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Nenad
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could somebody give me insight on the subject please.
Nenad said:could somebody give me insight on the subject please.
Gonzolo said:The interesting thing is that when we mean zero, we mean zero.
ZapperZ said:Exactly! These phenomena aren't achieved in a gradual fashion as one varies various relevant parameters like temperature, and the quantities such as electrical resistance just doesn't become smaller and smaller until they are too small to measure (but still non-zero in principle). They are an abrupt phase transition in which the material has undergone a definite change in state. So quantities such as electrical resistance, viscosity, and bulk magnetization would drop abruptly as one crosses over the critical parameter.
Zz.
Nenad said:so can this be acheved over a long period of time. I heard that you attain supeconductivity when you cool certain materials at super low temperatures. How would superfluidity work, and how is it tested?
Gonzolo said:At least one experiment has maintained superconductivity for more than a year.
Electrical currents have been observed to flow without attenuation in superconducting rings for more than a year,
until at last the experimentalist wearied of the experiment.
The decay of supercurrents in a solenoid was studied by File and Mills using precision nuclear resonance methods
to measure the magnetic field associated with the supercurrent.
They concluded that the decay time of the supercurrent is not less than 100,000 years.
kurious said:Superfluidity comes about when all the atoms of helium in a bucket of liquid helium
become one big atom! This happens because the Helium atoms change from being
spin 1/2 particles to spin 1 and obey bose-einstein statistics instead of fermi -dirac statistics.The helium climbs out of the bucket without any help.
Nenad said:that explains a lot, but could you explain the last sentince. I am not sure what you mean.
meteor said:Can Homes's law provide an answer to the mistery of high-temperature superconductors?
http://en.wikipedia.org/wiki/Homes's_law
Superfluidity is a state of matter in which a liquid exhibits zero viscosity, or resistance to flow. This means that a superfluid can flow without losing any energy, even against gravity, and can continue flowing indefinitely without any external force.
Superconductivity is a phenomenon in which certain materials exhibit zero electrical resistance when cooled below a certain temperature, known as the critical temperature. This allows for a nearly perfect flow of electricity, with no energy lost as heat.
Superfluidity and superconductivity are both caused by a quantum mechanical effect known as Bose-Einstein condensation. In this state, particles in the material lose their individual identities and behave as one collective entity, allowing for the unique properties of superfluids and superconductors.
Superfluids and superconductors have a wide range of potential applications, including in medical imaging technology, energy storage and transmission, and high-speed computing. Superconducting materials are also used in particle accelerators and MRI machines.
One of the biggest challenges in studying superfluidity and superconductivity is maintaining the extremely low temperatures required for these states to occur. Additionally, scientists are still working to fully understand the mechanisms behind these phenomena and how they can be harnessed for practical applications.