In thestockbrokers defence, he already covered that, and he's right. If we could get ductile superconductors we'd be using hydrogen in our MRI's and NMR's in a flash.
Literally! So the problem is that the current generation of superconductors don't work correctly at a balmy 20 K?
Yup got that.... Is that the issue though? Current superconductors need to be around 5K to work? Just curious its not my area of expertise.
From what I can tell is that while high temperature superconductors are feasable thy're just not practical for use in these situations.
On its own the He wouldn't escape at all, as you correctly said the escape velocity is nowhere near high enough. But once it gets up into the outer atmosphere (which being so light, it does) statistically some of it is hot enough to escape (tiny proportion), there's a half-decent wiki page about atmospheric escape and if you're really keen there's quite an interesting paper on it here, although it's primarily aimed at exospheres.
Yes and no. The superconductor I produced works at about 80K, that's hot enough that you can do it all with liquid nitrogen. The stuff I made was a brittle ceramic though. We need our superconductors in NMRs and MRIs to be ductile. Imagine trying to make wires or string out of the clay and you're approaching understanding of the problem. For the time being we can't make the superconductors we need for MRI and NMR work at high temperatures, or even liquid hydrogen temperatures.
I'm always happy to be educated; and given that I'm sitting here wondering what in my experience has ever become more ductile by getting cooler, this probably demonstrates my lack of knowledge in the matter even at it's most basic level! I also hadn't considered the temperatures in kelvin, where yes, it does cause the figures to appear a little more dramatic.
Sorry, there's no way of saying that, it's just scientists have been working on superconductors which'll work at high temperatures for about 40 years now, entire careers have been spent on producing materials which'll superconduct at higher temperatures and also be ductile and to them I expect 16C is rather a lot xD.
From a personal standpoint I don't disagree with you, but I also don't disagree with the other things highlighted by people; food, water, power. The list goes on. I have to 'spread the word' as part of my job though, and thanks for moving this to SD rather than in the thread. To continue though, where do you draw the line? We spewed out 20 litres in a matter of minutes today, but how many people do Extreme OCing versus the balloon industry? There have been a total of 3 LHe events globally so far, which is a drop in the ocean versus the global infatuation of filling coloured plastic bubbles. Are they not a waste? (All I will say is get ready for more LHe extreme OCing, because we just heard the other mobo players are getting interested too.)
How about casting them into hollow coil-shaped molds? It sounds so obvious that I'm sure it's been considered and rejected for a whole host of practical reasons.
Not sure to be honest, that's getting into engineer land so my knowledge drops off. All's I knows is despite 40 years of very active research, because we haven't found a high temperature ductile superconductor, we need our helium.
What about reclamation? I'm taking off a couple of hundred pounds of aluminum right now (it's not even all I have) to be melted down (100% reclamation rate cheesecake) and it just made me think, can't we reuse some of this?
The helium? To an extent we do, we recycle it where we can (mostly, I'm looking at you wasteful physicists!), but once it hits the air it's gone, as I said, damn stuff just wanders off into space.
Spec, Do you not have Helium recovery plants at your universities across the pond? Both of the universities I have gone to here in the US have Helium recovery units within the the physics building for use on the particle accelerators and for other experiments with that contain helium. It seems that it should be commonplace to put these throughout the research universities to help drive down costs and reduce helium escape and purchases.
At least when my family has balloons at parties they're filled via people power, i.e. lungs. It's a tough situation to be in. At the rate the world is using up various resources, it makes you wonder what else we might be able to do if only we used them wisely.
I'll have to admit that HE party baloons seem a aways seemed a bit frivolous. But had anyone got any up to date figures on usage levels? If party baloons are a piny fraction of consumption I can't get too stressed.
A contrasting opinion on the impact of party balloons: If the amount of helium used by party balloons was actually a significant portion of total helium usage and helium was becoming less plentiful wouldn't prices become too high for the typical party balloon customers because other users of helium would also be trying to buy out that share of the market? I can't claim to know the price of a helium filled balloon now and in the past but certainly it's not gone up by an unreasonable amount as they're still quite available. Because of this I can only assume that they aren't a significant impact on helium supplies. Of course, the fact that every bit counts as Elton says would still say that they're a complete waste no matter how little impact they have. Is even 1% of the world's helium supply really needed to watch some rubber float? Not in particular. But that gets into the issue of conserving resources when they're not totally needed: not something many people are a fan of.
