MAGICKAL THINKING

Can consciousness be explained by quantum physics? 

My research takes us a step closer to finding out

July 19, 2021 

Some scientists believe consciousness is generated by quantum processes, but the theory is yet to be empirically tested. vitstudio/Shutterstock


One of the most important open questions in science is how our consciousness is established. In the 1990s, long before winning the 2020 Nobel Prize in Physics for his prediction of black holes, physicist Roger Penrose teamed up with anaesthesiologist Stuart Hameroff to propose an ambitious answer.

They claimed that the brain’s neuronal system forms an intricate network and that the consciousness this produces should obey the rules of quantum mechanics – the theory that determines how tiny particles like electrons move around. This, they argue, could explain the mysterious complexity of human consciousness.

Penrose and Hameroff were met with incredulity. Quantum mechanical laws are usually only found to apply at very low temperatures. Quantum computers, for example, currently operate at around -272°C. At higher temperatures, classical mechanics takes over. Since our body works at room temperature, you would expect it to be governed by the classical laws of physics. For this reason, the quantum consciousness theory has been dismissed outright by many scientists – though others are persuaded supporters.

Instead of entering into this debate, I decided to join forces with colleagues from China, led by Professor Xian-Min Jin at Shanghai Jiaotong University, to test some of the principles underpinning the quantum theory of consciousness.

In our new paper, we’ve investigated how quantum particles could move in a complex structure like the brain – but in a lab setting. If our findings can one day be compared with activity measured in the brain, we may come one step closer to validating or dismissing Penrose and Hameroff’s controversial theory.
Brains and fractals

Our brains are composed of cells called neurons, and their combined activity is believed to generate consciousness. Each neuron contains microtubules, which transport substances to different parts of the cell. The Penrose-Hameroff theory of quantum consciousness argues that microtubules are structured in a fractal pattern which would enable quantum processes to occur.

Fractals are structures that are neither two-dimensional nor three-dimensional, but are instead some fractional value in between. In mathematics, fractals emerge as beautiful patterns that repeat themselves infinitely, generating what is seemingly impossible: a structure that has a finite area, but an infinite perimeter.


Read more: Explainer: what are fractals?

This might sound impossible to visualise, but fractals actually occur frequently in nature. If you look closely at the florets of a cauliflower or the branches of a fern, you’ll see that they’re both made up of the same basic shape repeating itself over and over again, but at smaller and smaller scales. That’s a key characteristic of fractals.

The same happens if you look inside your own body: the structure of your lungs, for instance, is fractal, as are the blood vessels in your circulatory system. Fractals also feature in the enchanting repeating artworks of MC Escher and Jackson Pollock, and they’ve been used for decades in technology, such as in the design of antennas. These are all examples of classical fractals – fractals that abide by the laws of classical physics rather than quantum physics.

This extension of Escher’s Circle Limit III shows its fractal, repeating nature. Vladimir-Bulatov/Deviantart, CC BY-NC-SA

It’s easy to see why fractals have been used to explain the complexity of human consciousness. Because they’re infinitely intricate, allowing complexity to emerge from simple repeated patterns, they could be the structures that support the mysterious depths of our minds.

But if this is the case, it could only be happening on the quantum level, with tiny particles moving in fractal patterns within the brain’s neurons. That’s why Penrose and Hameroff’s proposal is called a theory of “quantum consciousness”.

Quantum consciousness

We’re not yet able to measure the behaviour of quantum fractals in the brain – if they exist at all. But advanced technology means we can now measure quantum fractals in the lab. In recent research involving a scanning tunnelling microscope (STM), my colleagues at Utrecht and I carefully arranged electrons in a fractal pattern, creating a quantum fractal.

When we then measured the wave function of the electrons, which describes their quantum state, we found that they too lived at the fractal dimension dictated by the physical pattern we’d made. In this case, the pattern we used on the quantum scale was the Sierpiński triangle, which is a shape that’s somewhere between one-dimensional and two-dimensional.

This was an exciting finding, but STM techniques cannot probe how quantum particles move – which would tell us more about how quantum processes might occur in the brain. So in our latest research, my colleagues at Shanghai Jiaotong University and I went one step further. Using state-of-the-art photonics experiments, we were able to reveal the quantum motion that takes place within fractals in unprecedented detail.

We achieved this by injecting photons (particles of light) into an artificial chip that was painstakingly engineered into a tiny Sierpiński triangle. We injected photons at the tip of the triangle and watched how they spread throughout its fractal structure in a process called quantum transport. We then repeated this experiment on two different fractal structures, both shaped as squares rather than triangles. And in each of these structures we conducted hundreds of experiments.  

We also conducted experiments on a square-shaped fractal called the Sierpiński carpet. Johannes Rössel/wikimedia

Our observations from these experiments reveal that quantum fractals actually behave in a different way to classical ones. Specifically, we found that the spread of light across a fractal is governed by different laws in the quantum case compared to the classical case.

This new knowledge of quantum fractals could provide the foundations for scientists to experimentally test the theory of quantum consciousness. If quantum measurements are one day taken from the human brain, they could be compared against our results to definitely decide whether consciousness is a classical or a quantum phenomenon.

Our work could also have profound implications across scientific fields. By investigating quantum transport in our artificially designed fractal structures, we may have taken the first tiny steps towards the unification of physics, mathematics and biology, which could greatly enrich our understanding of the world around us as well as the world that exists in our heads.

1. Cristiane de Morais Smith

   Professor, Theoretical Physics, Utrecht University

Disclosure statement

Cristiane de Morais Smith receives funding from NWO.

Partners

Utrecht University provides funding as a member of The Conversation UK.

CYBORGS & TRANSHUMANISM

CABINET OF CURIOSITIES

The Anatomical Machines of Naples’ Alchemist Prince

Rumor had it that these machines were once the Prince’s servants, whom he murdered and transformed into anatomical displays. Scholars showed otherwise.

