Science News March 15 (Patreon)

[This is a transcript with references.]

Welcome everyone to this week’s science news. Today we’ll talk about a potential breakthrough in room temperature superconductivity, new clues about the origin of water on Earth, the best ever model of our geological past, a recent report on academic freedom, an image of the moon taken with a meta-lens, hybrid coral reefs, a new institution dedicated to finding the origin of life in the universe, the first cross-country storage for carbon dioxide, and of course, the telephone will ring.

A team of American physicists has announced a superconductor breakthrough, again.

The group led by Ranga Dias of the University of Rochester in New York says it has created a material that becomes superconducting at room temperature but it needs to be put under pressure.To be precise, they need 10 kilobar of pressure, which they call near-ambient. Where I live, 10 kilobar is about ten thousand times atmospheric pressure, but maybe it’s different if you publish in Nature.

High-temperature superconductivity is basically the holy grail of condensed matter physics. A room temperature superconductor could transport electricity without loss, which would dramatically improve the efficiency of the power grid and electronic devices. It would make magnetic levitation an everyday day thing. It would be a really really big deal which is why the topic attracts so much attention. And to be fair, while 10 kilobar is still a lot, it’s much lower than the pressure that was required in previous experiments.

Here’s what they did. They took a thin sheet of the rare earth metal lutetium, just about 100 micrometres thick, squished it between two tiny diamonds, bathed it in a gas made of 99 percent hydrogen, doped with 1 percent nitrogen, and left it alone in a pressurized reaction chamber overnight at 65 degrees celsius. It’s only mildly more complicated than lasagne.

Then they squeezed the resulting compound, lutetium hydride, between the diamonds and watched it change colour at around 3 kilo bar, from blue to pink to deep red. This clearly shows that something is going on. The question is, what.

Their major claim is that along with this colour change, the electric resistance also changes. In this figure you see how the electric resistance depends on temperature, and how the transition temperature depends on the pressure. The higher the pressure, the higher the transition temperature.

Other physicists are somewhat sceptical of this result, and for good reasons. The lead author, Dias, has a shaky reputation after it came out that he repurposed parts of someone else’s doctoral thesis for his own dissertation. And three years ago, a team also led by Dias already published a paper in Nature about a supposed superconductor breakthrough. However, Nature retracted that paper without the authors’ consent after other scientists questioned the data analysis and said they couldn’t reproduce the results.

And several people have already raised questions about the data analysis in the new paper. First, there is the way they get rid of noise in their data. The raw data for the resistance is available online and without subtracting the noise subtraction it looks like this graph on the left. Gone is the neat and sudden dip to zero resistance. However, this might look worse than it is because the tell-tale sign of the phase transition is this sharp drop and this tail could reasonably be due to other parts involved in the measurement.

Other people have pointed out that their spectral analysis seems to be wrongly labelled. This peak here isn’t lutetium. One would instead expect magnesium to show up here. But there’s no mentioning of magnesium in the preparation of the sample. Then again, if it works, this might not matter all that much.

Yet others have raised the point that the resistance seems to have hysteresis, which means that the curves for cool-down and warm-up are not the same. Superconducting phase transitions normally don’t have hysteresis. But while that’s unusual, it’s been seen before in some materials.

At the moment no one’s sure what to make out of this. But there are without doubt other groups trying to reproduce the results as we speak and we’ll hear more about this in the near future, so stay tuned.

An international team of astronomers has discovered new clues about the origin of water on Earth.

It’s long been a mystery why Earth has so much water, not just on the surface and in the atmosphere, but also in the crust, mantle and core. The issue is that when our planet formed from the same plasma that gave rise to the sun, it was too hot for water to form in appreciable amounts. So where does it come from? Did the water form later? Did it arrive with comets or meteoroids? Or do we not understand the way that planets form?

The new paper looked for answers in a young solar system, the Orion constellation, one thousand three hundred and five light years away. They use this system basically as a proxy for looking at the past of our own solar system. Here it is marked in red in the constellation, below the belt.

For their observations they use the ALMA telescope, a large radio telescope based in northern Chile, and the got lucky. Usually, water in the disk of a young solar system freezes out into ice at some distance from the sun, and then it can’t be examined with radio waves. But in this case, the star has recently gone through an accretion burst incident. This means it swallowed vast amounts of matter and then exploded, kind of like what happens when you read too many twitter comments. This burst incident heated the disk, turned much of the water into gas, and allowed the astronomers to measure it.

