Understanding Ultron: A Turing test for world domination – Peter McOwan’s reassuring article that robots probably aren’t out to get us ^JB

by Peter McOwan, Queen Mary University of London (written in 2015)

‘Robot Mech Machine’ Image by Computerizer from Pixabay

Avengers: Age of Ultron is the latest film about robots or artificial intelligences (AI) trying to take over the world. AI is becoming ever present in our lives, at least in the form of software tools that demonstrate elements of human-like intelligence. AI in our mobile phones apply and adapt their rules to learn to serve us better, for example. But fears of AI’s potential negative impact on humanity remain as seen in its projection into characters like Ultron, a super-intelligence accidentally created by the Avengers.

But what relation do the evil AIs of the movies have to scientific reality? Could an AI take over the world? How would it do it? And why would it want to? AI movie villains need to consider the whodunit staples of motive and opportunity.

 

Motive? What motive?

Let’s look at the motive. Few would say Intelligence in itself unswervingly leads to a desire to rule the world. In movies AI are often driven by self preservation, a realisation that fearful humans might shut them down. But would we give our AI tools cause to feel threatened? They provide benefits for us and there also seems little reason in creating a sense of self-awareness in a system that searches the web for the nearest Italian restaurant, for example.

Another popular motive for AIs’ evilness is their zealous application of logic. In Ultron’s case the goal of protecting the earth can only be accomplished by wiping out humanity. This destruction by logic is reminiscent of the notion that a computer would select a stopped clock over one that is two seconds slow, as the stopped clock is right twice a day whereas the slow one is never right. Ultron’s plot motivation, based on brittle logic combined with indifference to life, seems at odds with todays AI systems that reason mathematically with uncertainty and are built to work safely with users.

 

Opportunity Knocks

When we consider an AI’s opportunity to rule the world we are on somewhat firmer ground. The famous Turning Test of machine intelligence was set up to measure a particular skill – the ability to conduct a believable conversation. The premise being that if you can’t tell the difference between AI and human skill, the AI has passed the test and should be considered as intelligent as humans.

So what would a Turing Test for the ‘skill’ of world domination look like? To explore that we need to compare the antisocial AI behaviours with the attributes expected of human world domination. World dominators need to control important parts of our lives, say our access to money or our ability to buy a house. AI does that already – lending decisions are frequently made by an AI sifting through mountains of information to decide your credit worthiness. AIs now trade on the stock market too.

An overlord would give orders and expect them to be followed. Anyone who has stood helplessly at a shop’s self-service till as it makes repeated bagging related demands of them already knows what it feels like to be bossed about by AIs.

 

Kill Bill?

Finally, no megalomaniac Hollywood robot would be complete without at least some desire to kill us. Today military robots can identify targets without human intervention. It is currently a human controller that gives permission to attack but it’s not a stretch to say that the potential to auto kill exists in these AIs, but we would need to change the computer code to allow it.

These examples arguably show AI in control in limited but significant parts of life on earth, but to truly dominate the world, movie style, these individual AIs would need to start working together to create a synchronised AI army – that bossy self-service till talking to your health monitor and denying selling you beer, then both ganging up with a credit scoring system to only raise your credit limit if you both buy a pair of trainers with a built in GPS tracker and only eat the kale from your smart fridge but after the shoe data shows you completed the required five mile run.

It’s a worrying picture but fortunately I think it’s an unlikely one. Engineers worldwide are developing the Internet of things, networks connecting all manner of devices together to create new services. These are pieces of a jigsaw that would need to join together and form a big picture for total world domination. It’s an unlikely situation – too much has too fall into place and work together. It’s a lot like the infamous plot-hole in Independence Day – where an Apple Mac and an alien spaceship’s software inexplicably have cross-platform compatibility. [See video below for a possible answer!]

Our earthly AI systems are written in a range of computer languages, hold different data in different ways and use different and non-compatible rule sets and learning techniques. Unless we design them to be compatible there is no reason why adding two safely designed AI systems, developed by separate companies for separate services would spontaneously blend to share capabilities and form some greater common goal without human intervention.

So could AIs, and the robot bodies containing them, pass the test and take over the world? Only if we humans let them, and help them a lot. Why would we?

Perhaps because humans are the stupid ones!

 

Peter McOwan introducing Age of Ultron

You can see the author of this article giving a talk at the Genesis Cinema in Stepney Green in 2015 to introduce the film.

Background

This post was first published on CS4FN and a copy can also be found on page 8-9 in ‘Serious Fun’ – Issue 26 of CS4FN magazine, which celebrated the life of Peter McOwan, who died in 2019. Peter was the co-founder (with Paul Curzon) of the CS4FN magazine and website.

All of our material is free to download from: https://cs4fndownloads.wordpress.com

 

Further reading

April Fooling with computing – IP over avian carriers, PigeonRank ^JB

Happy April Fool’s Day everyone, here are a couple of examples of programmers having a little fun.

Winged messengers

In 1990 a joke memo was published for April Fool’s Day which suggested the use of homing pigeons as a form of internet, in which the birds might carry small packets of data. The memo, called ‘IP over Avian Carriers’ (that is, a bird-based internet), was written in a mock-serious tone (you can read it here) but although it was written for fun the idea has actually been used in real life too. Photographers in remote areas with minimal internet signal have used homing pigeons to send their pictures back.

The beautiful (and quite possibly wi-fi ready, with those antennas) Victoria Crowned Pigeon. Not a carrier pigeon admittedly, but much more photogenic. Image by Foto-Rabe from Pixabay

A company in the US which offers adventure holidays including rafting used homing pigeons to return rolls of films (before digital film took over) back to the company’s base. The guides and their guests would take loads of photos while having fun rafting on the river and the birds would speed the photos back to the base, where they could be developed, so that when the adventurous guests arrived later their photos were ready for them.

Further reading

Pigeons keep quirky Poudre River rafting tradition afloat (17 July 2017) Coloradoan.

You might also enjoy this attempt to make broadband work over wet string instead of the more usual wires. They actually managed it! Broadband over ‘wet string’ tested for fun (13 December 2017)

 

Serious fun with pigeons

On April Fool’s Day in 2002 Google ‘admitted’ to its users that the reason their web search results appeared so quickly and were so accurate was because, rather than using automated processes to grab the best result, Google was actually using a bank of pigeons to select the best results. Millions of pigeons viewing web pages and pecking picking the best one for you when you type in your search question. Pretty unlikely, right?

In a rather surprising non-April Fool twist some researchers decided to test out how well pigeons can distinguish different types of information in hospital photographs. They trained pigeons by getting them to view medical pictures of tissue samples taken from healthy people as well as pictures taken from people who were ill. The pigeons had to peck one of two coloured buttons and in doing so learned which pictures were of healthy tissue and which were diseased. If they pecked the correct button they got an extra food reward.

Pigeon, possibly pondering people’s photographs. Image by Davgood Kirshot from Pixabay

The researchers then tested the pigeons with a fresh set of pictures, to see if they could apply their learning to pictures they’d not seen before. Incredibly the pigeons were pretty good at separating the pictures into healthy and unhealthy, with an 80 per cent hit rate.

Further reading

Principle behind Google’s April Fools’ pigeon prank proves more than a joke (27 March 2019) The Conversation.

 

A version of this article was originally published on this blog as part of the CS4FN Christmas Advent Calendar, on 7 December 2021.