An anatomical machine of Prince Raimondo di Sangro
via Flickr

By: Amelia Soth

JSTOR DAILY
June 17, 2021


Two skeletons stand in a chapel in Naples. Their bones are knit together with an intricate web of veins and arteries that crawl over their ribs and skulls like gray lace. These were the “anatomical machines” of Prince Raimondo di Sangro, an alchemist, Freemason, inventor, and military historian. For centuries, eerie legends have swirled around these two figures.

The rumor goes that they were once the Prince’s servants, whom he murdered and transformed into anatomical displays. In 2007, however, a pair of scholars, Lucia Dacome and Renata Peters, published research revealing that the veins were in fact artificial, an astonishingly complex network of silk, wax, and wire, rather than the preserved remains of a living body.
He developed a method of mixing fireworks that detonated with the sound of birdsong, and lit up with an array of new colors.

Nothing could be more emblematic of di Sangro’s enduringly bizarre and contradictory legacy. The man seems to have resided somewhere between a true Renaissance polymath and a carnival huckster. Di Sangro’s inventions tended toward the spectacular. He developed a method of mixing fireworks that detonated with the sound of birdsong, and lit up with an array of new colors: the hues of milk, lemon peels, grass, rubies, and turquoise. In the pyrotechnical theaters he designed, fireworks seemed to trace in fiery light the outlines of temples, huts, and fountains.

Di Sangro was nothing if not theatrical. One writer described the scene on the street outside the alchemist’s laboratory:

Wandering flames, infernal lights—the people said—passed through the huge windows that look out, from the ground floor, onto Vico Sansevero… The flames disappeared, darkness returned, and then thuds and prolonged noises were heard there. From time to time, in the silence of the night, there was a sound like the clink of an anvil struck by a heavy hammer, or the cobble of the alley throbbed and trembled, as if with the nearby passage of huge invisible wagons.

At one point, an accidental fire in his laboratory revealed to him the formula for a “perpetual lamp” fueled by gunpowder mixed with pulverized human skull. He knew how to make faux lapis lazuli that was indistinguishable from the real thing, and how to bleach sapphires until they looked like diamonds. The floors of his palace were paved not with marble, but with a paste he invented which hardened into something with the appearance and texture of real stone.

Museo Cappella Sansevero

Then there are the more dubious “discoveries.” Di Sangro claimed to have found a means of extracting blood from manure. He claimed to have reduced river crabs to ash and then resurrected them with infusions of ox blood, and to have caused fennel plants to grow again from their cinders. Bringing Cicero back to life, one writer suggested, might be as simple as giving di Sangro one of the philosopher’s bones.

Some part of the prince’s mystique comes from superstitious rumors of murder and black magic; others come from the flattering myths that he himself spread. But both sources, positive and negative, center around one image: a gifted man on the threshold between life and death, capable of both killing and resurrection. This is perhaps most clear in the legend of di Sangro’s death, which recounts that before di Sangro died, he had himself hacked into pieces and placed in a chest. But the chest was opened too soon, “while the pieces of the body were still welding together.” He awoke for an instant, tried to rise, then shrieked and fell to pieces once again.

Di Sangro’s friend Giovanni Vincenzo Antonio Ganganelli, later to become Pope Clement XIV, wrote that the prince’s alchemical skill was powerful enough to create “a second world from the first.” It was a bit of a flim-flam world, however: wax and wire in the place of veins and arteries, hardened pastes in the place of gemstones, palaces of light that flicker into existence and then go out.

Nonetheless, you have to admire his sense of style. In one of his final public appearances, di Sangro stunned the citizens of Naples with a beautiful carriage that traveled not on the street but over the waves; it churned along on paddle-wheels, led by a pair of floating seahorses fashioned out of cork. The alchemist within was nearing the end of his life, suffering from an illness possibly brought on by inhaling the fumes of his own experiments. But what the Neopolitans saw was the glittering carriage riding proudly over the waves.

 K9

Don't try to replace pets with robots; design robots to be more like service animals

by L.f. Carver, The Conversation

Service robots can support people with caring for their pet companions. Credit: Shutterstock

Robopets are artificially intelligent machines created to look like an animal (usually a cat or dog, but they can be any animal). There are numerous robopets on the market right now, being sold to consumers as "pets" or companions. There is an especially fervent effort being made to set caregivers' minds at ease by buying these robopets for older adults to replace their deceased or surrendered companion animals.

Animal lovers will tell you they would rather have nothing than have a robot for a pet. While a robopet can be programmed to simulate the actions of a real animal, people know it is fake.

There should be a pivot from the companion-based marketing strategy for robopets —which has deep ethical issues associated with replacing emotional bonding between living beings —to address the needs currently being met by service animals.

In my research on the effects of the human-animal bond on human health, participants point out the reciprocal nature of their relationship with pets. The human showers the animal with love, yummy food, cuddles, scratches and pats, and the animal, in turn, responds with unconditional love. The vast majority also say that the non-human animals in their lives are family members, integral to their happiness and well-being.

It is condescending to present an adult with a robot and suggest that it will take the place of a loved one—whether that loved one is human or non-human.

New markets

However, there is a huge and, as of yet, untapped market for robopets and other social robots to perform the role of service robots. Let's call them Serv-U-Bots. These personal service robots are different from those developed to replace humans in some manufacturing and service sectors.

Serv-U-Bots would be much like a robotpet—small, portable and intended for personal use—and would employ many of the technologies already built into social robots. These onboard sensors could include cameras for observation, microphones for audio recording, temperature sensors, communication technologies and even autonomous motion, moving around based on programnming rather than human input.

Serv-U-Bots would be programmed to replace service animals, which are currently raised and trained to support human mobility and independence. However, this is an expensive endeavor.

Many organizations that provide service animals have breeding programs, training facilities and huge budgets that are subsidized by donors or get charged back to governments, insurers or families. The Canadian Guide Dogs for the Blind graduates approximately 23 dogs per year from its training program, at an average operating cost of more than $74,300 per dog.

These dogs are not considered pets by the organizations that breed and train them. They are service dogs, trained to provide assistance. If their current placement ends due to death of the person they were helping or for other reasons, they are generally returned to the organization for another placement.

