Science Article

With the relentless march of technological progress, robots and other automated systems are getting ever smarter. At the same time they are also being given greater responsibilities, driving cars, helping with childcareMovie Camera, carrying weapons, and maybe soon even pulling the trigger.

But should they be trusted to take on such tasks, and how can we be sure that they never take a decision that could cause unintended harm?

So are there things we can do to minimise the risks? Wallach and Allen take a look at six strategies that could reduce the danger from our own high-tech creations.

Keep them in low-risk situations

Make sure that all computers and robots never have to make a decision where the consequences can not be predicted in advance.

Likelihood of success: Extremely low. Engineers are already building computers and robotic systems whose actions they cannot always predict.

Do not give them weapons

Likelihood of success: Too late. Semi-autonomous robotic weapons systems, including cruise missiles and Predator drones, already exist. A few machine-gun-toting robots were sent to Iraq and photographed on a battlefield, though apparently were not deployed.

However, military planners are very interested in the development of robotic soldiers, and see them as a means of reducing deaths of human soldiers during warfare.

Give them rules like Asimov's 'Three Laws of Robotics'

Likelihood of success: Moderate. Isaac Asimov's famous rules are arranged hierarchically: most importantly robots should not harm humans or through inaction allow harm to them, of secondary importance is that they obey humans, while robotic self-preservation is the lowest priority.

However, Asimov was writing fiction, not building robots. In story after story he illustrates problems that would arise with even these simple rules, such as what the robot should do when orders from two people conflict.

Give them rules like Asimov's 'Three Laws of Robotics'

Likelihood of success: Moderate. Isaac Asimov's famous rules are arranged hierarchically: most importantly robots should not harm humans or through inaction allow harm to them, of secondary importance is that they obey humans, while robotic self-preservation is the lowest priority.

However, Asimov was writing fiction, not building robots. In story after story he illustrates problems that would arise with even these simple rules, such as what the robot should do when orders from two people conflict.

Sometimes identifying the best option under a given rule can be extremely difficult. For example, determining which course of action leads to the greatest good would require a tremendous amount of knowledge, and an understanding of the effects of actions in the world. Making such calculations would require time and a great deal of computing power.

Educate robots like children

Machines that learn as they "grow up" could develop sensitivity to the actions that people consider to be right and wrong.

Likelihood of success: Promising, although this strategy requires a few technological breakthroughs. While researchers have created robots able to learn in similar ways to humansMovie Camera, the tools presently available are very limited.

Make machines master emotion

Human-like faculties such as empathy, emotions, and the capacity to read non-verbal social cues should give robots much greater ability to interact with humans. Work has already started on equipping domestic robots with such faculties.

Likelihood of success: Developing emotionally sensitive robots would certainly help implement the previous three solutions discussed. Most of the information we use to make choices and cooperate with others derives from our emotions, as well as our capacity to read gestures and intentions and imagine things from another person's point of view.

Site reference : http://www.newscientist.com/

AT FIRST it's just noise: a stream of incoherent sounds, burbling away. But, after a few minutes, a fully formed word suddenly emerges: "red". Then another: "box". In this way, a babbling robot learns to speak its first real words, just by chatting with a human.

Ba, ba, ba, brick (Image: Pete Stevens)

Seeing this developmental leap in a machine may lead to robots that speak in a more natural, human-like way, and help uncover how children first start to make sense of language.

Between the ages of 6 and 14 months children move from babbling strings of syllables to uttering actual words. It's a necessary step en route to acquiring full language. Once a few "anchor" words have been established, they provide clues as to where words may start and finish and so it becomes easier for a child to learn to speak.

Inspired by this process, a team led by computer scientist Caroline Lyon at the University of Hertfordshire, UK, programmed their iCub humanoid robot, called DeeChee, with almost all the syllables that exist in English – around 40,000 in total. This allowed it to babble rather like a baby, by arbitrarily stringing syllables together.

The researchers also enlisted 34 people to act as teachers, who were told to treat DeeChee as if it were a child. DeeChee took part in an 8-minute dialogue with each teacher. Between each session, its memory was saved, wiped and reset, so that the experiment started anew with each teacher. At the outset of each dialogue, each of the syllables in DeeChee's lexicon had an identical score.

This learning by imitation was then reinforced by encouraging remarks from the teacher when DeeChee spoke a recognisable word. DeeChee was programmed to detect these comments and give extra points to the syllables that preceded the teacher's approval. Inevitably, some nonsense syllables would get extra points too. But as this process was repeated, only those syllables that made up words would keep showing up in strings that gained approval.

Though the robot was still uttering nonsense syllables, towards the end of the 8 minutes, real words kept popping up more often than if DeeChee were still selecting syllables at random.

Right now, DeeChee's speech is a far cry from full-blown language, but starting from babble could be the best way to create robots that speak naturally.

