The Fermi Paradox explores the haunting contradiction: if alien civilizations exist, why haven’t we found them? NASA advisor Paul Sutter unpacks this cosmic mystery.
Why is it important to know where earthquakes occur? They can cause a lot of damage and by predicting their locations, we could potentially prevent harm.
A magnetically controlled prosthetic hand, tested for the first time in a participant with an amputated lower arm, provided fine control of hand motion and enabled the user to perform everyday actions and grasp fragile objects. The robotic prosthetic, developed by a team at Scuola Superiore Sant’Anna in Pisa, uses tiny implanted magnets to predict and carry out intended movements.
Losing a hand can severely affect a person’s ability to perform everyday work and social activities, and many researchers are investigating ways to restore lost motor function via prosthetics. Most available or proposed strategies rely on deciphering electrical signals from residual nerves and muscles to control bionic limbs. But this myoelectric approach cannot reproduce the dexterous movements of a human hand.
Instead, Christian Cipriani and colleagues developed an alternative technique that exploits the physical displacement of skeletal muscles to decode the user’s motor intentions. The new myokinetic interface uses permanent magnets implanted into the residual muscles of the user’s amputated arm to accurately control finger movements of a robotic hand.
“Standard myoelectric prostheses collect non-selective signals from the muscle surface and, due to that low selectivity, typically support only two movements,” explains first author Marta Gherardini. “In contrast, myokinetic control enables simultaneous and selective targeting of multiple muscles, significantly increasing the number of control sources and, consequently, the number of recognizable movements.”
First-in-human test
The first patient to test the new prosthesis was a 34-year-old named Daniel, who had recently lost his left hand and had started to use a myoelectric prosthesis. The team selected him as a suitable candidate because his amputation was recent and blunt, he could still feel the lost hand and the residual muscles in his arm moved in response to his intentions.
For the study, the team implanted six cylindrical (2 mm radius and height) neodymium magnets coated with a biocompatible shell into three muscles in Daniel’s residual forearm. In a minimally invasive procedure, the surgeon used plastic instruments to manipulate the magnets into the tip of the target muscles and align their magnetic fields, verifying their placement using ultrasound.
Daniel also wore a customized carbon fibre prosthetic arm containing all of the electronics needed to track the magnets’ locations in space. When he activates the residual muscles in his arm, the implanted magnets move in response to the muscle contractions. A grid of 140 magnetic field sensors in the prosthesis detect the position and orientation of these magnets and transmit the data to an embedded computing unit. Finally, a pattern recognition algorithm translates the movements into control signals for a Mia-Hand robotic hand.
Gherardini notes that the pattern recognition algorithm rapidly learnt to control the hand based on Daniel’s intended movements. “Training the algorithm took a few minutes, and it was immediately able to correctly recognize the movements,” she says.
In addition to the controlled hand motion arising from intended grasping, the team found that elbow movement activated other forearm muscles. Tissue near the elbow was also compressed by the prosthetic socket during elbow flexion, which caused unintended movement of nearby magnets. “We addressed this issue by estimating the elbow movement through the displacement of these magnets, and adjusting the position of the other magnets accordingly,” says Gherardini.
During the six-week study, the team performed a series of functional tests commonly used to assess the dexterity of upper limb prostheses. Daniel successfully completed these tests, with comparable performance to that achieved using a traditional myoelectric prosthetic (in tests performed before the implantation surgery).
Importantly, he was able to control finger movements well enough to perform a wide range of everyday activities – such as unscrewing a water bottle cap, cutting with a knife, closing a zip, tying shoelaces and removing pills from a blister pack. He could also control the grasp force to manipulate fragile objects such as an egg and a plastic cup.
The researchers report that the myokinetic interface worked even better than they expected, with the results highlighting its potential to restore natural motor control in people who have lost limbs. “This system allowed me to recover lost sensations and emotions: it feels like I’m moving my own hand,” says Daniel in a press statement.
At the end of the six weeks, the team removed the magnets. Asides for low-grade inflammation around one magnet that had lost its protective shell, all of the surrounding tissue was healthy. “We are currently working towards a long-term solution by developing a magnet coating that ensures long-term biocompatibility, allowing users to eventually use this system at home,” Gherardini tells Physics World.
She adds that the team is planning to perform another test of the myokinetic prosthesis within the next two years.
We now know why some blood is missing a key antigen—leading to the creation of a new blood-grouping system. Experts believe even more discoveries are on the way.
The report was requested by Congress and published by the National Academies of Sciences, Engineering, and Medicine. It was written by a 13-member committee, which included representatives from industry, academia and government, and was chaired by Norman Augustine, former chief executive of Lockheed Martin. Members visited all nine NASA centres and talked to about 400 employees to compile the report.
