Science News Jan 25 (Patreon)

[This is a transcript with references.]

Welcome everyone to this week’s science news. Today we’ll talk about advances in room temperature superconductivity, greenwashing and carbon capture, an experiment that sheds light on the mystery of cosmic magnetic fields, a robot arm with a needle, a camera with only one pixel, the supposedly coming age of clean technology, better phone memory, why rats might not have brought the plague after all, and of course, the telephone will ring.

Every research area has its holy grail and in condensed matter physics that’s room temperature superconductors. Superconductors have nothing to do with keeping the brass section under control, they are materials that don’t impede the flow of electrical currents as they offer no electrical resistance. Superconductors don’t let magnetic field lines in or out, which is why they levitate above magnets and they transport electricity at 100 percent efficiency, at least theoretically. They’re used today in things like MRI scanners and particle accelerators to generate strong magnetic fields.

The problem is, the known superconducting materials must be cooled down to extremely low temperatures to work. Even the so-called “high temperature superconductors” still need to be cooled to below minus 180 degrees Celsius. A superconductor that would work at room temperature would be a really big deal because it would dramatically reduce energy loss over long distances, and remove the need to cool all these big magnets. Unfortunately, the only room temperature superconductors that have so far been found are those in which the room temperature is set to minus 180.

Physicists have searched for their holy grail of room temperature superconductivity for decades without much success. It’s been known for a long time that some of them become superconducting at somewhat higher temperature when you put them under pressure, but it isn’t a big difference and the mechanism remained mysterious.

A 2020 paper in Nature supposedly revealed a new material that became superconducting at a temperature of plus 15 degrees Celsius, which my husband seems to think is room temperature, but for that to work the material needed to be kept at 267 Giga Pascal of pressure. For context, that’s three-quarters the pressure at the centre of the Earth. This isn’t exactly every-day conditions either, but it got everyone’s hopes up by suggesting that pressure might actually get the job done. Then, however, other researchers raised doubts about the data processing methods used in the paper. Nature retracted it in 2022. The authors say they stand by their results.

The new research from Leipzig University now did not put forward a new room temperature superconductor. Rather, they were trying to understand how pressure affects the transition to superconductivity. They placed a much-studied type of superconductor, called cu’prates, under high pressure in a nuclear magnetic resonance spectrometer, and looked at the charge distribution between oxygen and copper atoms. 

The team was able to show that electrons moving between the two elements were responsible for an increase in its transition temperature. Professor Haase, who led the research thinks that thanks to this result it will take only a few more years to find a room temperature superconductor. Though I suspect that if he tries to convince his colleagues of this, he may face some resistance.

The phenomenon of superconductivity has been known for more than a century and it baffled even Einstein in his days, so he is pretty excited by this progress, even if it might not pan out in the end.

An investigation published by the Guardian und der Zeit suggests that rainforest carbon offsets from the world’s leading provider may be largely worthless and thereby making climate change worse.

The company, Verra, deals with initiatives that aim to prevent deforestation. They calculate how much deforestation will be prevented by a certain action, and convert this into credits that can be traded. Companies can then buy those credits to excuse their carbon emissions and the company uses the money to make sure the actions are taken.

However, several scientific studies have found that deforestation is only being stopped in small areas which makes the claims by Verra suspicious. The investigation looked at three of these studies, two from an international group of researchers, and one from the University of Cambridge. These groups studied different projects over different time periods, and used different methods, but the results broadly agree. The journalists used this to conclude that Verra overstated the efficiency of their projects by as much as 400 percent.

Verra disputes these results, questioning both the results and the methodology of the study, and says it will be publishing its own analysis, so we will probably hear more about this soon.

Meanwhile, another report by authors of Intergovernmental Panel on Climate Change looked into the state of atmospheric carbon dioxide removal. The news isn’t good. All remotely realistic scenarios to keep global warming below 2 degrees rely heavily on carbon capture and storage. 

Besides planting trees, carbon capture can be done by ocean fertilization, distributing minerals on the ground, or capturing the stuff at the power plants where it shouldn’t have been produced in the first place. We talked about this in our earlier video on carbon capture, and back then I came to the conclusion that besides capturing carbon dioxide directly at the production site and burying, all the other methods are too expensive or too inefficient to make much sense.