Journal reference: PLoS One, DOI: 10.1371/journal.pone.0038236

Site reference : http://www.newscientist.com/

The European Space Agency is continuing to prepare for the launch of its Gaia spacecraft set for 2013. Gaia's mission will see it creating a 3D map of a billion stars in the Milky Way using a 1.5-gigapixel camera.

In this photo, taken at the EADS CASA test facility in Madrid, Spain, checks are being made on Gaia's 1.5-metre-wide antenna panel to ensure data will reach Earth safely. The foam spikes on the walls of the test room block radio signals to simulate space. Electronic steering will ensure the antenna is always directed towards its target while the spacecraft rotates in space as it maps the stars, asteroids, extrasolar planets and other objects.

After launch, Gaia will take up an orbit around the sun 1.5 million kilometres beyond, but in pace with, Earth's to minimise the distance the weak signal has to travel. During its initial five-year mission, Gaia will send an estimated 200 terabytes of data to radio dishes in Spain and Australia. A working antenna is obviously central to downloading this data safely.

What's special?

Gaia will rely on the proven principles of ESA’s Hipparcos mission to create an extraordinarily precise three-dimensional map of more than a thousand million stars throughout our Galaxy and beyond. Gaia will also map the motions of stars, which encode their origins and evolution. Gaia will provide the detailed physical properties of each star observed, revealing luminosity, temperature, gravity and composition. This huge stellar census will provide the basic observational data to tackle an enormous range of important problems related to the origin, structure and evolutionary history of our Galaxy.

Gaia will achieve its goals by repeatedly measuring the positions of all objects down to magnitude 20 (about 400 000 times fainter than can be seen with the naked eye). Onboard object detection will ensure that variable stars, supernovae, other transient celestial events and minor planets will all be detected and catalogued to this faint limit. For all objects brighter than magnitude 15 (4000 times fainter than the naked eye limit), Gaia will measure their positions to an accuracy of 24 microarcseconds. This is comparable to measuring the diameter of a human hair at a distance of 1000 km. It will allow the nearest stars to have their distances measured to the extraordinary accuracy of 0.001%. Even stars near the Galactic centre, some 30 000 light-years away, will have their distances measured to within an accuracy of 20%.

Journey

Gaia will map the stars from an orbit around the Sun, at a distance of 1.5 million km beyond Earth’s orbit. This special location, known as the L2 Lagrangian point, keeps pace with Earth as we orbit the Sun.

L2 offers a stable thermal environment, a clear view of the Universe because the Sun, Earth and Moon are always outside the instruments’ fields of view, and a moderate radiation environment. An operational lifetime of five years is planned.
 

Site reference : http://www.esa.int/, http://www.newscientist.com/

The first concepts of Nanotechnology

The first use of the concepts in 'nano-technology' (but predating use of that name) was in "There's Plenty of Room at the Bottom," a talk given by physicist Richard Feynman at an American Physical Society meeting at Caltech on December 29, 1959.

Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed, using one set of precise tools to build and operate another proportionally smaller set, so on down to the needed scale. In the course of this, he noted, scaling issues would arise from the changing magnitude of various physical phenomena: gravity would become less important, surface tension and Van der Waals attraction would become more important, etc. This basic idea appears plausible, and exponential assembly enhances it with parallelism to produce a useful quantity of end products.

Today, in the young field of nanotechnology, scientists and engineers are taking control of atoms and molecules individually, manipulating them and putting them to use with an extraordinary degree of precision. Word of the promise of nanotechnology is spreading rapidly, and the air is thick with news of nanotech breakthroughs.

One of the most exciting technological advance in the world today is in the field of nanotechnology. Governments and bussines are investing billions of dollars in it. Public awareness of nanotech is clearly on the rise, too, partly because references to it are becoming more common in popular culture-with mentions in movies, books, video games, and television.

What is nanotechnology and how is it useful to us?

Some uses of nantechnology include :

China sent its first female astronaut into space on a mission to manually dock the Shenzhou- 9 spacecraft with an orbiting laboratory as part of the country’s plan to build a space station by 2020.

More than 50 female astronauts from seven countries have gone into space to date. The longest space flight by a female astronaut lasted 188 days. All countries that have completed manned space missions have attached great significance to their respective first female astronauts' maiden space flights, including the former Soviet Union's first female cosmonaut Valentina Tereshkova and Sally Ride, the first U.S. woman astrianut in space, and Iranian-American Anousheh Ansari, the first private-sector female space explorer. Now the name of Liu Yang will be added to space history books.

Liu Yang, 33, is a People's Liberation Army (PLA) Air Force major. She was a veteran pilot with 1,680 hours of flying experience and the deputy head of a flight unit of the PLA's Air Force before being recruited as a potential taikonaut in May 2010. Air-force pilot Liu Yang and two male astronauts blasted off at 6:37 p.m. Beijing time yesterday from Jiuquan in the northwestern Gansu province, according to a live broadcast on China’s Central Television. 

China will launch its Shenzhou-9 manned spacecraft at 6:37 p.m. Saturday (6:37 a.m. in Washington), if the launch preperations continue on schedule. The three-member taikonaut for the Shenzhou 9 mission is Jing Haipeng, Liu Wang and Liu Yang.

