Quicksilver memory

by Jo Brodie and Paul Curzon, Queen Mary University of London and Adrian Johnstone, Royal Holloway, University of London

Silvery liquid twisting as it flows downwards.
Image by Roman Shashko from Pixabay

Some 1950s computers used tubes filled with mercury as a memory to store numbers. Mercury is a metal that is liquid at room temperature. It’s also known as quicksilver as it flows very easily, but in computing it was actually used to trap information.

Early computers needed a way to store data that would survive indefinitely, even if the computer was stopped. ‘Delay lines’ provided the solution. Data arriving electronically at a mercury delay line struck a converter (called a ‘transducer’) which converted the information to a sound pulse in the mercury. The sound travelled through the tube at the speed of, yes, sound and when the pulse reached the other side it hit another transducer and was returned to its electronic form. That might not sound (sorry) like much of a delay but compared to the speed that an electrical signal moves through a wire (a fraction of the speed of light), it’s like a gentle stroll. Once inside the mercury tube the sound pulses could be looped back and forth, safely ‘parked’ until needed. The computer would use its clock to help it count how many pulses had passed and a microphone listened for the right time to release it from the memory store back into the circuitry to do a calculation with it.

Mercury is expensive, so computer pioneer Alan Turing recommended using gin instead. He claimed its mix of alcohol and water gave perfect properties for the job while being so much cheaper.

Think about tennis serving machines that shoot balls at you. If you put one in a squash court, then a ball being fired will bounce back and forth off the walls but quickly drop to the floor. A delay line works like having two machines facing each other. One fires a ball so that it hits a lever (the transducer) which tells the other machine to fire a ball back, which then hits a lever on the first machine… and so on. Now there is always a ball in flight (a pulse in the delay line) because the motion of the original ball is detected, and used to make a new ball (pulse) that is injected back into the system. Start the first machine by making it fire balls in an initial ball-no-ball pattern and the system stores that pattern, that information. Using cunning contraptions, motion can keep information firmly in one place.


More on …

Related Magazines …


This article was funded by UKRI, through Professor Ursula Martin’s grant EP/K040251/2 and grant EP/W033615/1.

A storm in a bell jar

by Paul Curzon, Queen Mary University of London

(from the archive)

lightning
Image by FelixMittermeier from Pixabay 

Ada Lovelace was close friends with John Crosse, and knew his father Andrew: the ‘real Frankenstein’. Andrew Crosse apparently created insect life from electricity, stone and water…

Andrew Crosse was a ‘gentleman scientist’ doing science for his own amusement including work improving giant versions of the first batteries called ‘voltaic piles’. He was given the nickname ‘the thunder and lightning man’ because of the way he used the batteries to do giant discharges of electricity with bangs as loud as canons.

He hit the headlines when he appeared to create life from electricity, Frankenstein-like. This was an unexpected result of his experiments using electricity to make crystals. He was passing a current through water containing dissolved limestone over a period of weeks. In one experiment, about a month in, a perfect insect appeared apparently from no-where, and soon after starting to move. More and more insects then appeared over time. He mentioned it to friends, which led to a story in a local paper. It was then picked up nationally. Some of the stories said he had created the insects, and this led to outrage and death threats over his apparent blasphemy of trying to take the position of God.

(Does this start to sound like a modern social networking storm, trolls and all?) In fact he appears to have believed, and others agreed, that the mineral samples he was using must have been contaminated with tiny insect eggs, that just naturally hatched. Scientific results are only accepted if they can be replicated. Others, who took care to avoid contamination couldn’t get the same result. The secret of creating life had not been found.

While Mary Shelley, who wrote Frankenstein, did know Crosse, sadly perhaps, for the story’s sake, he can’t have been the inspiration for Frankenstein as has been suggested, given she wrote it decades earlier!


