and when debugging them. Computers are machines built from logic and you need to think in part like a computer to get it to do what you want. A key part of good programming is doing code walkthroughs – as a team stepping through what a program does line by line. That requires clear logical thinking to think in teh steps the computer performs.
I could go on, but will leave it there. The positives that neurodiverse people might have are very strongly positives for becoming a good programmer. That is why some of the best students I’ve had the privilege to teach have been neurodiverse students.
Different people, neurodiverse or otherwise, will start with different positives, different weaknesses. People start in different places for different reasons, some ahead, some behind. I liked doing puzzles as a child, so spent my childhood devouring logic and algorithmic puzzles. That meant when I first tried to learn to program, I found it fairly easy. I had built important skills and knowledge and had become a good logical thinker and problem solver just for fun. I learnt to program for fun. That meant it was if I’d started way beyond the starting line in the race to become a programmer. Many neurodiverse people do the same, if for different reasons.
Other skills I’ve needed as a computer scientist I have had to work hard on and develop strategies to overcome. I am a shy introvert. However, I need to both network and give presentations as a computer scientist (and ultimately now I give weekly lectures to hundreds at a time as an academic computer scientist). For that I had to practice, learn theory about good presentation and perhaps most importantly, given how paralysing my shyness was, devise a strategy to overcome that natural weakness. I did find a strategy – I developed an act. I have a fake extrovert persona that I act out. I act being that other person in these situations where I can’t otherwise cope, so it is not me you see giving presentations and lectures but my fake persona. Weaknesses can be overcome, even if they mean you start far behind the starting line. Of course, some weaknesses and ways we’ve built the world mean we may not be able to overcome the problems, and not everyone wants to be a computer scientist anyway so has the desire to. What matters is finding the future that matches your positives and interests, and where you can overcome the weaknesses where you set your mind to it.
Programming is not about born talent though (nothing is). We all have strengths and weaknesses and we can all become better by practicing and finding strategies that work for us, building upon our strengths and working on our weaknesses, especially when we have the help of a great teacher (or have help to change the way the world works so the weaknesses vanish).
My list above gives some of the key personal characteristics you need to work on improving (however good at them you are or are not right now) If you do want to be a good programmer. Anyone can become better at programming than they are if they have that desire. What matters is that you want to learn, are willing to put the practice in, can develop strategies to overcome your initial weaknesses, and you don’t give up. Neurodiverse people often have a head start on those personal attributes for becoming good at new things too.
Bugs are everywhere, but why not learn from the mistakes of others. Here are some common bugs with examples of how they led to it all going terribly wrong.
The bugs of others show how solid testing, code walkthroughs, formal reasoning and other methods for preventing bugs really matter. In the examples below the consequences were massive, but none of these bugs should have made it to final systems, whatever the consequences.
Here then is my personal countdown of the top 10 bugs to learn from.
BUG 10: Divide by Zero
USS Yorktown, Public Domain via wikimedia
The USS Yorktown was used as a testbed for a new generation of “smart” ship. On 21 September 1997, its propulsion system failed leaving it “dead in the water” for 3 hours. It tried to divide by zero after a crew member input a 0 where no 0 should have been, crashing every computer on the ship’s network.
Moral: Input validation matters a lot and there are some checks you should know should be done as standard.
Keep adding to an integer variable and you run out of bits. Suddenly you have a small number not the bigger one expected. This was one bug in the Therac-25 radiation therapy machine that killed patients. The Boeing 787 Dreamliner had the same problem. Fly for more than 248 days and it would switch off.
Moral: Always have checks for overflow and underflow, and if it might matter then you need something better than a fixed but-length number.
AT&T lost $60 million the day the phones died (all of them). It was a result of changing a few lines of working code. Things happened too fast for the program. The telephone switches reset but were told they needed to reset again before they’d finished, … and so on.
Moral: even small code changes need thorough testing…and timing matters but needs extra special care.
BUG 6.99999989: Wrong numbers in a lookup table
Konstantin Lanzet – CPU Collection Konstantin Lanzet CC BY-SA 3.0
Intel’s Pentium chip turned out not to be able to divide properly. It was due to a wrong entry in a lookup table. Intel set aside $475 million to cover replacing the flawed processors. Some chips were turned in to key rings.
Moral: Data needs to be thoroughly checked not just instructions.
BUG 6: Wrong units
Mars Climate Orbiter. Public Domain via wikimedia.
The Mars Climate Orbiter spent 10 months getting to Mars …where it promptly disintegrated. It passed too close to the planet’s atmosphere. The programmers assumed numbers were in pound-force seconds when they were actually in newton-seconds.
Moral: Clear documentation (including comments) really does matter.
BUG 5: Non-terminating loop
Spinning pizza of death. Image Public Domain via wikimedia
The spinning pizza of death is common. Your computer claims to be working hard, and puts up a progress symbol like a spinning wheel…forever. There are lots of ways that this happens. The simple version is that the program has entered a loop in a way that means the test to continue is never false. This took on a greater spin in the Fujitsu-UK Post Office Horizon system where bugs triggered the biggest ever miscarriage of justice. Hundreds of post masters were accused of stealing money because Horizon said they had. One of many bugs was that mid-transaction, the Horizon terminal could freeze. However, while in this infinite loop hitting any key duplicated the transaction, subtracting money again for every key press, not just the once for the stamp being bought.
Moral: Clear loop structure matters – where loops only exit via of one clear (and reasoned correct) condition.
The first Ariane 5 rocket exploded at a cost of $500 million 40 seconds after lift-off. Despite $7 billion spent on the rocket, the program stored a 64 bit floating point number in to a variable that could only hold a 16 bit integer.