While the panel say that NASA had “motivate[ed] many of the nation’s youth to pursue careers in science and technology” and “been a source of inspiration and pride to all Americans”, they highlight a variety of problems at the agency. Those include out-of-date infrastructure, a pressure to prioritize short-term objectives, budget mismatches, inefficient management practices, and an unbalanced reliance on commercial partners. Yet according to Augustine, the agency’s main problem is “the more mundane tendency to focus on near-term accomplishments at the expense of long-term viability”.
As well as external challenges such as China’s growing role in space, the committee discovered that many were homegrown. They found that 83% of NASA’s facilities are past their design lifetimes. For example, the capacity of the Deep Space Network, which provides critical communications support for uncrewed missions, “is inadequate” to support future craft and even current missions such as the Artemis Moon programme “without disrupting other projects”.
There is also competition from private space firms in both technology development and recruitment. According to the report, NASA has strict hiring rules and salaries it can offer. It takes 81 days, on average, from the initial interview to an offer of employment. During that period, the subject will probably receive offers from private firms, not only in the space industry but also in the “digital world”, which offer higher salaries.
In addition, Augustine notes, the agency is giving its engineers less opportunity “to get their hands dirty” by carrying out their own research. Instead, they are increasingly managing outside contractors who are doing the development work. At the same time, the report identifies a “major reduction” over the past few decades in basic research that is financed by industry – a trend that the report says is “largely attributable to shareholders seeking near-term returns as opposed to laying groundwork for the future”.
Yet the committee also finds that NASA faces “internal and external pressure to prioritize short-term measures” without considering longer-term needs and implications. “If left unchecked these pressures are likely to result in a NASA that is incapable of satisfying national objectives in the longer term,” the report states. “The inevitable consequence of such a strategy is to erode those essential capabilities that led to the organization’s greatness in the first place and that underpin its future potential.”
Cash woes
Another concern is the US government budget process that operates year by year and is slowly reducing NASA’s proportional share of funding. The report finds that the budget is “often incompatible with the scope, complexity, and difficulty of [NASA’s] work” and the funding allocation “has degraded NASA’s capabilities to the point where agency sustainability is in question”. Indeed, during the agency’s lifetime, the proportion of the US budget devoted to government R&D has declined from 1.9% of gross domestic product to 0.7%. The panel also notes a trend of reducing investment in research and technology as a fraction of funds devoted to missions. “NASA is likely to face budgetary problems in the future that greatly exceed those we’ve seen in recent years,” Augustine told a briefing.
The panel now calls on NASA to work with Congress to establish “an annually replenished revolving fund – such as a working capital fund” to maintain and improve the agency’s infrastructure. It would be financed by the US government as well as users of NASA’s facilities and be “sufficiently capitalized to eliminate NASA’s current maintenance backlog over the next decade”. While it is unclear how the government and the agency will react to that proposal, as Augustine warned, for NASA, “this is not business as usual”.
In the middle of one of the most expensive neighbourhoods in St Petersburg, Russia, is a vacant and poorly kept lot about half an acre in size. It’s been empty for years for a reason: on it stood the first scientific research laboratory in Russia – maybe even the world – and for over two and a half centuries generations of Russian scientists hoped to restore it. But its days as an empty lot may be over, for the land could soon be sold to the highest bidder.
The laboratory was the idea of Mikhail Lomonosov (1711–1765), Russia’s first scientist in the modern sense. Born in 1711 into a shipping family on an island in the far north of Russia, Lomonosov developed a passion for science that saw him study in Moscow, Kyiv and St Petersburg. He then moved to Germany, where he got involved in the then revolutionary, mathematically informed notion that matter is made up of smaller elements called “corpuscles”.
In 1741, at the age of 30, Lomonosov returned to Russia, where he joined the St Petersburg Academy of Science. There he began agitating for the academy to set up a physico-chemistry laboratory of its own. Until then, experimental labs in Russia and elsewhere had been mainly applied institutions for testing and developing paints, dyes and glasses, and for producing medicines and chemicals for gunpowder. But Lomonosov wanted something very different.
His idea was for a lab devoted entirely to basic research and development that could engage and train students to do empirical research on materials. Most importantly, he wanted the academy to run the lab, but the state to pay for it. After years of agitating, Lomonosov’s plan was approved, and the St Petersburg laboratory opened in 1748 on a handy site in the centre of St Petersburg, just a 20-minute walk from the academy, near the university, museums and the city’s famous bridges.
The laboratory was a remarkable place, equipped with furnaces, ovens, scales, thermometers, microscopes, grindstones and other instruments for studying materials
The laboratory was a remarkable place, equipped with furnaces, ovens, scales, thermometers, microscopes, grindstones and various other instruments for studying materials and their properties. Lomonosov and his students used these to analyse ores, minerals, silicates, porcelain, silicates, glasses and mosaics. He also carried out experiments with implications for fundamental theory.