A Wookie for three minutes please – how Foley artists can manipulate natural and synthesised sounds for film, TV and radio

by Jane Waite and Paul Curzon, Queen Mary University of London.
This story was originally published on CS4FN and in an issue of the magazine (see below).

Theatre producers, radio directors and film-makers have been trying to create realistic versions of natural sounds for years. Special effects teams break frozen celery stalks to mimic breaking bones, smack coconut shells on hard packed sand to hear horses gallop, rustle cellophane for crackling fire. Famously, in the first Star Wars movie the Wookie sounds are each made up of up to six animal clips combined, including a walrus! Sometimes the special effect people even record the real thing and play it at the right time! (Not a good idea for the breaking bones though!) The person using props to create sounds for radio and film is called a Foley artist, named after the work of Jack Donovan Foley in the 1920’s. Now the Foley artist is drawing on digital technology to get the job done.

Black and white photo of a walrus being offered a fish, with one already in its mouth
“Are you sure that’s a microphone?” Walrus photo by Kabomani-Tapir from Pixabay

Designing sounds

Sound designers have a hard job finding the right sounds. So how about creating sound automatically using algorithms? Synthetic sound! Research into sound creation is a hot topic, not just for special effects but also to help understand how people hear and for use in many other sound based systems. We can create simple sounds fairly easily using musical instruments and synthesisers, but creating sounds from nature, animal sounds and speech is much more complicated.

The approaches used to recognize sounds can be the basis of generating sounds too. You can either try and hand craft a set of rules that describe what makes the sound sound the way it does, or you can write algorithms that work it out for themselves.

Paying patterns attention

One method, developed as a way to automatically generate synthetic sound, is based on looking for patterns in the sounds. Computer scientists often create mathematical models to better understand things, as well as to recognize and generate computer versions of them. The idea is to look at (or here listen to) lots of examples of the thing being studied. As patterns become obvious they also start to identify elements that don’t have much impact. Those features are ignored so the focus stays on the most important parts. In doing this they build up a general model, or view, that describes all possible examples. This skill of ignoring unimportant detail is called abstraction, and if you create a general view, a model of something, this is called generalisation: both important parts of computational thinking. The result is a hand-crafted model for generating that sound.

That’s pretty difficult to do though, so instead computer scientists write algorithms to do it for them. Now, rather than a person trying to work out what is, or is not important, training algorithms work it out using statistical rules. The more data they see, the stronger the pattern that emerges, which is why these approaches are often referred to as ‘Big Data’. They rely on number crunching vast data sets. The learnt pattern is then matched against new data, looking for examples, or as the basis of creating new examples that match the pattern.

The rain in train(ing)

Number crunching based on Big Data isn’t the only way though, sometimes general patterns can be identified from knowledge of the thing being investigated. For example, rain isn’t one sound but is made up of lots of rain drops all doing a similar thing. Natural sounds often have that kind of property. So knowledge of a phenomenon can be used to create a basic model to build a generator around. This is an approach Richard Turner, now at Cambridge University, has pioneered, analysing the statistical properties of natural sounds. By creating a basic model and then gradually tweaking it to match the sound-quality of lots of different natural sounds, his algorithms can learn what natural sounds are like in general. Then, given a specific natural ‘training’ sound, it can generate synthetic versions of that sound by choosing settings that match its features. You could give it a recorded sample of real rain, for example. Then his sound processing algorithms apply a bunch of maths that pull out the important features of that particular sound based on the statistical models. With the critical features identified, and plugged in to his general model, a new sound of any length can then be generated that still matches the statistical pattern of, and so sounds like, the original. Using the model you can create lots of different versions of rain, that all still sound like rain, lots of different campfires, lots of different streams, and so-on.

For now, the celery stalks are still in use, as are the walrus clippings, but it may not be long before film studios completely replace their Foley bag of tricks with computerised solutions like Richard’s. One wookie for 3 minutes and a dawn chorus for 5 please.

 


Become a Foley Artist with Sonic Pi

You can have a go at being a Foley artist yourself. Sonic Pi is a free live-coding synth for music creation that is both powerful enough for professional musicians, but intended to get beginners into live coding: combining programming with composing to make live music.

It was designed for use with a Raspberry Pi computer, which is a cheap way to get started, though works with other computers too. Its also a great, fun way to start to learn to program.

Play with anything, and everything, you find around the house, junk or otherwise. See what sounds it makes. Record it, and then see what it makes you think of out of context. Build up your own library of sounds, labelling them with things they sound like. Take clips of films, mute the sound and create your own soundscape for them. Store the sound clips and then manipulate them in Sonic Pi, and see if you can use them as the basis of different sounds.

Listen to the example sound clips made with Sonic Pi on their website, then start adapting them to create your own sounds, your own music. What is the most ‘natural sound’ you can find or create using Sonic Pi?

 


 

This article was also originally published in issue 21 of the CS4FN magazine ‘Computing Sounds Wild’ on p16. You can download a PDF copy of Issue 21, as well as all of our previous published material, free, at the CS4FN downloads site.

Computing Sounds Wild explores the work of scientists and engineers who are using computers to understand, identify and recreate wild sounds, especially those of birds. We see how sophisticated algorithms that allow machines to learn, can help recognize birds even when they can’t be seen, so helping conservation efforts. We see how computer models help biologists understand animal behaviour, and we look at how electronic and computer generated sounds, having changed music, are now set to change the soundscapes of films. Making electronic sounds is also a great, fun way to become a computer scientist and learn to program.

Front cover of CS4FN Issue 21 – Computing sounds wild

 

 

The cure that just folds away: understanding protein folding to tackle diseases, and how computers (and people) can help ^JB

by Paul Curzon, Queen Mary University of London.
This article was originally published on CS4FN.

Biologists want you to play games in the name of science. A group of researchers at the University of Washington have invented a computer game, Foldit, in which you have to pack what looks like a 3D nest of noodles and elastics into the smallest possible space. You drag, turn and squeeze the noodles until they’re packed in tight. You compete against others, and as you get better you can rise through the ranks of competitors around the world. How can that help science? It’s because the big 3D jumbles represent models of proteins, and figuring out how proteins fold themselves up is one of the biggest problems in biology. Knowing more about how they do it could help researchers design cures for some of the world’s deadliest diseases.

The perfect fit

Proteins are in every cell in your body. They help you digest your food, send signals through your brain, and fight infection. They’re made of small molecules called amino acids. It’s easy for scientists to figure out what amino acids go together to make up a protein, but it’s incredibly difficult to figure out the shape they make when they do it. That’s a shame, because the shape of a protein is what makes it able to do its job. Proteins act by binding on to other molecules – for example, a protein called haemoglobin carries oxygen around our blood. The shape of the haemoglobin molecule has to fit the shape of the oxygen molecule like a lock and key. The close tie between form and function means that if you could figure out the shape that a particular protein folds into, you would know a lot about the jobs it can do.

Completely complex

Tantrix rotation puzzle

Protein folding is part of a group of problems that are an old nemesis of computer scientists. It’s what’s known as an NP-complete problem. That’s a mathematical term that means it appears there’s no shortcut to calculating the answer to a problem. You just have to try every different possible answer before you arrive at the right one. There are other problems like this, like the Tantrix rotation puzzle. Because a computer would have to check through every possible answer, the more complex the problem is the longer it will take. Protein folding is particularly complex – an average-sized protein contains about 100 amino acids, which means it would take a computer a billion billion billion years to figure out. So a shortcut would be nice then.