More on …

Related Magazines …


EPSRC supported this article through research grants (EP/K040251/2 and EP/K040251/2 held by Professor Ursula Martin as well as grant EP/W033615/1). 

Pass the screwdriver, Igor

Mary Shelley, Frankenstein’s monster and artificial life

by Paul Curzon and Peter W McOwan, Queen Mary University of London

(Updated from the archive)

Frankenstein's Monster
Image by sethJreid from Pixabay

Shortly after Ada Lovelace was born, so long before she made predictions about future “creative machines”, Mary Shelley, a friend of her father (Lord Byron), was writing a novel. In her book, Frankenstein, inanimate flesh is brought to life. Perhaps Shelley foresaw what is actually to come, what computer scientists might one day create: artificial life.

Life it may not be, but engineers are now doing pretty well in creating humanoid machines that can do their own thing. Could a machine ever be considered alive? The 21st century is undoubtedly going to be the age of the robot. Maybe it’s time to start thinking about the consequences in case they gain a sense of self.

Frankenstein was obsessed with creating life. In Mary Shelley’s story, he succeeded, though his creation was treated as a “Monster” struggling to cope with the gift of life it was given. Many science fiction books and films have toyed with these themes: the film Blade Runner, for example, explored similar ideas about how intelligent life is created; androids that believe they are human, and the consequences for the creatures concerned.

Is creating intelligent life fiction? Not totally. Several groups of computer scientists are exploring what it means to create non-biological life, and how it might be done. Some are looking at robot life, working at the level of insect life-forms, for example. Others are looking at creating intelligent life within cyberspace.

For 70 years or more scientists have tried to create artificial intelligences. They have had a great deal of success in specific areas such as computer vision and chess playing programs. They are not really intelligent in the way humans are, though they are edging closer. However none of these programs really cuts it as creating “life”. Life is something more than intelligence.

A small band of computer scientists have been trying a different approach that they believe will ultimately lead to the creation of new life forms: life forms that could one day even claim to be conscious (and who would we be to disagree with them if they think they are?) These scientists believe life can’t be engineered in a piecemeal way, but that the whole being has to be created as a coherent whole. Their approach is to build the basic building blocks and let life emerge from them.

A sodarace in action

The outline of the idea could be seen in the game Sodarace, where you could build your own creatures that move around a virtual world, and even let them evolve. One approach to building creatures, such as a spider, would be to try and work out mathematical equations about how each leg moves and program those equations. The alternative artificial life way as used in Sodarace is to instead program up the laws of physics such as gravity and friction and how masses, springs and muscles behave according to those laws. Then you just put these basic bits together in a way that corresponds to a spider. With this approach you don’t have to work out in advance every eventuality (what if it comes to a wall? Or a cliff? Or bumpy ground?) and write code to deal with it. Instead natural behaviour emerges.

The artificial life community believe, not just life-like movement, but life-like intelligence can emerge in a similar way. Rather than programming the behaviour of muscles you program the behaviour of neurones and then build brains out of them. That it turns out has been the key to the machine learning programs that are storming the world of Artificial Intelligence, turning it into an everyday tool. However, if aiming for artificial life, you would keep going and combine it with the basic biochemistry of an immune system, do a similar thing with a reproductive system, and so on.

Want to know more? A wonderful early book is Steve Grand’s: “Creation”, on how he created what at the time was claimed to be “the nearest thing to artificial life yet”… It started life as the game “Creatures”.

Then have a go at creating artificial life yourself (but be nice to it).


More on …

Related Magazines …


EPSRC supported this article through research grants (EP/K040251/2 and EP/K040251/2 held by Professor Ursula Martin as well as grant EP/W033615/1). 

Babbage’s triumph over brutal reality

by Adrian Johnstone, Royal Holloway, University of London and Paul Curzon, Queen Mary University of London

A red rose on a gravestone
Image by Goran Horvat from Pixabay

Charles Babbage is famous for his amazing technical skills in designing a computer, but also infamous for his apparent spiky and obsessive personality.

