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Ask Slashdot: How Would Room-Temp Superconductors Affect Us?
Bananatree3 writes "While we have sci-fi visions of room temperature superconductors like in the movie Avatar, the question still remains: How would the discovery of a such a material impact our everyday lives? How would the nature of warfare change? How would the global economy react? What are the cultural pros and cons of such a technological shift?" And just as important, in what contexts would you want to see it first employed?
From a human perspective I am rather fond of living at or around room temperature.
Not really: radiative emission is the only type of cooling you can get in space. Depending how much power you're bleeding off elsewhere on your ship, it could be quite difficult to keep things suitably cool. Especially considering that any part of your ship facing the sun is going to be picking up quite a high thermal load.
The most realistic answer, but not the one you want to hear, is: Nobody really knows.
If history teaches us one thing than it is that we are horrible at predicting the outcomes of anything major. In hindsight, we can "explain" things, but our predictions suck so badly, it's a surprise we haven't given up on the subject. And that's for both experts and non-experts.
Nobody came even close to predicting the impact of computers. Or electricity. People didn't think WW1 would become the slaughterhouse it did. There are refugees around the globe who are living in "temporary" shelters, waiting to return home because the conflict will surely be over any day now. Some of them have been waiting for a decade and more.
The real impact of this technology, as most, will most likely not be anything that anyone today predicts, but something that someone in the future comes up with that nobody thought of before. That includes the inventors. I don't think Graham Bell ever thought that "please turn off your mobile phones" would be a screen shown in these newfangled movie theatres that just came about in his time.
Assorted stuff I do sometimes: Lemuria.org
While you're correct in the second half of your comment, you are ignoring the very good reasons that are driving our search for a room-temperature superconductor. Without doing the calculations, I very much doubt that there is enough fuel on Earth to lift the entire population into a near-Earth orbit, not to mention the massive amounts of infrastructure required to keep them there, (and breathing).
Therefore, a superconductor which would allow us to eliminate the massive amounts of wastage in our electrical infrastructure is certainly useful. Conveniently, most of Earth is at a "room temperature" or similar, making it a far less arbitrary concept. In terms of effect on everyday life, I like to think that in the long run it'll be beneficial, hopefully removing some of the lack of resources which drives most conflicts. Of course, most of human history is against me on that one, technological leaps like these tend to trigger conflicts in the short term, before providing net benefit to the populations, hopefully we survive the next one.
Laughter is the best medicine, except if you have a broken rib.
Is it hell, space isn't cold, it is inert. I seriously wish people would stop thinking this.
The only way heat gets out of things in space is radiative or an infinitely small amount of conductive.
Direct sunlight on a person would burn them in space, likewise heating up metals and components.
Space is actually probably harder to cool things down in simply due to sunlight.
On earth it is pretty easy to have something in shadow and vented so that an incredible amount of heat is exchanged over to the flowing air.
In space, you can only rely on highly-resistant insulators and/or mirrors to get rid of heat unless you liquid cool things. (which is good too since you can then use that heat inside the ship)
The first use will be warfare as is always the case sadly. You'll probably first see rail- and coil-guns show up. Next you'll find its uses in radars and specifically in trying to make them useless. Then it will proceed into gimmicks for rich people. After that it'll go to civil scientists (space exploration, particle accelerators, ...) and maybe a few years later into people's houses. Somewhere in between all of that somebody might find a use for it in medicine (other than improving your standard NMRI).
OLED monitor floating in midair. pen floating in midair. FLUX PIN ALL THE THINGS
100% computational efficiency, 0% heat release
You can't do that. Any non-reversible computation causes an increase in entropy, and reversible computation is not particularly practical. Achieving practical reversible computation would be a leap at least as large as room temperature superconductors.
Finally! A year of moderation! Ready for 2019?
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This is true but one of the great things about a superconductor is that R (and thus the power dissipated) goes to zero. So while it is difficult to dissipate heat in space, you won't be building up heat in the superconductors themselves.
