Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

A room-temperature superconductor? New developments

science.org

Post reply on HN
Print view View original

521–530 of 821 posts

Re: A room-temperature superconductor? New developments

#521

Post by highwaylights »

derefr wrote: post #451
postmodest wrote: post #442

Earlier quoted context omitted.

Wouldn't the battery itself still have resistance? Or is the superconducting material itself a battery?

Depends. A single battery cell would have nontrivial resistance, yes. But a big bank of batteries, like are in an EV? Very hard to give them enough current to heat them up. Most of the "heat problem" is from the bottlenecked current path into the car; once you fan out across all the individual cells, each individual cell isn't receiving much current. And a bank of supercapacitors? You could charge it effectively inst…

Additionally you need to have the current to deliver in the first place. Having a grid that can dump 25-100 kwh into any given car in a couple of minutes is no small task if everyone is doing it.

Re: A room-temperature superconductor? New developments

#522

Post by ars »

andrepd wrote: post #391
Teever wrote: post #353

Earlier quoted context omitted.

We'll use them to build spacecraft that retrieve asteroids so rich in gold that it permanently crashes the price of gold? People don't seem to realize how radically society will change if this superconductor thing is legit.

How does room temperature superconductivity lead to the feasibility of asteroid mining? Could you please explain?

Magnetic launch. See: https://en.wikipedia.org/wiki/Mass_driver

Re: A room-temperature superconductor? New developments

#523

Post by whimsicalism »

scrlk wrote: post #392
ajuc wrote: post #366

Earlier quoted context omitted.

They were underachieving for 2 centuries, ceasing to kill their own citizens by millions and imprisoning anybody who tried to think for themselves is enough to grow if you did so for a long time. But it does not make you a new hegemon. I highly doubt they can preserve their pace of growth for next few decades without significant changes to the regime and liberalization. Once they return to the mean - they will very l…

> I highly doubt they can preserve their pace of growth for next few decades without significant changes to the regime and liberalization. "Demographics is destiny" also comes to mind. Note how the era of "Japan Inc." during the 1980s was also the time when the post-war baby boom population were in their 30s-40s (i.e. peak productive worker population). As this cohort has aged and are now in retirement, Japan's econo…

The difference with the Japan case is that China is going to have a larger base of young, very well educated people than the US for at least the next century unless something changes dramatically with either birth rates or immigration.

Re: A room-temperature superconductor? New developments

#524

Post by MayeulC »

baq wrote: post #455
hinkley wrote: post #153

Earlier quoted context omitted.

I saw a video the other day that pointed out that the breakdown current for their sample was 260 mA. Now there's a lot of things you can do with 260mA, but I don't believe high-tesla electromagnets are in that list, so no MRIs, no fusion, and probably no electromotive devices (generators, motors).

I assure you if 260mA room temperature and pressure superconducting wire can be consistently produced we’ll be living in the future.

> we’ll be living in the future

This is a tautological statement if I ever saw one!

Re: A room-temperature superconductor? New developments

#525

Post by whimsicalism »

pizzalife wrote: post #517
missedthecue wrote: post #464

Earlier quoted context omitted.

Median age China, 2022: 38.5 Median age USA, 2022: 38.9

Look at the actual age distributions rather than collapsing the data into a single number. https://en.wikipedia.org/wiki/Demographics_of_China https://en.wikipedia.org/wiki/Demographics_of_the_United_Sta...

I see a country with triple the young people we do.

Re: A room-temperature superconductor? New developments

#526

Post by TheAceOfHearts »

greggsy wrote: post #406
epistasis wrote: post #363

Earlier quoted context omitted.

I would expect to see such failed replications even if LK99 is the real deal. Getting the exact conditions correct for any sort of novel lab science is non-trivial, and often times the crucial variables might not even be measured in initial publications. People use this fact to try to bash things like cancer research, but it is unfortunately just a fundamental problem of science. Scientific publications are not kerne…

These are just as important as successes, as they build knowledge about what is not possible.