Robots as service animals

But what about replacing service dogs with Serv-U-Bots: social robots that are programmed to perform service related functions? We have the technological know-how to create Serv-U-Bots that can increase independence through programming that can provide an alert if the toast is burning, the kettle boiling, the doorbell ringing and so on. They could even take on the functions of medical alert dogs which can detect medical issues such as a seizure or low blood sugar, or alert the user to the presence of allergens.

Serv-U-Bots could even support older adults to continue to enjoy the companionship of animals by feeding them, checking that they have water and even cleaning the litter box.

If an automobile can be programmed to drive itself, avoiding obstacles and life forms, why not program a Serv-U-Bot to guide people around the city? They could also be programmed to facilitate actual interactions with living beings. This technology can save and enrich lives and help people to be mobile.

Serv-U-Bots would be able to support the independence and mobility needs of humans without exploiting non-human animals.

How the human-animal bond complements treatment for veterans

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Provided by The Conversation 

Alchemy Arrives in a Burst of Light
Researchers have shown how to effectively transform one material into another using a finely shaped laser pulse.




Though it’s not quite as dramatic as changing a bunny into a unicorn, the right laser pulse can make one material behave like another.


Runbo Chen for Quanta Magazine


Philip Ball

Contributing Writer

September 30, 2020


The idea sounds like magic, pure and simple. You create a light beam that can make substances vanish, give them properties they shouldn’t possess, or turn them into a perfect mimic of another substance entirely. It’s 21st-century alchemy, in principle capable not just of making lead resemble gold, but of turning ordinary materials into superconductors.

The general approach, developed over the course of decades, is to use tailored optical pulses to reshape the electron clouds of atoms and molecules. Earlier this summer, a team of researchers at Tulane University in New Orleans and their collaborators extended the idea. They figured out how to apply the pulse strategy to solids and bulk materials, rewriting the usual laws governing how their properties are dictated by their chemical composition and structure. Using quantum control, said Gerard McCaul at Tulane, “you can almost make anything look like anything.”

Meanwhile, other researchers have already used light pulses to conjure up superconductivity — the ability to conduct electricity without resistance — in materials that would not otherwise behave this way.

But perhaps the real potential of the technique doesn’t lie in enabling marvels of mimicry, but in inducing other kinds of transformation. Light beams might be used to create optical computers powerful enough to solve difficult problems such as factorization. Chemical substances could become temporarily and selectively invisible, which would assist the analysis of complex mixtures. The theoretical possibilities seem limited only by our imagination. In practice, the limitations may stem from how well we can understand and control the interactions of light and matter.
A Plan for a Pulse

After the invention of the laser in the early 1960s, many researchers quickly realized that these devices could be used to manipulate molecules, since the molecules’ electron clouds feel and respond to the laser light’s electromagnetic fields, in which all the waves oscillate in step (that is, coherently). But to truly control something, you need to be able to prod or guide it on the timescale on which its trajectory changes — which is very fast for molecules and even faster for electrons. At first, laser pulses simply couldn’t be made short enough to deliver a sufficiently rapid sequence of nudges.

During the late 1980s and early 1990s, however, the pulse durations were brought down to as little as a few femtoseconds (a femtosecond is equal to 10–15 second), approaching the time frame of atomic motions. This enabled lasers to stimulate and probe those motions selectively. However, to actually control such movements, in the early 1990s Herschel Rabitz, a chemist at Princeton University, and his co-workers pointed out that one would need shaped pulses: complex waveforms that might guide molecular behavior along particular paths. That technology for pulse-shaping was, by good fortune, being developed at the time for optical telecommunications.






Herschel Rabitz, a chemist at Princeton University, pioneered the use of laser pulses to alter a substance’s quantum properties.


C. Todd Reichart, Dept. of Chemistry, Princeton University

But the challenge is immense. To control the path taken by a macroscopic object — a glider, say — you need to know the trajectory that you’re seeking to modify. For a quantum mechanical system, the equivalent is to know how its quantum wave function evolves in time, which is determined by a mathematical function called the Hamiltonian. And there’s the rub — in all but the simplest systems, such as a hydrogen atom, the Hamiltonian becomes too complicated for researchers to calculate the dynamics of the wave function exactly.

In the absence of that knowledge — needed to calculate in advance what control pulse you need — the only alternative seemed to be trial and error: trying out some initial control pulse and then iterating it by running the same experiment again and again. It’s like a glider pilot learning to land by trying out random motions of the control stick and then gradually refining those movements after seeing what works.

That’s a lot more complicated (if less hazardous) for quantum systems than gliders. Shaping the pulse means adding more frequencies. The challenge is to figure out which combination of frequencies is needed. “It’s like a piano, but worse, because it had about 128 keys,” said Rabitz. (Today, pulse-shaping might involve a thousand or so frequency components.)

Now McCaul, working with Denys Bondar at Tulane and his colleagues, has described a theoretical scheme for calculating the required pulse in advance.

In quantum mechanics, a particular property of a substance — electrical conductivity, say, or optical transparency or reflectivity — corresponds to the average or “expectation value” of an observable quantity. If you have the wave function of a substance and you know what kind of light pulse you’re using, you can predict the result — the expectation value — you’re going to get.

Bondar’s team inverts the problem: You start with the outcome you want to achieve (the expectation value) and calculate the light pulse that will produce it. To do that, you also need to know the system’s wave function, or equivalently its Hamiltonian — which in general you don’t. But that’s OK, so long as you can identify a good enough approximation: a kind of “toy” wave function that comes close enough to capturing the important features of the real one.






Gerard McCaul, a theoretical physicist at Tulane University, has shown exactly what kinds of light pulses are needed to change a material’s properties.


Sally Asher

In this way, the researchers figured out how to extend the methods from small collections of molecules, where there are just a handful of electrons to control, to large, bulky solids with a whole sea of electrons. “We look at the system as a cloud of electrons, and we start deforming the cloud,” said Bondar. The control pulse creates a kind of track that the electrons must follow, so the approach is called tracking control.