They will complete an automated docking with the Tiangong-1, or “Heavenly Palace,” laboratory module in two days and will then attempt a manual docking that is considered a major step in the space station program, the state-run Xinhua News Agency reported.

Chinese state media have lauded Liu’s accomplishments during the past week, framing her selection as part of the country’s broader push to expand its space program while other nations cut back. China aims to put a person on the moon by 2020 as well as operate a permanent manned space station.

(continued)

 

Precision surgeons

Operating on the human body requires high skill but also great control, something robots can provide. The idea of robotic surgery prompted early fears of unsupervised robots let loose to operate, but the reality is that robots now assist surgeons to perform precision procedures. The most successful of these is arguably the da Vinci robotic surgical system, which is used for keyhole surgery, to operate on anything from gall bladder removals and brain surgery to heart bypasses.

Similarly, tiny, wireless and robotic camera-capsules have been used diagnostically, by allowing them to pass through a patient's digestive system. Others have been designed to move about by remote control in the abdominal cavity, beaming images back to the surgeon, or even taking biopsy samples. Robot hands have even been developed to scan for breast cancer.

Actuators and sensors

But despite all the successes, there are still many challenges in robotics. These include producing better actuators (which control how robots move), sensors (which allow them to detect their environment) and ultimately making bots much smarter. Current motors, and hydraulic or pneumatic actuators, are either too weak, or too bulky and noisy. 

Bipedal and humanoid robots have proved a particular problem. Robots on wheels, or those that move like insects, have found it much easier to balance and get around.

And while much early research in robotics focused on using sonar sensors because they were cheap and easy to use, the focus today is on the more challenging, yet richer, vision-based navigation systems.

Similarly, while there is much research on making robotic arms and hands, the difficulty lies in making electronic skin sensitive enough to detect fragile or slippery objects by touch alone. A robot that mimics human speech is also under development.

The ultimate test perhaps is robot soccer. This is driving development in just about every area of robotics from the ability to run and kick a ball to communicating and demonstrating teamwork. The grand aim is to have a team of humanoid robots that can beat the best human soccer team in the world by 2050.

LIKE PCs, robots may soon become a key part of our everyday lives, but they present unique communication challenges that PCs do not. So roboticists are turning to people who have already solved many of these problems - actors, animators and dancers. 

Old Robot

The Merriam Webster Dictionary, 1998, defines robotics as “technology dealing with the design, construction, and operation of robots”.

Robotics encompasses such diverse areas of technology as mechanical, electrical, and electronic systems; computer hardware; and computer software. 

Ever since the Czech writer Karel Èapek first coined the term "robot" in 1921, there has been an expectation that robots would some day deliver us from the drudgery of hard work. The word - from the Czech "robota", for hard labour and servitude - described intelligent machines used as slaves in his play R.U.R. (Rossum's Universal Robots).

Today, over one million household robots, and a further 1.1 million industrial robots, are operating worldwide. Robots are used to perform tasks that require great levels of precision or are simply repetitive and boring. Many also do jobs that are hazardous to people, such as exploring shipwrecks, helping out after disasters, studying other planets and defusing bombs or mines.

Domestic invasion

Despite the longevity of the robot concept, robotic butlers that roam our homes and relieve us from housework still seemed far from reality until very recently. Instead, the vast majority of robots worked in factories performing the industrial functions of brainless machines.

However, a combination of increased computing power and advances made in the field of artificial intelligence, or AI, have now made software smart enough to make robots considerably more useful.

Suddenly people were happy to pay for robots that had no specific functional value. Instead these bots, such as Sony's Aibo robotic dog and its robo-pups served as robo-pets and companions, rather than slaves.

 
Movers and shakers

Nao Robot

And while we often think of robots being humanoid, such as Honda's Asimo and Sony's Qrio, there is as much interest, if not more, in emulating other creatures like insects, lobsters, orang-utans, alligators, snakes and fish. A robot guard dragon has even been created.

Whether they have two legs, many legs, or no legs at all, considerable advances have been made in robot locomotion, including bipedal walking, rambling, crawling, rock-climbing, bouncing, slithering and swimming.

Robot wars

One area where even more advances in autonomy have been made is the development of unmanned aerial vehicles, or UAVs. These are essentially remotely-controlled spy planes that are capable of flying themselves if they lose contact with their pilot. These planes can also be used to monitor forest fires. Some robots have even learnt to fly of their own accord.

Mars Rover robot

The Pentagon has started arming some UAVs, making them capable of responding with firepower against aggressive attacks - so-called unmanned combat vehicles, or UCVs. Robots that act as battlefield spies have also been designed.

In addition, NASA has already sent robotic rovers to Mars, developed robotic dirt scoopers, "flying eyes" and probes for interplanetary exploration and even sent droids off to try to explore asteroids. Space probes such as Huygens (which landed on Titan) and Russia's Venera 9 (which landed on Venus) are sometimes considered robots too. A robotic rover has even been used to explore Egyptian pyramids.