He certainly seems to have had poor social skills in that he often immensely irritated the people who funded his work. Part of the reason he never managed to complete a working version of his computer is that his funders pulled the plug on him. If only he had had better people skills to complement his technical skills and creativity, perhaps we would have had computers a century earlier! However, perhaps we should be less harsh. He wasn’t a total social misfit: his salons (Victorian high society parties) were extremely popular, and attended by what would now be considered celebrity A-listers. They often centred around demonstrations of science and engineering wonders, so presumably he could be the life and soul of the party… as long as he had a technological wonder to talk about. The young Ada Lovelace attended one such salon and was enthralled by his machines. Encouraged by her mathematically trained mother, Lady Byron, she studied maths and in 1840 collaborated with Babbage on a description of his Analytical Engine.

More to the point, if you consider the context of Babbage’s life, he suffered extremes of grief. In one year alone, 1827, he buried three of his children as well as his wife. Of his eight children only three survived beyond the age of ten. That was the brutal reality of the pre-antibiotic world.

In this context perhaps it is better to think about his work and achievements, as a response to adversity. That he achieved so much is a triumph of ambition over terrible loss.


More on …

Related Magazines …


This article was funded by UKRI, through Professor Ursula Martin’s grant EP/K040251/2 and grant EP/W033615/1.

Nikola Tesla: the invisible genius

by Peter W. McOwan and Paul Curzon, Queen Mary University of London

(From the archive)

Nikola Tesla is an enigma wrapped in a mystery. Not bad going for an electronic engineer. Born, so the stories go, in the middle of a thunderstorm in Serbia, Tesla has left a fascinating legacy to the world today. Magnetism is measured in Tesla, a unit named after him. But it is perhaps one victory we owe most to Tesla for. He fought a battle to show that alternating current (A/C) was superior to direct current (D/C) when it came to transmitting electricity over a distance. His opponent was none other than America’s most respected celebrity inventor, Thomas Edison.

Absolutely shocking behaviour

In the so called Battle of the Currents Tesla and his entrepreneurial partner George Westinghouse eventually won (they had maths on their side). If he hadn’t the world would have been filled with electrical substations at the end of each road, because D/C doesn’t do distance well.

Why is A/C better?

AC is better for distributing power over a distance because it allows the easy changing of voltages using a transformer. Power is calculated as current times voltage (P = IV). For a given amount of power to be sent, a low voltage requires a higher current. But metal conducting wires have resistance. That means some of that precious power will be lost as heat in the wires. Theory (always important to know the theory) says that power loss is given by P = I²R. So from this its obvious that low-voltage, high-current transmissions will cause a much greater power loss than high-voltage, low-current ones. This fact holds whether DC or AC is used. But, and here is the clincher, transforming DC power from one voltage to another is difficult and expensive. In Tesla’s day it needed a large spinning device called a rotary converter, and moving parts are always a problem. But with AC these voltage changes can be done with simple and cheap transformer coils with no moving parts and no maintenance. Tesla wins in theory and in practice.

A Dirty Fight

Tesla ultimately won, but the fight was a really dirty one – there was ego and money at stake. Edison got his employees to badmouth A/C, to try and convince the public it was dangerous. They used A/C to execute stray cats and dogs to try to prove to the press that A/C was more dangerous than Edison’s system of D/C. They even filmed the A/C electrocution of Topsy, a circus elephant from Coney Island! Edison’s spin doctors also tried to popularise the term “Westinghoused” (the rival company to Edison’s that Tesla was working with) to mean being electrocuted. The battle cost an astronomical amount, and toward the end Tesla pulled out, tearing up the contract that could have made him the world’s first billionaire, and leaving Westinghouse to capitalise on the final victory.