Puzzling out a cure

Obviously the proteins themselves have found a shortcut. They fold up all the time without having to have computers figure it out for them. In order to get to the bottom of how they do it, though, scientists are hoping that human beings might provide a shortcut. Humans love puzzles, and we’re awfully good at visual ones. Our good visual sense means we see patterns everywhere, and we can easily develop a ‘feel’ for how to use those patterns to solve problems. We use that sense when we play games like chess or Go. The scientists behind Foldit reckon that if it turns out that humans really are more efficient at solving protein folding problems, we can teach some of our tricks to computers.

HIV-1 proteasean illustration showing the folded shape of a protein used by HIV, created by ‘Boghog’ in 2008, via Wikipedia.

If there were an efficient way to work out protein structure, it could be a huge boon to medicine. Diseases depend on proteins too, and lots of drugs work by targeting the business end of those proteins. HIV uses two proteins to infect people and replicate itself, so drugs disrupt the workings of those proteins. Cancer, on the other hand, damages helpful proteins. If scientists understood how proteins fold, they could design new proteins to counteract the effects of disease. So getting to the top of the tables in Foldit could hold even more glory for you than you bargained for – if your protein folding efforts help cure a dreaded disease, hey, maybe it’s the Nobel Prize you’ll end up winning.

 

Further reading

The coloured diagram of the enzyme above is a 3D representation to help people see how the protein folds. These are called ribbon diagrams and were invented by Jane S Richardson, find out more here.

Executable Biology – computing cancer using computational modelling

by Paul Curzon, Queen Mary University of London
Image by Colin Behrens from Pixabay

Can a robot get cancer? Silly question. Our bodies are made of cells. Robots aren’t. Cells are the basic building blocks of life and come in lots of different forms from long thin nerve cells that allow us to sense the world, to round blood cells that carry oxygen around our bodies. Cancer occurs when cells go rogue and start reproducing in an uncontrolled way. A computer can’t get cancer, but you can allow virtual diseases to attack virtual cells inside a computer. Doing that may just help find cures. That is what Jasmin Fisher, who leads a research group at Microsoft Research in Cambridge, has devoted her career to.

Becoming a medic isn’t the only way to help save lives!

Computational Modelling is changing the way the sciences are done. It is the idea that you can run experiments on virtual versions of things you are investigating. A computer model is essentially just a program that simulates the phenomena of interest. For example, by writing a program that simulates the laws of Physics, you can use it to run virtual Physics experiments about the motion of the planets, say. If your virtual planets do follow the paths real planets do, then you have evidence the laws are right. If they don’t your laws (or the models) need to change. You can also make predictions such as when an eclipse will happen. If you are right it suggests the laws you coded are good descriptions of reality. If wrong, back to the drawing board.

Jasmin has been pioneering this idea with the stuff of life and death. She focusses on modelling cells and the specific ways that we think cancer attacks them. It gives a way of exploring what is going on at the level of the molecules inside cells, and so how well new medicines might, or might not, work. Experiments can be done quickly and easily on the programmed models by running simulations. That means the real experiments, taking up expensive lab time, can focus on things that are most likely to be successful. Jasmin’s work has helped researchers design more effective actual experiments because they start with a better understanding of what is going on. One of the most important questions she is studying is how cells end up becoming what they are, and how this differs between normal cells and cancer cells. Understand this and we will be much closer to understanding how to stop cancer.

Further reading: Books We Loved – ‘Critical Mass’, by Philip Ball, on the physics of society and how this is about computational modelling too.

This story was originally published here and is an article from CS4FN, a free computer science magazine from Queen Mary University of London which is sent to subscribing UK schools. To find out more please visit our About page. The article was also published in issue 23, The Women Are (Still) Here, on p3.

CS4FN Advent – Day 25: Merry Christmas! Today’s post is about the ‘wood computer’

Today is the final post in our CS4FN Christmas Computing Advent Calendar – it’s been a lot of fun rummaging in the CS4FN back catalogue, and also finding out about some new things to write about.

Each day we published a blog post about computing with the theme suggested by the picture on the advent calendar’s ‘door’. Our first picture was a woolly jumper so the accompanying post was about the links between knitting and coding, the door with a picture of a ‘pair of mittens’ on led to a post about pair programming and gestural gloves, a patterned bauble to an article about printed circuit boards, and so on. It was fun coming up with ideas and links and we hope it was fun to read too.

We hope you enjoyed the series of posts (scroll to the end to see them all) and that you have a very Merry Christmas. Don’t forget that if you’re awake and reading this at the time it’s published (6.30am Christmas Day) and it’s not cloudy, you may be able to see Father Christmas passing overhead at 6.48am. He’s just behind the International Space Station…

And on to today’s post which is accompanied by a picture of a Christmas Tree, so it’ll be a fairly botanically-themed post. The suggestion for this post came from Prof Ursula Martin of Oxford University, who told us about the ‘wood computer’.

It’s a Christmas tree!

 

The Wood Computer

by Jo Brodie, QMUL.

Other than asking someone “do you know what this tree is?” as you’re out enjoying a nice walk and coming across an unfamiliar tree, the way of working out what that tree is would usually involve some sort of key, with a set of questions that help you distinguish between the different possibilities. You can see an example of the sorts of features you might want to consider in the Woodland Trust’s page on “How to identify trees“.

Tree silhouettes image by Clker-Free-Vector-Images from Pixabay

Depending on the time of year you might consider its leaves – do they have stalks or not, do they sit opposite from each other on a twig or are they diagonally placed etc. You can work your way through leaf colour, shape, number of lobes on the leaf and also answer questions about the bark and other features of your tree. Eventually you narrow things down to a handful of possibilities.

What happens if the tree is cut up into timber and your job is to check if you’re buying the right wood for your project. If you’re not a botanist the job is a little harder and you’d need to consider things like the pattern of the grain, the hardness, the colour and any scent from the tree’s oils.

Wooden bridge image by Peter H from Pixabay

Historically, one way of working out which piece of timber was in front of you was to use a ‘wood computer’ or wood identification kit. This was prepared (programmed!) from a series of index cards with various wood features printed on all the cards – there might be over 60 different features.

Every card had the same set of features on it and a hole punched next to every feature. You can see an example of a ‘blank’ card below, which has a row of regularly placed holes around the edge. This one happens to be being used as a library card rather than a wood computer (though if we consider what books are made of…).

Image of an edge-notched card (actually being used as a library card though), from Wikipedia.

I bet you can imagine inserting a thin knitting needle into any of those holes and lifting that card up – in fact that’s exactly how you’d use the wood computer. In the tweet below you can see several cards that made up the wood computer.

One card was for one tree or type of wood and the programmer would add notch the hole next to features that particularly defined that type. For example you’d notch ‘has apples’ for the apple tree card but leave it as an intact hole on the pear tree card.  If a particular type of timber had fine grained wood they’d add the notch to the hole next to “fine-grained”. The cards were known, not too surprisingly, as edge-notched cards.

You can see what one looks like here with some notches cut into it. You might have spotted how knitting needles can help you in telling different woods apart.

Holes and notches

Edge-notched card overlaid on black background, with two rows of holes. On the top a hole in the first row is notched, on the right hand side two holes are notched. Image from Wikipedia.

 

Each card would end up with a slightly different pattern of notched holes, and you’d end up with lots of cards that are slightly different from each other.