A military reconnaissance robot being developed at a British lab can keep moving even if it gets damaged on the battlefield. When any of the snake-like robot's "muscle" segments are damaged, clever software "evolves" a different way for it to wriggle across any terrain. The serpentine spy is a research project funded by aerospace company BAE Systems to make a low-cost military robot that can be dropped out of helicopters to carry out reconnaissance missions. 

A self-healing robot has long been a dream of robotics engineers, not least because the machines are notoriously unreliable and absolutely terrible at dealing with unforeseen circumstances. The snakebot is made up of modular vertebral units that "snap" together to form a snake-like body (see picture). 

Shape-memory Alloy

Each unit contains three separate "muscles" running down its length. The muscles are made out of wires of a shape-memory alloy called nitinol, an alloy of nickel and titanium whose crystal structure shrinks when an electric current is applied to it. Usefully, it regains its original shape and length once the current is removed.

To make the snakebot move in a particular direction, a current is applied to certain wires. When the current is removed, the wires spring back and the robot will jump forward.

The software for making a robot wriggle like a snake is fairly straightforward. But ensuring that the snake will keep moving even if a segment is damaged is trickier, and relies on different segments taking over from the damaged ones.

Genetic Algorithm

The program starts off with a population of 20 digital chromosomes, with each consisting of an initially random binary digit that corresponds to a muscle wire - where a 1 represents its activation and a 0 its deactivation. Each of these chromosomes forms the basis of a series of movements in the robot.

The two best chromosomes are then saved, the remainder are mixed up or randomly mutated and the process is repeated. After a number of generations, the amount of improvement finally tends to taper off.

Bentley and his colleague Siavash Haroun Mahdavi at University College London borrowed a trick from evolution to allow their robot to adaptive ability and so tend to give up the ghost when circumstances change.

So, they make a bot like snake, thr name of is SNAKEBOT.

Your DNA contains a set of instructions for "building" a human. These instructions are inscribed in the structure of the DNA molecule through a genetic code. DNA has no reason to feel special. For decades it seemed that only a handful of molecules could store genetic information and pass it on. But now synthetic biologists have discovered that six others can pull off the same trick, and there may be many more to find.

A host of alternative nucleic acids have been made in labs over the years, but no one has made them work like DNA.

This problem has now been cracked. "This unique ability of DNA and RNA to encode information can be implemented in other backbones," says Philipp Holliger of the MRC Laboratory of Molecular Biology in Cambridge, UK.

Evolving XNA

Holliger's team focused on six XNAs (xeno-nucleic acids). DNA and RNA are made of a sugar, a phosphate and a base. The XNAs had different sugars, and in some of them the sugars are replaced with completely different molecules.

A key hurdle for the team was to create enzymes that could copy a gene from a DNA molecule to an XNA molecule, and other enzymes that could copy it back into DNA.

They started with enzymes that do this in DNA only. Over the years the team made incremental tweaks until they produced enzymes that could work on XNAs.

Once they had created these enzymes, they were able to store information in each of the XNAs, copy it to DNA, and copy it back into a new XNA. In effect, the first XNA passed its information on to the new one – albeit in a roundabout way.

This is the first time artificial molecules have been made to pass genes on to their descendants. Because the XNAs can do this, they are capable of evolution.

Journal reference: Science DOI: 10.1126/science.1217622

Tiny carbon nuggets in meteorites from Mars were formed by cooling magma, not left by ancient alien microbes. That's both good news and bad news for astrobiologists.

The 1996 discovery of carbonate structures in meteorite ALH-84001 – which travelled to Earth from Mars more than 13,000 years ago – was hailed at the time as evidence that alien microbes once lived on the red planet. However, subsequent studies of both the carbonate structures and tiny nuggets of macromolecular carbon (MMC) in the meteorite cast doubt on the claims.

Paradoxically, the find actually boosts prospects for finding signs of ancient life in Martian rocks. The carbon in MMC was originally chemically reduced – meaning it carries extra electrons and is quick to react. Such readily available and reactive carbon could have joined with other elements to create complex chemical molecules, perhaps even life.

NASA and the European Space Agency (ESA) were planning a pair of joint missions to Mars that could have made important strides in the search for past or present life.

The ExoMars Trace Gas Orbiter, which was to launch in 2016, would have followed up on hints of methane discovered in the Martian atmosphere by previous missions. The gas is of particular interest as it is commonly produced by microbes on Earth.

ExoMars ( Mars Rover)

The ExoMars rover, which had been slated for launch in 2018, would have drilled beneath the Martian surface to get samples of pristine material, possibly including complex carbon-based molecules that could have provided clues to past Martian life.

The Mars budget was slashed as a result, with NASA's contribution to the flagship ExoMars mission the main casualty.

NASA still hopes to mount a less costly mission to Mars in 2018, but it might not land on the surface. The agency has not specified exactly where it would go, but orbiters tend to be less expensive than rovers.