Tesla retreated, and focussed on wireless control inventing the world’s first remote controlled boat, but he also had another card up his sleeve – he had invented the radio, and had the patent. But success was short lived. After a few years the US courts decided that Guglielmo Marconi was the inventor of radio and Tesla lost out again. In fact in 1909 Marconi was awarded the Nobel Prize for Physics for the invention of radio, and the rumour was that Tesla and Edison’s fight had lost them the chance of being included in the award.

Springing back into action

Never daunted, in 1899, Tesla moved to Colorado Springs, Colorado, where he could have enough room for his high-voltage, high-frequency experiments. He told reporters that he was conducting wireless telegraphy experiments, transmitting signals from a mountain called Pikes Peak in Colorado to Paris. He transmitted extremely low frequencies through the ground as well as between the earth’s surface and the ionosphere, and patented the ideas. He also calculated that the resonant frequency of the Earth was approximately 8 Hertz (Hz). Later in the 1950s, researchers confirmed that the resonant frequency of the Earth’s ionosphere was in this range, but chose to name it the Schumann resonance. Tesla was invisible again.

This is the end?

Tesla was no good with money. His genius and lifetime of invention led to him dying alone of heart failure, in a New York hotel room, impoverished at the age of 86. The story goes that the documents he had were seized by the American secret service under the direct orders of J Edgar Hoover. Tesla had been developing his radical ideas about transmitting power without wires through the earth over great distances. He called this a peace ray; it could manifest electrical power in mid-air wherever it was needed on the Earth. He also claimed to have worked out a ‘dynamic theory of gravity’ – even Einstein failed at this – but it was never published.

Tesla’s life has of course been the subject of movies; he most recently appeared in the film ‘The Prestige’, played by David Bowie: who else could play such an enigma.

Tesla is also featured on the bank notes of Serbia. So when you next plug in your mobile phone charger or use wifi, remember Tesla, the invisible genius who made it all possible.


More on …

Related Magazines …


EPSRC supports the cs4fn blog through research grants (EP/K040251/2 and EP/K040251/2 held by Professor Ursula Martin as well as grant EP/W033615/1). 

Babbage’s Adders

by Paul Curzon, Queen Mary University of London and Adrian Johnstone, Royal Holloway, University of London

Blue smoke curling over a black background

image by Hanjörg Scherzer from Pixabay

Charles Babbage famously designed the first computer: a steam powered contraption that was never built. At its core was something very simple and elegant: a cunning contraption that allowed his machines to store numbers and do arithmetic, all made of Victorian tech: metal wheels and levers.

Babbage’s Analytical Engine, had it been built, would have been the first working general-purpose computer. The size of a factory, and powered by a steam engine, it was the ultimate cunning contraption. A giant whirring, clanking, puffing mechanical brain. Babbage’s first attempt at mechanical computation, though, was a simpler machine, the Difference Engine. It could only do a fixed, if very useful, kind of calculation. It computed what are called polynomials: patterns of additions and multiplications. It used a complicated adding mechanism. Later, whilst working on designs for his ambitious Analytical Engine he thought of a much simpler adder (described below). His second Difference Engine used this new adder and so needed about 16,000 fewer parts! The Science Museum built it in the twentieth century.

Representing Numbers

First he had to devise a way to represent numbers. Unlike modern computers which use binary, so only two digits, Babbage stuck to decimal. He was going to do all his calculations using our normal ten digits, 0 – 9. But how? His solution was to use metal cog-like wheels. His wheels had 40 teeth corresponding to the digits 0 to 9 repeated four times. To get the idea of how they worked, imagine a wheel with only 10 teeth, each with a digit 0-9 in order, next to a tooth. The wheel lays flat and one digit faces you. That digit is the number that the wheel represents. Turn it one place to the left and it represents one digit higher. Turn it a place to the right and it represents one digit lower.

One of Babbage's wheels with teeth at the bottom and digits 0 to 9 repeated round the edge abocve the teeth. Nibs (ridges) are used to drive the carry to the next wheel.

