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Supersolid Created from Helium-4

Discussion in 'Serious' started by Astrum, 15 Jan 2004.

  1. Astrum

    Astrum Dare to dream.

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    Researchers in the United States think they have found a new state of matter - a supersolid.

    If their findings are correct, this state is deeply bizarre. Although it is a crystalline solid, it can 'flow' like the most slippery liquid imaginable - in fact, like a liquid with no viscosity.

    Liquids that can do this have been known about for years. They are called superfluids, and because they have no viscosity they behave in strange ways. Once stirred, a superfluid will keep swirling forever, whereas a vortex stirred into a normal liquid will eventually exhaust itself and disappear. A superfluid will even creep up the side and out the top of a container.

    The first two superfluids made by researchers were created using helium-4 and helium-3. Both need to be cooled close to absolute zero (-273 °C) before their superfluid behaviour appears.

    Eun-Seong Kim and Moses Chan of Pennsylvania State University now claim to have turned frozen helium-4 into a supersolid1. They did this by filling the narrow channels of a porous form of glass (called Vycor) with helium, and freezing it by cooling it down and squeezing it to more than 60 times atmospheric pressure. A disk of the helium-filled glass was then set spinning. At about 0.175 °C above absolute zero, the disk suddenly started to rotate more easily - precisely what would be expected if the helium became a supersolid.




    The rest of the article can be found here.

    This is quite interesting. Superfluids are exciting in their own right, but supersolids open up quite a number of doors. But what is a supersolid? I noticed the article didn't really explain it much, infact it explained what a superfluid was more :rolleyes: . From what I gather it's a solid that can propagate waves without dampening, much like a superfluid can swirl without slowing in a bowl.

    This also has other implications. If this can be proven to be a supersolid it would show that Bose-Einstein condensation can happen for all states of matter.
     
  2. AcEmAsTr

    AcEmAsTr Banned

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    thats amazing!! especially the fact it doesnt stop swirling!
     
  3. RPC_Student

    RPC_Student Banned

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    Aha!!!!!!

    and they said perpetual motion wasnt possible...
     
  4. fump

    fump What's a Dremel?

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    supersolids sound cool, as do supersolids. makes hydrodynamcs so much simpler.

    1x10^9 rpm hard disks are winging their way into the shops rite now!!!!
    :D
     
  5. Guest-16

    Guest-16 Guest

    Regardless of the fact that this technology is useless in anything other than a lab or specialist industrial environment. Near absolute zero sustainability isnt easy or economically viable on a long term basis.
     
  6. Astrum

    Astrum Dare to dream.

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    Not useless, undeveloped ;) .
     
  7. Altron

    Altron Minimodder

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    If they got the superfluid all the way down to 0K (which is nearly impossible) would it stay as a superfluid or would it freeze?
     
  8. Astrum

    Astrum Dare to dream.

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    So if you simply bring helium down to absolute zero it won't freeze. Isn't quantum mechanics great?
     
  9. Malvolio

    Malvolio .

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    Well, the best I could guess is that it has no friction, just like the superliquid doesn't have any viscosity (basicly friction) So, they say that the supersolids are basicly the same thing, one would have to assume that they are reffering to the whole lack of friction thing. And in a case like that, just think of what it could do. Think of how powerful your motor could be if it was made of supersolids? Or fans ("we don't need no stinkin bearings!")? Something like this (if they could get the supersubstances to remain in their forms under normal tempuratures) could totaly revolutionize metal as we know it. Nothing would be the same.
     
  10. Guest-16

    Guest-16 Guest

    Nobody knows, its a physical impossibility - you have to put energy in to take energy out. Absolute Zero is where no energy exists - no motion/vibration/ossilation - no thermal energy.

    AstrumPreliator - i meant currently useless ;)
     
  11. jonesie

    jonesie What's a Dremel?

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    Well, you've got an article called 'Probable Observation of...' written by a physicist, which is never a good. I got hold of paper the article is based on as i'm within a uni network (so I'm not going to post a link, even if you guys wwere actually interested :) However it is 0130 AM and I have been reading about quantum computing all day, so my brain has switched off. suffice to say it has something to do with 'torsional oscillator measurements' and drops in rotational inertia. All together now, "Que?" :lol:

    A major point you've got to understand is that at almost Absolute Zero things start behaving very weirdly as you come up against fundamental limits of one kind or another. It's one of those times you stop explaining and wing it with maths.

    Apart from the fact that it's damn difficult to get anything that cold anyway, it also means that a lot of these effects simply cannot exist at room temperature. So dont stop buying grease yet.