Maglevs comes to mind - you only once load the magnets along the track, and then they will keep the magnetic field forever.
Imagine roadrails along the interstates which keep the cars on track. Also the hover car will suddenly be feasible - as soon as the car moves forward, induction will load the magnets inside the car and let it hover along the supra conducting magnets in the road. You can see the effect already today at some science shows where they have supraconducting maglevs. Zero friction against the track, just air friction left. One can imagine subways with supracontucting tracks, which work with air pressure along the tubes.
Super strong magnets can be build, which you once load with electricity and which then keep the magnetism forever. Construction could get rid of glue and screws, just put the elements together, load the magnets once, and they will keep everything in shape. You could lock your house with magnetic bars, which once locked, keep tight until you unload the electricity from the bars and they open again.
You could store electricity in giant coils instead of chemical cells, making loading and unloading the electricity much faster, and enabling lots of non-constant electricity creators like windwheels and solar panels to work within a giant grid and finally overcome the problem of the electric base load.
Most people think of superconductors as merely a "perfectly efficient" conductor. While this is true, it just scratches the surface of what's possible with superconductors. Using superconductors just to improve efficiency wouldn't be that big a deal by itself. It would improve battery life a little bit, and maybe drop bulk electricity transmission overheads, but not by much, and certainly not immediately. Making most superconductors into high-tensile wire is a non-trivial exercise, even if cooling isn't a problem -- and it will be! Just because a material is discovered that can conduct at "room" temperature isn't helpful for wire outdoors in direct sunlight, or in a hot environment inside high-temperature machinery. Last but not least, superconductors have current and magnetic field limits that increase as they are cooled past the transition temperature. A superconductor with a transition temperature of 26C would probably have only a few limited applications above 20C.
The other uses are more interesting, and often more amenable to thermal control:
The Meissner_effect provides magnetic shielding, which is useful for all sorts of things, like amplifiers, or for protecting sensitive electronics. This is also what causes magnets to levitate above Type 2 superconductors. I assume that a room-temperature superconductor would be Type 2, so levitation would likely be possible.
The London moment could be used in gyroscopes and the like.
Josephson junctions provide all sorts of functions, like ultra-sensitive magnetic field sensors (think hard-drives and MRIs).
Still, all of that is a bit... meh. I mean sure, you get less noise in your now ultra-sensitive amplifier, and electricity will cost 10% less than it would have otherwise in 30 years. Is this life changing? Probably not really.
A much more interesting potential application than all of those combined is Rapid Single Flux Quantum digital circuitry. That stuff makes silicon look like vacuum tubes. Think 100GHz+, self-clocking, 1000x as efficient as CMOS, and manufacturable now, with only the cooling requirement the big down-side. If RSFQ could be made to work at room-temperature (or even near it), you could be looking at a sudden massive leap forward in computer power like never before. For example, with a power draw 1000x lower, it would be possible to stack every chip in a typical computer into a little "cube", with much shorter wire lengths, and hence, latencies. We can't do this now, because that cube would literally melt in seconds form the heat.
The reality-check of all this is that many MRI machines are still cooled by liquid helium, even though superconductors that work at liquid nitrogen temperatures have been available for a while. This tells you a lot about the limitations that might restrict the application of even a hypothetical room-temperature superconductor. For example, ultra-sensitive sensors and RSFQ may not work at all, because the tiny signal quanta may be swamped by the background thermal noise. Similarly, manufacturability of wire and maximum magnetic field strength is a key requirement for a lot of applications, like MRIs and electric motors.
Personally, I suspect that the first room-temperature superconductor will be initially manufacturable in bulk only as a thin-film, so expect the first decade or two to be mostly about improved circuitry and sensors more than anything else. This might be closer than people think. For example, there's a harmless quack who claims to have achieved superconductivity at 28C by manufacturing extremely complex copper-based crystals as a thin layer between two different traditional copper-based superconductors. Assuming for a second that he's onto something, it gives you an idea
"Therefore, a superconductor which would allow us to eliminate the massive amounts of wastage in our electrical infrastructure "
The wastage in the electric infrastructure, on a whole, is about 7% in the US. Speaking of long-distance transmission only, it's closer to 3%
There's not much to fix here, so unless the new superconductor is also free, I don't think you'd see the massive uptake people imagine.