Christian Arenz, a theoretical chemist in Rabitz’s group at Princeton who is collaborating with Bondar’s team, explained that this approach makes it much easier to find the right control field for manipulating a substance’s properties. Previously, designing the control field was a matter of gradual, iterative improvement, but the tracking approach establishes “a new avenue for controlling many-body systems,” Arenz said. “I believe that this work will greatly inspire future control methods.”
To Reshape a Solid

Much of the early work on quantum coherent control focused (literally) on inducing well-defined changes in individual molecules — for example, selectively pumping energy into a given chemical bond to make it vibrate to breaking point, and perhaps thereby controlling the course of a chemical reaction. But manipulating many electrons coherently all at once in a material is a tougher challenge.

When atoms come together in solids, the outermost electron shells of neighbors overlap and form “bands” that extend throughout the material. The electronic and optical properties depend on the features of these bands. In metals, for example, the electrons with the highest energies occupy a band that is not filled to capacity, so the electrons can move throughout the atomic lattice, allowing the material to conduct electricity. In an insulating material, meanwhile, the highest-energy band occupied by electrons is entirely filled, so there are no “spaces” for these electrons to move into. They remain localized on their atoms, and the material won’t conduct.

More exotic types of electronic behavior can arise from quantum mechanical effects that make the electrons’ movements interdependent (that is, correlated), like the movement of groups of people in a crowd. In conventional superconductors, for example, the highest-energy electrons form correlated pairs (called Cooper pairs) that move in synchrony even though the two electrons might be some distance apart — like a person chasing another through a crowd. These Cooper pairs all behave identically, giving them an unstoppable momentum that enables a superconductor to conduct electricity without any resistance. It’s as if the electrons no longer notice the underlying lattice of atomic nuclei.

But what kinds of materials give rise to such properties? Usually in order to find them you need to go fishing in the sea of permutations of different elements. That’s very slow and labor-intensive — witness the huge amount of time and effort spent on developing new superconducting materials.

Imagine, though, that it’s possible to invoke a desired property in more or less any material by using light pulses to reshape the way the electrons are distributed. In this view, electron band structure is not something fixed by the material itself: The bands instead become a kind of putty that can be molded into whatever form you desire. Find the right control pulse and you might be able to join an array of mobile electrons into Cooper pairs, say, and thereby make a superconductor, perhaps from some humble substance such as iron or copper, under conditions in which it would otherwise be impossible.






Denys Bondar, a theoretical physicist at Tulane, believes that it should be possible to implement a quantum factorization algorithm in an optical computing device.


Sally Asher

This notion of using shaped laser pulses to specify and control the properties of materials has already borne fruit. For example, researchers have used it to switch materials between insulating and metallic behavior, to control magnetic properties, and to trigger superconductivity. The general idea is that the light pulses redistribute electrons among the energy bands in a way that tips the balance between one phase of the system and another — between a metal and an insulator, say. In this way, researchers have produced superconductivity at temperatures tens of degrees above the frigid extremes usually needed.

Yet despite its early promise, researchers caution that the experimental work is just getting underway. “Moving this research into the domain of extended solids, especially in the presence of strong [electron] correlation effects, is very much in its infancy,” said George Booth, a theoretical physicist at King’s College London who is collaborating with Bondar’s team. It remains to be seen, cautioned Arenz, to what extent their calculations for simple models of materials “can be generalized to other phenomena and systems.”

And no matter how successful the strategy is, these altered properties will persist only as long as you apply the control pulse. The remolded electronic structure won’t stay in place of its own accord, just as a piece of elastic won’t stay stretched if you don’t keep pulling. But for some applications — in electronic devices, say — that may not matter: You might be able to “write” the desired properties into the material only at the moment they are needed.
All That Can Be

You might object that the approach creates only superficial mimicry — the way some alchemists claimed to have “made gold” by applying some surface treatment to another metal that induced chemical reactions to gave the metal a golden sheen. That wasn’t gold in any real sense.

Bondar disagrees: The optically induced transformation, he said, “is really fundamental, actually.” To induce one type of alkali metal atom (like sodium) to optically mimic another (like rubidium), you have to use the control beam to manipulate the dipole moment of the atoms — the nonuniform way each atom’s electrical charge is distributed in space, which determines its interactions with the electric fields of light. “The dipole moment affects other things — including some chemical properties,” Bondar said. The transformation goes deeper than mere appearance.

This does not mean that would-be laser alchemists will have the ability to turn any substance into anything else, though. Michael Först, a physicist at the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, thinks that it’s only feasible to induce behaviors that potentially exist already in the material under certain conditions. “We can’t mimic a response of a material if it doesn’t exist at all,” he said. “There has to be something in the equilibrium properties — maybe at a different temperature or pressure or in a magnetic field, say — where the material already holds the property you’re looking for.”

So rather than turning lead into gold, researchers are awakening a particular gold-like response from something that is and always remains lead. Light-induced superconductivity, then — which Först has studied experimentally — isn’t a matter of creating superconductivity from scratch, but of enabling it at higher temperatures than would otherwise be possible. “Our coherent control pulse just wakes it up,” he said. Först’s collaborator Michele Buzzi at the Max Planck Institute agrees. “You can access very fancy states using driving, but I wouldn’t go so far as saying you can take a material and make it something totally different.”

If that’s so, how far does the light-induced transformation actually go? Are you really making Cooper pairs in such a superconductor? That’s not yet entirely clear. Buzzi thinks that in their experiments “we are synchronizing Cooper pairs rather than creating them to begin with” — that is, allowing them to act in a concerted way to produce the superconducting state. “But we’re not completely sure about this,” he said.

Christiane Koch of the Free University of Berlin, who works on quantum control methods for many-particle systems, thinks that to truly change the material at a fundamental level, rather than getting it to superficially mimic a specific response, researchers will need to dig very deep into the electron clouds. That will require very intense control beams, so that the strengths of the electromagnetic fields involved rival the internal forces that shape the intrinsic electronic structure. Maybe it can be done, she said — but not easily.
Making Light of Hard Problems

Some potential uses of quantum coherent control don’t hinge on mimicry, but trade instead on the way it couples light and matter in a “designed” fashion. One such use is optical computing. Light beams are in principle great carriers of information for computing, said Bondar, not least because you can cram a lot of information into them by using many wavelengths at once. But the fundamental problem is that it’s hard to get two or more beams to talk to one another. Unlike electrons, Bondar said, “light hates to interact with light.”