Babbage’s wheel from a 3D model by Adrian Johnstone.

That is fine for numbers between 0 and 9. For larger numbers, just do as we do: use the decimal place system where the value of a digit changes with its position. That first wheel is in the ones row so stands for 0-9. Put a wheel above it in a 10s row and it stands for 10 times the value shown. If a 5 is facing you on that wheel it stands for 50. You can now represent numbers 0 – 99. Put more wheels on top and you can represent hundreds, thousands, and so on.

It’s a neat way of representing numbers using the system we do (though our numbers run right to left not bottom to top). It makes it not only easy for a machine to manipulate the numbers by turning the wheels, but also easy for a human operator to read the numbers. His Difference Engine used several stacks of them, but Babbage envisaged a gigantic room-sized data store of column after column of these number wheels as the memory of his analytical engine, each column storing one potentially very large number.

A machine that can count

We now have a way to represent numbers but it isn’t yet enough to allow a machine to manipulate them automatically. As it stands it can’t even count properly. We have seen only how to count on one wheel, so only up to 9: every time we turn a crank the 1s wheel turns one notch and so the number represented moves on one. However, we need the other wheels to turn too, but only when the wheel below turns from a 9 to a 0 (so should really become 10). We need a mechanism to carry up to the wheel above. Babbage did this by adding a ridge (a ‘nib’) on the wheel that triggered the carry. When the wheel got to 0, the nib caught against a mechanism above and pushed it, before allowing it to spring back. That nudged the wheel above along one place as required. The 1s wheel was controlled by the crank. The 10s wheel was turned by the 1s wheel moving to 0. The 100s wheel was turned by the 10s wheel moving to 0, and so on. Babbage had a machine that could count!

A machine that can add

The next problem is how to add numbers stored on wheels. Imagine two wheels, interlocked by their teeth, When one is turned it turns the other the same amount. However if you lift one of the wheels they no longer interlock and move independently.

To do addition, the first wheel is used to hold the number to be added. The second holds the total so far: the answer. That answer wheel starts off set to 0. Now, with the wheels interlocked, turn the first wheel one position at a time counting up to the first number of the addition. It turns the answer wheel exactly the same number of positions transferring the number on to it.

Oops. When cogs interlock, the second wheel turns in the opposite direction to the first! Our machine is subtracting! To make it add, you need a connecting wheel between them. The middle wheel then turns backwards, turning the answer wheel forwards as required. With three wheels like this, any number on the first wheel is added to the answer wheel.

To add a second number, just lift the first wheel to disconnect it, spin it back to zero, drop it back in place and turn it to the second number. The answer wheel then holds the sum of both numbers. If you want to add more numbers, just keep doing this, loading one number at a time onto the first wheel. Each time the total passes 10, the carry mechanism passes the 10 onto the higher wheel and the full decimal total is stored up the stack of wheels.

We have a machine for doing addition!

A machine that can multiply

Babbage’s machines could multiply as well. How do you do multiplication on wheels? Well, multiplication is just repeated addition. If you want to work out 5 x 3, then it can be calculated as 5 + 5 + 5. So multiplication can simply be done using the adder, adding the same number over and over again. A counter keeps track of how many times to add it. There are faster ways to multiply though. For the Analytical Engine, Babbage designed an efficient table-based multiplier that he was justifiably very proud of.

Putting it together

Put this together and you have both a number store (a computer memory) and temporary storage areas (registers). You can transfer numbers from one place to another in the machine, and you have the basics of an arithmetic unit that can do calculations. That is about as far as Babbage managed to build. However, he also envisioned programs on punch cards that determined what instruction to execute, mechanisms that allowed instructions to make decisions, and to repeat instructions…everything needed for a general-purpose computer.

Sadly, only parts of his Analytical Engine were ever built, the Victorians did not start the digital age, and we had to wait nearly a century for the first working computers.


