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#432882 Why the Discovery of Room-Temperature ...
Superconductors are among the most bizarre and exciting materials yet discovered. Counterintuitive quantum-mechanical effects mean that, below a critical temperature, they have zero electrical resistance. This property alone is more than enough to spark the imagination.
A current that could flow forever without losing any energy means transmission of power with virtually no losses in the cables. When renewable energy sources start to dominate the grid and high-voltage transmission across continents becomes important to overcome intermittency, lossless cables will result in substantial savings.
What’s more, a superconducting wire carrying a current that never, ever diminishes would act as a perfect store of electrical energy. Unlike batteries, which degrade over time, if the resistance is truly zero, you could return to the superconductor in a billion years and find that same old current flowing through it. Energy could be captured and stored indefinitely!
With no resistance, a huge current could be passed through the superconducting wire and, in turn, produce magnetic fields of incredible power.
You could use them to levitate trains and produce astonishing accelerations, thereby revolutionizing the transport system. You could use them in power plants—replacing conventional methods which spin turbines in magnetic fields to generate electricity—and in quantum computers as the two-level system required for a “qubit,” in which the zeros and ones are replaced by current flowing clockwise or counterclockwise in a superconductor.
Arthur C. Clarke famously said that any sufficiently advanced technology is indistinguishable from magic; superconductors can certainly seem like magical devices. So, why aren’t they busy remaking the world? There’s a problem—that critical temperature.
For all known materials, it’s hundreds of degrees below freezing. Superconductors also have a critical magnetic field; beyond a certain magnetic field strength, they cease to work. There’s a tradeoff: materials with an intrinsically high critical temperature can also often provide the largest magnetic fields when cooled well below that temperature.
This has meant that superconductor applications so far have been limited to situations where you can afford to cool the components of your system to close to absolute zero: in particle accelerators and experimental nuclear fusion reactors, for example.
But even as some aspects of superconductor technology become mature in limited applications, the search for higher temperature superconductors moves on. Many physicists still believe a room-temperature superconductor could exist. Such a discovery would unleash amazing new technologies.
The Quest for Room-Temperature Superconductors
After Heike Kamerlingh Onnes discovered superconductivity by accident while attempting to prove Lord Kelvin’s theory that resistance would increase with decreasing temperature, theorists scrambled to explain the new property in the hope that understanding it might allow for room-temperature superconductors to be synthesized.
They came up with the BCS theory, which explained some of the properties of superconductors. It also predicted that the dream of technologists, a room-temperature superconductor, could not exist; the maximum temperature for superconductivity according to BCS theory was just 30 K.
Then, in the 1980s, the field changed again with the discovery of unconventional, or high-temperature, superconductivity. “High temperature” is still very cold: the highest temperature for superconductivity achieved was -70°C for hydrogen sulphide at extremely high pressures. For normal pressures, -140°C is near the upper limit. Unfortunately, high-temperature superconductors—which require relatively cheap liquid nitrogen, rather than liquid helium, to cool—are mostly brittle ceramics, which are expensive to form into wires and have limited application.
Given the limitations of high-temperature superconductors, researchers continue to believe there’s a better option awaiting discovery—an incredible new material that checks boxes like superconductivity approaching room temperature, affordability, and practicality.
Tantalizing Clues
Without a detailed theoretical understanding of how this phenomenon occurs—although incremental progress happens all the time—scientists can occasionally feel like they’re taking educated guesses at materials that might be likely candidates. It’s a little like trying to guess a phone number, but with the periodic table of elements instead of digits.
Yet the prospect remains, in the words of one researcher, tantalizing. A Nobel Prize and potentially changing the world of energy and electricity is not bad for a day’s work.
Some research focuses on cuprates, complex crystals that contain layers of copper and oxygen atoms. Doping cuprates with various different elements, such exotic compounds as mercury barium calcium copper oxide, are amongst the best superconductors known today.
Research also continues into some anomalous but unexplained reports that graphite soaked in water can act as a room-temperature superconductor, but there’s no indication that this could be used for technological applications yet.