The proposed budget also confirms that NASA plans to continue building the James Webb Space Telescope with a launch targeted for 2018, and continue payments to private space companies like SpaceX to help them develop space taxis that could take crew to the International Space Station.

NASA wants $830 million for space taxi development in 2013. It asked for a similar amount in 2012, but Congress cut it by more than half, to about $400 million.

Computation is any type of calculation or the use of computer technology in Information processing. Computation is a process following a well-defined model understood and expressed in an algorithm, protocol, network topology, etc. Computation is also a way for find solve problem from some quetion about mathematics. Many software about computation has created and easy to use. Computation also can to be created animated.

Turing's achievements matter today begins with the story of how he set out to solve one of his era's biggest mathematical conundrums - and in the process defined the basis of all computers

The first computer

Up until the second world war, the word "computer" meant a person, These human computers were an essential part of the industrial revolution and performed often repetitive calculations, such as those necessary for the creation of books of log tables. 

But in 1936, Turing, aged just 24, laid the foundations for a new type of computer - one we would still recognise today - and so played a seminal role in the information technology revolution.

Turing did not set out to invent the model for the modern computer, though. He wanted to resolve a conundrum in mathematical logic. In the mid-1930s, he decided to attack the fearsomely named Entscheidungsproblem - or "decision problem" - posed by mathematician David Hilbert in 1928. In other words: does a step-by-step procedure exist that can determine whether any given statement in mathematics is true or false?

In 1936, Turing published a paper that provided a definitive answer to Hilbert's question: no procedure exists for determining whether any given mathematical statement is true or false. Moreover, many of the important unresolved questions in mathematics are "undecidable" (Proceedings of the London Mathematical Society, Vol 42, p 230). This was good news for human mathematicians, because it meant that they would never be replaced by machines. But with his paper, Turing had achieved more than the resolution of Hilbert's question. To arrive at his result, he had also come up with the theoretical basis for modern computers.

First, he imagined a machine capable of reading symbols from a paper tape. You would feed the paper tape in, and the machine would examine the symbols, then make a decision about what to do next by following a set of internal rules. It could, for example, add two numbers that were written on the tape and print the result further along the tape. This would later come to be known as a Turing machine.

Turing realised that it would be possible to make a machine that could initially read a procedure from the tape, and use that to define its internal rules. By doing so, it was programmable, and could perform the same actions of any individual Turing machine, which had fixed internal rules. That flexible device, which we call a universal Turing machine, is a computer.

June 23 marks the 100th birthday of Alan Turing. If I had to name five people whose personal efforts led to the defeat of Nazi Germany, he helped decipher the messages created by the Nazi's Enigma coding machines.

My, my, my Delilah

Turing is often associated with breaking codes, but in 1943 he also spent time making them. At the secret UK government laboratory at Hanslope Park in Buckinghamshire, Turing led the development of a portable device for speaking securely with another person. It was named Delilah and could be used to scramble a telephone or radio conversation.

Delilah was revolutionary because the scrambling system was very hard to break, yet was portable. By contrast, the secure phone system that linked the British prime minister at 10 Downing Street to the US president in the White House was so large that it had to be installed in the basement of the Selfridges store on London's Oxford Street. Called SIGSALY, it weighed 50 tonnes and required thousands of watts of power. Other, smaller voice scramblers were insecure and easily decoded by the Nazis.

Delilah worked by combining the speech to be scrambled with what sounded like random noise, similar to an untuned radio. When put together, all an eavesdropper would hear was noise, but by careful synchronisation between two Delilah machines at either end, it was possible to filter out the random noise and hear the original speech.

Delilah generated a sequence of numbers that both the sender and receiver could reproduce from a secret key (a way of setting the machine known only to them). By sampling the waveform of the voice to be transmitted - just as modern computers sample music to produce numbers that are stored on a CD or in an MP3 music file - the voice became a stream of numbers. These could then be enciphered by adding each number to a corresponding number from the random sequence. At the other end, a subtraction of the same random number would reveal the original number, which could then be used to reproduce the voice waveform.

Cracking Nazi Codes

When studying at Princeton University in 1936, Turing wrote to his mother saying that he had discovered a way to use mathematics to encrypt messages. Three years later, he was back in the UK using his skills to break Nazi codes. His efforts at the British military intelligence base Bletchley Park significantly affected the course of the second world war.

At Bletchley, Turing was known universally as "The Prof". He quickly became arguably the most important code breaker there. Most famously, he helped decipher the messages created by the Nazi's Enigma coding machines. To do so, he and his colleagues had to use a combination of insight, intelligent guesses and clever engineering.

An Enigma machine employed rotating wheels that assigned each typed letter to a different coded letter of the alphabet. A second machine at the receiver's end would reverse the process, deciphering the message.