More on …

Related Magazines …


This article was funded by UKRI, through Professor Ursula Martin’s grant EP/K040251/2 and grant EP/W033615/1.

Making core rope memory

A coloured bead version of core rope memory with J encoded on its 8 beads (01001010)

by Jo Brodie, Queen Mary University of London

We have explained how core rope memory was used as the computer memory storing the Apollo guidance computer program that got us to the moon. A team from the University of Washington came up with a fun craft activity to make your own core memory. It may not fly you to the moon, but is a neat way to store information in a bracelet. Find their activity pages here [EXTERNAL].

What it involves is threading 8 beads onto a string, with a gap between them to form a storage space for bytes of data. Each byte is 8 binary bits (Eight pieces of information, each a 1 or a 0). Each bead represents the position of one bit in your core rope memory. You then take other threads and weave them through the beads. Each thread will store another byte of actual data. Pass the thread through a bead when you want that bead to read 1, or over, when you want that bead to read 0.

Each thread weaving past or through 8 beads can then encode the information for one letter. By adding lots of threads you can store a word or even a sentence on each core rope memory string (perhaps your name, or some secret message).

Using a binary encoding for each letter (so capital letter A would be the 8 bits 01000001 if you’re following this conversion from binary to letters table) you put that letter’s thread through or over each of the 8 beads to ‘spell’ out the letter in binary.

My name is Jo so a core rope memory encoding my name would have only three threads (one to hold the 8 beads and two to spell my name). The second thread would go over, through, over, over, through, over, through, over to spell the capital letter J (01001010). The second thread would go over, through, through, over, through, through, through, through to spell lowercase o (01101111).

Let’s hope you have a slightly longer name so can have more fun time creating your own personalised core rope memory!


More on …

Related Magazines …


This article was funded by UKRI, through Professor Ursula Martin’s grant EP/K040251/2 and grant EP/W033615/1.

Core rope memory

by Jo Brodie and Paul Curzon, Queen Mary University of London

A view of the Earth from the Moon
Image by WikiImages from Pixabay

Weaving, in the form of the Jacquard loom, with its swappable punch cards controlling the loom’s patterns inspired Charles Babbage. He intended to use the same kind of punch card to store programs in his Analytical Engine, which had it been built would have been the first computer. However, weaving had a much more direct use in computing history. Weaving helped get us to the Moon.

In the 1960s, NASA’s Apollo moon mission needed really dependable computers. It was vital that the programs wouldn’t be corrupted in space. The problem was solved using core rope memory.

Core rope memory was made of small ‘eyelets’ or beads of a metal called ferrite that can be magnetised and copper wire which was woven through some of the eyelets but not others. The ring-shaped magnets were known as magnetic cores. An electrical current passing through the wires made the whole thing work.

Representing binary

Both data and programs in computers are stored as binary: 1s and 0s. Those 1s and 0s can be represented by physical things in the world in lots of different ways. NASA used weaving. A wire that passed through an eyelet would be read as a binary 1 when the current was on but if it passed around the eyelet then it would be read as 0. This meant that a computer program, made up of sequences of 1s and 0s, could be permanently stored by the pattern that was woven. This gave read-only memory. Related techniques were used to create memory that the computer could change too, as the guidance computer needed both.

The memory was woven for NASA by women who were skilled textile workers. They worked in pairs using a special hollow needle to thread the copper wire through one magnetic core and then the other person would thread it back through a different one.

The program was first developed on a computer (the sort that took up a whole room back then) and then translated into instructions for a machine which told the weavers the correct positions for the wire threads. It was very difficult to undo a mistake so a great deal of care was taken to get things right the first time, especially as it could take up to two months to complete one block of memory. Some of the rope weavers were overseen by Margaret Hamilton, one of the women who developed the software used on board the spacecraft, and who went on to lead the Apollo software team.

The world’s first portable computer?