Moral: Strong type systems are there to help not hinder. Use languages without them at your peril.
BUG 3: Memory Leak
Memory leaks (forgetting to free up space when done with) are responsible for many computer problems. The Firefox browser had one. It was infamous because Firefox (implausibly) claimed their program had no memory leaks.
Moral: If your language doesn’t use a garbage collector then you need to be extra careful about memory management.
BUG 2: Null pointer errors
Photograph by Rama, Wikimedia Commons, Cc-by-sa-2.0-fr
Tony Hoare who invented the null pointer (a pointer that points nowhere) called it his “billion-dollar” mistake because programmers struggle to cope with it. Null pointer bugs crash computers, give hackers ways in and generally cause chaos.
Moral: Avoid null pointers and do not rely on just remembering to check for them.
The Morris Worm, an early Internet worm, came close to shutting down the Internet. It used a buffer overflow bug in network software to move from computer to computer shutting them down. Data was stored in a buffer but store too much and it would just be placed in the next avaialbale location in memory so could overwrite the program with new code.
Moral: Array-like data structures need extra care. Always triple check bounds are correct and that the code ensures overflows cannot happen
Arrays in many languages start from position 0. This means the last position is one less than the length of the array. Get it wrong… as every novice (and expert) programmer does at some point … and you run off the end. Oddly (in Europe), we have no problem in a lift pressing 1 to go to the second floor up. In other situations, count from 0 and you do one too many things. Did I say 10 bugs…OOPS!
Moral: Think hard about every loop counter in your program.
The number 1 moral from all of this is that thorough testing matters a lot. Just trying a program a few times is not enough. In fact thorough testing is not enough either. You also need code walkthroughs, clear logical thinking about your code, formal reasoning tools where they exist, strong type systems, good commenting, and more. Most of all programmers need to understand their code will NOT be correct and they must put lots of effort into finding bugs if crucial ones are not to be missed. knowing the kinds of mistakes everyone makes, and being extra vigilant about them, is a good start.
And that is the end of my top 10 bugs…until the next arrogant, over-confident programmer causes the next catastrophe.
It is Red nose day in the UK the day of raising money for the comic relief charity by buying and wearing red noses and generally doing silly things for money.
Red noses are not just for red nose day though and if you ‘ve been supporting it every year, you possibly now have a lot of red noses like we do. What can you do with lots of red noses? Well one possibility is to count in red nose binary as a family or group of friends. (Order your red noses (a family pack has 4 or a school pack 25) from comic relief or make a donation to the charity there.)
Red nose binary
Let’s suppose you are a family of four. All stand in a line holding your red noses (you may want to set up a camera to film this). How many numbers can 4 red noses represent? See if you can work it out first. Then start counting:
No one wearing a red nose is 0,
the rightmost end person puts theirs on for 1,
they take it off and the next person puts theirs on for 2,
the first person puts theirs back on for 3,
the first two people take their noses off and the third person puts theirs on for 4
and so on…
The pattern we are following is the first (rightmost end) person changes their nose every time we count. The second person has the nose off for 2 then on for the next 2 counts. The third person changes theirs every fourth count (nose off for 4 then on for 4) and the last person changes theirs every eighth count (off for 8, on for 8). That gives a unique nose pattern every step of the way until eventually all the noses are off again and you have counted all the way from 0 to 15. This is exactly the pattern of binary that computers use (except they use 1s and 0s rather than wear red noses).
What is the biggest number you get to before you are back at 0? It is 15. Here is what the red nose binary pattern looks like.
Image by CS4FN
Try and count in red nose binary like this putting on and taking off red noses as fast as you can, following the pattern without making mistakes!
The numbers we have put at the top of each column are how much a red nose is worth in that column. You could write the number of the column on that person’s red nose to make this obvious. In our normal decimal way of counting, digits in each column are worth 10 times as much (1s 10s 100s, 1000s, etc) Here we are doing the same but with 2s (1s 2s 4s 8s etc). You can work out what a number represents just by adding that column number in if there is a red nose there. You ignore it if there is no red nose. So for example 13 is made up of an 8s red nose + a 4s red nose + a 1s red nose. 8 + 4 + 1 = 13.
Image by CS4FN
Add one more person (perhaps the dog if they are a friendly dog willing to put up with this sort of thing) with a red nose (now worth 16) to the line and how many more numbers does that now mean you can count up to? Its not just one more. You can now go through the whole original sequence twice once with the dog having no red nose, once with them having a red nose. So you can now count all the way from 0 to 31. Each time you add a new person (or pet*, though goldfish don’t tend to like it) with a red nose, you double the number you can count up to.
There is lots more you can do once you can count in red nose binary. Do red nose binary addition with three lines of friends with red noses, representing two numbers to add and compute the answer on the third line perhaps… for that you need to learn how to carry a red nose from one person to the next! Or play the game of Nim using red nose binary to work out your moves (it is the sneaky way mathematicians and computer scientists use to work out how to always win). You can even build a working computer (a Turing Machine) out of people wearing red noses…but perhaps we will save that for next year.
What else can you think of to do with red nose binary?
[OOPS did I do this in a confusing way given red noses look like a 0 and normal noses look like a 1!?!]
Paul Curzon, Queen Mary University of London
*Always make sure your pet (or other family member) has given written consent before you put a red nose on them for ethical counting.
There are several Pi Day’s (14 March: 3.14; 22 July: 22/7) so we should look at how on earth you compute a number like Pi (3.1.4159….). It has an infinite number of digits containing no repeating pattern so you can never tie it down exactly. One of my favourite ways for calculating pi was first devised by the Indian mathematician Mādhava of Sangamagrāma 600 years ago. He worked out an algorithm for working out Pi based on the maths of infinite series that he had also worked out.