Example ‘wood computer’. At the end of your search (to find out which tree your piece of wood came from) you are left with two cards for fine-grained wood. If your sample has a strong scent then it’s likely it’s the tree in the card on the right (though you could arrive at the same conclusion by using the differences in colour too). The card at the top is the blank un-notched card.

How it works

Your wood computer is basically a stack of cards, all lined up and that knitting needle. You pick a feature that your tree or piece of wood has and put your needle through that hole, and lift. All of the cards that don’t have that feature notched will have an un-notched hole and will continue to hang from your knitting needle. All of the cards that contain wood that do have that feature have now been sorted from your pile of cards and are sitting on the table.

You can repeat the process several times to whittle (sorry!) your cards down by choosing a different feature to sort them on.

The advantage of the cards is that they are incredibly low tech, requiring no electricity or phone signal and they’re very easy to use without needing specialist botanical knowledge.

You can see a diagram of one on page 8 of the 20 page PDF “Indian Standard: Key for identification of commercial timbers”, from 1974.

Teachers: we have a classroom sorting activity that uses the same principles as the wood computer. Download our Punched Card Searching PDF from our activity page.

 

The creation of this post was 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.

 

 

Previous Advent Calendar posts

CS4FN Advent – Day 1 – Woolly jumpers, knitting and coding (1 December 2021)

 

CS4FN Advent – Day 2 – Pairs: mittens, gloves, pair programming, magic tricks (2 December 2021)

 

CS4FN Advent – Day 3 – woolly hat: warming versus cooling (3 December 2021)

 

CS4FN Advent – Day 4 – Ice skate: detecting neutrinos at the South Pole, figure-skating motion capture, Frozen and a puzzle (4 December 2021)

 

CS4FN Advent – Day 5 – snowman: analog hydraulic computers (aka water computers), digital compression, and a puzzle (5 December 2021)

 

CS4FN Advent – Day 6 – patterned bauble: tracing patterns in computing – printed circuit boards, spotting links and a puzzle for tourists (6 December 2021)

 

CS4FN Advent – Day 7 – Computing for the birds: dawn chorus, birds as data carriers and a Google April Fool (plus a puzzle!) (7 December 2021)

 

CS4FN Advent – Day 8: gifts, and wrapping – Tim Berners-Lee, black boxes and another computing puzzle (8 December 2021)

 

CS4FN Advent – Day 9: gingerbread man – computing and ‘food’ (cookies, spam!), and a puzzle (9 December 2021)

 

CS4FN Advent – Day 10: Holly, Ivy and Alexa – chatbots and the useful skill of file management. Plus win at noughts and crosses – (10 December 2021)

 

CS4FN Advent – Day 11: the proof of the pudding… mathematical proof (11 December 2021)

 

CS4FN Advent – Day 12: Computer Memory – Molecules and Memristors – (12 December 2021)

 

CS4FN Advent – Day 13: snowflakes – six-sided symmetry, hexahexaflexagons and finite state machines in computing (13 December 2021)

 

CS4FN Advent – Day 14 – Why is your internet so slow + a festive kriss-kross puzzle (14 December 2021)

 

CS4FN Advent – Day 15 – a candle: optical fibre, optical illusions (15 December 2021)

 

CS4FN Advent – Day 16: candy cane or walking aid: designing for everyone, human computer interaction (16 December 2021)

 

CS4FN Advent – Day 17: reindeer and pocket switching (17 December 2021)

 

CS4FN Advent – Day 18: cracker or hacker? Cyber security(18 December 2021)

 

CS4FN Advent – Day 19: jingle bells or warning bells? Avoiding computer scams (19 December 2021)

 

CS4FN Advent – Day 20: where’s it @? Gift tags and internet addresses (20 December 2021)

 

CS4FN Advent – Day 21: wreaths and rope memory – weave your own space age computer (21 December 2021)

 

 

CS4FN Advent – Day 22: stars and celestial navigation (22 December 2021)

 

 

CS4FN Advent – Day 23: Father Christmas – checking his list, spotting the errors (23 December 2021)

 

CS4FN Advent – Day 23: Bonus material – see “Santa’s sleigh” flying overhead (23 December 2021) – this was an extra post so that people could get ready to see “Father Christmas” passing overhead on Christmas Day at 6:48am)

 

CS4FN Advent – Day 24: Santa’s Sleigh – track its progress through the skies (24 December 2021)

 

CS4FN Advent – Day 25: Merry Christmas! Today’s post is about the ‘wood computer’ (25 December 2021) – this post

 

 

 

CS4FN Advent – Day 24: Santa’s Sleigh – track its progress through the skies

We are nearly coming to the end of our CS4FN Christmas Computing Advent Calendar with one more post to come tomorrow. If you’ve missed any you can catch up by scrolling to the end where there’s a complete list so far.

Today’s advent calendar window shows Father Christmas’ sleigh with a sack full of presents ready for delivery. Today’s theme is about the many different online ways that you can now ‘track’ his movements around the world. This follows on from yesterday’s bonus post about how you can actually see (cloud permitting) his sleigh ‘in person’ as it flies overhead at 6:48am on Christmas Day. In reality it’s International Space Station whizzing past – but other interpretations are available.

You can track Father Christmas as he dashes through the sky, delivering presents.

 

1. NORAD Santa tracker

https://www.noradsanta.org/en/ (you can also track him on NORAD’s apps too)

In 1955, so the story goes, an American department store published a newspaper advert with a phone number for children to call so that they could speak to Father Christmas. Unfortunately a misprint meant that the wrong number was given and instead people found they were talking to the US military’s Air Defense Command (now called North America Air Defense Command or NORAD).

Realising the mistake, but also spotting a great public relations opportunity, the team capitalised on this and began to make an annual event of it.

NORAD uses radar and geosynchronous* satellites to monitor Father Christmas. The satellites are able to detect infrared (heat) radiation and apparently Rudolph’s red nose gives quite a strong signal. This data is then shared with everyone via their website, though they don’t know in advance what route he’ll take.

If you’re visiting the website hover over the different bits of the picture as there are linked activities and extra information too.

*geo = Earth, synchronous = matching / following (like when you sync devices), the satellite follows the Earth’s orbit and is always above the same spot, so effectively (from the Earth’s point of view) the satellite appears not to move (it is moving but it follows the Earth’s rotation).

 

2. FlightRadar24 Santa tracker

https://www.flightradar24.com/R3DN053/2a47aa0e

FlightRadar24 is a great website for telling you the answer to “what was that aircraft that’s just flown by?” It tracks the flight of aircraft all over the globe in real time, using a signal transmitted by the aircraft’s beacon (called a transponder) which announces where it is. Father Christmas’ sleigh has its own transponder too which is transmitting its location to receivers around the world.

An aircraft, or Santa’s sleigh, gets information about where it is from a GPS satellite (very similar to using a maps app on a smartphone and it telling you where you are and whether you should go left or right) and it then transmits this location info, along with other data, through its transponder.

There are thousands of receivers here on Earth, many of them in people’s homes and gardens (you can even apply to host a receiver antenna, or build your own with a Raspberry Pi) and whenever Santa’s sleigh passes over one of these ‘ground stations’ its signal is picked up and collected by FlightRadar24. The receivers are in different places so they are receiving the same signal at slightly different times and this information can be used to work out (by triangulation) how fast the sleigh is moving and in what direction.

Apparently Santa has been “able to extend the reach of his transponder by using the reindeer antlers as additional antenna” so the tracking should be fairly accurate.

FlightRadar24’s Santa Tracker animated icon.

