I don't really know whether the analogy holds, but I find reasonable reasons to think it does (we could finally get our low-voltage DC home \o/ maglevs \o/ routine/cheap IRMs \o/. that's just the "simple" applications that we can already foresee right now)

No, they were colloquially called (void) lamps in at least French and Slavic languages, because they looked like incandescent bulbs, that were called lamps (lampe/лампа) as well.

[1] https://es.wikipedia.org/wiki/V%C3%A1lvula_termoi%C3%B3nica

Room temperature superconductors would not just just make a host of things more efficient, it would also enable devices that rely on high-strength magnetic fields to become much more widespread. For example, if you could remove the cooling requirements for MRI scanners then they could become much more usable "in the field".

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.

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

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

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

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

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

Yeah, I really meant coal-powered steam engines.

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.

(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... )

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

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.

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.

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.

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

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.

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

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

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

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.

Additionally it has no internal resistance, so you can charge such battery virtually immediately, but you can also discharge it immediately. This will be important for energy based weapons.

An electromagnet, superconducting or otherwise, has large internal forces. If the support structure lets go, it will move. And, if part of the circuit becomes non-conducting, an inductive kickback will occur, generating enough voltage to (initially) sustain the original current.

You could cut a Li-ion battery in half, and the two halves will continue to store their chemical energy, at least until they burn up. If you cut an inductor in half (which is what this type of energy storage device is), that energy will dissipate very quickly whether you like it or not.

When working with large battery arrays I use tools that are taped in all the way except for the business end, just in case. All you need to do is drop a wrench in the wrong spot and it's party time.

Agreed about taped tools, I figured that one out right after replacing the fuse :)

A BMS typically has a small shunt that helps to figure out the state of charge as well as a large transistor in series with the current to allow switching the battery in and out of circuit.

Indeed they do.

> Not a whole lot, but enough that whether you short out with copper wire or superconductor, the effect would be the same.

Not necessarily, assuming a charged battery in many cases with a copper wire the wire will simply heat up to the point of evaporation and then break the circuit as it sprays molten copper bits all over the place. Some heat will be generated in the battery as well. Watch people mess up with starter cables for some ideas on how this tends to go (and do so from a distance...).

Using a massive copper connector that you some how instantly put across the terminal and manage to keep there would indeed make the balance of the resistance shift to the guts of the battery, which would heat up faster than that that energy can be shed and hence in all likelihood (violently) explode. Besides bits of molten lead and zinc for a car battery you now also have the joy of having to deal with spraying acid. Which depending on the state of charge of the battery can be really nasty stuff.

With a superconductor there would be no chance of the conductor evaporating first, there isn't any work done in the superconductor so it will stay cold, an explosion of the battery would be all but guaranteed.

An idle superconducting energy storage at full “charge” is not carrying a charge at all — it’s carrying a current. If you cut the wire (or blow a fuse), V = L dI/dt will generate an arbitrarily high voltage to keep that current flowing.

I imagine one would need some spark gaps and/or capacitors to limit the voltage.

https://www.lorentz.leidenuniv.nl/history/cold/DelftKes_HKO_...

The LHC had a quench event in 2008, which explosively vapourised about 6 tonnes of helium, resulting in considerable damage, and it took more than a year for the accelerator to come back online.

Probably along with a large electromagnetic pulse...

Fortunately the energy density[0] is comparable with rubber bands[1] and supercapacitors[1], so while the EMP is large, it's not terrifyingly large.

[0] at least according to wikipedia, 4-40 kJ/kg: https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...

[1] 1.6-6.6 kJ/kg and 10-30 kJ/kg respectively: https://en.wikipedia.org/wiki/Energy_density

Edit: they were clear that the limiting factor on energy and power density was the forces exerted on the coils.

For now, this is restricted to special applications due to great size and cost. The great size and cost are caused mainly by the cooling systems.

(Inductors are very frequently used for very short-term energy storage (~fractions of a millisecond). For example, all energy output by a flyback converter was briefly stored in the transformer’s magnetic field. Unlike a regular transformer/forward converter, where the magnetic field is just a side effect of coupled inductors, so none of the energy is stored in it.)

And that's before we get into the purely mechanical stresses created by such an event, which likely will destroy the vicinity of the carrier of the current.

Just look at what happens if you leave something made out of metal lying around near an MRI machine when it is switched on and that's not for want of attempts to shield it.

Unlike the effect on nuclear fusion, the idea of using SC as storage devices is pretty much pure theory.

Of course it is, any kind of use of this stuff is still theoretical. That's a content free statement. But GP was making the assumption that if it works it can be used for storage. But that doesn't really follow from the properties of the material as described so far. You'd need a lot more current carrying capacity for that to become a realistic possibility.

[1] LHC Magnet Quench Protection System https://cds.cern.ch/record/259538/files/P00021565.pdf

I don't know the superconductivity mechanism here (does anyone?), but IIRC Cooper pairs in BCS theory can be separated by much larger gaps than the transistors in a modern CPU — hundreds, rather than single-digits, of nanometers.

Might make fully-3D processors much more viable though, from lack of heat dissipation; and if it does, that in turn might be able to make up for a coarser resolution.

Also, the transistors themselves generate a lot of the heat... So you still have large amounts of heat to handle even if the interconnect traces are heatless.

undoubtably. We can't make things infinately fast. But being able to put the most powerful desktop processors and graphics cards we have today into a phone would definately be useful, not to mention laptops. It would also dramatically change how server farms work (their existance right now revolves around cooling, they could be so much more dense)

You can't a priori plan out a path to new technology, it's usually surprising. This new category of materials can be a platform for lots of surprising uses

you can just pump electricity into the superconductor capacitor and it wouldn't have any loss it would just stay there until discharge.

Superconductors don't help with this (much - just maybe with the wires leading up to a capacitor). Superconductors allow much better inductors instead. You can also store energy in an inductor, but it's different because in a capacitor the charge stays put and in an inductor the current is constantly flowing.

https://en.wikipedia.org/wiki/Point-contact_transistor

that said, it was still manufactured and sold before being replaced by more "conventional" transistors.

Energy weapons are still mostly science fiction right now. This changes that. Energy storage increases by an order of magnitude and with no resistance you can charge and discharge batteries instantaneously.

Probably some other really interesting uses, but energy weapons is what we'll figure out first. And not just giant ship mounted rail guns—if true this will start a new arms race for personal handheld weapons. No more gunpowder. Think rifles with almost no maintenance. Outrageous magazine capacity with shot capacity limited only by energy storage capacity… which can easily and quickly be resupplied if you are behind a supply line.

For reference, gasoline is 33,000 kJ/L.

https://en.wikipedia.org/wiki/Lithium-ion_battery

1–10 Wh/kg for superconductors, 100–265 Wh/kg for batteries.