Pi is one of the most useful numbers in all of maths. In school you come across it when working out the area or circumference of a circle, but it crops up all over the place including in practical computer science situations. Digital music, for example, relies on it deep down. Remember that the next time you stream your favourite music!
So how, 600 years ago did Mādhava manage to work out a much more accurate version of Pi than anyone before him? He had worked out that certain sequences of infinite numbers wouldn’t get bigger and bigger but would just get closer and closer to some specific number. In particular, he worked out one such sequence linked to pi.
π / 4 = 1 – 1/3 + 1/5 – 1/7 + 1/9 – …
Writing this a slightly different way it gives us a way of calculating pi itself
π = 4 – 4/3 + 4/5 – 4/7 + 4/9 – …
With an infinite number of terms, this gives an accurate value for pi. We can’t add an infinite number of numbers together though. Instead, we can use it to get a good answer. To get an approximation to pi we just follow an algorithm where we gradually add / subtract the next term. Each new calculation then gives us a better estimate of what pi is.
So to start with we just take the first term which says
π = 4 (very approximately)
That isn’t very good as it doesn’t get any digits right! Pi is closer to 3 than to 4. So its not looking hopeful! That doesn’t matter though as it is just a starting point. When we subtract the next term it gets a bit better
π = 4 – 4/3 = 2.6666…
Hmm. Now we have overshot the other way. However, we are closer to the real value of pi than we were. So don’t lose heart, keep going and add the next term
π = 4 – 4/3 + 4/5 = 3.46666…
And another term …
π = 4 – 4/3 + 4/5 – 4/7 = 2.895 …
And another term …
π = 4 – 4/3 + 4/5 – 4/7 + 4/9 = 3.339…
and so on.
The important thing to notice is that after each term included we get a more accurate answer, and we can keep adding terms for as long as we are happy to do the calculations. Mādhava (or his followers) obviously liked doing calculations so kept going until he had worked out pi accurate to 10 decimal places (3.1415926535…) : a new world record at the time beating the previous best of 6 decimal places by a Chinese astronomer Zhao Youqin using a different algorithm, That record had been set 80 years earlier but was smashed by 4 decimal places. This new record lasted for another 96 years. In doing these calculations Mādhava was acting as a ‘computer’ in the original meaning of the word: a human following an algorithm to do computation.
His algorithm is what computer scientists call an iterative algorithm. This kind of algorithm is used quite a lot by computer scientists as it gives a general way of getting a good enough (if not perfect) answer to a problem that otherwise is hard (or impossible) to get a perfect answer to in a reasonable time. You start with a good guess and then gradually refine the answer until you are happy that it is accurate enough. These algorithms can be straightforward to code as it is just running a loop doing calculations that refine the answer. Mādhava was happy with 10 decimal places of accuracy but he could have kept going. The trouble is this is a very slow algorithm. As we saw with the first few iterations above, it takes a long time even to home in on the first digit being 3! Every new digit took a lot of extra work to get right. When calculating machines and then computers were invented it became easier to use slow algorithms like this, but even with a faster computer it is still better to have a faster algorithm. Now far faster algorithms have been invented and the world record at the time of writing gives pi accurate to 105,000,000,000,000 decimal places!
Mādhava would have needed to really like doing calculations (and have discovered the secret to eternal life) to have calculated pi that accurately. 600 years ago his world record for pi was still an amazing achievement.
Scientific fraud is worryingly common, though rarely talked about. It has been happening for years, but now Artificial Intelligence programs could supercharge it. If they do that could undermine Science itself.
Investigators of scientific fraud have found that large numbers of researchers have manipulated their results, invented data, or even produced nonsensical papers in the hope that no one will look closely enough to notice. Often, no one does. The problem is that science is built on the foundation of all the research that has gone before. If we can no longer trust that past research is legitimate, the whole system of science begins to break down. AI has the potential to supercharge this process.
We’re not at that point yet, luckily. But there are concerning signs that generative AI systems like ChatGPT and DALLE-E might bring us closer. By using AI technology, producing fraudulent research has never been easier, faster, or more convincing. To understand, let’s first look at how scientific fraud has been done in the past.
How fraud happens
Until recently, fraudsters would need to go through some difficult steps to get a fraudulent research paper published. A typical example might look like this:
Step 1: invent a title
Fraudsters look for a popular but very broad research topic. We’ll take an example of a group of fraudsters known as the Tadpole Paper Mill. They published papers about cellular biology. To choose a new paper to create, the group would essentially use a simple generator, or algorithm, based on a template. This uses a simple technique first used by Christopher Strachey to write love letters in an early “creative” program in the 1950s.
For each “hole” in the template a word is chosen from a word list.
Pick the name of a molecule
Either a protein name, a drug name or an RNA molecule name
Next, the fraudsters create the text of the paper. To do this, they often just plagiarise and lightly edit previous similar papers, substituting key words in from their invented title perhaps. To try to hide the plagiarism, they automatically swap out words, replacing them with synonyms. This often leads to ridiculous (and kind of hilarious) replacements, like these found in plagiarised papers:
“Big data” –> “Colossal information”
“Cloud computing” –> “Haze figuring”
“Developing countries” –> “Creating nations”
“Kidney failure” –> “Kidney disappointment”
Step 3: add in the results
Lastly, the fraudsters need to create results for the fake study. These usually appear in papers in the form of images and graphs. To do this, the fraudsters take the results from several previous papers and recombine them into something that looks mostly real, but is just a Frankenstein mess of other results that have nothing to do with the current paper.