Enigma messages were impossible to crack by brute force, using either raw manpower or simple mechanical calculators, because of the huge number of "keys" used. A key is the crux of any code system: it is a secret "password" agreed on by two people communicating in code. In the case of Enigma, the key consisted of the way each machine was set up before a message was transmitted. Both sender and receiver would arrange their wheels in a pre-agreed fashion, as well as arranging a plugboard similar to that used in a telephone exchange. Depending on whether three or four wheels were used, that meant there were 26x26x26 (17,576) or 26x26x26x26 (456,976) possible keys. And the additional variations in the plugboard settings made messages even more secure.

Alan Turing is my favorite Scientist, (23 June 1912 – 7 June 1954). Maths genius Alan Turing honoured with an interactive Google doodle on 100th birthday in 23 June 2012.

A new short film about Alan Turing’s contribution to the birth of the modern computer and his work in Britain following the war is now available. Based on Turing’s work with the National Physics Laboratory (NPL), the film features Tom Vickers, who knew Turing and worked on the Pilot ACE at the Laboratory.

In space, a year can be a long time. Back at the beginning of 2004, the idea that the Red Planet had once been covered with rivers, lakes and seas was just a hypothesis. By 2005, two quad-bike-sized, roving-laboratories had collected abundant evidence on the ground that turned the idea into an established fact, including stratified sediments, and minerals that probably formed in the presence of water.

Anatomy of Mars Rovers

The story could so easily have been otherwise. After a year of stunning successes by NASA's twin Mars rovers Spirit and Opportunity, it is hard to remember just how much tension surrounded the landings. Following the loss of both the Japanese Mars orbiter Nozomi and the ESA's Beagle 2 probe just weeks earlier, and the Columbia space shuttle disaster in February 2003, much was riding on the missions' success. The roll call of past Mars missions is littered with other failures.

Landing sites were carefully selected to be those that might have flowed with water in warmer periods of the planet's history. NASA's Mars Odyssey orbiter, launched in 2001, had revealed features resembling old lakes, rivers and flood plains, as had its predecessor the Mars Global Surveyor. After a series of delays, rover-laden rockets were launched in June and July 2003.

First to arrive was Spirit on 3 January 2004, at the Gusev Crater - the possible site of a prehistoric lakebed, just south of the Martian equator. Three weeks later, Spirit was followed by its twin, Opportunity, which landed on the other side of the planet at the Meridiani Planum - a site of possible ancient water action.

Both landings were virtually flawless. It has pretty much been that way ever since. Everything has worked better than expected, with just a few glitches, such as problems with a wheel mechanism, computer chips and onboard memory. Future rovers will be able to overcome some problems by self-diagnosis.

On the other side of the planet, Opportunity found good evidence of water much more rapidly. Haematite, a mineral which usually forms in the presence of water, was found to be the main component of tiny spherules termed "blueberries" that littered the plains. While Spirit was trundling its way to the Columbia Hills, Opportunity was set on a course for Endurance Crater - a feature where it later uncovered hints of possible past wet-dry climatic cycles.

Designed to last for 90 days, both rovers have now gone about four times that long and show no signs of stopping any time soon. In fact, with the Martian winter over and dust mysteriously getting cleaned off the solar panels, the rovers are actually gaining power and should continue to do so for a few more months.

Now that we know Mars had water, future missions are aimed at discovering how long it lasted and whether it persists today. More elaborate orbiters, giant rovers and - one day - human landings (plus perhaps even a permanent settlement) are planned to help answer these questions and continue the hunt for life on Mars.

A swallowable ultrasound device called uPill could end the need for painful daily injections

DAILY injections are a painful fact of life for many people with diabetes or cancer. Pills are an easier and more pleasant treatment method but substances like insulin do not penetrate tissue quickly enough to be effective when taken orally. Now a pill that uses ultrasound to speed up drug delivery could remove the need for needles.

Ultrasound has been used for years to accelerate the transfer of drugs through skin and can increase drug absorption by a factor of 10. The method works by heating up molecules inside skin tissue, making cell membranes more permeable. It is particularly good for delivering protein-based drugs such as some cancer medicines, insulin and various vaccinations.

This technique has now been applied to a pill. Designed by biomedical engineering company Zetroz, the uPill will use ultrasound to increase the absorption rate of drugs through tissue in the gastrointestinal tract, says Daniel Anderson at the Massachusetts Institute of Technology, who is part of the team developing the device.

The required drug would be applied as a coating to the uPill and, once swallowed, the device would send ultrasound waves through the patient's gut to aid absorption. It would then pass through the digestive system, as a camera pill does. The device was presented at the IdeaStream conference at MIT in May. Animal tests are now being carried out to see if the device can pass through the digestive system safely.

"The key thing here is the miniaturisation technology we are using to make an already small device a lot smaller," says George Lewis, co-founder of Zetroz and lead engineer for the uPill. The firm previously developed an ultrasound patch to deliver drugs through the skin. "We are developing the smallest ultrasound system in the world."

Anderson hopes the uPill could hit the market in the next couple of years. "It is far too early to claim victory but we are excited about the potential applications," he says. "It could create an entirely new class of drugs."