In early 2017, as part of the ongoing effort to explore the most extreme and exotic forms of matter we can create on Earth, researchers managed to compress hydrogen into a metal.
The pressure required to do this was more than that at the core of the Earth and thousands of times higher than that at the bottom of the ocean. Some researchers in the field, called condensed-matter physics, doubt that metallic hydrogen was produced at all.
It’s considered possible that metallic hydrogen could be a room-temperature superconductor. But getting the samples to stick around long enough for detailed testing has proved tricky, with the diamonds containing the metallic hydrogen suffering a “catastrophic failure” under the pressure.
Superconductivity—or behavior that strongly resembles it—was also observed in yttrium barium copper oxide (YBCO) at room temperature in 2014. The only catch was that this electron transport lasted for a tiny fraction of a second and required the material to be bombarded with pulsed lasers.
Not very practical, you might say, but tantalizing nonetheless.
Other new materials display enticing properties too. The 2016 Nobel Prize in Physics was awarded for the theoretical work that characterizes topological insulators—materials that exhibit similarly strange quantum behaviors. They can be considered perfect insulators for the bulk of the material but extraordinarily good conductors in a thin layer on the surface.
Microsoft is betting on topological insulators as the key component in their attempt at a quantum computer. They’ve also been considered potentially important components in miniaturized circuitry.
A number of remarkable electronic transport properties have also been observed in new, “2D” structures—like graphene, these are materials synthesized to be as thick as a single atom or molecule. And research continues into how we can utilize the superconductors we’ve already discovered; for example, some teams are trying to develop insulating material that prevents superconducting HVDC cable from overheating.
Room-temperature superconductivity remains as elusive and exciting as it has been for over a century. It is unclear whether a room-temperature superconductor can exist, but the discovery of high-temperature superconductors is a promising indicator that unconventional and highly useful quantum effects may be discovered in completely unexpected materials.
Perhaps in the future—through artificial intelligence simulations or the serendipitous discoveries of a 21st century Kamerlingh Onnes—this little piece of magic could move into the realm of reality.
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#432646 How Fukushima Changed Japanese Robotics ...
In March 2011, Japan was hit by a catastrophic earthquake that triggered a terrible tsunami. Thousands were killed and billions of dollars of damage was done in one of the worst disasters of modern times. For a few perilous weeks, though, the eyes of the world were focused on the Fukushima Daiichi nuclear power plant. Its safety systems were unable to cope with the tsunami damage, and there were widespread fears of another catastrophic meltdown that could spread radiation over several countries, like the Chernobyl disaster in the 1980s. A heroic effort that included dumping seawater into the reactor core prevented an even bigger catastrophe. As it is, a hundred thousand people are still evacuated from the area, and it will likely take many years and hundreds of billions of dollars before the region is safe.
Because radiation is so dangerous to humans, the natural solution to the Fukushima disaster was to send in robots to monitor levels of radiation and attempt to begin the clean-up process. The techno-optimists in Japan had discovered a challenge, deep in the heart of that reactor core, that even their optimism could not solve. The radiation fried the circuits of the robots that were sent in, even those specifically designed and built to deal with the Fukushima catastrophe. The power plant slowly became a vast robot graveyard. While some robots initially saw success in measuring radiation levels around the plant—and, recently, a robot was able to identify the melted uranium fuel at the heart of the disaster—hopes of them playing a substantial role in the clean-up are starting to diminish.
In Tokyo’s neon Shibuya district, it can sometimes seem like it’s brighter at night than it is during the daytime. In karaoke booths on the twelfth floor—because everything is on the twelfth floor—overlooking the brightly-lit streets, businessmen unwind by blasting out pop hits. It can feel like the most artificial place on Earth; your senses are dazzled by the futuristic techno-optimism. Stock footage of the area has become symbolic of futurism and modernity.
Japan has had a reputation for being a nation of futurists for a long time. We’ve already described how tech giant Softbank, headed by visionary founder Masayoshi Son, is investing billions in a technological future, including plans for the world’s largest solar farm.