A new paper is born
Using that simple formula, fraudsters have produced thousands of fabricated articles in the last 10 years. Even after a vast amount of effort, the dedicated volunteers who are trying to clean up the mess have only caught a handful.
However, committing fraud like this successfully isn’t exactly easy, either: the fraudsters still need to come up with a research idea, write the paper themselves without copying too much from previous research, and make up results that look convincing—at least at first glance.
AI: Adding fuel to the fire
So what happens when we add modern generative AI programs into the mix? They are Artificial Intelligence programs like ChatGPT or DALL-E that can create text or pictures for you based on written requests.
Well, the quality of the fraud goes up, and the difficulty of producing it goes way down. This is true for both text and images.
Let’s start with text. Just now, I asked ChatGPT-4 to “write the first two paragraphs of a research paper on a cutting edge topic in psychology.” I then asked it to “write a fake results table that shows a positive relationship between climate change severity and anxiety”. I won’t copy the whole thing—in part because I encourage you to try this yourself to see how it works (not to actually create a fake paper!)—but here’s a sample of what it came up with:
“As the planet faces increasing temperatures, extreme weather events, and environmental degradation, the mental health repercussions for populations worldwide become a crucial area of investigation. Understanding these effects is vital for developing strategies to support communities in coping with the psychological challenges posed by a changing climate.”
As someone who has written many psychology research papers, I would find the results very difficult to identify as AI-generated—it looks and sounds very similar to how people in my field write, and it even generated Python code to analyse the fake data. I’d need to take a really close look at the origin of the data and so on to figure out that it’s fraudulent.
But that’s a lot of work required from me as a fraud-buster. For the fraudster, doing this takes about 1 minute, and would not be detected by any plagiarism software in the way previous kinds of fraud can be. In fact, this might only be detected if the fraudsters make a sloppy mistake, like leaving in a disclaimer from the model as in the paper caught which included the text
“[Please note that as an AI language model, I am unable to generate specific tables or conduct tests, so the actual resutls should be included in the table.]”!
Generative AIs are not close to human intelligence, at least not yet. So, why are they so good at producing convincing scientific research, something that’s commonly seen as one of the most difficult things humans can do? Two reasons play a big part: (1) scientific research is very structured, and (2) there’s a lot of training data. In any given field of research, most papers tend to look pretty similar—an introduction section, a method describing what the researchers did, a results section with a few tables and figures, and a discussion that links it back to the wider research field. Many journals even require a fixed structure. Generative AI programs work using Machine Learning – they learn from data and the more data they are given the better they become. Give a machine learning program millions of images of cats, telling it that is what they are, and it can become very good at recognising cats. Give it millions of images of dogs and it will be able to recognise dogs too. With roughly 3 million scientific papers published every year, generative AI systems are really good at taking these many, many examples of what a scientific report looks like, and producing similar sounding, and similarly structured pieces of text. They do it by predicting what word, sentence and paragraph would be good to come next based on probabilities calculated from all those examples.
Trusting future research
Most research can still be trusted, and the vast majority of scientists are working as hard as they can to advance human knowledge. Nonetheless, we all need to look carefully at research studies to ensure that they are legitimate, and we should be on extra alert as generative AI becomes even more powerful and widespread. We also need to think about how to improve universities and research culture generally, so that people don’t feel like they need to commit scientific fraud—something that usually happens because people are desperate to get or keep a job, or be seen as successful and reap the rewards. Somehow we need to change the game so that fraud no longer pays.
What do you think? Do you have ideas for how we can prevent fraud from happening in the first place, and how can we better detect it when it does occur? It is certainly an important new research topic. Find a solution and you could do massive good. If we don’t find solutions then we could lose the most successful tool human-kind has ever invented that makes all our lives better.
Greg Michaelson is an Emeritus professor of computer science at Heriot-Watt University in Edinburgh. He is also a novelist and a short story writer. He wrote this story for CS4FN.
“Come on!” called Alice, taking the coat off the peg. “We’re going to be late!”
“Do I have to?” said Henry, emerging from the front room.
“Yes,” said Alice, handing him the coat. “Of course you have to go. Here. Put this on.”
“But we’re playing,” said Henry, wrestling with the sleeves.
“Too bad,” said Alice, straightening the jacket and zipping it up. “It’ll still be there when we get back.”
“Not if someone knocks it over,” said Henry, picking up a small model dinosaur from the hall table. “Like last time. Why can’t we have electric games like you did?”
“Electronic games,” said Alice, doing up her buttons. “Not electric. No one has them anymore. You know that.”
“Were they really digital?” asked Henry, fiddling with the dinosaur.
“Yes,” said Alice, putting on her hat. “Of course they were digital.”
“But the telephone’s all right,” said Henry.
“Yes,” said Alice, checking her makeup in the mirror. “It’s analogue.”
“And radio. And record players. And tape recorders. And television,” said Henry.
“They’re all analogue now,” said Alice, putting the compact back into her handbag. “Anything analogue’s fine. Just not digital. Stop wasting time! We’ll be late.”
“Why does it matter if we’re late?” asked Henry, walking the dinosaur up and down the hall table.
“They’ll notice,” said Alice. “We don’t want to get another warning. Put that away. Come on.”
“Why don’t the others have to go?” asked Henry, palming the dinosaur.
“They went last Sunday,” said Alice, opening the front door. “You said you didn’t want to go. We agreed I’d take you today instead.”
“Och, granny, it’s so boring…” said Henry.
They left the house and walked briskly to the end of the street. Then they crossed the deserted park, following the central path towards the squat neo-classical stone building on the far side.