Several of these pre-programmed core rope memory units were combined and installed in the guidance computers of the Apollo mission spacecraft that had to fly astronauts safely to the Moon and back. NASA needed on-board guidance systems to control the spacecraft independently of Mission Control back on Earth. They needed something that didn’t take up too much room or weigh too much, that could survive the shaking and juddering of take-off and background radiation: core rope memory fitted the bill perfectly.

It packed a lot of information (well, not by modern standards! The guidance computer contained only around 70 kilobytes of memory) into a small space and was very robust as it could only break if a wire came loose or one of the ferrite eyelets was damaged (which didn’t happen). To make sure though, the guidance computer’s electronics were sealed from the atmosphere for extra protection. They survived and worked well, guiding the Landing Modules safely onto the Moon.

One small step for man perhaps, but the Moon landings were certainly a giant leap for computing.


More on …

Related Magazines …


This article was funded by UKRI, through Professor Ursula Martin’s grant EP/K040251/2 and grant EP/W033615/1.

An ode to technology

by Paul Curzon, Queen Mary University of London

Cunning contraptions date back to ancient civilisations.

A female statue staring with head turned
Image by Devanath from Pixabay

People have always been fascinated by automata: robot-style contraptions allowing inanimate animal and human figures to move, long before computers could take the place of a brain.

Records show they were created in ancient Egypt, China, and Greece. In the renaissance Leonardo designed them for entertainment, and more recently magicians have bedazzled audiences with them.

The island of Rhodes was a centre for mechanical engineering in Ancient Greek times, and the Greeks were great inventors who loved automata. According to an Ode by Pindar the island was covered with automata:

The animated figures stand.

Adorning every public street.

And seem to breathe in stone,

Or move their marble feet.

Pindar

More on …

Cunning Computational Contraptions

Related Magazines …


This article was funded by UKRI, through Professor Ursula Martin’s grant EP/K040251/2 and grant EP/W033615/1.

Swallow a slug-bot to catch a …

by Paul Curzon, Queen Mary University of London

Imagine swallowing a slug (hint not only a yucky thought but also not a good idea as it could kill you)…now imagine swallowing a slug-bot … also yucky but in the future it might save your life.

When people accidentally swallow solid objects that won’t pass through their digestive system, or are toxic, it can be a big problem. Once an object passes beyond your stomach it becomes hard to get at.

That is where the slug shaped robot comes in. The idea of scientists at the Chinese University of Hong Kong is that a robot like a slug could crawl down your throat to retrieve whatever you had swallowed.

If you think of robots as solid, hard things then that would be the last thing you might want to swallow (aside from an actual slug), and certainly not to catch the previous solid thing you swallowed. You may be right. However, that is where the soft slug-shaped robot comes in.

It is easy to make or buy slime-like “silly” putty. Add iron filings to slime putty and you can make it stretch and sway and even move around with magnets yourself. You can buy such magnetic slime at science museums…it is fun to play with though you definitely shouldn’t swallow it.

The scientists have taken that general idea though and using special materials created a similar highly controllable bot that can be moved around using a magnet-based control system. It is made of a special material that is magnetic and slime-like but coated in silicon dioxide to stop it being poisonous.

They have shown that they can control it to squeeze through narrow gaps and encircle small objects, carrying them away with it…essentially what would be needed to recover objects that have been swallowed.

It needs a lot more work to make sure it is safe to really be swallowed. Also to be a real autonomous robot it would need to have sensors included somehow, and be connected to some sort of intelligent system to automatically control its behaviour. However, with more research that all may become possible.

So in the future if you don’t fancy swallowing a slug-bot, you’d better be far more careful about what else you swallow first. Of course, if it turns out slug like robots can break down, so get stuck themselves, you may then be in a position of needing to swallow a bird-bot to catch the slug-bot. How absurd …


More on …

Related Magazines …


The cs4fn blog is funded by EPSRC, through grant EP/W033615/1.