In 1756, for instance, Lomonosov found that certain experiments involving the oxidation of lead carried out by the British chemist Robert Boyle were in error. Indirectly, Lomonosov also suggested a general law of conservation covering the total weight of chemically reacting substances. The law is, these days, usually attributed to the French chemist Antoine Lavoisier, who also came up with the notion three decades later. But Lomonosov’s work had suggested it.
A symbol for science
Lomonosov left the formal leadership of the laboratory in 1757, after which it was headed by several other academy professors. The lab continued to serve the academy’s research until 1793 when several misfortunes, including a flood and a robbery, led to it running down. Still, the lab has had huge significance as a symbol that Russian scientists have appealed to ever since as a model for more state support. It also inspired the setting-up of other chemical laboratories, including a similar facility built at Moscow University in 1755.
For the last two and a half centuries, however, the laboratory’s allies have struggled to keep the site from becoming just real estate in a pricey St Petersburg neighbourhood. In 1793 an academician bought the land from the Academy of Sciences and rebuilt the lab as housing, although preserving its foundations and the old walls. Over the next century, a series of private owners owned the plot, again rebuilding the laboratory and associated house.
The area was levelled again during the Siege of Leningrad in the Second World War, though the lab’s foundations remained intact. After the war, the Soviet Union tried to reconstruct the lab, as did the Russian Academy of Sciences. More recently, advocates have tried to rebuild the lab in time for the 300th anniversary of the Russian Academy of Science, which takes place in 2024–2025.
A piece of history The current state of the Lomonosov lab plot in St Petersburg. Fermilab accelerator physicist Vladimir Shiltsev (with umbrella, left) visited the site with lab restoration enthusiasts in 2021. A limited view can be seen from outside the plot on 2nd Linia Street (top right). Locked gates prevent general access to the land. (Courtesy: Vladimir Shiltsev (left image); Victor Borisov (right-hand images))
All these attempts have failed. Meanwhile, ownership of the site was passed around several Russian administrative agencies, most recently to the Russian State Pedagogical University. Last March, the university put the land in the hands of a private real estate agent who advertised the site in a public notice with the statement that the land was “intended for scientific facilities”, without reference to the lab. The plot is supposed to open for bids this fall.
But scientists and historians worry about the vagueness of that phrase and are distrustful of its source. There is nothing to stop the university from succumbing to the extremely high market prices that developers would pay for its enticing location in the centre of St Petersburg.
The critical point
Money, wrote Karl Marx in his famous article on the subject, is “the confounding and confusing of all natural and human qualities”. As he saw it, money strips what it is used for of ties to human life and meaning. Monetizing Lomonosov’s lab makes us speak of it quantitatively in real-estate terms. In such language, the site is simply a flat, featureless half-acre plot of land that, one metre down, has pieces of stone that were once part of an earlier building.
It also encourages us to speak of the history of this plot as just a series of owners, buildings and events. Some might even say that we have already preserved the history of Lomonosov’s lab because much of its surviving contents are on display in a nearby museum called the Kunstkamera (or art chamber). What, therefore, could be the harm of selling the land?
The land is where Lomonosov, his spirited colleagues and students, shared experiences and techniques, made friendships and established networks
Turning the history of science into nothing more than a tale of instruments promotes the view that science is all about clever individuals who use tools to probe the world for knowledge. But the places where scientists work are integral to science too. The plot of land on the 2nd avenue of Vasilevsky Island is where Lomonosov, his spirited colleagues and students, shared experiences and techniques, made friendships and established networks.
It’s where humans, instruments, materials and funding came together in dynamic events that revealed new knowledge of how materials behave in different conditions. The lab is also historically important because it impressed academy and state authorities enough that they continued to support scientific research as essential to Russia’s future.
Sure, appreciating this dimension of science history requires more than restoring buildings. But preserving the places where science happens keeps alive important symbols of what makes science possible, then and now, in a world that needs more of it. Selling the site of Lomonosov’s lab for money amounts to repudiating the cultural value of science.
For decades, a black hole that has as much spin or charge as it can given it mass was considered mathematically impossible. A new proof reveals otherwise.
Simulations of space–times that contain negative energies can help us to better understand wormholes or the interior of black holes. For now, however, the physicists who performed the new study, who admit to being big fans of Star Trek, have used their result to model the gravitational waves that would be emitted by a hypothetical failing warp drive.
Gravitational waves, which are ripples in the fabric of space–time, are emitted by cataclysmic events in the universe, like binary black hole and neutron star mergers. They might also be emitted by more exotic space–times such as wormholes or warp drives, which unlike black hole and neutron mergers, are still the stuff of science fiction.