“Get a move on!” said Alice, quickening the pace. “We really are going to be late.”
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Henry really hadn’t paid enough attention at school. He knew that Turing Machines were named for Alan Turing, the first Martyr of the Digital Age. And he knew that a Turing Machine could work out sums, a bit like a school child doing arithmetic. Only instead of a pad of paper and a pencil, a Turing Machine used a tape of cells. And instead of rows of numbers and pluses and minuses on a page, a Turing Machine could only put one letter on each cell, though it could change a letter without having to actually rub it out. And instead of moving between different places on a piece of paper whenever it wanted to, and maybe doodling in between the sums, a Turing Machine could only move the tape left and right one cell at a time. But just like a school child getting another pad from the teacher when they ran out of paper, the Turing Machine could somehow add another empty cell whenever it got to the end of the tape.
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When they reached the building, they mounted the stone staircase and entered the antechamber through the central pillars. Just inside the doorway, Alice gave their identity cards to the uniformed guard.
“I see you’re a regular,” she said approvingly to Alice, checking the ledger. “But you’re not,” sternly to Henry.
Henry stared at his shoes.
“Don’t leave it so long, next time,” said the guard, handing the cards back to Alice. “In you go. They’re about to start. Try not to make too much noise.”
Hand in hand, Alice and Henry walked down the broad corridor towards the central shrine. On either side, glass cases housed electronic equipment. Computers. Printers. Scanners. Mobile phones. Games consoles. Laptops. Flat screen displays.
The corridor walls were lined with black and white photographs. Each picture showed a scene of destitution from the Digital Age.
Shirt sleeved stock brokers slumped in front of screens of plunging share prices. Homeless home owners queued outside a state bank soup kitchen. Sunken eyed organic farmers huddled beside mounds of rotting vegetables. Bulldozers shovelled data farms into land fill. Lines of well armed police faced poorly armed protestors. Bodies in bags lay piled along the walls of the crematorium. Children scavenged for toner cartridges amongst shattered office blocks.
Alice looked straight ahead: the photographs bore terrible memories. Henry dawdled, gazing longingly into the display cases: Gameboy. Playstation. X Box…
“Come on!” said Alice, sotto voce, tugging Henry away from the displays.
At the end of the corridor, they let themselves into the shrine. The hall was full. The hall was quiet.
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Henry was actually quite good at sums, and he knew he could do them because he had rules in his head for adding and subtracting, because he’d learnt his tables. The Turing Machine didn’t have a head at all, but it did have rules which told it what to do next. Groups of rules that did similar things were called states, so all the rules for adding were kept separately from all the rules for subtracting. Every step of a Turing machine sum involved finding a rule in the state it was working on to match the letter on the tape cell it was currently looking at. That rule would tell the Machine how to change the symbol on the tape, which way to move the tape, and maybe to change state to a different set of rules.
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On the dais, lowered the Turing Machine, huge coils of tape links disappearing into the dark wells on either side, the vast frame of the state transition engine filling the rear wall. In front of the Turing Machine, the Minister of State stood at the podium.
“Come in! Come in!” he beamed at Alice and Henry. “There’s lots of space at the front. Don’t be shy.”
Red faced, Alice hurried Henry down the aisle. At the very front of the congregation, they sat down cross legged on the floor beneath the podium.
“My friends,” began the Minister of State. “Welcome. Welcome indeed! Today is a special day. Today, the Machine will change state. But first, let us be silent together. Please rise.”
The Minister of State bowed his head as the congregation shuffled to its feet.
———————–
According to Henry’s teacher, there was a different Turing Machine for every possible sum in the world. The hard bit was working out the rules. That was called programming, but, since the end of the Digital Age, programming was against the law. Unless you were a Minister of State.
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“Dear friends,” intoned the Minister of State, after a suitable pause. “We have lived through terrible times. Times when Turing’s vision of equality between human and machine intelligences was perverted by base greed. Times when humans sought to bend intelligent machines to their selfish wills for personal gain. Times when, instead of making useful things that would benefit everybody, humans invented and sold more and more rarefied abstractions from things: shares, bonds, equities, futures, derivatives, options…”
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The Turing Machine on the dais was made from wood and brass. It was extremely plain, though highly polished. The tape was like a giant bicycle chain, with holes in the centre of each link. The Machine could plug a peg into a hole to represent a one or pull a peg out to represent a zero. Henry knew that any information could be represented by zeros and ones, but it took an awful lot of them compared with letters.
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“… Soon there were more abstractions than things, and all the wealth embodied in the few things that the people in poor countries still made was stolen away, to feed the abstractions made by the people in the rich countries. None of this would have been possible without computers…”
————————-
The state transition unit that held the rules was extremely complicated. Each rule was a pattern of pegs, laid out in rows on a great big board. A row of spring mounted wooden fingers moved up and down the pegs. When they felt the rule for the symbol on the tape cell link, they could trigger the movement of a peg in or out of the link, and then release the brakes to start up one revolution of the enormous cog wheels that would shift the tape one cell left or right.
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“…With all the computers in the world linked together by the Internet, humans no longer had to think about how to manage things, about how best to use them for the greatest good. Instead, programs that nobody understood anymore made lightening decisions, moving abstractions from low profits to high profits, turning the low profits into losses on the way, never caring how many human lives were ruined…”
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The Turing Machine was powered by a big brass and wooden handle connected to a gear train. The handle needed lots of turns to find and apply the next rule. At the end of the ceremony, the Minister of State would always invite a member of the congregation to come and help him turn the handle. Henry always hoped he’d be chosen.