The main upside would be size, not cost. Assuming it has higher current density, piping power into urban areas becomes easier.
The idea that the superconductor won't be adding to the thermal load is all well and good, but it doesn't cope with the problem of heat that comes in from solar radiation or heat generated by other parts of the ship like engines. Furthermore, it becomes a self-reinforcing problem, because being unable to dissipate heat makes the superconductor stop superconducting, which only adds to the problem.
Virg
First of all, mod+1 for the reference to the minimum amount of heat -- I knew that such a limit existed but it was good to see the estimate and have links to the formal argument and beyond. Second, while we may or may not be able to reduce the heat released from the bits themselves as they change state, room temperature superconductors will still make two very significant improvements in processor design. First, reducing the resistance of everything BUT the bits will reduce the heat released by a chip by a nontrivial amount, rather a nontrivial fraction -- presuming that one can lay down the superconductor in VLSI circuits and mass produce them, as opposed to build them a molecule at a time. Second, electrical superconductors are usually thermal superconductors as well.
It is this latter property that is probably by far the most important. Note e.g. this article: http://www.sciencedaily.com/releases/2003/11/031112072719.htm -- if one were able to make the base of a chip out of a superconductor in good thermal contact with the actual semiconductor matrix a thin film on top of it, and couple that base directly to a superconducting heat sink, one could e.g. produce 10x to 50x the heat in the actual CPU and still remove it fast enough to keep the chip itself sufficiently cool. If the traces within the chip itself were superconducting, if clever use of superconducting material let one reduce the heat associated with switching closer to the limit, so much the better. Ultimately, it would probably mean that one could run chips at higher voltage and higher clock to produce faster reliable switching and still deal with the heat.
I don't have time to do a formal estimate of the speedup possible, but I'm guestimating that a real thermal superconductor -- one with "zero" resistance to the flow of heat -- suitable for use as the base material for a chip would permit a very rapid scale-up of chip speed by up to an order of magnitude in clock or effective clock. It also might make it possible to build a three dimensional CPU -- one reason chips are 2D is so that one can get the heat out; if one had a thermal/electrical superconductor one could in principle stack up layers and scale performance by one or more orders of magnitude, at first multiple cores on steroids but all at much higher clocks, later true 3d design and layout.
In any event, the impact would very probably be profound, at least if the hypothetical RTS was cheap and suitable for nanoscale integration as a substrate and/or trace material (and functioned as a thermal superconductor as well as noted).
Still, I think that simply eliminating resistivity in power transmission would have the greatest societal impact. PV solar power, for example, "instantly" becomes feasible because one can generate in the Mojave and use the electricity in Maine without transmission loss. That isn't huge, that is game-changing enormous. The Sahara become the electrical source for Europe and Africa, India for Asia, etc. Depending on the hypothetical materials magnetic properties (big if, actually!) it may well revolutionize electrical motor design, maglev trains and roadways, and more, but just letting us move power for free to where we use it makes Edison have the last laugh over Tesla -- human civilization can convert to low voltage DC electrical service. A civilization run on 5 VDC would make electrocution a historical oddity from pre-RTS times -- one can manage to kill yourself with as little as 9 volts (see my favorite Darwin Award, "Resistance is Futile" -- http://www.darwinawards.com/darwin/darwin1999-50.html) but 50 mA should be below the fatal threshold even for somebody that tries very hard.
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Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
While these facts may be true on the surface (I haven't actually checked), what you are missing is that most energy production is relatively local, and hence generating capacity is built & run to deal with local maximal demand. Truly efficient long, long distance transmission lines would allow distant capacity to be factored in to the system. Think wind, solar, day vs night etc. There is currently a project (Tres Amigos) designed around a superconducting hub to connect the three major energy networks in the US. In addition there are (at least) plans for several other superconducting trunks, including one to link a number of off shore wind projects. The net efficiency gains for the system as a whole would far exceed the 3-7% mentioned above.