Bondar’s tracking control scheme shows how that coupling could be achieved: with a piece of matter, in principle as small as a single atom, that is manipulated by a control beam. A second beam that contains incoming data then interacts with the matter. The interaction transforms the data to enact a computation. “This opens the way to single-atom computing,” said Bondar.

More strikingly, it might be possible to use this optical approach to solve difficult problems such as factorization much more quickly than classical electronic computers can. Bondar and McCaul believe it should be possible to implement a quantum factorization algorithm called Shor’s algorithm, one of the first to be proposed for quantum computers, using what amounts to just classical optics. “It’s too early to put classical computing in the dustbin of history,” Bondar said.

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The New Science of Seeing Around Corners

McCaul also hopes to use tracking control to analyze complex chemical mixtures — a problem often faced, for example, in drug discovery. Say you have a large mixture of different chemicals, he said. If you know each component’s spectrum — how it absorbs light of different frequencies to create a characteristic signature — then you can work out which compounds are in the mixture. “But the spectra can often be similar to each other, and so it becomes very hard if there are many components,” said McCaul. Tracking control could allow researchers to “turn off the optical response of each species one at a time,” he said, making them selectively invisible. McCaul has shown that in principle this could boost the discrimination between different chemicals by orders of magnitude.

Add invisibility, then, to the feats of optical alchemy that may be made possible by tracking control. In theory at least, it shows us that, seen in the right light, nothing may be quite what it seems.

This article was reprinted on Wired.com.

POSTMODERN ALCHEMY

Bacteria enlisted in French push for rare earths autonomy

Issued on: 20/07/2021

Glass jars containing pulverised electronics are injected with bacteria

 at a lab in western France by engineers aiming to extract rare earth metals 

Christophe ARCHAMBAULT AFP

Orléans (France) (AFP)

As Europe seeks to reduce its reliance on China for the rare earth metals needed for modern batteries and electronics, French researchers have found a potentially potent ally: bacteria that can help extract the elements from mine slag heaps.

The tonnes of discarded ore, which contain nickel, copper and cobalt, are the continent's only domestic source of rare earths, along with discarded phones, computers and other tech gear.

"Europeans have woken up to this dependence on China and said, 'We need to find alternative supply sources'," said Anne-Gwenaelle Guezennec, an engineer with the French Geological Survey (BRGM) in Orleans.


The 17 rare earth metals, also vital for magnets, wind turbines and other advanced applications, are found in minute quantities within various ores, most of which are in Asia.

Gritty powders in their pure states, they have unique physical and electronic properties that can enhance a range of materials, from chemical catalysts to magnets and glass.#photo1

But the mining and extraction techniques to obtain them are difficult, requiring toxic chemicals applied at high pressure and temperatures, consuming significant amounts of energy.

The French geologists are exploring instead more environmentally-friendly approaches.

"We enlist the very specific properties of certain micro-organisms, bacteria that we find in the subsoil," Guezennec said.

- Rock soup -

At the Orleans lab, the process starts by pulverising mounds of rocks, or "tailings," left over from traditional mining and dissolving them in liquid.

Different bacteria are then injected, depending on the metal sought, along with oxygen and common nutrients like potassium or nitrogen to "feed" the bacteria.

A bioreactor machine then heats and rapidly agitates the solutions, in colours like grey-green or mustard yellow, setting the extraction process in motion.#photo2

"The bacteria allows us to do this at relatively low temperatures, between 30 and 50 degrees (85-120 Fahrenheit)," Guezennec said.

"And it doesn't need to be pressurised, so these are very stable processes that are not very expensive."

After years of testing, the lab is preparing to launch tests for large-scale production, extracting rare earths and cobalt, copper and nickel from slag heaps in Finland and New Caledonia.

"This is really aimed at being used anywhere there are slag heaps that contain metal," Guezennec said.

But that process, requiring specialised equipment to remove the metals from the liquid using electrolysis, is beyond the lab's capacities.

"We're waiting for industrial players" to step in, Guezennec said.

- 'Urban mine' -

At a noisier part of the Orleans lab, piles of electronic trash clatter onto conveyor belts where powerful magnets pick out other magnets and other metallic parts from the rest of the detritus.

"Normally magnets make up 1.5 to 3 percent of a hard disk," said Nour-eddine Menad, an engineer at the lab's waste and raw materials unit.

"That means in two tonnes, you can recover 30 to 35 kilogrammes (65-75 pounds) of magnets," he said. "And a magnet contains 30 percent of rare earths."#photo3

Once anti-corrosion coatings of nickel and copper are removed, the magnets go through a multi-step process to separate the rare earths and other metals, this time using standard -- and more energy-consuming -- acidic solutions.

Exploiting this "urban mine" is crucial, said Yannick Menard, the head of the Survey's recycling programme.

"It's basically our only alternative to make an economy less dependent on Asian suppliers."

SPACE WEATHER

The Earth will be battered by ‘high-speed’ solar winds this weekend, according to the forecast. 

BY HELENA SUTAN 

ON JULY 18, 2021

SCIENCE

Solar storm forecast: ‘High-speed’ solar winds set to batter Earth this weekend.

This weekend, a million-mile-per-hour solar winds are projected to pound the earth, potentially triggering a geomagnetic storm above the world.

A flood of charged particles from the Sun is heading our way, according to space weather forecasters. The “high-speed” stream is expected to reach our planet sometime between Sunday and Monday (July 11 to 12). A hole has opened up in the Sun’s atmosphere and is spewing a stream of solar wind in Earth’s direction.

According to SpaceWeather.com, the stream might cause a minor solar storm in the Earth’s magnetosphere, which is an area of space dominated by the magnetic field of the planet.

At night, people living in northern or southern latitudes can expect to see gorgeous aurora.

Solar storm: Charged particles from the Sun can impact tech on Earth

Solar winds are charged particle or plasma streams that erupt from the Sun and travel into space.

According to NASA, these winds may reach speeds of up to one million miles per hour on average, but they can go even faster.

