(Roughly) Daily

Posts Tagged ‘superconductivity

“You must not fool yourself, and you are the easiest person to fool”*…

One hallmark of superconductivity is the Meissner effect, which expels all magnetic fields from a material — a property that allows a superconductor to levitate, as seen here.

The quest for room-temperature superconducting seems a bit like the hunt for the Holy Grail. A superconductor is a material that will transmit electricity with no resistance– thus very quickly and with no loss. (Estimates of loss in the U.S. electric grid, most of it due to heat loss from resistance in transmission, range from 5-10%; at the low end, that’s enough to power all seven Central American countries four times over.) Beyond that (already extraordinary) benefit, superconductivity could enable high-efficiency electric motors, maglev trains, low-cost magnets for MRI and nuclear fusion, a promising form of quantum computing (superconducting qubits), and much, much more.

Superconductivity was discovered in 1911, and has been the subject of fervent study ever since; indeed, four Nobel prizes have gone to scientists working on it, most recently in 2003. But while both understanding and application have advanced, it has remained the case that superconductivity can only be achieved at very low temperatures (or very high pressures). Until the mid-80s, it was believed that it could be established only below 30 Kelvin (-405.67 degrees Farenheit); by 2015, scientists had gotten that up to 80 K (-316 degrees Farenheit)… that’s to say, still requiring way too much cooling to be widely practical.

So imagine the excitement earlier this month, when…

In a packed talk on Tuesday afternoon at the American Physical Society’s annual March meeting in Las Vegas, Ranga Dias, a physicist at the University of Rochester, announced that he and his team had achieved a century-old dream of the field: a superconductor that works at room temperature and near-room pressure. Interest was so intense in the presentation that security personnel stopped entry to the overflowing room more than fifteen minutes before the talk. They could be overheard shooing curious onlookers away shortly before Dias began speaking.

The results, published in Nature, appear to show that a conventional conductor — a solid composed of hydrogen, nitrogen and the rare-earth metal lutetium — was transformed into a flawless material capable of conducting electricity with perfect efficiency.

While the announcement has been greeted with enthusiasm by some scientists, others are far more cautious, pointing to the research group’s controversial history of alleged research malfeasance. (Dias strongly denies the accusations.) Reactions by 10 independent experts contacted by Quanta ranged from unbridled excitement to outright dismissal…

Interesting if true– a paper in Nature divides the research community: “Room-Temperature Superconductor Discovery Meets With Resistance,” from @QuantaMagazine.

* Richard Feynman

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As we review research, we might pause, on Pi Day, for a piece of pi(e)…

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… in celebration of Albert Einstein’s birthday; he was born on this date in 1879.

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“Everything should be made as simple as possible, but not simpler.”

Written by (Roughly) Daily

March 14, 2023 at 1:00 am

“Electricity is really just organized lightning”*…

A diagram from Galvani’s De viribus electricitatis in motu musculari commentarius, 1791.

In Mary Shelley’s Frankenstein, written in 1818, the young Victor Frankenstein becomes obsessed with the idea that electricity is a kind of fluid that endows living things with their life force. This obsession leads to tragedy.

Shelley’s view of electricity was, in fact, not an uncommon perspective at the time: just a few decades earlier the Italian scientist Luigi Galvani had shown that a shock of static electricity applied to the legs of a dismembered frog would cause the legs to kick. Galvani concluded that there existed a kind of “animal electric fluid” that was responsible for the animation of living creatures.

In the two hundred years since Frankenstein our view of electricity has certainly evolved, as has our ability to generate and control electric currents. But do we really understand what we’re doing? Do we even know what electricity is?

Physicist Brian Skinner (@gravity_levity) explains “Here’s why we don’t understand what electricity is.”

Pair with “Bruno Latour, the Post-Truth Philosopher, Mounts a Defense of Science.”

* George Carlin

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As we plug in, we might send really fast birthday greetings to Leon Cooper; he was born on this date in 1930. A physicist, he shared the Nobel Prize in 1972 (with John Bardeen and John Robert Schrieffer) for contributing the concept of Cooper electron pairs which forms the basis of the BCS (their initials) theory of superconductivity. He is also one of the the namesakes and co-developers of the BCM theory of synaptic plasticity.

He went on to become a cofounder and co-chairman of Nestor, Inc., a company that applies neural-network systems to complex applications. The company built computer-based adaptive pattern-recognition and risk-assessment systems that could, for example, accurately classify complex patterns in sonar, radar or imaging systems. He also founded and was director of Brown University’s Institute for Brain and Neural Systems, which develops cognitive pharmaceuticals and intelligent systems for electronics, automobiles and communications.

The character “Sheldon Cooper” in Big Bang Theory is partially named for Cooper.

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In vino volo…

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In Slashdot “cold fjord” reports:

Red wine is a popular marinade for meat, but it turns out that it may become a popular treatment for creating iron based superconductors as well (Link to academic paper): Last year, a group of Japanese physicists grabbed headlines around the world by announcing that they could induce superconductivity in a sample of iron telluride by soaking it in red wine. They found that other alcoholic drinks also worked–white wine, beer, sake and so on — but red wine was by far the best. The question, of course, is why. What is it about red wine that does the trick? Today, these guys provide an answer, at least in part. Keita Deguchi at the National Institute for Materials Science in Tsukuba, Japan, and a few buddies, say the mystery ingredient is tartaric acid and have the experimental data to show that it plays an important role in the process. . . It turns out that the best performer is a wine made from the gamay grape–for the connoisseurs, that’s a 2009 Beajoulais from the Paul Beaudet winery in central France.

 

As we soak our cable connections, we might recall that on this date in 1860, M L. Byrn of New York City, N.Y., was issued a patent for an improved corkscrew – a “covered gimlet screw with a ‘T’ handle” (No. 27,615). The inventor claimed the design would provide greater strength and durability and which could be manufactured at less cost than prior construction methods using a spiral twist of steel wire that gradually tapered from the handle to the point. Byrn claimed the gimlet-type screw with wider threads would also be strong enough to “remove a bung of the hardest wood from a barel or hogshead.”

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Written by (Roughly) Daily

March 27, 2012 at 1:01 am

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