They were looking for what’s known as the “flavour” of the water. Yes, water comes in different flavours. Besides Coke zero, it could be that one of the hydrogen or oxygen atoms are isotopes of the most common ones, so they have different numbers of neutrons in the nucleus. For this study, they specifically looked for the fraction of water in which one hydrogen has been replaced with deuterium, known as “semi-heavy water”. They found the ratio of semi-heavy water to normal water to be roughly 2 parts in a thousand. This is comparable to the ratio found in the interstellar medium, that’s the stuff that floats around between solar systems.

The researchers suggest that this means the protoplanetary systems directly inherit their water from the interstellar medium, and where it’s cold enough it freezes onto planets, and more mobile asteroids and comments which can then redistribute it.  This doesn’t entirely solve the mystery of where Earth got its water, because the ratio of semi-heavy water to water on earth is much lower than what they observed in this other solar system.

However, if the water in protoplanetary systems comes directly from the interstellar medium, this means that it’s probably abundant in many solar systems, so if we ever move to another planet, there’s a good chance you can surf there, too.

A group of Australian and French geoscientists has developed the most detailed model ever of how the landscape of Earth evolved over the past 100 million years.

The new computer simulation allows scientists to trace the rise and fall of mountains, the forming of the continents, the flow of rivers and sediments, the transfer of sediments to the ocean, the movement of tectonic plates, the effects of climate and precipitation and how all these interactions shaped the conditions for life on Earth.

Remarkably enough, the model is precise down to a spatial resolution of about ten kilometres, everywhere on the globe, including the deep ocean. This little movie shows the last one hundred million years’ evolution of our planet.

Bringing past landscapes back to life is not just interesting to look at. It’s also important for predicting how Earth will respond to climate change, because we still don’t fully understand how carbon is reabsorbed from the atmosphere. Ocean chemistry, atmospheric composition, surface conditions, tectonic plate activity, and biodiversity all interact with the carbon cycle through feedback loops. It’s really complicated. I guess someone’s got to figure it out, but I’m glad it isn’t me.

Academic freedom has deteriorated significantly over the past decade in 22 countries whose population makes up more than 4 billion people, half the world’s total, according to the latest release of the Academic Freedom Index. The Academic Freedom Index surveys the state of academic freedom in 179 countries. It is coordinated by the V-Dem institute in Gothenburg, Sweden and a group and the University of Erlangen-Nürnberg, Germany.

The best academic freedom score this year goes to Czechia, though much of Europe is in the top group. At the rock bottom is North Korea.

In this map, the pinker the colour the worse the situation for academic freedom. For their evaluation they looked at freedom to research, teach, exchange and disseminate information, cultural expression, institutional autonomy and campus integrity. You can see that across big parts of the globe, the state of academic freedom is poor. What’s particularly worrisome in this year’s report is that academic freedom has declined in the three most populous nations in the world, China, India, and the United States, as well as Mexico and the UK.

In India, academic freedom began to decline in 2009 and then took a steep dive after Modi became prime minister in 2014. Since 2016, the report classifies India as an electoral autocracy, rather than a democracy.

The United States used to have a very high level of academic freedom, but things changed when Donald Trump took office as president in 2016.

More worrying, four of five indicators of academic freedom have continued to fall in the U.S. since his successor, Joe Biden, came to power. According to the report, that’s because individual states have taken aim at academic authority, that includes banning certain topics such as critical race theory and targeting tenure. In some states, lobby groups are trying to have funding withdrawn from gender and environmental studies, and various groups are maintaining public “watchlists” of researchers they claim are radical leftists. However, the authors of the report also note that despite all that scholars in the United States remain able to publicly voice their opinion.

In the UK, things have been slowly going downhill for about ten years or so. As for Mexico, the trigger for diminishing academic freedom has been the country’s harsh austerity measures under president Lopez Obrador who came into office in 2018.

In China, things were bad already but got worse after Xi Jinping became secretary general of the Chinese Communist Party. Though, as you can see academic freedom hasn’t yet reached absolute zero. That’s because you still have freedom of expression. You can say you agree with the communist party or that you support the communist party or that you admire the communist party. Plenty of options. The choice is only yours.

An American team of electrical engineers, mainly at Pennsylvania State University, has taken the first image of the moon using a telescope fitted with a meta-lens.

Conventional telescopes have large lenses and apertures made of bulky, heavy materials such as glass. This for example is the lens for the telescope that will be installed in the Vera Rubin Observatory in Chile.

So materials scientists have been trying to figure out how to make lighter, less expensive, lenses by designing materials with nanostructures, the meta-lenses.