First predicted by Albert Einstein in his general theory of relativity, gravitational waves were observed directly in 2015 by the Advanced LIGO detectors, which are laser interferometers comprising pairs of several-kilometre-long arms positioned at right angles to each other. As a gravitational wave passes through the detector, it slightly expands one arm while contracting the other. This creates a series of oscillations in the lengths of the arms that can be recorded as interference pattern variations.
The first detection by LIGO arose from the collision and merging of two black holes. These observations heralded the start of the era of gravitational-wave astronomy and viewing extreme gravitational events across the entire visible universe. Since then, astrophysicists have been asking themselves if signals from other strongly distorted regions of space–time could be seen in the future, beyond the compact binary mergers already detected.
Warp drives or bubbles
A “warp drive” (or “warp bubble”) is a hypothetical device that could allow space travellers to traverse space at faster-than-light speeds – as measured by some distant observer. Such a bubble contracts spacetime in front of it and expands spacetime behind it. It can do this, in theory, because unlike objects within space–time, space–time itself can bend, expand or contract at any speed. A spacecraft contained in such a drive could therefore arrive at its destination faster than light would in normal space without breaking Einstein’s cosmic speed limit.
The idea of warp drives is not new. They were first proposed in 1994 by the Mexican physicist Miguel Alcubierre who named them after the mode of travel used in the sci-fi series Star Trek. We are not likely to see such drives anytime soon, however, since the only way to produce them is by generating vast amounts of negative energy – perhaps by using some sort of undiscovered exotic matter.
A warp drive that is functioning normally, and travelling at a constant velocity, does not emit any gravitational waves. When it collapses, accelerates or decelerates, however, this should generate gravitational waves.
A team of physicists from Queen Mary University of London (QMUL), the University of Potsdam, the Max Planck Institute (MPI) for Gravitational Physics in Potsdam and Cardiff University decided to study the case of a collapsing warp drive. The warp drive is interesting, say the researchers, since it uses gravitational distortion of spacetime to propel a spaceship forward, rather than a usual kind of fuel/reaction system.
Decomposing spacetime
The team, led by Katy Clough of QMUL, Tim Dietrich from Potsdam and Sebastian Khan at Cardiff, began by describing the initial bubble by the original Alcubierre definition and gave it a fixed wall thickness. They then developed a formalism to describe the warp fluid and how it evolved. They varied its initial velocity at the point of collapse (which is related to the amplitude of the warp bubble). Finally, they analysed the resulting gravitational-wave signatures and quantified the radiation of energy from the space–time region.
While Einstein’s equations of general relativity treat space and time on an equal footing, we have to split the time and space dimensions to do a proper simulation of how the system evolves, explains Dietrich. This approach is normally referred to as the 3+1 decomposition of spacetime. “We followed this very common approach, which is routinely used to study binary black hole or binary neutron star mergers.”
It was not that simple, however: “given the particular spacetime that we were investigating, we also had to determine additional equations for the simulation of the material that is sustaining the warp bubble from collapse,” says Dietrich. “We also had to find a way to introduce the collapse that then triggers the emission of gravitational waves.”
Since they were solving Einstein’s field equation directly, the researchers say they could read off how spacetime evolves and the gravitational waves emitted from their simulation.
Very speculative work
Dietrich says that he and his colleagues are big Star Trek fans and that the idea for the project, which they detail in The Open Journal of Astrophysics, came to them a few years ago in Göttingen in Germany, where Clough was doing her postdoc. “Sebastian then had the idea of using the simulations that we normally use to help detect black holes to look for signatures of the Alcubierre warp drive metric,” recalls Dietrich. “We thought it would be a quick project, but it turned out to be much harder than we expected.”
The researchers found that, for warp ships around a kilometre in size, the gravitational waves emitted are of a high frequency and, therefore, not detectable with current gravitational-wave detectors. “While there are proposals for new gravitational-wave detectors at higher frequencies, our work is very speculative, and so it probably wouldn’t be sufficient to motivate anyone to build anything,” says Dietrich. “It does have a number of theoretical implications for our understanding of exotic spacetimes though,” he adds. “Since this is one of the few cases in which consistent simulations have been performed for spacetimes containing exotic forms of matter, namely negative energy, our work could be extended to also study wormholes, the inside of black holes, or the very early stages of the universe, where negative energy might prevent the formation of singularities.
Even though they “had a lot of fun” during this proof-of-principle project, the researchers say that they will now probably go back to their “normal” work, namely the study of compact binary systems.
Protracted flooding has engulfed the country’s Sudd region due to more water entering the Nile upstream, which is driving conflict and disease and is potentially leaving the region uninhabitable.
Cedric Dark is a gun-owning emergency physician, a father, and the cousin of a man who was shot to death. This is what he—and the science—say needs to change.
As unpleasant as this guilt is, the good news is that those feelings, if you listen to them, can help encourage healthier choices for you and your kids.
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