When Google sold pioneering robotics company Boston Dynamics in 2017, Softbank added it to their portfolio, alongside the famous Nao and Pepper robots. Some may think that Son is taking a gamble in pursuing a robotics project even Google couldn’t succeed in, but this is a man who lost nearly everything in the dot-com crash of 2000. The fact that even this reversal didn’t dent his optimism and faith in technology is telling. But how long can it last?
The failure of Japan’s robots to deal with the immense challenge of Fukushima has sparked something of a crisis of conscience within the industry. Disaster response is an obvious stepping-stone technology for robots. Initially, producing a humanoid robot will be very costly, and the robot will be less capable than a human; building a robot to wait tables might not be particularly economical yet. Building a robot to do jobs that are too dangerous for humans is far more viable. Yet, at Fukushima, in one of the most advanced nations in the world, many of the robots weren’t up to the task.
Nowhere was this crisis more felt than Honda; the company had developed ASIMO, which stunned the world in 2000 and continues to fascinate as an iconic humanoid robot. Despite all this technological advancement, however, Honda knew that ASIMO was still too unreliable for the real world.
It was Fukushima that triggered a sea-change in Honda’s approach to robotics. Two years after the disaster, there were rumblings that Honda was developing a disaster robot, and in October 2017, the prototype was revealed to the public for the first time. It’s not yet ready for deployment in disaster zones, however. Interestingly, the creators chose not to give it dexterous hands but instead to assume that remotely-operated tools fitted to the robot would be a better solution for the range of circumstances it might encounter.
This shift in focus for humanoid robots away from entertainment and amusement like ASIMO, and towards being practically useful, has been mirrored across the world.
In 2015, also inspired by the Fukushima disaster and the lack of disaster-ready robots, the DARPA Robotics Challenge tested humanoid robots with a range of tasks that might be needed in emergency response, such as driving cars, opening doors, and climbing stairs. The Terminator-like ATLAS robot from Boston Dynamics, alongside Korean robot HUBO, took many of the plaudits, and CHIMP also put in an impressive display by being able to right itself after falling.
Yet the DARPA Robotics Challenge showed us just how far the robots are from truly being as useful as we’d like, or maybe even as we would imagine. Many robots took hours to complete the tasks, which were highly idealized to suit them. Climbing stairs proved a particular challenge. Those who watched were more likely to see a robot that had fallen over, struggling to get up, rather than heroic superbots striding in to save the day. The “striding” proved a particular problem, with the fastest robot HUBO managing this by resorting to wheels in its knees when the legs weren’t necessary.
Fukushima may have brought a sea-change over futuristic Japan, but before robots will really begin to enter our everyday lives, they will need to prove their worth. In the interim, aerial drone robots designed to examine infrastructure damage after disasters may well see earlier deployment and more success.
It’s a considerable challenge.
Building a humanoid robot is expensive; if these multi-million-dollar machines can’t help in a crisis, people may begin to question the worth of investing in them in the first place (unless your aim is just to make viral videos). This could lead to a further crisis of confidence among the Japanese, who are starting to rely on humanoid robotics as a solution to the crisis of the aging population. The Japanese government, as part of its robots strategy, has already invested $44 million in their development.
But if they continue to fail when put to the test, that will raise serious concerns. In Tokyo’s Akihabara district, you can see all kinds of flash robotic toys for sale in the neon-lit superstores, and dancing, acting robots like Robothespian can entertain crowds all over the world. But if we want these machines to be anything more than toys—partners, helpers, even saviors—more work needs to be done.
At the same time, those who participated in the DARPA Robotics Challenge in 2015 won’t be too concerned if people were underwhelmed by the performance of their disaster relief robots. Back in 2004, nearly every participant in the DARPA Grand Challenge crashed, caught fire, or failed on the starting line. To an outside observer, the whole thing would have seemed like an unmitigated disaster, and a pointless investment. What was the task in 2004? Developing a self-driving car. A lot can change in a decade.
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