Always gotta be careful about what we record as not being possible though. Just because some research claims something isn't possible doesn't always guarantee the claim is accurate. If some factors are mistakenly overlooked, it's entirely possible that something which is actually doable becomes regarded as impossible.

Re: A room-temperature superconductor? New developments

#527

Post by jacquesm »

fallingknife wrote: post #519
jacquesm wrote: post #478

Earlier quoted context omitted.

> you can make the wire as thin as you want No, superconductors have a specific current above which they stop superconducting so you will want to stay away from that limit. This particular superconductor has been presented with a very low Ic (150 mA in the original paper0 which would not make it particularly useful in such applications but future iterations (assuming it is all true) may improve on that (they should o…

I assume this would rule out things like fusion reactors, MRIs, and other high energy stuff. Would it still be revolutionary tech with a 150 mA limit?

Yes, it would be upending just about everything because the race would be on to improve on that. Think of it this way: once you show that something is possible at all there will be substantial funding available to improve on it. As long as you can't show that it is possible at all you're on your own. So if it works and that 150 mA is the limit then you can expect a ton of effort to be expended to improve on that and I fully expect those improvements not to take decades to show up. The more interesting question is if it really is that low of a limit what the reason is for that and I don't recall seeing any explanation so far.

On another note: a superconductor that can only do 150 mA / cm^2 seems intuitively strange, as though that figure is somehow off, it's a gigantic cross section for such a small current. It is very well possible that this is somehow an error in the reporting or an actual measurement on a thin sample with small cross section. So there are many explanations possible and only one of those is a true limit of the material.

Re: A room-temperature superconductor? New developments

#529

Post by marcosdumay »

klysm wrote: post #422
jtchang wrote: post #418

The ramifications of the inflection point we are currently at is mind boggling. I had a hard time explaining this last night but we may very well be witnessing the beginnings of a technological transformation era much like when the p-n junction was invented. From the 1940s standpoint it would be hard to envision all we had today. - Lossless transport of energy - Batteries that don't take any time to recharge - Faster…

> Batteries that don't take any time to recharge Huh? Is this actually a thing that this enables? I don't initially see how

Nah, the GP is just completely out of reality.

We won't see lossless transmission in a very long time, and no place where an aluminum cable is too expensive today will become viable because something a million times more expensive is 9% more efficient.

Batteries won't see a revolution because of this, there's simply no reason for them to (but they are currently in a revolution, and there are more to come). AC storage in the superconductor will probably be the most expensive storage mechanism you can buy, and flywheels will keep having atrocious energy density, they won't even get twice as good. But it will completely revolutionize some niches in storage.

This won't replace metal layers in CPU for a really long time. Superconductors are hard enough to make, CPUs are absurdly hard to make, and the wins on power savings aren't very large. If people make superconducting chips, it will be ones where the superconductors do active switching, what is much farther away and can enable much faster CPUs too.

I really wish people would stop repeating those. If you are going out of your way for an outlandish claim, I'm much more interested on discussing if this can replace rockets for near Earth space travel than those absurd costly low gain things.

Re: A room-temperature superconductor? New developments

#530

Post by panax »

codeulike wrote: post #161
digdugdirk wrote: post #25

Earlier quoted context omitted.

It's a conductor of electricity. But super good at it. i.e. - It has zero resistance to electricity. Currently, the best superconducting materials we can create have to be chilled to near absolute zero, which means designing them to work in liquid helium baths. This is expensive, and difficult. If a material can superconduct at room temperature, now we're talking usage in general purpose consumer goods. As for why we…

Would help with fusion, right?

The limiting factors for superconductors in fusion power generation efficiency is the strength of the magnetic field they can generate which is limited by how much force the superconductor can withstand since the strong magnetic field induces enormous forces on the material. It also requires very high currents. This material seems fragile and can carry very little current.
Post reply on HN