> For example, if you could remove the cooling requirements for MRI scanners

But MRI is almost the only tech we know today to be affected by this (and we could count maglev as well, but I don't think it'll change the landscape too much here, as the deployment of high speed trains un general is less technologically limited than it is by limited politcal will).

And even for MRI, room-temperature SC is only a big deal if you can find zone that works for high current, wich isn't the case here son far.

Petrol is just "better" coal. Except that you can't make flight with steam engines.

When room-temperature SC becomes possible, previously unthinkable applications suddenly become viable.

Maybe, but the same was already said when cuprate SC appeared in the late eighties with their relatively high critical T°, but they haven't really fulfilled their promise…

Are they really the same though? I mean we are talking about room temperature, not the"(relatively) high temperature", a term that is arguably misleading to a layperson.

I'd imagine most people who are informed of the difference would recognize that cuprate SC is nowhere near as useful.

Every article older than a couple weeks talking about superconductors goes on and on about how useful they are, except for the logistics of keeping them cold

Example: https://en.m.wikipedia.org/wiki/Superconducting_magnetic_ene...

Superconductors suporting high current are incredibly useful, but that's a big caveat. There's a reason MRI scans still use the super tedious helium-cooling instead of a much simpler nitrogen cooking allowed by cuprates: the cuprates SC aren't good enough for MRI.

Iirc the LHC experiment would not be possible without those superconductors. That’s a pretty big deal.

Just to be the pedantic one… I did some searching and found one single example of a steam-powered aircraft that actually flew. A bunch of other attempts are listed on wiki, all unsuccessful.

https://books.google.com/books?id=AygDAAAAMBAJ&dq=Popular+Sc...

And thanks, now I am researching small steam boilers that I could install in a Pietenpol homebuilt aircraft that a friend and I have been talking about building for a few years now. All I need is 30 kilowatts.

https://en.wikipedia.org/wiki/Pietenpol_Air_Camper

I knew it!

Yeah, I really meant coal-powered steam engines.

If you built a coal gasifier, or maybe used a powdered/pelletized form of coal, I could see it being plausible. (but still dumb)

Having just returned from a week at the Experimental Aircraft Association’s yearly gathering, I’m kind of interested in using up some of my employer’s time to see if I can make it work, at least on paper. Luckily I even have a budget line available for silly studies like this.

Sweet! I found a video clip at https://archive.org/details/turner_video_11514 at timestamp 54:47 for about 20 seconds.

(Found that reference via https://web.archive.org/web/20030203103015/http://www.flyste... which I found via https://archive.org/details/australian_model_engineering-iss... )

But not visiting Andromeda, the next star system. Which would be the only such application I can think of now.

As if the US is the only country. Plenty of EU countries, China, and Japan would invest in developing even higher speed rail options.

I'm French, and France has one of the biggest high-speed train network, and the limitation to build additionnal lines isn't a technological one…

I'd agree that it's not technological: it's cost and practicality.

trains that float above the rail means less maintenance. the high cost of trains is partly due to the maintenance of the rail network.

The speed of trains is generally not limited by engineering. It’s limited by corners, i.e. obstacles. There are already very fast trains in existence that don’t use maglev.

You're assuming they'd replace existing routes rather than build new routes that would suit the higher speeds.

That's the main problem, building a rail line zigzagging around the country is arguably a ton easier than having to legislate, seize, steal and forcibly bulldoze a straight path for a maglev.

…and sometimes there are obstacles that you can’t bulldoze. Mountains, rivers, towns, etc. You can build tunnels and bridges but it’s very expensive just to get people to their destination a little faster. The temptation to add a little bend is strong, but the smaller the minimum turning radius, the slower the maximum speed, and the higher the chance that you don’t need maglev at all.

It’s very dependent on geography. Ironically the US is a much better candidate for maglev than Europe with its wide unpopulated expanses.

Ah, but how many countries would develop superconducting maglevs just to fund their defense program that's using similar research to make superconducting rail guns?