 

3. Google Santa tracker

https://santatracker.google.com/

Google’s Santa Tracker has lots of games to play while you wait for Santa and his sleigh to take flight, including Code Boogie where you can try and program some dancing elves. You move little blocks (a bit like Scratch) to copy the dance moves and, if you get it right, it will show you the underlying JavaScript code.

Dave Holmes, a developer who works at Google and who works on the Santa Tracker project says “Santa Tracker launched in 2004, and has been an important project at Google ever since. While there’s a small core team dedicated to Santa, up to 20 or so Googlers volunteer to help make it happen every year, and it’s become a true community effort. It’s also a way for our developers to try things and see what Google products can do … I like to say that everything I’ve learned at Google, I learned from Santa.”

Google has also added some ‘Easter eggs‘ to its search page – try typing in Christmas or where is Santa to https://www.google.com/. You can also colour in some images online at their Christmas-themed Art Coloring Book, from Google’s Arts and Culture.

Further reading

The Googlers who help track Santa each Christmas (22 December 2021) Google Blog

 

4. Early internet Santa-themed humour

Back in the early 1990s email was very new but right from the start people used it to send each other amusing things. One of them was a rather literal consideration of the physics of a sleigh that is laden with gifts and a traditionally overweight Santa, led by a team of reindeer moving at unlikely speeds (after all Father Christmas has to get around the entire world to deliver presents, in just one day). The author (unknown) began –

No known species of reindeer can fly. BUT there are 300,000 species of living organisms yet to be classified, and while most of these are insects and germs, this does not COMPLETELY rule out flying reindeer which only Santa has ever seen.”

But then goes on to point out that such a gift-delivery system would be working far beyond normal levels and would probably end in disaster, suggesting that –

In short, they will burst into flame almost instantaneously, exposing the reindeer behind them, and create deafening sonic booms in their wake. The entire reindeer team will be vaporized within 4.26 thousandths of a second. Santa, meanwhile, will be subjected to centrifugal forces 17,500.06 times greater than gravity. A 250-pound Santa (which seems ludicrously slim) would be pinned to the back of his sleigh by 4,315,015 pounds of force.”

Fortunately Father Christmas has his own magic, meaning that we don’t need to worry too much about him disobeying the laws of physics. But he and his reindeer really deserve those cookies, milk and carrots!

You can read the full post here: The Physics of Santa and His Reindeer Snopes.com

 

The creation of this post was 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.

 

 

4. Previous Advent Calendar posts

CS4FN Advent – Day 1 – Woolly jumpers, knitting and coding (1 December 2021)

 

CS4FN Advent – Day 2 – Pairs: mittens, gloves, pair programming, magic tricks (2 December 2021)

 

CS4FN Advent – Day 3 – woolly hat: warming versus cooling (3 December 2021)

 

CS4FN Advent – Day 4 – Ice skate: detecting neutrinos at the South Pole, figure-skating motion capture, Frozen and a puzzle (4 December 2021)

 

CS4FN Advent – Day 5 – snowman: analog hydraulic computers (aka water computers), digital compression, and a puzzle (5 December 2021)

 

CS4FN Advent – Day 6 – patterned bauble: tracing patterns in computing – printed circuit boards, spotting links and a puzzle for tourists (6 December 2021)

 

CS4FN Advent – Day 7 – Computing for the birds: dawn chorus, birds as data carriers and a Google April Fool (plus a puzzle!) (7 December 2021)

 

CS4FN Advent – Day 8: gifts, and wrapping – Tim Berners-Lee, black boxes and another computing puzzle (8 December 2021)

 

CS4FN Advent – Day 9: gingerbread man – computing and ‘food’ (cookies, spam!), and a puzzle (9 December 2021)

 

CS4FN Advent – Day 10: Holly, Ivy and Alexa – chatbots and the useful skill of file management. Plus win at noughts and crosses – (10 December 2021)

 

CS4FN Advent – Day 11: the proof of the pudding… mathematical proof (11 December 2021)

 

CS4FN Advent – Day 12: Computer Memory – Molecules and Memristors – (12 December 2021)

 

CS4FN Advent – Day 13: snowflakes – six-sided symmetry, hexahexaflexagons and finite state machines in computing (13 December 2021)

 

CS4FN Advent – Day 14 – Why is your internet so slow + a festive kriss-kross puzzle (14 December 2021)

 

CS4FN Advent – Day 15 – a candle: optical fibre, optical illusions (15 December 2021)

 

CS4FN Advent – Day 16: candy cane or walking aid: designing for everyone, human computer interaction (16 December 2021)

 

CS4FN Advent – Day 17: reindeer and pocket switching (17 December 2021)

 

CS4FN Advent – Day 18: cracker or hacker? Cyber security(18 December 2021)

 

CS4FN Advent – Day 19: jingle bells or warning bells? Avoiding computer scams (19 December 2021)

 

CS4FN Advent – Day 20: where’s it @? Gift tags and internet addresses (20 December 2021)

 

CS4FN Advent – Day 21: wreaths and rope memory – weave your own space age computer (21 December 2021)

 

 

CS4FN Advent – Day 22: stars and celestial navigation (22 December 2021)

 

 

CS4FN Advent – Day 23: Father Christmas – checking his list, spotting the errors (23 December 2021)

 

CS4FN Advent – Day 23: Bonus material – see “Santa’s sleigh” flying overhead (23 December 2021) – this was an extra post so that people could get ready to see “Father Christmas” passing overhead on Christmas Day at 6:48am)

 

CS4FN Advent – Day 24: Santa’s Sleigh – track its progress through the skies (24 December 2021) – this post

 

 

 

CS4FN Advent – Day 23: Bonus material – see “Santa’s sleigh” flying overhead

This short post, part of our CS4FN Christmas Computing Advent Calendar, is to let you know that you may be able to watch Santa’s sleigh as it goes overhead. It doesn’t matter if you believe in Father Christmas or not, whether you’ll actually see his sleigh really only depends on how cloudy it is! In fact Santa’s sleigh follows the orbit of the International Space Station (ISS) remarkably closely…

Santa’s sleigh. Father Christmas will soon be tethering the sack of gifts to the sleigh with very strong straps (not shown) because he’ll be flying very fast and very high.

 

In the unlikely event that any small children are awake early on Christmas Day and it’s not as cloudy as it is today in London then you might be able to catch a bright light passing overhead at 6:48 in the morning. It’s a largely overhead pass so the easiest of the three listed below to see. The others are lower in the sky and may be harder depending on what else is in your landscape.

Father Christmas does a number of ‘test runs’ before heading back to the North Pole, apparently.

The timings below are for London, UK but you can enter your own city and see when Father Christmas is passing by.

Day Date Time Visible Max Height Appears Disappears
Fri 24 Dec 6:01 am 5 min 47° 26° above SW 10° above E
Sat 25 Dec 5:15 am 2 min 30° 30° above ESE 10° above E
Sat 25 Dec 6:48 am 6 min 87° 14° above W 10° above E

See ‘How to spot the station‘ and find out what ‘max height’ and ‘appears’ means in context.

