sanctus Posted May 5, 2004 Report Posted May 5, 2004 I know that the He (helium 2 if I remember right) turns into a superfluid if it's colder than 2.2 degrees kelvin. My question is: is there any other known superfluid? Is there any research done on it? If yes, does the theorie predict that there could be superfluids at high temperature?
Tim_Lou Posted May 5, 2004 Report Posted May 5, 2004 hmm, is it that superfluid flows in air?? since He's density is low when cool to a liquid.
sanctus Posted May 6, 2004 Author Report Posted May 6, 2004 I don't know if I understood your question well, but if you wonder what it is then it is a fluid that has no friction: if you have a close tube, you make the fluid turn while it's a normal fluid and then you cool it down so that it becomes a superfluid it will continue turn for hours.
GAHD Posted May 7, 2004 Report Posted May 7, 2004 Yes, they are looking into higher temperature superflluids. It's about the same priority as a room temperature superconductor. BOth are immensely useful, though in different ways.
Freethinker Posted May 7, 2004 Report Posted May 7, 2004 Actually a extremely well chilled vodka shot is MY idea of a superfluid!
Becca Posted May 14, 2004 Report Posted May 14, 2004 If you drop something into a superfluid would it fall with acceleratuin due to gravity because there is no viscosity?
alexander Posted May 14, 2004 Report Posted May 14, 2004 The superfluid transition is displayed by quantum liquids below a characteristic transition temperature. Helium-4, the most abundant isotope of helium, becomes superfluid at temperatures below 2.17 K (?270.98 °C). The less abundant isotope helium-3 becomes superfluid at a much lower temperature of 2.6 mK, only a few thousandths of a kelvin above absolute zero. Although the phenomenology of superfluidity in these two systems is very similar, the nature of the two superfluid transitions is very different. Helium-4 atoms are bosons, and their superfluidity can be understood in terms of the Bose statistics that they obey. Specifically, the superfluidity of helium-4 can be regarded as the generalisation of Bose-Einstein condensation (which takes place only in a non-interacting gas) to interacting systems. On the other hand, helium-3 atoms are fermions, and the superfluid transition in this system is described by a generalisation of the BCS theory of superconductivity. In it, Cooper pairing takes place between atoms rather than electrons, and the attractive interaction between them is mediated by spin fluctuations rather than phonons. - wikipaedia Actually a extremely well chilled vodka shot is MY idea of a superfluid! Good one! Well, it gets you to relax, and works extermely well in the summer... P.S. Did you know that vodka is supposed to consist of exactly 40% of alcohol? A patent filed by Mendeleev clearly states that at that prescise concentration, after drinking vodka at knight you would not have a headache in the morning no matter how much you drank....
alexander Posted May 14, 2004 Report Posted May 14, 2004 Becca Said: If you drop something into a superfluid would it fall with acceleratuin due to gravity because there is no viscosity? I would imagine not; there is a concepr in Physics that says that 2 object can not travel through the same space at the same time, so when something you drop is going to hit the fluid, it will have to push the molecules of the fluid out of it's way in order to get through and thus decelerate (and that has nothing to do with friction). So no, it will not accelerate to a velocity higher than that of an object falling through another gas or vacume, but i think that the speed will be higher than that of an object that falls through water.... Interesting question though.
Freethinker Posted May 14, 2004 Report Posted May 14, 2004 If superfluidity is based on an extremely low temp, based on Alex's post esp. (great post BTW) and the closer you get to absolute zero, the slower the particles move, perhaps the object would not be able to move thru it. The fluid might move over it the way it would flow out of a jar. Just as the reaction of a superfluid to light is like an explosion, the reaction of the superfluid to any other element could be extreme.
Becca Posted October 14, 2004 Report Posted October 14, 2004 Thanks guys. Do you know if anybody ever did an experiment on this? If not, I think someone should.
Recommended Posts