The report finds there is a big gap between what countries are doing and what is needed, and that there are few plans to scale up carbon dioxide removal. Who’d have thought.

Hi Rishi,

Eating insects mite bee a good idea, but I doubt it’ll fly.

I’ve tried crickets. They were okay, but the legs kept getting stuck between my teeth. It really bugged me.

French flies? Nah, but cricket on toast sounds pretty British to me!

Sure thing.

The universe is full of magnetic fields, but physicists don’t understand why. “On the first day at 3 minutes past 2 God created magnetic fields”, didn’t pass peer review, so the origin of cosmic magnetic fields has remained a mystery. But according to researchers in California a solution to this long-standing problem just came a step closer.

Cosmic magnetic fields are weak, about one millionth of the strength of the magnetic field of Earth, but they’re measurable because they affect the polarization of electromagnetic waves and the motion of charged particles. Cosmic magnetic fields span through intergalactic space, between galaxy clusters, and have been measured even in voids. The issue is, while they’re weak, they’re still stronger than expected, so where do they come from?

Scientists believe that these magnetic fields grew from small seeds in the early universe, but just how they grow has remained difficult to explain. New research published in the Proceedings of the National Academy of Sciences now supports the idea that magnetic fields can arise spontaneously in plasma from temperature differences, and that that’s what happened in the intergalactic medium.

Known as Weibel instability, this effect was predicted in 1959 by the Swiss physicist Erich Weibel. Astrophysicists have long suspected that it might play a role for the formation of cosmic magnetic fields, but the Weibel instability isn’t well-understood. While some types of this instability have previously been observed, the very one that’ s interesting for cosmology turned out to be difficult to produce in the laboratory. 

Researchers from UCLA now succeeded at this. This instability converts differences in temperature into energy of magnetic fields by a kind of self-organisation of plasma currents. The instability is characterized by the growth of small, filamentary structures called “Weibel filaments” that form in the plasma and can generate magnetic fields. These filaments can then merge to form larger structures, which can in turn amplify the original magnetic field.

This doesn’t put the problem to rest. But being able to measure the effect in the laboratory might help with understanding what’s happening in the cosmos.

A lot of lab work involves getting tiny amounts of fluids from one place to another which is somewhat of a pain, but researchers from ETH have now built a robot that could take over much of this work.

Published in Nature Communications, the work details a tiny glass needle that oscillates at ultrasonic frequencies, and which can be attached to a robotic arm. If the needle is dipped into liquid, then varying the frequency of its oscillations creates vortices that can do a number of useful jobs. Not only can the vortices be used to mix liquids, but they can pump fluids through a mini-​channel system, and the right pattern of oscillations can attract large particles present in a liquid toward the needle. To show that this works, the scientists captured zebrafish embryos, but they believe it could also be used to capture cells.

The researchers want to add extra needles to the end of the arm to create even more complex vortex patterns and hope that one day the robot can handle a variety of lab jobs. The poor robot’s got really tiny arms though, so let’s hope it doesn’t walk off and buy a sports car to compensate.

The age of clean technology is near, according to a new report from the International Energy Agency. They looked at the production of renewable energy and the supply chains it requires to make the technology work. According to the IEA, the number of US jobs in the green manufacturing sector will more than double by 2030, to 14 million. By then, the global market for clean energy technologies could be worth 650 billion dollars, if countries fully implement their announced energy and climate pledges. That’s a pretty big “if” if you ask me, but you didn’t, so I’ll shut up.

Overall, the report predicts a bright future for green technologies. It also points out though that diversification of the supply chain is necessary to avoid that increased demand will push up prices. For example, prices for the batteries used in electric vehicles, rose by 10percent in 2022, the first rise ever in this sector. It’s been caused by an increase of the prices for the raw materials cobalt, nickel, and lithium.

And despite its overall positive outlook, the IEA acknowledges there are still challenges ahead. They note for example that only 25 percent of announced solar manufacturing projects are actually under construction, so there’s a lot of talk and very little walk.

I certainly wish my children would finally reach the age of clean technology.

The working memory that’s in your PC or smartphone is pretty fast, probably running at around three thousand cycles per second, unless you’ve got something particularly high-end, in which case, please consider supporting us on Patreon.