Hailing from the Sun’s corona – the inner atmosphere – the winds can mingle with Earth’s magnetic field and trigger a number of phenomena.


Among the weaker impacts are colourful aurora effects around the planet’s poles – Aurora Borealis in the north and Aurora Australis in the south.

Stronger winds, on the other hand, can sometimes cause a geomagnetic or solar storm.

Satellite operations, radio communications, and even power outages have all been reported to be disrupted by these space weather occurrences.

Satellites’ frictional drag can be increased by solar winds, and their orbits can be degraded to the point where they crash onto the planet’s surface.


Nicky Fox, of NASA’s Director of the Heliophysics Science Division, explained: “As the wind flows toward Earth, it carries with it the Sun’s magnetic field.

Solar storm: The Carrington Event was the biggest solar storm on record

“It moves very fast, the smacks right into Earth’s magnetic field.

“The blow causes a shock to our magnetic protection, which can result in turbulence.”

Solar winds can be especially damaging for astronauts who aren’t totally protected by our atmosphere.

The charged particles flowing towards Earth put them at risk of absorbing damaging radiation while also putting their spaceship at risk of destruction.

Solar storms have been known to cause havoc in various places of the planet in the past.

A solar storm in March 1989 caused a nine-hour blackout Hydro-Québec’s electricity transmission system in Canada.

Solar storm: The Carrington Event was the biggest solar storm on record

And in 1859, the infamous Carrington event is said to have triggered the largest solar storm of all time.

Triggered by a series of coronal mass ejections (CMEs) – a massive release of plasma from the sun – the event is said to have burned through telegraph poles around the world.

NASA warned in 2014, “A similar storm today could have catastrophic effects on modern power grids and telecommunications networks.”

A National Academy of Science study estimates that such a storm today could cause more than 1.45 trillion pounds ($2 trillion) in damage – 20 times more than Hurricane Katrina.

And a Carrington-strength CME just missed us in July 2012.

Fortunately, the good news is that incoming solar winds are not expected to have a major impact on our planet.

Space Weather said, “A high-speed stream of solar wind is approaching Earth. ETA: July 11-12.

“The gaseous material is streaming out of an equatorial hole in the sun’s atmosphere.

“Minor geomagnetic storms and auroras are possible as the solar wind arrives.”

 

Using archeology to better understand climate change

by University of Montreal

Credit: CC0 Public Domain

Throughout history, people of different cultures and stages of evolution have found ways to adapt, with varying success, to the gradual warming of the environment they live in. But can the past inform the future, now that climate change is happening faster than ever before?

Yes, say an international team of anthropologists, geographers and earth scientists in Canada, the U.S. and France led by Université de Montréal anthropologist Ariane Burke.

In a paper published today in the Proceedings of the National Academy of Sciences, Professor Burke and her colleagues make a case for a new and evolving discipline called "the archeology of climate change."

It's an interdisciplinary science that uses data from archeological digs and the palaeoclimate record to study how humans interacted with their environment during past climate-change events such as the warming that followed the last ice age, more than 10,000 years ago.

What the scientists hope to identify are the tipping points in climate history that prompted people to reorganize their societies to survive, showing how cultural diversity, a source of human resilience in the past, is just as important today as a bulwark against global warming.

"The archaeology of climate change combines the study of environmental conditions and archaeological information," said Burke, who runs the Hominin Dispersals Research Group and the Ecomorphology and Paleoanthropology Laboratory.

"What this approach allows us to do identify the range of challenges faced by people in the past, the different strategies they used to face these challenges and ultimately, whether they succeeded or not."

For instance, studying the rapid warming that occurred between 14,700 and 12,700 years ago, and how humans coped with it as evidenced in the archeological record, can help climate specialists model possible outcomes of climate change in the future, Burke said.

Her paper is co-authored with UdeM anthropologist Julien Riel-Salvatore and colleagues from Bishop's University, Université du Québec à Montréal, the University of Colorado and the CNRS, in France.

Historically, people from different walks of life have found a variety of ways to adapt to the warming of their climate, and these can inform the present and help prepare for the future, the researchers say.

For example, traditional farming practices—many of which are still practiced today—are valid alternatives that can be used to redesign industrial farming, making it more sustainable in the future, they say.

Indigenous cultures have a major role to play in teaching us how to respond to climate change -in the Canadian Arctic, for instance, Indigenous people have a detailed knowledge of the environment that's key to be essential to planning a sustainable response, said Burke.

"Similarly, indigenous farmers all over the world cultivate a wide variety of crop types that won't all respond to changing climate conditions in the same way," she said. "They are preserving crop diversity in the global food chain and if and when the main crop types we currently rely on fail, this diversity could well prove to be a lifeline.

Another example is the readoption in northeastern North America of multi-cropping agriculture based on the "three sisters": corn, squash and beans. "There are archeological models for that," said Burke, "and the point is to use them to come up with more sustainable, locally scaled ways of farming that will ensure food security in the years to come.

"The archeology of climate change: the case for cultural diversity," by Ariane Burke et al, was published July 19 in the Proceedings of the National Academy of Sciences.

Researchers find climate change impacts plankton, a key marine food source

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More information: Ariane Burke el al., "The archaeology of climate change: The case for cultural diversity," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2108537118

Journal information: Proceedings of the National Academy of Scie

Provided by University of Montreal 

Land Plants Changed The Way Earth Regulates Its Own Climate

David Bressan
Contributor

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I deal with the rocky road to our modern understanding of earth

The ancient ancestors of all modern land plants - with 298,900 species among the most successful ... [+] D.BRESSAN

The carbon cycle, the process through which carbon moves between rocks, oceans, living organisms and the atmosphere, acts as Earth’s natural thermostat, regulating its temperature over long time periods.

In a new study, published in the journal Nature, researchers looked at samples from rocks spanning the last three billion years and found evidence of a dramatic change in how this cycle functioned about 400 million years ago, when plants started to colonize land.

“Our study suggests that the carbon cycle operated in a fundamentally different way for most of Earth’s history compared to the present day."