 

 

Previous Advent Calendar posts

CS4FN Advent – Day 1 – Woolly jumpers, knitting and coding (1 December 2021)

 

CS4FN Advent – Day 2 – Pairs: mittens, gloves, pair programming, magic tricks (2 December 2021)

 

CS4FN Advent – Day 3 – woolly hat: warming versus cooling (3 December 2021)

 

CS4FN Advent – Day 4 – Ice skate: detecting neutrinos at the South Pole, figure-skating motion capture, Frozen and a puzzle (4 December 2021)

 

CS4FN Advent – Day 5 – snowman: analog hydraulic computers (aka water computers), digital compression, and a puzzle (5 December 2021)

 

CS4FN Advent – Day 6 – patterned bauble: tracing patterns in computing – printed circuit boards, spotting links and a puzzle for tourists (6 December 2021)

 

CS4FN Advent – Day 7 – Computing for the birds: dawn chorus, birds as data carriers and a Google April Fool (plus a puzzle!) (7 December 2021)

 

CS4FN Advent – Day 8: gifts, and wrapping – Tim Berners-Lee, black boxes and another computing puzzle (8 December 2021)

 

CS4FN Advent – Day 9: gingerbread man – computing and ‘food’ (cookies, spam!), and a puzzle (9 December 2021)

 

CS4FN Advent – Day 10: Holly, Ivy and Alexa – chatbots and the useful skill of file management. Plus win at noughts and crosses – (10 December 2021)

 

CS4FN Advent – Day 11: the proof of the pudding… mathematical proof (11 December 2021)

 

CS4FN Advent – Day 12: Computer Memory – Molecules and Memristors – (12 December 2021)

 

CS4FN Advent – Day 13: snowflakes – six-sided symmetry, hexahexaflexagons and finite state machines in computing (13 December 2021)

 

CS4FN Advent – Day 14 – Why is your internet so slow + a festive kriss-kross puzzle (14 December 2021)

 

CS4FN Advent – Day 15 – a candle: optical fibre, optical illusions (15 December 2021)

 

CS4FN Advent – Day 16: candy cane or walking aid: designing for everyone, human computer interaction (16 December 2021)

 

CS4FN Advent – Day 17: reindeer and pocket switching (17 December 2021)

 

CS4FN Advent – Day 18: cracker or hacker? Cyber security(18 December 2021)

 

CS4FN Advent – Day 19: jingle bells or warning bells? Avoiding computer scams (19 December 2021)

 

CS4FN Advent – Day 20: where’s it @? Gift tags and internet addresses (20 December 2021)

 

CS4FN Advent – Day 21: wreaths and rope memory – weave your own space age computer (21 December 2021)

 

 

CS4FN Advent – Day 22: stars and celestial navigation (22 December 2021)

 

 

CS4FN Advent – Day 23: Father Christmas – checking his list, spotting the errors (23 December 2021)

 

 

CS4FN Advent – Day 23: Bonus material – see “Santa’s sleigh” flying overhead  (23 December 2021) – this post (an extra one so that people can get ready to track Father Christmas!)

 

 

 

CS4FN Advent – Day 23: Father Christmas – checking his list, spotting the errors

Our CS4FN Christmas Computing Advent Calendar has now been running for 23 days! That’s one post every single day, matching a computing-themed blog post to the image on the front of the advent calendar. If you’d like to see how well we’ve managed this please scroll to the end where you can find all of our previous Advent Calendar posts.

Today’s picture is of Father Christmas who, we’ll assume, is re-checking his list and packing his sleigh ready for a long flight around the world, where he’ll be collecting cookies as he goes.

Father Christmas, about to do his pre-flight checks (twice).

As the song implies, he takes particular care over his list checking it twice to make sure there are no mistakes. In that respect he’s a little like computer scientists who put systems in place to make sure that when they send data to someone else that person can tell quickly if it’s arrived correctly. Today’s post is about reducing errors (and trying to avoid introducing errors). (We don’t know what data collection methods Father Christmas used though.)

 

1. Reducing errors: check digits

Once I’d reached the age of about 12 my parents started to let me go by myself to my friend’s house which was about a 15 minute walk away. When I arrived I would use my friend’s parents’ landline phone (with permission) to “give 3 rings” to my parents. This meant that I rang my parents’ number – but they didn’t answer, instead they let the phone ring three times and then I hung up. That way they knew the call was from me (our pre-agreed code) but no-one was charged to make or receive a call and they knew I’d arrived safely. (Obviously if the phone rang for longer they’d know it was probably from someone else and answer it).

Computer scientists also use an agreed code when sending data to another person or computer over a network – they want to make sure their data arrived safely too. Data is* sent as binary 1s and 0s and sometimes there’s a scrambling error in the transmission resulting in a 1 arriving as a 0, or a 0 arriving as a 1. A neat way to find out if this might have happened is to double-check what it was supposed to be, by using something called a parity bit (parity means ‘equal’) or check digit. This digit is added to each block of data you’re sending and computer scientists came up with this to let you check if the arriving data looks correct.

Here’s how it works

Suppose you want to send a message consisting of the numbers 6, 13, 2 and 12. These numbers can be converted into binary for data transmission: for example 6 in binary is 0110, 13 is 1101, 2 is 0010 and 12 is 1100. In the 5-row table below these are written in black (the top line is 6 and the fourth row is 12 – we’ll come to the red numbers in a moment).

We’ll now add a parity bit to each row, according to a rule, to make them five digits long.

The rule is that if the binary number has an odd number of 0s we even it up by adding another 0. If there’s an even number of 0s we just add a 1.

In the 1st row 0110 has an even number of zeroes so a 1 is added, 1101 has an odd number of zeroes so an extra 0 is added. Once we’ve checked all four rows we end up with a new parity column (shown in red on the right to make it stand out) on the right. We can also add a new parity row at the bottom as well, by doing the same thing for each of the numbers but read as a column. The first column has an even number of zeroes so we add a 1, the next just has one odd zero so we add a 0 there and so on.

We’ve added extra data to be sent, but this redundancy check (the extra info isn’t part of the message itself but helps support it) makes it easier for the person receiving the information to know if it’s OK or where any problem is.

0 1 1 0 1
1 1 0 1 0
0 0 1 0 0
1 1 0 0 1
1 0 1 0 1

Let’s pretend you’ve just pressed send and your 1s and 0s are winging their way to your friend.

Binary image by Gerd Altmann from Pixabay

Unfortunately there was a small error in transmission and one of the numbers has ‘flipped’. Will your friend be able to tell which one it is? (Remember they don’t know what your message actually said, they can only see what’s arrived).

Here’s the (slightly scrambled) data that they receive.

0 1 1 0 1
1 0 0 1 0
0 0 1 0 0
1 1 0 0 1
1 0 1 0 1

They can use the parity bit information to check each row and column. The first row looks fine – two zeroes (even) and the parity bit one says 1 so that’s right. The second row looks wrong though – there’s an even number of zeroes so you’d expect a 1 in the parity bit – but it says 0, so you know there’s a mistake somewhere in row 2, but your friend won’t know where yet. They need to check the columns too.

Column 1 looks good, there are two zeroes and the parity bit says 1 so that’s correct. Column 2 has an even number of zeroes so you’d expect the parity bit to be 1, but it’s 0. So we know the problem is in Row 2 and Column 2. If we look at where they intersect we can see that a 1 has flipped to a 0, shown below in bold and blue. Your friend can correct the data and translate the binary back into the original numbers.

0 1 1 0 1
1 0 0 1 0
0 0 1 0 0
1 1 0 0 1
1 0 1 0 1

You could try this with a friend or family member. Think up any 4 numbers between 0 (binary 0000) and 15 (binary 1111) then transmit your binary code with one error and see if they can work out which data bit flipped. Or… you can do it as a magic trick with a pack of cards (see the activity at the end).