Probably zero. The problem with current railguns is not that they have too much electrical resistance but that their barrel wear is much too high for practical use. Superconductors wouldn't solve that.

In any case countries that want to spend money on military research just do so, using the budget they allot to military R&D. There's no need to try and hide that you are researching railguns.

SMES systems offer grid-level energy storage at about 98% efficiency. You could also move nuclear reactors to the middle of the desert because no one wants them in their backyard, then losslessly transport their power back to the grid. Same for bringing power from solar and wind installations. These are just two examples with immediate commercial application. The economics of energy production shift when you eliminate 15% of the cost and distance limitations. That would have a big impact on decarbonization. Longer term, josephson junctions replace transistors in processors.

You could put nuclear reactors in the middle of the desert today (ignoring cooling for now). The reasons we don't typically do it has nothing to do with resistance.

> Transistors "just" made it more efficient.

Sort of, the thing about transistors isn't the efficiency as much as the scalability.

You'd be very hard-pressed to make a modern processor out of vacuum tubes. It would be enormous, tedious to build (couldn't use modern lithography), and also consume tons of power.

> [...] tedious to build [...]

It (or major parts of it at least) could be built by a fully automatic / robotized manufacturing plant. That isn't "tedious". Even for a one of its kind processor that would be much cheaper than the manual way.

> . It would be enormous, tedious to build (couldn't use modern lithography), and also consume tons of power.

Sounds to me like you're saying that Transistors are more efficient than vacuum tubes, both in terms of space and power consumption.

Many orders of magnitude so.

The last generations of vacuum tube processors were the size of large multi-story office buildings and had 50k tubes.

Compare to your smartphone, it would take billions of tubes to duplicate it.

Later research into thermionic devices did produce miniaturized versions, but nothing close to the scale of silicon transistors today.

If the same R&D might went into thermionics, we might just have devices of similar scales.

Yes. But at some point a quantitative difference becomes qualitativ.

If you're simply using efficient as a synonym for better, then every improvement is tautologically more efficient than what it immediately replaces. But solid state transistors were pursued specifically for their reduced power consumption while their scalability, which at the time was an afterthought, wound up making them revolutionary.

Tubes also burn out regularly (literally every day) when you have thousands of them.

This wouldn't have any effect on MRI scanners generating such magnetic fields.. they would be too dangerous to use in a non-prepared environment. They'd be small and use less power but still require a prepared environment wouldn't they?

Use it on a battle field and it'd be like Magneto was throwing shrapnel around I'd think.

Building a room from copper RF shielding panels [1] and soldering them together is a lot easier in the field than supplying a whole liquid helium or nitrogen cooling system. The former is well within the capabilities of a forward operating base - they can just ship the shielding in on plywood and the electrical technicians are more than capable of soldering copper.

[1] https://www.nelcoworldwide.com/medical-shielding-products/rf...

Sounds like a good idea for supermagnetic landmine or a grenade. Throw one into a trench and all enemies lose their weapons.

It sounds absolutely absurd but I'm thinking of how the military generates EMPs (explosive forcing a puck through inductive coil to generate a huge current which then generates the EMP), and maybe you actually could get some serious "deployable", very strong magnetic fields. Basically take the explosive EMP, and instead of directly trying to maximise EM induction in a pulse, you somehow try and stretch that pulse and apply it to a superconducting coil, generating a brief instant of strong magnetic pull.

The "pull weapons" thing is silly, it's a magnetic field so if you're that close the same weight in explosives should kill them, and with the forces it would need it's not going to be non-lethal.

I could maybe see this as an active defence system. Have a little turret, if you detect an incoming slug you fire your little grenade at the slug, it sets off a pulse that imparts substantial impulse to anything that's magnetic, diamagnetic, paramagnetic (lead, steel, uranium all included). Maybe it could send a high speed slug tumbling, or off course, not sure.

In general I think RTAPS is much more likely to have civilian uses than military ones, aside from banal military uses like "the generator works more efficiently because parts are superconductive now". Maybe railguns, but I don't think electric resistivity is the limiting factor there, more friction or plasma confinement.