Comandante Posted February 17, 2005 Posted February 17, 2005 About an hour ago I saw something quite interesting on one of the science channels. An experiment with superconductor, liquid nitrogen and a magnet was done - and it was amazing. What they did is put this 1inch circular superconductor in place and then poured liquid nitrogen over it and after that they put this little cubic magnet on top. What happened is that the magnet was hovering above the surface of the superconductor and it was suprisingly stable, it could even keep spinning in the 'air' above the surface at about 2cm... It might be that you have already seen this but it's the first time I see it and I have no idea of how it works, so I thought if anyone could fire a few words about it ps. Also, I do not know if this is related more to physics or chemistry, or maybe both, but since it involves superconductors and magnets I'll leave it here. Anyway, here are some pictures; http://www.fieldlines.com/other/superconductor.html
5614 Posted February 17, 2005 Posted February 17, 2005 It is, I believe a demonstration of the Meissner effect, I'm affraid I can't tell you a lot about it, so look here: http://en.wikipedia.org/wiki/Meissner_effect
YT2095 Posted February 17, 2005 Posted February 17, 2005 my understanding is that the permanent magnet induces an electrical current in the super con, the super con then in turn converts this into a magnetic field in opposition to the perm mag that created it and so it repels it. since this action is dynamic as opposed to the forces in 2 perm magnets that have a tendancy to flip over and stick together when trying such a ballancing act, were the perm magnet to flip over above the super con, the same action would take place and it would still be in opposition, and thus stay aloft. I realise this is very simplified, but so am I
Comandante Posted February 17, 2005 Author Posted February 17, 2005 i sure will remember the name meissner effect, quite fascinating, i wonder if it could be done in a larger scale... i'm going to have to buy one of those kits for the experiment, cant wait to test it myself
Comandante Posted February 17, 2005 Author Posted February 17, 2005 oh, thanks YT2095, nicely explained - now i have some idea of how it works
5614 Posted February 17, 2005 Posted February 17, 2005 cant wait to test it myself the stronger the magnet stronger the magnetic field but the smaller the magnet weighs the higher it can be lifted... in other words a small piece of a powerful magnet. the NIB ones they sell are powerful (the most powerful natural magnet), they do break quite easily, maybe not with your hands, but easily for a chunk of metal, so if you broke a little chunk off you could see the difference. Remember you dont have an unlimited supply of liquid nitrogen, so have a camera ready, you'll probably only get a few chances.
5614 Posted February 17, 2005 Posted February 17, 2005 you already know the results... it was photoed on the orignal site: http://www.fieldlines.com/other/superconductor.html What they are selling is an exact replica, it will probably look and the same and will certainly have the same effects.
Comandante Posted February 18, 2005 Author Posted February 18, 2005 you already know the results... it was photoed on the orignal site:http://www.fieldlines.com/other/superconductor.html What they are selling is an exact replica' date=' it will probably look and the same and will certainly have the same effects.[/quote'] yeah i do, but i'm not eager to do it because i want to find out the results they already found, i want to see it myself and try to add a few other things to the experiment ... the only problem is that i don't have enough equipment at home, in fact i have almost no equipment at all so it's probably going to take me a while to set this thing up... oh, and those containers for liquid nitrogen are fairly expensive... if i manage to get everything i need i'll post my results here, but nothing's guaranteed... oh, and if anyone else tries this one at home please share your results
labview1958 Posted March 13, 2005 Posted March 13, 2005 How small can a NIB magnet be? How small a superconductor can go? Anyone tried using the smallest NIB and the smallest superconductor?
YT2095 Posted March 14, 2005 Posted March 14, 2005 "small" could be down to the molecular level if you wanted to go that far, not very practical to handle though
labview1958 Posted March 15, 2005 Posted March 15, 2005 "SMALL" here means how small can be made in a factory or lab at a reasonable price say not more than US100 dollar a piece. How "small" a NIB magnet and a superconductor can go and still show MESINER effect?
Comandante Posted March 22, 2005 Author Posted March 22, 2005 hmmm, still haven't done it... cant even afford 1hr of time to do it.. i think i'll use schools' lab to try it out,if they let me... hopefully.
labview1958 Posted April 11, 2005 Posted April 11, 2005 I intend to make a superconductor. Where can I get the superconductor powder not a disk? I want to use the powder to custom make my own custom disk.
YT2095 Posted April 11, 2005 Posted April 11, 2005 sounds tricky! are you going to use some sort of Binder?
Johnny5 Posted May 5, 2005 Posted May 5, 2005 Anyone OUT there? What do you want to make a superconductor for? Regards
labview1958 Posted May 10, 2005 Posted May 10, 2005 I want to levitate a magnet on a superconductor. Out of curiosity I want to know whether the height of levitation varies with different superconductors. My hunch is that for the SAME magnet but DIFFERENT superconductors the height of levitation is the same. Is that TRUE?
Klaynos Posted May 11, 2005 Posted May 11, 2005 It depends on how well the superconductor reacts to the drop in temperature, which I belive changes between differnt types so for differnt superconductors the resistance to it's electron being induced into a current will be different and therefore the B fields induced by the flowing current will be different, if you can work out the resistance for different temperatures and use differnt liqufied gases and mixes of them to get different superconductors to the same resistance then the height would be the same. Or at least that is my interpritation of my sketcy understanding of it
nomadd22 Posted May 12, 2005 Posted May 12, 2005 I don't think the type of superconductor will matter. You can think of the superconductor as sort of a magnetic mirror. It puts out a magneting field the same polarity and strength as the magnet near it, so they repel. The height should mostly depent on the strength of the magnet and how much it weighs. Assuming that it's small comapred to the superconductor disk.
labview1958 Posted May 14, 2005 Posted May 14, 2005 If the magnet is small compared to the disk then the height of levitation would always be the SAME for the same magnet but different types of superconductors which exhibit the meisnner effect. Is there any good theory or experimental data to back this hunch?
5614 Posted May 15, 2005 Posted May 15, 2005 If the magnet is small compared to the disk then the height of levitation would always be the SAME for the same magnet but different types of superconductors which exhibit the meisnner effect The magnet's weight and magnetic field are the main things which effect it. More weight means it's harder to lift... stronger magnet means more induced current, so more lift. As for the superconductor itself, I'm not sure, although I would assume they are all similar.
labview1958 Posted May 26, 2005 Posted May 26, 2005 I want to levitate a type 2 superconducting disk between two permanent magnets. One magnet is below the superconductor and one is above the superconductor. Here is a sketch. S magnet N N superconductor disk S S magnet N Is it possible? If the lower magnet is glued to a table and the upper magnet moved further up, would the superconductor move up or down?
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