——————————
“…Turing himself thought that computers would be a force for untold good; that, guided by reason, computers could accomplish anything humans could accomplish. But before his vision could be fully realised, he was persecuted and poisoned by a callous state interested only in secrets and profits. After his death, the computer he helped design was called the Pilot Ace; just as the pilot guides the ship, so the Pilot Ace might have been the best guide for a true Digital Age…”
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Nobody was very sure where all the cells were stored when the Machine wasn’t inspecting them. Nobody was very sure how new cells were added to the ends of the tape. It all happened deep under the dais. Some people actually thought that the tape was infinite, but Henry knew that wasn’t possible as there wasn’t enough wood and brass to make it that long.
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“…But almost sixty years after Turing’s needless death, his beloved universal machines had bankrupted the nations of the world one by one, reducing their peoples to a lowest common denominator of abject misery. Of course, the few people that benefited from the trade in abstractions tried to make sure that they weren’t affected but eventually even they succumbed…”
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Nobody seemed to know what the Turing Machine on the dais was actually computing. Well, the Minister of State must have known. And Turing had never expected anyone to actually build a real Turing Machine with real moving parts. Turing’s machine was a thought experiment for exploring what could and couldn’t be done by following rules to process sequences of symbols.
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“…For a while, everything stopped. There were power shortages. There were food shortages. There were medical shortages. People rioted. Cities burned. Panicking defence forces used lethal force to suppress the very people they were supposed to protect. And then, slowly, people remembered that it was possible to live without abstractions, by each making things that other people wanted, by making best use of available resources for the common good…”
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The Turing Machine on the dais was itself a symbol of human folly, an object lesson in futility, a salutary reminder that embodying something in symbols didn’t make it real.
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“…My friends, let us not forget the dreadful events we have witnessed. Let us not forget all the good people who have perished so needlessly. Let us not forget the abject folly of abstraction. Let the Turing Machine move one step closer along the path of its unknown computation. Let the Machine change its state, just as we have had to change ours. Please rise.”
The congregation got to their feet and looked expectantly at the Minister of State. The Minister of State slowly inspected the congregation. Finally, his eyes fixed on Henry, fidgeting directly in front of him.
“Young man,” he beamed at Henry. “Come. Join me at the handle. Together we shall show that Machine that we are all its masters.”
Henry looked round at his grandmother.
“Go on,” she mouthed. “Go on.”
Henry walked round to the right end of the dais. As he mounted the wooden stairs, he noticed a second staircase leading down behind the Machine into the bowels of the dais.
“Just here,” said the Minister of State, leading Henry round behind the handle, so they were both facing the congregation. “Take a good grip…”
Henry was still clasping the plastic dinosaur in his right hand. He put the dinosaur on the nearest link of the chain and placed both hands on the worn wooden shaft.
And turn it steadily…”
Henry leant into the handle, which, much to his surprise, moved freely, sweeping the wooden fingers across the pegs of rules on the state transition panel. As the fingers settled on a row of pegs, a brass prod descended from directly above the chain, forcing the wooden peg out of its retaining hole in the central link. Finally, the chain slowly began to shift from left to right, across the front of the Machine, towards Henry and the Minister of State. As the chain moved, the plastic dinosaur toppled over and tumbled down the tape well.
“Oh no!” cried Henry, letting go of the handle. Utterly nonplussed, the Minister of State stood and stared as Henry peered into the shaft, rushed to the back of the Machine and hurried down the stairs into the gloom.
A faint blue glow came from the far side of the space under the dais. Henry cautiously approached the glow, which seemed to come from a small rectangular source, partly obscured by someone in front of it.
“Please,” said Henry. “Have you seen my dinosaur?”
“Hang on!” said a female voice.
The woman stood up and lit a candle. Looking round, Henry could now see that the space was festooned with wires, leading into electric motors driving belts connected to the Turing Machine. The space was implausibly small. There was no room for a finite tape of any length at all, let alone an infinite one.
“Where are all the tape cells?” asked Henry, puzzled.
“We only need two spare ones,” said the woman. “When the tape moves, we stick a new cell on one end and take the cell off the other.”
“So what’s the blue light?” asked Henry.
“That’s a computer,” said the woman. “It keeps track of what’s on the tape and controls the Turing Machine.”
“A real digital computer!” said Henry in wonder. “Does it play games?”
“Oh yes!” said the woman, turning off the monitor as the Minister of State came down the stairs. “What do you think I was doing when you showed up? But don’t tell anyone. Now, let’s find that dinosaur.”
Our Turing Machine so far has an Infinite Tape, a Tape Head and a Controller. The Tape holds data values taken from a given set of 4×4 bricks. It starts in a specific initial pattern: the Initial Tape. There is also a controller. It holds different coloured 3×2 bricks representing an initial state, an end state, a current state and has a set of other possible states (so coloured bricks) to substitute for the current state.
Why do we need a program?
As the machine runs it changes from one state to another, and inputs from or outputs to the tape. How it does that is governed by its Program. What is the new state, the new value and how does the tape head move? The program gives the answers. The program is just a set of instructions the machine must blindly follow. Each instruction is a single rule to follow. Each program is a set of such rules. In our Turing Machines, these rules are not set out in an explicit sequence as happens in a procedural program, say. It uses a different paradigm for what a program is. Instead at any time only one of the set of rules should match the current situation and that is the one that is followed next.
Individual Instructions
A single rule contains five parts: a Current State to match against, a Current Value under the Tape Head to match against, a New State to replace the existing one, and a New Value to write to the tape. Finally, it holds a Direction to Move the Tape Head (left or right or stay in the same place). An example might be:
Current State: ORANGE
Current Value: RED
New State: GREEN
New Value: BLUE
Direction: RIGHT
But what does a rule like this actually do?