Meta-lenses are not lenses in the traditional sense. They consist of several layers, each about 100 nanometres thick, carefully configured so that they refract light in just the right way to focus it.  But it’s been a challenge to make a meta-lens with an aperture big enough to focus on celestial objects.

In this new work, they made a meta-lens by laser-etching patterns into silicon, and then fused that to a silica substrate. You can see the lens itself here in the middle of the bottom row. And the nanostructures that act as tiny antennas are here in image f. With this method they were able to create a refractive metalens with an 8-cm aperture.

And that was big enough to get an image of the moon, even if it’s a blurry one. Here’s what they got.

In case you’re kind of unimpressed because your five year old took a better pic with his phone.That’s quite possible, but the lenses in your phone are one of the reasons for its width, and meta-lenses could be smaller, thinner, and cheaper. And then you wouldn’t have to worry so much that the five year old drops it.

Hi Elon,

Yes they used to say that money only makes you happier up to a point. But this new paper now found that more money makes you happier. Unless it doesn’t.

Basically they say some people just don’t get any happier. Why are you asking?

Yes, I understand it must be difficult to be rich. But buying twitter was a really good start to solving that problem.

Love you too. Bye.

Researchers at the University of Miami are building artificial coral reefs to protect the city from storms and sea level rise.

Earlier this month, they sank twenty-seven concrete structures into shallow water 215 meters off the coast of North Miami Beach. You can see from this overhead drawing that they are nine meters apart, in a line spanning thirty-five meters.

Miami is a hurricane hotspot. And hurricanes can damage coastlines. So the researchers came up with structures that can absorb the energy of storm surges. The next step is to seed them with corals that have been hand-reared at the university. According to their estimates, adding corals to the structures will reduces both wave heights and wave energy by 10 to 15 percent.

The project is important not just to protect people living near the coast, but also an attempt to restore sea life. Since the 1950s, half of living corals across the ocean have died off from ocean warming, ocean acidification, overfishing, and disease. And the concrete blocks are ugly enough to deter tourists.

An international group of scientists, including two Nobel Laureates, has established the “Origins Federation.” It’s multi-disciplinary research consortium aimed at understanding how life emerged in the universe – and whether it exists anywhere else.

The question’s been around ever since humans have figured out there are other stars in the universe, but now that we have found so many exoplanets it’s become even more pressing. I find this an interesting development because up to now the attempt to find alien life hasn’t been taken very seriously and this is changing now. And while the field has traditionally been dominated by astronomers and astrophysicists the new federation plans to draw on disciplines as diverse as synthetic biology and paleoecology.

Why did they call it the origins federation? I guess it’s either because there is already an origins institute or because they’ve watched too much Star Trek or possibly, both.

The federation was announced during a panel discussion last week at the annual meeting of the American Association for the Advancement of Science in Washington, D.C. The founding institutions are Harvard, Cambridge University, ETH Zurich and the University of Chicago.

Notable people that’ll contribute to the project are the Swiss astronomer Didier Queloz who shared the Nobel Prize in physics in 2019 for discovering the first exoplanet, and Jack Szostak of Harvard, who shared the Nobel Prize in medicine in 2009. His lab is currently trying to understand the transition from chemical evolution to biological evolution.

The federation’s inaugural conference is scheduled to take place at Harvard University in September. All this would be easier if we could at least agree on what we mean by “life”.

The Danish government has launched a deep-sea graveyard for liquefied carbon dioxide. It’s called Project Greensand, and it’s part of the current spate of 200 or so carbon capture and storage projects around the world that are supposed to save us. CCS has become all the rage as nations try to meet net zero targets by 2050.

At the moment, the world has about 3 dozen or so carbon capture and storage facilities in operation. The Danish project is so-far unique because it’s the first to store carbon dioxide from another country, in this case, from a chemical production plant in Belgium.

At the plant, the carbon dioxide is liquefied, then shipped to the site of a depleted Danish oil field underneath the North Sea. There, it’s injected by a dedicated well into a sandstone reservoir. The plan is that it stays there forever, or at least until no one can remember we put it there in the first place.

The plan is that by 2030 this carbon cemetery will store up to 8 million tonnes of carbon dioxide a year. That’s about 13 per cent of current Danish emissions and a sizeable share. But it’s not all peaches and cream. It takes about a fifth of those emissions just to capture, transport, and store the liquefied gas.

So, another little step of progress, but I guess we’re still not done dusting off the solar panels this week.