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A room-temperature superconductor? New developments

science.org

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Re: A room-temperature superconductor? New developments

#731

Post by burnished »

r2_pilot wrote: post #658
Vicinity9635 wrote: post #623

Earlier quoted context omitted.

> The ramifications of the inflection point we are currently at is mind boggling. No joshing, I just got done posting this on facebook: "If this is practical it will change the world like the transistor; maybe more."

Ha, I just posted about a dragonfly I saw while walking, and how it seemed unperturbed by the possibility of room temperature superconductors on Earth. I added that I should probably learn from the dragonfly.

Have you ever seen a dragonfly sit still? I'm just saying, I wouldn't describe them as unperturbed.

Re: A room-temperature superconductor? New developments

#732

Post by whatshisface »

robot_no_421 wrote: post #653
whimsicalism wrote: post #525

Earlier quoted context omitted.

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

You should be measuring that population as a % of their total population. Not sure why you're comparing absolute numbers. China has triple the young people we do, but quadruple the old people that depend on the young people.

Depend on them for what, the cost of a bowl of rice? What is it exactly about 80 year olds that will collapse a country with a brutal government like China has?

Re: A room-temperature superconductor? New developments

#733

Post by petesergeant »

elfbargpt wrote: post #77
7moritz7 wrote: post #17

Earlier quoted context omitted.

I have seen three now from China alone. Plus a calculation from some respected institute from today that confirms the theory

Throughout this whole saga I've had this feeling that at the very least we can rely on China to really pursue this new development to it's logical end. It's kind of sad, but I don't think I can say the same about the US at this moment. You know for a fact China's going to JUMP on this, figure out if it works or not, and iterate.

I think you’re off here. The miracle of America (and the worldwide system of capitalism) is that there exists enough private investment, competition, and appetite for risk to squeeze every iota of gain from this, without explicit government intervention.

China’s growth currently appears magical simply because of scale and a shittier starting point, also a lack of whatever it is that ails India.

Re: A room-temperature superconductor? New developments

#734

Post by tomxor »

heisenzombie wrote: post #659
cogman10 wrote: post #633

Earlier quoted context omitted.

> The efficiency of high voltage AC power lines is limited by capacitive coupling to ground. And to this point, HVDC has been slowly rising as a viable alternative beyond just undersea transmission. A mistaken belief is that AC is more efficient than DC. What AC is is more easy to transform from one voltage to another (until somewhat recently). That makes it easier to run AC at 1 MV and then step it down to 240V for…

Minor nitpick — "now we can run 1 billion amps at 100V" — there is a limit to how much current you can put down a superconductor. For example I think commercial YBCO superconductor tape will do roughly 1000A/mm^2 (and even that requires being significantly below its critical temperature). That’s a pretty high current density compared to what’s feasible with copper — don’t get me wrong — but a billion amps would still…

Presumably everything in the chain, every junction, would also need to be a pure super conductor? Anything else would be susceptible to instantly melting or vaporising.

So unless someone comes up with super conducting welding I guess that would mean no junctions.

Re: A room-temperature superconductor? New developments

#735

Post by Beldin »

sheepscreek wrote: post #644
fsh wrote: post #516

Earlier quoted context omitted.

None of the things you listed are limited by the conductors in them. The efficiency of high voltage AC power lines is limited by capacitive coupling to ground. Battery charging is limited by the cell chemistry. CPU heat output is limited by the resistance of the semiconductors. Turns out metals (in particular copper) are already incredibly good conductors.

But it is. A significant part of electronics engineering is dedicated to heat dissipation. So what do we stand to gain? At least a slight improvement in efficiency of transmission. And a huge improvement due to simpler heat dissipation needs. So this might mean way faster battery charging - like 500 miles worth of charge in 5 mins. We’re mainly limited by how hot the batteries get during charging.

We're about halfway there already, just by cooling: 250km in under 4 min (1).

(1) https://www.tue.nl/en/news-and-events/news-overview/13-07-20...

Re: A room-temperature superconductor? New developments

#736

Post by yinser »

bobsmooth wrote: post #710
keepamovin wrote: post #691

Apart from levitation and resistance, free conductivity, what are superconductors really good for? Like how could an iPhone become better with super conductive room temperature materials?

Imagine if every doctor's office had an MRI machine and they were a fraction of the size they are now.

And they had 12x the resolution.

Re: A room-temperature superconductor? New developments

#737

Post by skykooler »

XorNot wrote: post #613
therein wrote: post #590

Earlier quoted context omitted.

We already have incredible supercapacitors. https://www.eaton.com/gb/en-gb/catalog/electronic-components... I have 4 at home and blows people's minds when you melt a wire with it. Incredible rapid current delivery.

They don't store any meaningful amount of electricity (which is why they haven't supplanted Li-Ion batteries for power tools) and more importantly they have a cycle-life - they degrade from usage (source: my wife works for a supercapacitor manufacturer). You also get losses from practical usage - i.e. no one can build a 3V supercapacitor that has decent endurance (you can totally build one which will work, but you're…

Why do cycles damage supercapacitors? My understanding is that in batteries this is caused by ions not returning to their original spot in the electrodes, but I thought only the electrons moved in capacitors?

Re: A room-temperature superconductor? New developments

#738

Post by rtsil »

r2_pilot wrote: post #658
Vicinity9635 wrote: post #623

Earlier quoted context omitted.

> The ramifications of the inflection point we are currently at is mind boggling. No joshing, I just got done posting this on facebook: "If this is practical it will change the world like the transistor; maybe more."

Ha, I just posted about a dragonfly I saw while walking, and how it seemed unperturbed by the possibility of room temperature superconductors on Earth. I added that I should probably learn from the dragonfly.

I'd be terrified if I was the dragonfly. Its life and the lives of all other living beings depend more on what we do with our technology than on anything else.

Re: A room-temperature superconductor? New developments

#740

Post by kragen »

dharmab wrote: post #721
kragen wrote: post #714

Earlier quoted context omitted.

soap is a good one for sure; the others might turn out to be less important than the transistor time will tell

Haber-Bosch is the reason there are over 7 billion humans on Earth instead of closer to 2 billion. It's very difficult for any digital technology to compete with that.

agriculture is the reason there were 2 billion instead of 20 million, which is a much bigger difference

it seems likely that digital technology will be crucial in enabling there to be far more humans off earth than on earth; o'neill cylinders could enable many orders of magnitude more physical humans even within this solar system

to say nothing of the possibility of backing up your mind with a brain scan and thus becoming immortal, and possibly forking into more copies of your mind than there are humans alive today

(nitpick, transistors aren't digital)

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