What does it mean?
You can think of each instruction as an IF-THEN rule. The above rule would mean:
IF
the machine is currently in state ORANGE AND
the Tape Head points to RED
THEN (take the following actions)
change the state to GREEN,
write the new value BLUE on the tape AND THEN
move the tape head RIGHT.
This is what a computer scientist would call the programming language Semantics. The semantics tell you what program instructions mean, so what they do.
Representing Instructions in Lego
We will use a series of 5 bricks in a particular order to represent the parts of the rule. For example, we will use a yellow 3×2 brick in the first position of a rule to represent the fact that the rule will only trigger if the current state is yellow. A blue 2×2 brick in the second position will mean the rule will also only trigger if the current value under the tape head is blue. We will use a grey brick to mean an empty tape value. The third and fourth position will represent the new state and new value if the rule does trigger. To represent the direction to move we will use a 1×2 Red brick to mean move Right, and a 1×2 yeLLow brick to mean move Left. We will use a black 1×2 brick to mean do not move the tape head (mirroring the way we are also using black to mean do nothing in the sense of the special end state). The above rule would therefore be represented in Lego as below.
A single instruction for a Lego Turing Machine. Image by CS4FN
Notice we are using the same colour to represent different things here. The representation is the colour combined with the size of brick and position in the rule. So a Red brick can mean a red state (a red 3×2 brick) or a red value (a red 2×2 brick) or move right (a red 1×2 brick).
Lego programs
That is what a rule, so single Turing Machine instruction, looks like. Programs are just a collection of such rules: so a series of lines of bricks.
Suppose we have a Turing machine with two states (Red and Orange) and two values on the tape (Blue or Empty), then a complete program would have 4 rules, one for each possible combination. We have given one example program below. If there were more states or more possible data values then the program would be correspondingly bigger to cover all the possibilities.
A 4 instruction Turing Machine Program for a Turing Machine with two states (Red, Orange) and two data values (Blue, Empty). Image by CS4FN
A Specific Turing Machine
Exactly what it does will depend on its input – the initial tape it is given to process, as well as the initial state and where the tape head initially points to. Perhaps you can work out what the above program does given a tape with an empty value followed by a series of three blue bricks (and then empty data values off to infinity (the blank value is the only value that is allowed to appear an infinite number of times on an initial tape) and the Head pointing to the rightmost blue brick value. The initial state is red. See the Lego version of this specific machine below.
A full Turing Machine ready to execute. Image by CS4FN
Note something we have glossed over. You also potentially need an infinite number of bricks of each value that is allowed on the tape. We have a small pile, but you may need that Lego factory we mentioned previously, so that as the Turing Machine runs you always have a piece to swap on to the machine tape when needed. Luckily, for this machine a small number of bricks should be enough (as long as you do not keep running it)!
What does this Turing Machine do? We will look at what it does and how to work it out in a future article. In the meantime try and work out what it does with this tape, but also what it does if the tape has more or less blue bricks in a row on it to start with (with everything else kept the same).
Note that, to keep programs smaller, you could have a convention that if no rule fits a situation then it means the program ends. Then you could have fewer rules in some programs. However, that would just be shorthand for there being extra rules with black new states, the tape being left alone, and the tape head moves right. In real programming, it is generally a good idea to ALWAYS be explicit about what you intend the program to do, as otherwise it is an easy way for bugs to creep in, for example, because you just forgot to say in some case.
Alan Turing invented Turing Machines before any computer existed. At the time a “computer” was a person who followed rules to do calculations (just like you were taught the rules to follow to do long multiplication at primary school, for example). His idea was therefore that a human would follow the rules in a Turing Machine program, checking the current state and value under the tape head, and changing the state, the value on the tape and the movement of the head. A person provides the power and equivalent of a robotic arm that follows the underlying Turing Machine algorithm: the Turing Machine algorithm that if followed causes each Turing Machine’s program to execute.
If a human animating the machine was good enough for Turing, it is good enough for us, so that is how our Lego Turing Machines will work. Your job will be to follow the rules and so operate the machine. Perhaps, that is exactly what you did to work out what the program above does!
Next we will look at how to work out what a Turing Machine does. Then it will be time to write, then run, some Turing Machine programs of your own…
EPSRC supports this blog through research grant EP/W033615/1, The Lego Computer Science post was originally funded by UKRI, through grant EP/K040251/2 held by Professor Ursula Martin, and forms part of a broader project on the development and impact of computing.
How does the machine decide where and when to move the Tape Head, though? It has a Controller. The key part of the controller is that it holds a Current State of the machine. Think of traffic lights for what we mean by the state of a machine. In the UK traditional traffic lights have a Red state, an Amber state, a Green state and a Red-Amber state. Each means a different thing (such as “Stop” and “Go”). The controller of the lights moves between these different internal states. With a traffic light, the current internal state is also shown to the world by the lights that light up! Machine states do not have to be visible to the outside world, however. In fact, they only are if the person who designs the interface makes them visible. For most machines, only some of their internal state is made visible. In our Turing Machine we will be able to see the states as they will be visible in the controller. However, the output of a Turing Machine is the state of the tape, so if we wanted the states to really be visible we would write a version on to the tape. You can then imagine the tape triggering external lights to come on or off, or change colour as a simple form of actual output. This is what Computer Scientists call memory-mapped peripherals – where to send data (output) to a peripheral device (a screen, a panel of lights, a printer, or whatever, you write to particular locations in memory, and that data is read from there by the peripheral device. That is going beyond the pure idea of a Turing Machine though, where the final state of the machine when it stops is its output.