This working memory is currently dynamic random access memory, DRAM for short. The data in this memory gets lost when you switch the power off. This is why your phone or laptop has a second type of memory, for example your hard drive, which keeps your data when the device shuts down. This memory, however, is much slower. And then there’s Magnetoresistive RAM, MRAM for short, a promising new technology that is both fast and keeps data when you shut down and that could one day be used both for working memory and long-term storage.

DRAM stores data as electrical charges, and is limited by the speed at which the charges can be drained or stored. This gives it an access time of around 60 nanoseconds. MRAM is faster because the technology relies on measuring voltages rather than currents. It has access times as low as a nanosecond.

But access times are not the whole story, you also need to be able to manipulate the memory entries. An experimental breakthrough from the University of Tokyo’s Department of Physics, just published in Nature, set a new record. Usually MRAMs are made from ferromagnets, that’s the things normal people just call magnets. In ferromagnets, the magnetic moments of atoms want to align. 

The new work uses antiferromagnets, in which the magnetic moments of neighbouring atoms want to point in opposite directions. The benefit of using antiferromagnets for data storage is that they don’t need to be arranged in parallel lines. The researchers claim that with this method, switching speeds in the order of a trillion cycles a second could be possible, and then we’ll be able to receive and delete lottery scams faster than ever.

A group of researchers from Canada has developed the so far fastest single pixel camera. Yes, just one pixel. You’re currently enjoying this video at about 8 million pixels, if your bandwidth allows. If not, keep it that way, because I look much better at lower resolution.YouTube videos will probably trend toward even higher resolution in the next couple of years, though personally I think that’s more information than anyone wants or needs. Single pixel cameras are on the very other end of camera technology.

These cameras aren’t going to revolutionize Tik-Tok, but they do have a couple of advantages that make them suitable for certain tasks. For one, single pixel cameras don’t need a sensor array, so they are small. They also have a high dynamic range, which means they work well in cases where the brightness of an image changes a lot from one place to another. They work in the infrared and in the ultraviolet, don’t require a lot of light to work, and they don’t produce huge image files. Single pixel cameras are used for example to inspect medical samples or surfaces of electronics.

These single-pixel cameras work by putting different masks in front of the camera so that the one pixel can capture different light distributions from the same scene. The full image is then reconstructed by computation. But an issue with these single-pixel cameras is that so far their frame rate has been low.

The new prototype improves on this with a framerate of one hundred frames per second for real-time video streaming. For reference, this video runs at 25 frames per second. But at that framerate the single pixel camera reaches barely a resolution of 59 times 61 pixels. That’s about the same resolution of those weird gifs we all had on our homepages in the 90s.

For offline recording, they make it to 12 thousand frames per second – admittedly at a resolution of just 11 times 13 pixels, that’s low even in 90s standards. Still this is enough to scan surfaces, and this isn’t a theoretical breakthrough, this is finished, patented, and actively looking for commercial applications.

Hi Elon, I saw they found out your autopilot video was staged.

Yes, I also stage my phone calls, but people don’t literally die from it.

It kept crashing it into a fence. Oh, well, I guess it’s alright then. Love you too.

The Black Death, an outbreak of bubonic plague ravaged Europe in the 1300s. The plague is caused by a bacterium, and can now be treated with antibiotics but back then it killed as much as 60 percent of the population. The plague has given rats a bad reputation because the story has it, the bacterium was spread by fleas that in return were spread by rats.

This story has been questioned before, but new research from the University of Oslo   has now found evidence that it’s indeed not true. Based on long-term environmental data, the researchers find that climate conditions in Europe, then and now, just can’t sustain a reservoir of plague bacteria in rats. The Black Death was part of what’s known as the second plague pandemic. While other plague outbreaks indeed developed in step with the fertility cycles of rat fleas, the second pandemic moved much faster, showing no correlation with those cycles.

The researchers say that what instead happened is that the plaque was probably repeatedly introduced to Europe by wildlife from Asia and that it partly spread by person-to-person contact, a possibility that had previously been suggested to explain why it spread so rapidly. This research isn’t just of historical interest. The plague still exists: a 1994 outbreak in India killed 50 people.

This may be the first time that rats have received positive press since Disney’s Ratatouille.