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Comment by mkoryak | Hacker News Reader

Is bringing a substance to 1.5 million atm cheaper than cooling it to under -70C ?

All the articles I read on the topic seem to imply that higher temperatures are much more important than a bit of super high pressure, but can someone explain why?

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The big application for superconductors is wire, and it's much harder to compress a wire to a million atm than it is to cool it to -70 C. However, this result is important (if independently replicated) because it demonstrates that the established theory of low temperature superconductivity [1] has predictive power all the way up to these high temperatures and likely to room temperature, providing new motivation for theoretical chemists to dream up new materials that the theory predicts would superconduct under more accessible conditions. Practical room temperature superconductors would, in my opinion, change the world as much as the development of semiconductors.

[1] a modified version of BCS Theory https://en.wikipedia.org/wiki/BCS_theory

"Practical room temperature superconductors would, in my opinion, change the world as much as the development of semiconductors"

It would be huge, definitely. Even the most obvious application (reducing electric power transmission losses) would be worth billions. According to the Googles, ~4000 TWh generated annually, 6% transmission losses, $.09/kWh gives about $22 billion in annual savings in the United States alone (if I didn't mess up the arithmetic).

Not necessarily. Even if we successfully developed a room temperature superconductor, there would still be huge commercial hurdles. Cost, mechanical stability, thermal stability, manufacturability, transportability, sensitivity to heat waves, reliability, critical field (which limits current), density, tensile strength, etc. Also, while $22 billion in annual savings sounds big, the grid is extremely capital intensive, and would take decades and trillions of dollars to upgrade.

really interesting! question I have is: are there other areas with high losses that this could change the game for? For instance, large induction furnaces, or a space elevator?

high current/field applications: magnetic energy storage, magnetic plasma confinement for fusion, particle accelerators, rail guns, magnetic levitation/bearings

extreme sensitivity applications: portable NMR spectrometers/MRI scanners, practical quantum computing, very fast and sensitive microwave processing, easy access to large scale fermion condensates for scientific research

Tokamak fusion reactors? Portable MRI equipment aka tricorders (probably not the latter. Those cannot work with huge magnetic fields)?

Magnetic levitation for trains.

Really high torque and power electric motors and generators in a small package.

That's why the US navy is heavily into this - for submarines and ships.

It'd also make very large offshore wind power plants potentially cheaper.

Electric / hybrid propulsion in aircraft is another. When your thruster is just a light fan, you can place it in the best aerodynamic / least noise generating position, then put the power generator and batteries where there's space and it makes sense for center of gravity. You could have rejuvenation of near city airfields again.

Not only saving but also added opportunities. Superconducting wire would make it possible to transport electricity over longer distance.

The reason why this is so important is that simpler molecules are much easier to simulate and work with from the theoretical side to create a bulletproof model of how the high temperature superconductors work. All of the cooper pairs and all that stuff took years and years to figure out because the molecule was something like yttrium barium copper oxide.. which is complicated as all hell to figure out what the electrons are doing inside of it while in a crystalline form.. H2S is basically like "sulfur plus some protons" is so much more simple to simulate with something like molecular dynamics methods to figure out what is going on with it. What the researchers probably are hoping to come out of this is a recipe for superconductivity based upon a crystalline form of some material that can be made in a low-cost fashion that superconducts at high temp..

Maintaining a low temperature requires continuous work as you can't stop heat transfer completely. This consumes energy and requires some machinery to produce or deliver the coolant.

Establishing and maintaining a high pressure on the other hand is a one time effort, for example screwing back the front of a ballpoint pen puts the spring inside under permanent pressure, and even gases can be contained at high pressure with no significant loss.

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