The pills won't come cheap - each one will cost $20 to $30. But while the device is, in theory, reusable, Anderson admits this probably won't be a hugely popular option.

Growing evidence suggests that not all cases of early-stage breast cancer would be deadly. Should surgeons be leaving well alone?

THE lump in her right breast was smaller than a pea. When she first noticed it, last August, 28-year-old photographer Ellen Doherty was busy working on an exhibition. She put off visiting the doctor for a month.

When Doherty finally went, the doctor said it was probably nothing to worry about. But they did a scan to be sure - and that led to several more tests. Finally they said she had a 2.8-millimetre tumour known as ductal carcinoma in situ, or DCIS.

Like many women given this diagnosis, Doherty had never heard of it before. She quickly devoured any information she could find, but came away confused.

The term "in situ" means that the cancerous cells are contained within the breast's milk ducts and have not invaded the surrounding tissue. This kind of lesion is not harmful unless it progresses past that stage and becomes invasive, but it is treated just as aggressively as invasive cancer. Yet this approach is increasingly being questioned as evidence emerges that for some women DCIS would not turn out to be dangerous.

In fact, DCIS could be regarded as a creation of modern medicine, as most cases are found through breast screening - 30 years ago it was rarely diagnosed. The fear is that screening may be leading us to cut out lumps that, left alone, would have never caused a problem. "Are we helping people by diagnosing it, or are we making things worse?" asks Beth Virnig, who monitors cancer surveillance and detection data at the University of Minnesota in Minneapolis. Breast cancer used to be discovered only if it formed a noticeable lump or caused other symptoms such as nipple discharge. Since the advent of breast screening programmes using X-rays known as mammograms in the 1980s, it is more commonly found that way. And that means growing numbers of DCIS cases are being detected. In the US, the incidence has grown more than eight-fold since the 1980s (see graph). DCIS now makes up about a quarter of breast cancer cases found through screening.

When a mammogram turns up an abnormality the next step is a biopsy to remove a small sample of the tissue in question. If the diagnosis is DCIS, the options are the same as for invasive cancer: excision of a lump containing the growth, if possible, or removal of the breast. To Doherty this seemed bizarre: "How can they cut one of your boobs off for something that's not going to kill you?"

Doherty had a lumpectomy in November, but while she was recovering, a doctor called to say the affected tissue was more widespread than they thought and they hadn't cut out enough. In January she had a mastectomy.

This zero-tolerance approach to DCIS is based on the assumption that, given the chance, it will progress to invasive cancer. Yet no one knows how often that assumption is correct.
Disappearing tumours

It may sound surprising but people can have small cancers that do them no harm; autopsies can reveal "incidental cancers" that were not the cause of death. Some tumours are so slow-growing that they never cause a problem, while others, including some cases of breast cancer, go away on their own, presumably eliminated by the immune system.

Scour the medical literature for a figure for how often DCIS progresses to invasive cancer if left untreated and you will find estimates as low as 14 per cent and as high as 75 per cent, a range so broad as to be almost meaningless. There has never been a large study of women given this diagnosis who don't have surgery, so the progression rate can only be inferred by indirect means.

Take, for instance, a study of laboratory tissue samples from women who had a breast lump biopsied many decades ago, and went untreated because tests at the time indicated it was benign. Re-examining those biopsies turned up some in which a mistake had been made and the woman actually had DCIS. Of 71 such cases where they could track down the women, about half had gone on to develop invasive breast cancer.

That figure is probably an overestimate, though, because the women in that study had DCIS that had grown big enough to be felt as a lump. "Mammographically detected DCIS has a much lower risk of invasive cancer than DCIS detected [as a lump]," says Karla Kerlikowske, an epidemiologist at the University of California, San Francisco (UCSF).

There is another kind of evidence that suggests our current approach might be wrong. If this condition usually progresses to invasive cancer, then catching and cutting out more cases of DCIS should lead to a drop in cases of invasive cancer. That is what has happened with colon cancer: the removal of small precancerous growths, or polyps, in the colon detected through screening by colonoscopy has coincided with falling rates of colon cancer (see graph).

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In a vacuum-sealed flask on a lab bench in Germany sits an emerald-green crystal that will cause some jaws to drop. The crystal is the first stable compound containing a triple chemical bond between two boron atoms, a feat that had previously been limited to only two other non-metal elements – carbon and nitrogen.

BORON has been hiding secret skills but its cover is finally blown.

In a tightly sealed flask in a German lab sits an emerald-green crystal that is the first stable compound with a triple chemical bond between two boron atoms. Such bonds were previously reserved for an elite club of atoms, including carbon, which sits next to boron in the periodic table.

In another first, boron atoms have linked up with each other in chains. Carbon's tendency to do so is the basis for organic chemistry, making possible DNA, proteins, alcohols and plastics. Synthetic, or alien, life based on boron remains far-fetched - boron still can't link to other life-related compounds, for one thing. But the feats pave the way for boron-based polymers, and other structures previously undreamed of. "Certainly this will go into the textbooks," says Holger Braunschweig of the University of Würzburg in Germany.