*are, for the pedants 🙂

Further reading

Writing together: Clarence ‘Skip’ Ellis – about Clarence Ellis who used his knowledge of computing to bypass parity checks. The company he worked for was running out of punched cards (we’ll look at these in more depth later in the week) which the company’s computer used to store data. He was able to find a way for his colleagues to re-use the cards they already had, without triggering parity check problems – in doing so the payroll program could be run and everyone could get paid.

Handy binary cheat sheet. (Repeated after the dividing black line to show how the binary number is formed).

 

 

2. Trying not to introduce errors: when spellcheck goes worng

Another thing Father Christmas needs to do is check that he has the correct names of all the good children he’ll be giving presents to. He might use a spellchecker for this – this is something that reads the words in a document and compares them to a pre-set list. If a word is spelled in an unusual way the computer will alert you and ask if you want to change it to the one in the list or if you want to add it as a new spelling to the list. It would spot that I spelled ‘wrong’ wrongly in the heading for this section and ask if I meant ‘wrong’ instead of ‘worng’.

Find and replace

Sometimes people want to change a word in their document that appears many times. For example you might put TBA (which can mean ‘to be agreed’ or ‘to be arranged’) as a temporary placemarker in a Word document and later decide that every time the document says ‘TBA’ you’d prefer it to say “to be determined” instead. You don’t have to manually delete and retype every single instance of ‘TBA’, you can ‘automate’ the process using the Find and Replace option. Word will then find every ‘TBA’ automatically and change it to ‘to be determined’.

Sometimes this doesn’t go quite as expected.

In the UK the word ‘ass’ just means donkey but in the US it’s a slightly less polite word for bottom. A slightly more polite word might be ‘butt’ so you – being polite – want to make sure that any time the word ‘ass’ appears in a particular document it’s replaced with the word ‘butt’. This is unfortunate though if you happen to be the editor of a book about donkeys, which is now suddenly about bottoms.

Not donkeys’ bottoms, but zebras image by chezbeate from Pixabay

It’s much worse if your document talks about your class at school (clbutt?). Or perhaps it’s some homework about the assassination of an American president (buttbuttination?). Or maybe you need a new password (pbuttword), or even a new passport (pbuttport). Your document is now absolute gibberish and you would not pbutt any exams with that. Where’s spellcheck when you need it?

These types of mistakes are not that uncommon, I’ve even done it myself with the addresses of schools where I send copies of our CS4FN magazine to teachers.

I had a column in my address database which said things like UK, U.K. or United Kingdom and I decided I wanted them all to match and say “United Kingdom”. So… I used find and replace and asked my computer to turn every mention of ‘UK’ or ‘U.K.’ into United Kingdom. It worked beautifully… but I didn’t check the other columns.

I discovered my mistake when ‘Luke’ at a school on ‘Duke Road’ didn’t get his copy of the magazine and it was returned to me by the Post Office as the address was unreadable. I then had to correct both Lunited Kingdome’s name and his DUnited Kingdome Road address 😉 Oops.

Here are some other examples

and here’s what happened when someone changed TBA to ‘to be determined’ without noticing that the string of letters also appears in the word basketball.

 

3. Magic trick activity: parity check with playing cards

You could demonstrate the parity checking (that we did above with 1s and 0s) as a card trick – you just need an assistant and an audience. If you look closely at the pattern of cards in the picture above, and the pattern of 1s and 0s further up in this post you might notice a similarity…

Give a pack of shuffled cards to an audience member and ask them to deal out 16 cards in four rows either face up or face down (their choice). An example is shown in the left of the picture above. Tell them that in a moment you’re going to ask them to turn over a card while you’re not looking and later, you’ll tell them which card they flipped over. Announce that your assistant is going to make it ‘even harder’ by adding an extra column and row (I bet you can see where this is going). Of course, your assistant is adding a parity bit to the rows and columns (but your audience doesn’t know that) – an example is shown in the middle picture above.

Now avert your eyes (or get someone to blindfold you) and ask the audience member to turn over one card from the grid without telling you which. (Example in the picture on the right, above).

When you look at the grid you can quickly work out which one has been turned over, using exactly the same method we used with the 1s and 0s above.

This trick is a variation of one invented by New Zealand computer scientist, Tim Bell, and you can find more information about it and detailed instructions (as well as ideas to make it seem like you’re really a magician) in our free booklet called The Magic of Computer Science: card tricks special. The trick is called ‘The Out of Body Experience‘ and you can find it on pages 24-31 (pages 13 – 16 of the 33 page PDF).

The Magic of Computer Science 1

 

 

The creation of this post was 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.

Other picture credits: the card (faces) comes from Wikipedia and the back is by Clker-Free-Vector-Images from Pixabay

 

4. Previous Advent Calendar posts

CS4FN Advent – Day 1 – Woolly jumpers, knitting and coding (1 December 2021)

 

CS4FN Advent – Day 2 – Pairs: mittens, gloves, pair programming, magic tricks (2 December 2021)

 

CS4FN Advent – Day 3 – woolly hat: warming versus cooling (3 December 2021)

 

CS4FN Advent – Day 4 – Ice skate: detecting neutrinos at the South Pole, figure-skating motion capture, Frozen and a puzzle (4 December 2021)

 

CS4FN Advent – Day 5 – snowman: analog hydraulic computers (aka water computers), digital compression, and a puzzle (5 December 2021)

 

CS4FN Advent – Day 6 – patterned bauble: tracing patterns in computing – printed circuit boards, spotting links and a puzzle for tourists (6 December 2021)

 

CS4FN Advent – Day 7 – Computing for the birds: dawn chorus, birds as data carriers and a Google April Fool (plus a puzzle!) (7 December 2021)

 

CS4FN Advent – Day 8: gifts, and wrapping – Tim Berners-Lee, black boxes and another computing puzzle (8 December 2021)

 

CS4FN Advent – Day 9: gingerbread man – computing and ‘food’ (cookies, spam!), and a puzzle (9 December 2021)

 

CS4FN Advent – Day 10: Holly, Ivy and Alexa – chatbots and the useful skill of file management. Plus win at noughts and crosses – (10 December 2021)

 

CS4FN Advent – Day 11: the proof of the pudding… mathematical proof (11 December 2021)

 

CS4FN Advent – Day 12: Computer Memory – Molecules and Memristors – (12 December 2021)

 

CS4FN Advent – Day 13: snowflakes – six-sided symmetry, hexahexaflexagons and finite state machines in computing (13 December 2021)

 

CS4FN Advent – Day 14 – Why is your internet so slow + a festive kriss-kross puzzle (14 December 2021)

 

CS4FN Advent – Day 15 – a candle: optical fibre, optical illusions (15 December 2021)

 

CS4FN Advent – Day 16: candy cane or walking aid: designing for everyone, human computer interaction (16 December 2021)

 

CS4FN Advent – Day 17: reindeer and pocket switching (17 December 2021)

 

CS4FN Advent – Day 18: cracker or hacker? Cyber security(18 December 2021)

 

CS4FN Advent – Day 19: jingle bells or warning bells? Avoiding computer scams (19 December 2021)

 

CS4FN Advent – Day 20: where’s it @? Gift tags and internet addresses (20 December 2021)

 

CS4FN Advent – Day 21: wreaths and rope memory – weave your own space age computer (21 December 2021)

 

 

CS4FN Advent – Day 22: stars and celestial navigation (22 December 2021)

 

 

CS4FN Advent – Day 23: Father Christmas – checking his list, spotting the errors (23 December 2021) – this post

 

 

 

CS4FN Advent – Day 22: stars and celestial navigation

Every day from the 1st to the 25th of December this blog will publish a Christmas Computing post, as part of our CS4FN Christmas Computing Advent Calendar. On the front of the calendar for each day is a festive cartoon which suggests the post’s theme – today’s is a star, so today’s post is about finding your way: navigation.