    But like a good scientist I wont mind being proved wrong... :geek:
     
  12. Guest-16

    Guest-16 Guest

    So i know very few good scientists then? Clever ones, not good..
     
  13. jonesie

    jonesie What's a Dremel?

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    touché... :lol:
     
  14. phaSe

    phaSe What's a Dremel?

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    well theres a whole lotta science in this one!

    firstly, the superfluidity of He3 and He4 are due to different effects, althouhg they appear the same:
    He4 is a boson, and when its superfluid its a liquid form ofBose-Einstein condenstaion,
    He3 superfluidity is more similar to superconductivity and is a state where the He atoms form Cooper pairs.

    In this case they are using He4, so are excited as they think they have discovered Bose Einstein condensation in a solid (it has previously only been in a solid or gas)

    As AstrumPreliator you cant just 'freeze' helium by cooling it, you need enormous pressures as well as being close to Absolute Zero, and in anycase, no-one has actually managed to freeze pure He4 in a bulk solid (ie just a lump of it) so these guys have used something called Vycor (sounds similar to aerogel for those who know what that is) to induce solidification (!) in the helium.

    They then tested how easily a disk of this vycor and solid helium moved, ie seeking a loss of friction underneath a certain transition temperature (as is seen in superfluidity). They discovered that under 0.175 degrees above absolte zero the disk moved more easily. Implying a supersolid state.
    They also checked that there results werent due to any other effects (such as a superfluid film on the base of the disk, etc and believe they are due to a supersolid)

    Currently supersolidity (as if thas a word! :hehe: ) is much more an intersting bit of physics than anything useful, so sadly we are gonna hold off on frictionless fans and hdd for a while!

    i hope this vaguely makes sense, and sheds a bit more light onto what the article is actaully going on about!:idea:

    RoB
     
  15. Confusitron

    Confusitron What's a Dremel?

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    Just think of how efficient motors would be. If we use Hydrogen fuel-cell engines and use this as a lubricant, then it would probably be the most efficient engine ever. If we could master it, the excess water (contains Hydrogen) from the engine could be recycled and used again in the engine. The car would basically never stop.

    These are definitely exciting possibilities.
     
  16. Altron

    Altron Minimodder

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    Well, damn, I posted here because I thought I had pretty good knowledge of science.

    Now I feel stupid :lol:

    How would the fuel cell keep it at 0.1* K?
     
  17. jonesie

    jonesie What's a Dremel?

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    I think he's refering to the new fuel-cell engines that generate electricity by recombining water from oxygen and hydrogen. BMW have some new fuel cell 7 series cars. So Confusitron isnt suggesting he's solved the cooling problem (I still reckon it cant be done/wouldnt be worth doing).


    Hey, dont sweat it, I think at least 3 of us are at uni studying physics or something related, and even we dont totally know what's going on! (NB not trying to be patronising here!)
     
  18. Altron

    Altron Minimodder

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    Ah yes, forgot we have physicists here. Now I feel smart again :hip:

    Unless we find a efficent method of breaking down water, I don't think the endlessly moving car would work well. Breaking down the water into hydrogen and oxygen (with electrosys I would assume) would probably use up a high percentage of the energy output by the fuel cell. Thus if you only got 20% of the power out of it you'd need a much larger fuel cell, resulting in a very large engine to pwoer a small car.
     
  19. jonesie

    jonesie What's a Dremel?

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    Well, there's the Law of Energy Conservation that says you dont get something for nothing, so the best case you could ever hope for in the electrolysis to get back to where you started, i.e. x amount of hydrogen and y amount of oxygen. to do this the absolute minimum amount of energy you would require by the above law is all the energy that came out when you used the fuel cell. In other words your car could go nowhere.

    And this is assuming all your processes are 100% efficient. Besides friction etc there is also another issue involving the laws of thermodynamics, which says that there is a fundamental limit on the efficiency of any process involving heat transfer (even if that transfer is not immediately obvious). if this applies there is no way you could get back to where you started, and this is one of the most fundamental arguments against perpetual motion. :sigh:

    However unfortunately I dont have the time or inclination atm to explain how the laws of thermodynamics apply here, so if someone else will oblige? :)
     
    Last edited: 19 Jan 2004
  20. phaSe

    phaSe What's a Dremel?

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    jonsie - beat me to it funboy! :D

    And of course one of the main benefits of a hydrogen fuel cell is that it uses hydrogen, the most abumdant element in the universe, so breaking down water to get it is somewhat counter productive!

    RoB
     

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