That said, I am partial to local production, as finely grained as possible, to cover the baseline requirements and minimize the opportunity for system-wide failures.
That 7% is transmission loss only. Now consider using it in computing to prevent waste heat from being generated. In radio transmitters for better efficiency. In house wiring. In appliances. In cars. In electric cars. Now you're talking about at least a 50% boost. And that's before you consider using it in electric motors and generators.
If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
You need to have resistance in the actual bits that use the electricity to do something useful. The resistance is the electricity being converted into "useful."
What you don't need is resistance in all the wires that are carrying that electricity around - any resistance there is pure waste, generating heat. And the smaller the wires, the more electricity they waste, which is why processors get so hot.
Motor efficiency would go way high as transducers become more effective, too. Add in transmission line efficiency, less loss from heat transfer, and should the material otherwise have little/no environmental impact, could add huge capacity and make mass transportation vastly more cost-effective through electrically-driven trains and transports overall.
The cost of manufacture of these superconductors and their overall lifecycle costs have to be known, too. Still, very nice to dream about.
---- Teach Peace. It's Cheaper Than War.
In practice, you can cool satellites pretty darned far. WMAP is cooled to 90K passively. Planck is cooled to 50K passively. So yes, it is very possible to cool satellites to within the superconductivity range of modern high-temperature superconductors.
This is an active area of research because at the quantum level everything is reversable. If the hardware implementation difficulties of quantum computers ever get solved, we need to have both theories and "practical" languages to handle it. (By "practical" I mean one that actually looks like programming versus "programming" in terms of Hilbert spaces.)
My understanding is that to implement a hash function you have one of two choices. The first is to pay the "kT" cost by calling the "erase" operator (i.e. pipe it to /dev/null). The second is to have it generate "garbage" bits. These bits provide enough information for the computation to be reversed and are not hard to define (even for something like hash functions). For example, with a hash function, the data from which the hash was computed can be used as the garbage. By carrying the garbage bits around instead of erasing them, you might be able to (1) use them in some other computation, (2) be able to localize where and when you pay the heat cost of the garbage, or (3) be able to cheaply backtract the computation.
If you are interested in this, James and Sabry ("Information Effects" POPL 2012, "The Two Dualities of Computation", etc.) are actively developing the foundational theories of a language for programming in a reversable language (disclaimer: the authors are both personal friends of mine). Their stuff might still be a bit heavy for Joe Programmer, but it should be accessable to anyone familiar with higher-order, typed languages.
The inefficiency of modern digital circuits comes from two things:
1. Leakage through gate oxides (insulators) and switched-off transistors (semiconductor action).
2. Charging and discharging transistor gates during turn-on and turn-off (capacitance).
Unfortunately, superconductors won't help with either of those. Even switching power supplies lose a lot of power through transistor switching and diode drops. For most electronic products, imperfect semiconductor devices are a bigger problem than imperfect conductors.
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Shiny surfaces do not radiate heat well, they reflect heat. Dark surfaces radiate heat, the nature of light generated indicates the real surface area of an object at the molecular level.
The perverse reality is there is no real profitable way to use superconductors. Superconductors save energy, save costs hence as a technology it is to be bitterly opposed by the insanely rich and greedy.
Cheap energy is an anathema to greed. The cheaper the energy, the less psychopaths are able to exclude others from accessing the benefits. In psychopathic capitalism it is all about exclusion, owning beach front to deny others access to the beach, owning all sources of production to deny wealth to others and, owning politicians to deny others access to democracy. Ostentatious egotistic posing (driven by psychopathy and narcissism) only has impact when the majority are forced to live in poverty.
The first use of superconductors is in cheap energy, cheap energy is the enemy of psychopathic exclusivity, so what will happen?
Chaos - everything, everywhere, everywhen