Specifically, the researchers noted a change in the chemistry of seawater recorded in the rock that indicates a major shift in the global formation of clay – the “clay mineral factory” – from the oceans to the land.

First author Boriana Kalderon-Asael, a PhD student at Yale University, said: “By measuring lithium isotopes in rocks spanning most of Earth’s history, we aimed to investigate if anything had changed in the functioning of the carbon cycle over a large time scale. We found that it had, and this change appears to be linked to the growth of plant life on land and silicon-using animal life in the sea.”

When clay forms slowly on land, it strongly favours lithium-6, leaving surrounding water enriched with the other, heavier isotope, lithium-7. Analysing 600 sediment samples at roughly 100 sites worldwide, the researchers found a rise in the levels of lithium isotope-7 in seawater recorded in the rock occurring between 400 and 500 million years ago.

One of sites sampled for the study - Middle-Upper Ordovician outcrop near Reedsville, Pennsylvania, ... [+] ASHLEIGH HOOD


“The shift, which occurred gradually between 400 to 500 million years ago, appears to be linked to two major biological innovations at the time: the spread of plants on land and the growth of marine organisms that extract silicon from water to create their skeletons and cells walls."

Clay minerals forms on land as a residue of chemical weathering, the primary long-term process through which carbon dioxide is removed from the atmosphere. Eventually, the clay minerals are washed into the sea , where they decay leading to carbon dioxide being released into the atmosphere.

The researchers suggest a significant shift in this cycle was caused by the spread of land plants keeping soils and clays on land, stopping carbon from being washed into the ocean, and by the growth in marine life using silicon for their skeletons and cell walls, such as sponges, single-celled algae and radiolarians, leading to a drop in silicon in the seawater required for clay mineral formation.

“Before this change, atmospheric carbon dioxide remained high, leading to a stable, greenhouse climate. Since then, our climate has bounced back and forth between ice ages and warmer periods. This kind of change promotes evolution and during this period the evolution of complex life accelerated, with land-based animals forming for the first time," the study concludes.

Besides explaining the long-term evolution of Earth's climate, this discovery also helps understand human-made climate change.

“A less carbon-rich atmosphere is also more sensitive to change, allowing humans to influence the climate more easily through the burning of fossil fuels.”

 

Climate change threatens food security of many countries dependent on fish

by Lancaster University

School of Jackfishin Sipadan Island, Malaysia. Credit: Emily Darling, Director, Coral Reef Conservation, Wildlife Conservation Society (WCS)

Millions of people in countries around the world could face an increased risk of malnutrition as climate change threatens their local fisheries.

New projections examining more than 800 fish species in more than 157 countries have revealed how two major, and growing, pressures—climate change and over-fishing—could impact the availability of vital micronutrients from our oceans.

As well as omega-3 fatty acids, fish are an important source of iron, zinc, calcium, and vitamin A. A lack of these vital micronutrients is linked to conditions such as maternal mortality, stunted growth, and pre-eclampsia.

Analyses by an international team from the UK and Canada and led by scientists from Lancaster University reveal that climate change is the most pervasive threat to the supply of essential micronutrients from marine fish catches, and threatens the supply of vital micronutrients from fisheries in 40 percent of countries. Fisheries micronutrient supplies were found to be less vulnerable to overfishing.

Countries among those whose fisheries micronutrient sources are at risk from climate change tend to be tropical nations and include East Asian and Pacific countries such as Malaysia, Cambodia, Indonesia, and Timor Leste, as well as Sub-Saharan African countries such as Mozambique and Sierra Leone.

This vulnerability to climate change for these nations' fisheries is particularly acute given dietary deficiencies in calcium, iron, zinc, and vitamin A are particularly prevalent in the tropics. And these tropical countries are also less resilient to disruptions of their fisheries by climate change because they strongly rely on fisheries to support their national economies and their population's diets and have limited societal capacity to adapt.

The study, which is outlined in the paper 'Micronutrient supply from global marine fisheries under climate change and overfishing', is published today by Current Biology.

Previous studies, most notably research into the micronutrient content of fish, which was led by Professor Christina Hicks and published by Nature, showed that fish are unequal when it comes to their nutritional content. A range of factors, such as diet, sea water temperature and energetic expenditure influence the amount of micronutrients that fish contain. Tropical fish tend to be richer in micronutrients than cold water species.

When it comes to resilience to climate change and fishing, again not all fish are equal. Earlier studies by Professor William Cheung and colleagues have shown large fish species that have a small range tend to be more vulnerable to climate change. While species that take longer to reach maturity and grow slower, are more vulnerable to fishing—because it takes longer for their stocks to replenish.

Coral reef fishes, fish market, Ambilobe, Madagascar. Credit: Eva Maire, Lancaster University

Their findings show only a weak link between the micronutrient density of an individual fish species' and its vulnerability to climate change or overfishing.

However, when the scientists looked at countries' overall fisheries catches then their findings revealed a clear impact from climate change on the overall availability of micronutrients for around 40 percent of nations—threatening the food security of millions of people living in these countries.

A key reason for why climate change is such a threat comes down to the species of fish that the countries are targeting as part of their catches.

Some tropical nations' fishers are targeting micronutrient-dense species that have an increased vulnerability to climate change, such as Indian and short mackerels (Rastrelliger kanagurta and Rastrelliger brachysoma), bonga and hilsa shads (Ethmalosa fimbriata and Tenualosa ilisha) and dolphinfish (Coryphaena hippurus).

However, there is a silver-lining to the study's findings which offers some hope for the future. Some countries may be able to adapt their fisheries to switch from vulnerable species and instead target alternative micronutrient-rich species that are also resilient to both climate change and overfishing, but which are currently under-represented within catches.

Dr. Eva Maire, of Lancaster University and Lead author of the study, said: "As climate change and over-fishing are significant and growing pressures on global fish stocks, it is essential for the dietary requirements of millions of people to know the extent that these pressures will have on the availability of micronutrients in our seas in the future.

"We have shown that climate change is the most pervasive threat to the supply of vital micronutrients for many countries around the world, and in particular in the tropics.

This study draws on the 'FishNutrients' model, a recently released finfish nutrient composition database.