Until now largely obscure, boron occupies a special spot in the periodic table. On one side are metals like beryllium, which give away their outermost electrons to form ionic bonds. On the other side are the non-metals carbon and nitrogen, which prefer sharing electrons in covalent bonds.

A single covalent bond is two electrons shared between two atoms. Carbon, with four outer electrons, and nitrogen with five, form triple covalent bonds consisting of six shared electrons, or three pairs. Boron has three outer electrons, so in principle should be capable of this too, but it has remained aloof. In 2002, Mingfei Zhou and colleagues at Fudan University in Shanghai, China, managed to make a boron triple bond - but only at 8 degrees above absolute zero.

Boron can hold up to eight outer electrons: a pair in each of four slots. In atomic boron, one of these slots is completely empty and the other three are half-full, with one electron apiece. To make triple-bonded boron that could survive at room temperature, Braunschweig and his colleagues filled all four slots. They filled up the empty slot by bonding each boron atom to a molecule that donated two electrons. Each boron atom then completed the filling of its slots by pairing up with another boron atom and pooling its original three electrons (see diagram). In the resulting compound, each boron atom has a full suite of eight outer electrons, making it stable (Science, DOI: 10.1126/science.1221138).

Braunschweig and his team have already begin investigating the reactivity of the novel compound. "It turns out that it shows a rich chemistry," he says.

Triple-bonding is not the only way the researchers got boron to mimic its superstar neighbour, carbon, though. They also coaxed boron atoms into forming a chain. Previous attempts to do this with boron failed and resulted in messy clusters. "It is extremely difficult to form chains of boron atoms," says Braunschweig. The secret was to attach the boron atoms to an iron scaffold, which allowed up to four to form a chain (Nature Chemistry, DOI: 10.1038/nchem.1379).

Next, Braunschweig and his team hope to free this boron chain from its scaffold and increase the chain length to form the boron equivalent of polyethylene, a common plastic. "The material, if it could be made, would have completely different physical behaviour from an ordinary carbon chain," Braunschweig says

There is something unnatural lurking in the waters of the port of Gijon, Spain, and researchers are tracking its every move. It is not some bizarre new form of marine life, but an autonomous robotic fish designed to sense marine pollution, taking to the open waves for the first time.

"With these fish we can find exactly what is causing the pollution and put a stop to it right away," explains Luke Speller, a scientist at the British technology firm BMT and the leader of SHOAL, a European project involving universities, businesses and the port of Gijon, which have joined forces to create the fish.

Currently the port relies on divers to monitor water quality, which is a lengthy process costing €100,000 per year. The divers take water samples from hundreds of points in the port, then send them off for analysis, with the results taking weeks to return. By contrast, the SHOAL robots would continuously monitor the water, letting the port respond immediately to the causes of pollution, such as a leaking boat or industrial spillage, and work to mitigate its effectsMovie Camera.

The SHOAL fish are one and a half metres long, comparable to the size and shape of a tuna, but their neon-yellow plastic shell means they are unlikely to be mistaken for the real thing. A range of onboard chemical sensors detect lead, copper and other pollutants, along with measuring water salinity. They are driven by a dual-hinged tail capable of making tight turns that would be impossible with a propeller-driven robot.

They are also less noisy, reducing the impact on marine life. The robots are battery powered and capable of running for 8 hours between charges. At the moment the researchers have to recover them by boat, but their plan is that the fish will return to a charging station by themselves.

Working in a group, the fish can cover a 1 kilometre-square region of water, down to a depth of 30 metres. They communicate with each other and a nearby base-station using very low-frequency sound waves, which can penetrate the water more easily than radio waves. However, this means the fish have a low data transmission rate and can only send short, predefined messages. "It's a good solution, but it requires thinking carefully about what data to transmit and how to use that data," says Kristi Morgansen, a roboticist at the University of Washington, who was not involved in the research.

Navigation relies on a related system that communicates with four "pingers" at the corners of the port, which act much like GPS satellites for the fish. If one fish senses pollution in an area it can call the others to create a detailed map of high and low concentrations around it, helping port authorities to locate the exact source of the pollutant.

Versions of the fish have been working successfully in the lab for a few years now, but trialling them in a real-life port has proved more difficult. Rough weather has often prevented the researchers from venturing out on the waves, though Speller says the fish would be fine as they can simply dive below the water. But depth has also been a problem – the waterproofing on one component is unable to withstand the pressure at 30m underwater, so it requires a last-minute replacement.

Thankfully the fish are fitted with a variety of safety features if something goes wrong, such as airbags that inflate to make the fish surface, and a GPS and cellphone chip in the fin so that a distressed fish can send its location details to Speller's phone via text message.

Having demonstrated that the fish can sense pollution and communicate underwater, the SHOAL group now plans to commercialise the design and sell it to other ports in Europe and the rest of the world. The prototypes currently cost around £20,000 each, but mass production should bring that price down.

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