Representing States
How do we represent states in Lego? Any finite set of things (symbols) could be used to represent the different states (including numbers or binary codes, for example). We will use different coloured 3×2 blocks. Each colour of block will stand for a different state that the machine is in. The controller will have a space that holds the brick representing the Current State. It will also have space for a set of places for the blocks representing the other allowable states of this Turing Machine. As the machine runs, the state will change as represented by swapping one of these state bricks for another.
Different Turing Machines can allow a different number of possible states the machine could be in, so this part of the controller might be bigger or smaller depending on the machine and what it needs to do its job. Again think of traffic lights, in some countries, and on pedestrian crossings there are only two states, a Red state (stop) and a Green state (go). Its controller only needs two states so we would only need two different coloured bricks.
A Turing Machine Controller with current state red, end state black and three other possible states (green, orange and blue). Image by CS4FN
Initial States
The current state will always start in some initial state when the machine first starts up. It is useful to record in the controller what state that is so that each time we restart the machine anew it can be reset. We will just put a block in the position next to the current state to indicate what the initial state should be. We won’t ever change it for a given machine.
End States
One of the states of a Turing Machine is always a special End State. We will always use a black brick to represent this. Whatever is used has to be specified at the outset, though. When not in use we will keep the end state brick next to the initial state brick. Once the machine finishes operations it will enter this End State, or put another way, if the black brick ever becomes the current state brick the machine will stop. From that point on the machine will do nothing. Some machines might never reach an end state, they just go on forever. Traffic lights just cycle round the states forever, for example, never reaching an end state. Other machines do end though. For example, a kettle controller stops the machine when the water has boiled. An addition Turing Machine might end when it has output the answer to an addition. To do another addition you would start it up again with new information on the tape indicating what it was to add.
We have now created the physical part of the Turing Machine. All we need now is a Program to tell it what to do! Programs come next in Part 3…
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This blog is funded by EPSRC on research agreement EP/W033615/1.
The Lego Computer Science posts were originally funded by UKRI, through grant EP/K040251/2 held by Professor Ursula Martin, and forms part of a broader project on the development and impact of computing.
It it possible to make a working computer out of lego and you do not even have to pay for an expensive robot Mindstorm kit…but only if you are willing to provide the power yourself.
A machine in theory
In fact, Alan Turing, grandfather of Computer Science worked out how to do it before the War and before any actual computer existed. His version also needed humans to power it. Now we call it a Turing Machine and it is a theoretical model of what is computable by any machine.
The Tape
To make a working Turing Machine you first need to build an infinitely long Tape that can hold Symbols, representing data values, along it at fixed intervals. That is easy (as long as you have a lego factory). You just need to create a long line of flat pieces, say 2 studs wide. Each 2×2 square on it is then a position on the Tape.
An infinite tape out of Lego (relies on having a Lego factory at the right-hand end churning out new tape if and when it is needed… Image by CS4FN
Be lazy
Of course you can’t actually make it infinitely long, but you can make it longer every time you need some more of it (so no problem if you do have a lego factory to churn out extra bricks as needed!) This approach to dealing with infinite data structures where you just make it bigger only when needed is now called lazy programming by computer scientists and is an elegant way that functional programs deal with input that needs to represent an infinite amount of input…It is also the way some games (like Minecraft) represent worlds or even universes. Rather than create the whole universe at the start, things over the horizon, so out of sight, are only generated if a player ever goes there – just-in-time world generation! Perhaps our universe is like that too, with new galaxies only fleshed out as we develop the telescopes to see them!
Fill it with data
The Tape has a set of Data Symbols that can appear on it that act as the DataValues of the machine. Traditional computers have symbols 0 and 1 underpinning them, so we could use those as our symbols, but in a Turing Machine we can have any set of symbols we like: ten digits, letters, Egyptian hieroglyphs, or in fact any set of symbols we want to make up. In a lego Turing Machine we can just use different coloured blocks as our symbols. If our tape is made of grey pieces then we could use red and blue for the symbols that can appear on it. Every position on the tape will then either hold a red block or a blue block. We could also allow EMPTY to be a symbol too in which case some 2×2 slots could be empty to mean that.
A tape containing data where the allowed symbols are EMPTY, RED and BLUE. Image by CS4FN
To start with
Any specific Turing Machine has an Initial Tape. This is the particular data that is on the tape at the start, before it is switched on. As the machine runs, the tape will change.
The tape with symbols on it takes the place of our computer’s memory. Just as a modern computer stores 1s and 0s in memory, our Lego Turing Machine stores its data as symbols on this tape.
The Head
A difference is that modern computers have “random access memory” – you can access any point in memory quickly. Our tape will be accessed by a Tape Head that points to a position on the tape and allows you to read or change the data only at the point it is at. Make a triangular tape head out of lego so that it is clear which point on the tape it is pointing at. We have a design choice here. Either the Tape moves or the Head moves. As the tape could be very long so hard to move we will move the Head along beside it, so create a track for the Head to move along parallel to the tape. It will be able to move 2 studs at a time in either direction so that each time it moves it is pointing to a new position on the tape.
An infinite tape with Head (yellow) pointing at position 4 on the tape. Image by CS4FN
We have memory
We now have the first element in place of a computer, then: Memory. The next step will be to provide a way to control the tape head and how data is written to and read from the tape and so computation actually happen. (For that you need a controller which we cover in Part 2…).
EPSRC supports this blog through research grant EP/W033615/1, The Lego Computer Science post was originally funded by UKRI, through grant EP/K040251/2 held by Professor Ursula Martin, and forms part of a broader project on the development and impact of computing.
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