"These data open up a whole new area of research and are crucial to address global food security challenges" said co-author Aaron MacNeil, Associate Professor in the Ocean Frontier Institute at Dalhousie University. "Our research highlights that efforts to improve food security and to tackle malnutrition there is a need to integrate fisheries, climate and food policies to secure these micronutrients for existing and future generations."

Professor William Cheung, co-author from the University of British Columbia, said: "As well as highlighting the growing threat of climate change to the food security of millions of people, our study also offers hope for the future. Armed with nutritional information about different fish species, many countries have the capacity to adapt their fisheries policies to target different more resilient fish species. By doing this then these nations can ensure a more reliable supply of micronutrients for their people."

Fish nutrition database to help combat malnutrition across the globe

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More information: Current Biology (2021). DOI: 10.1016/j.cub.2021.06.067

Journal information: Nature  , Current Biology 

Provided by Lancaster University 

Epicenter of major Amazon droughts and fires saw 2.5 billion trees and vines killed

Date: July 19, 2021

Source: Lancaster University

Summary:

Triggered by the 2015-16 El Niño, extreme drought and associated mega-wildfires caused the death of around 2.5 billion trees and plants and emitted 495 million tons of CO2 from an area that makes up just 1.2 per cent of the entire Brazilian Amazon rainforest, and 0.01 per cent of the whole biome.

A major drought and forest fires in the Amazon rainforest killed billions of trees and plants and turned one of the world's largest carbon sinks into one of its biggest polluters.

Triggered by the 2015-16 El Niño, extreme drought and associated mega-wildfires caused the death of around 2.5 billion trees and plants and emitted 495 million tonnes of CO2 from an area that makes up just 1.2 per cent of the entire Brazilian Amazon rainforest, and 1 per cent of the whole biome.

The stark findings, discovered by an international team of scientists working for more than eight years on a long-term study in the Amazon before, during and after the El Niño, have significant implications for global efforts to control the atmospheric carbon balance.

In normal circumstances, because of high moisture levels, the Amazon rainforest does not burn. However, extreme drought makes the forest temporarily flammable. Fires started by farmers can escape their land and trigger forest fires.

According to climate predictions, extreme droughts will become more common and, until now, the long-term effects of drought and fires on the Amazon rainforest, and particularly within forests disturbed by people through activities such as selective or illegal logging, were largely unknown.

Examining the Amazonian epicentre of the El Niño -- Brazil's Lower Tapajós, an eastern Amazonia area around twice the size of Belgium -- the research team, led by scientists from Lancaster University, the University of Oxford, and The Brazilian Agricultural Research Corporation found the damage lasts for multiple years.

The study revealed that trees and plants in drought-affected forests, as well as burned forests, continued to die at a rate above the norm for up to three years after the El Niño drought -- releasing more CO2.into the atmosphere.

The total carbon emissions from the drought and fires in the Lower Tapajós region alone were higher than a whole year's deforestation within the entire Amazon. And, as a result of the drought and fires, the region released as much over a three-year period as some of the world's worst polluting countries' yearly carbon emissions -- exceeding the emissions of developed countries such as the UK and Australia.

After three years, only around a third (37%) of the emissions were re-absorbed by plant growth in the forest. This shows that the Amazon's vital function as a carbon sink can be hampered for years following these drought events.

Dr Erika Berenguer, lead author of the report from Lancaster University and the University of Oxford, said: "Our results highlight the enormously damaging and long-lasting effects fires can cause in Amazonian forests, an ecosystem that did not co-evolve with fires as a regular pressure."

The scientists gathered data by regularly revisiting 21 plots across a mixture of primary forest, secondary re-growing forest and forests where people have selectively logged. The results from these plots were then extrapolated to the region.

Although previous research has shown human-disturbed forests are more susceptible to fires, it was unknown if there was any difference in the vulnerability and resilience of trees and plants in these forests when drought and fires happen.

The study showed that while many trees died in primary forest affected by drought, the loss of trees was much worse in secondary and other human-disturbed forests. The researchers found that trees and plants with lower wood density and thinner barks were more prone to dying from the drought and fires. These smaller trees are more common in human-disturbed forests.

The researchers estimate that around 447 million large trees (greater than 10cm Diameter at Breast Height) died, and around 2.5 billion smaller trees (less than 10cm DBH) died across the Lower Tapajós region.

The researchers also compared the effect on different forest types from drought alone, as well as the combined stresses of drought and fire.

Tree and plant mortality was higher in secondary forests from drought alone when compared with primary forests. Impact from drought was not higher in human-modified forests, but was significantly greater in those human-modified forests that experienced a combination of drought and fire.

Carbon emissions from those forests burned by wildfires were almost six times higher than forests affected by drought alone.

These findings highlight how interference by people can make the Amazon forests more vulnerable and underline the need to reduce illegal logging and other large-scale human disturbances of forests in the Amazon, as well as investments in fire-fighting capabilities in the Amazon.

Professor Jos Barlow of Lancaster University and the Universidade Federal de Lavras, and Principal Investigator of the research, said: "The results highlight the need for action across different scales. Internationally, we need action to tackle climate change, which is making extreme droughts and fires more likely. At the local level, forests will suffer fewer negative consequences from fires if they are protected from degradation."



Story Source:

Materials provided by Lancaster University. Note: Content may be edited for style and length.


Journal Reference:
Erika Berenguer, Gareth D. Lennox, Joice Ferreira, Yadvinder Malhi, Luiz E. O. C. Aragão, Julia Rodrigues Barreto, Fernando Del Bon Espírito-Santo, Axa Emanuelle S. Figueiredo, Filipe França, Toby Alan Gardner, Carlos A. Joly, Alessandro F. Palmeira, Carlos Alberto Quesada, Liana Chesini Rossi, Marina Maria Moraes de Seixas, Charlotte C. Smith, Kieran Withey, Jos Barlow. Tracking the impacts of El Niño drought and fire in human-modified Amazonian forests. Proceedings of the National Academy of Sciences, 2021; 118 (30): e2019377118 DOI: 10.1073/pnas.2019377118