Follow that star…

 

In modern cities looking up at the night sky is perhaps not as dramatic as it might have been in the past, or in a place with less light pollution. For centuries people have used stars and the patterns they form to help them find their way.

GPS Orbital Navigator Satellite (DRAGONSat), photograph by NASA.

There are many ways our explorations of space have led to new technologies, though satellites have perhaps had the most obvious effect on our daily lives. Early uses were just for communication, allowing live news reports from the other side of the world, with networks that span the globe. More recently GPS – the Global Positioning System has led to new applications and now we generally just use our phones or satnav to point us in the right direction.

 

The very first computers

by Paul Curzon, QMUL. This post was first published on the CS4FN website.

Victorian engineer Charles Babbage designed, though never built the first mechanical computer. The first computers had actually existed for a long time before he had his idea, though. The British superiority at sea and ultimately the Empire was already dependent on them. They were used to calculate books of numbers that British sailors relied on to navigate the globe. The original meaning of the word computer was actually a person who did these calculations. The first computers were humans.

An American almanac from 1816. Image by Dave Esons from Pixabay

Babbage became interested in the idea of creating a mechanical computer in part because of computing work he did himself, calculating accurate versions of numbers needed for a special book: ‘The Nautical Almanac’. It was a book of astronomical tables, the result of an idea of Astronomer Royal, Nevil Maskelyne. It was the earliest way ships had to reliably work out their longitudinal (i.e., east-west) position at sea. Without them, to cross the Atlantic, you just set off and kept going until you hit land, just as Columbus did. The Nautical Almanac gave a way to work out how far west you were all the time.

Maskelyne’s idea was based on the fact that the angle from the moon’ to a person on the Earth and back to a star was the same at the same time wherever that person was looking from (as long as they could see both the star and moon at once). This angle was called the lunar distance.

The lunar distance could be used to work out where you were because as time passed its value changed but in a predictable way based on Newton’s Laws of motion applied to the planets. For a given place, Greenwich say, you could calculate what that lunar distance would be for different stars at any time in the future. This is essentially what the Almanac recorded.

Moon image by PollyDot from Pixabay

Now the time changes as you move East or West: Dawn gradually arrives later the further west you go, for example, as the Earth rotates the sun comes into view at different times round the planet). That is why we have different time zones. The time in the USA is hours behind that in Britain which itself is behind that in China. Now suppose you know your local time, which you can check regularly from the position of the sun or moon, and you know the lunar distance. You can look up in the Almanac the time in Greenwich that the lunar distance occurs and that gives you the current time in Greenwich. The greater the difference that time is to your local time, the further West (or East) you are. It is because Greenwich was used as the fixed point for working the lunar distances out, that we now use Greenwich Mean Time as UK time. The time in Greenwich was the one that mattered!

This was all wonderful. Sailors just had to take astronomical readings, do some fairly simple calculations and a look up in the Almanac to work out where they were. However, there was a big snag. it relied on all those numbers in the tables having been accurately calculated in advance. That took some serious computing power. Maskelyne therefore employed teams of human ‘computers’ across the country, paying them to do the calculations for him. These men and women were the first industrial computers.

Book of logarithms, image by sandid from Pixabay

Before pocket calculators were invented in the 1970s the easiest way to do calculations whether big multiplication, division, powers or square roots was to use logarithms (not to be confused with algorithm). The logarithm of a number is just the number of times you can divide it by 10 before you get to 1. Complicated calculations can be turned in to simple ones using logarithms. Therefore the equivalent of the pocket calculator was a book containing a table of logarithms. Log tables were the basis of all other calculations including maritime ones. Babbage himself became a human computer, doing calculations for the Nautical Almanac. He calculated the most accurate book of log tables then available for the British Admiralty.

The mechanical computer came about because Babbage was also interested in finding the most profitable ways to mechanise work in factories. He realised a machine could do more than weave cloth but might also do calculations. More to the point such a machine would be able to do them with a guaranteed accuracy, unlike people. He therefore spent his life designing and then trying to build such a machine. It was a revolutionary idea and while his design worked, the level of precision engineering needed was beyond what could be done. It was another hundred years before the first electronic computer was invented – again to replace human computers working in the national interest…but this time at Bletchley Park doing the calculations needed to crack the German military codes and so win the World War II.

 

The creation of this post was 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.

 

 

Previous Advent Calendar posts

CS4FN Advent – Day 1 – Woolly jumpers, knitting and coding (1 December 2021)

 

CS4FN Advent – Day 2 – Pairs: mittens, gloves, pair programming, magic tricks (2 December 2021)

 

CS4FN Advent – Day 3 – woolly hat: warming versus cooling (3 December 2021)

 

CS4FN Advent – Day 4 – Ice skate: detecting neutrinos at the South Pole, figure-skating motion capture, Frozen and a puzzle (4 December 2021)

 

CS4FN Advent – Day 5 – snowman: analog hydraulic computers (aka water computers), digital compression, and a puzzle (5 December 2021)

 

CS4FN Advent – Day 6 – patterned bauble: tracing patterns in computing – printed circuit boards, spotting links and a puzzle for tourists (6 December 2021)

 

CS4FN Advent – Day 7 – Computing for the birds: dawn chorus, birds as data carriers and a Google April Fool (plus a puzzle!) (7 December 2021)

 

CS4FN Advent – Day 8: gifts, and wrapping – Tim Berners-Lee, black boxes and another computing puzzle (8 December 2021)

 

CS4FN Advent – Day 9: gingerbread man – computing and ‘food’ (cookies, spam!), and a puzzle (9 December 2021)

 

CS4FN Advent – Day 10: Holly, Ivy and Alexa – chatbots and the useful skill of file management. Plus win at noughts and crosses – (10 December 2021)

 

CS4FN Advent – Day 11: the proof of the pudding… mathematical proof (11 December 2021)

 

CS4FN Advent – Day 12: Computer Memory – Molecules and Memristors – (12 December 2021)

 

CS4FN Advent – Day 13: snowflakes – six-sided symmetry, hexahexaflexagons and finite state machines in computing (13 December 2021)

 

CS4FN Advent – Day 14 – Why is your internet so slow + a festive kriss-kross puzzle (14 December 2021)

 

CS4FN Advent – Day 15 – a candle: optical fibre, optical illusions (15 December 2021)

 

CS4FN Advent – Day 16: candy cane or walking aid: designing for everyone, human computer interaction (16 December 2021)

 

CS4FN Advent – Day 17: reindeer and pocket switching (17 December 2021)

 

CS4FN Advent – Day 18: cracker or hacker? Cyber security(18 December 2021)

 

CS4FN Advent – Day 19: jingle bells or warning bells? Avoiding computer scams (19 December 2021)

 

CS4FN Advent – Day 20: where’s it @? Gift tags and internet addresses (20 December 2021)

 

CS4FN Advent – Day 21: wreaths and rope memory – weave your own space age computer (21 December 2021)

 

 

CS4FN Advent – Day 22: stars and celestial navigation (22 December 2021) – this post