Most of the conductors we use in our daily life are metals such copper wire. While these conductors are useful in many applications, they are not perfect as they have at least a small amount of resistance, which implies that some of the current is wasted. However with a special type of conductor (superconductor), this is not true.
The rationale behind a superconductor was put forward by a Dutch physicist Heike Kamerlingh Onnes. He postulated that the resistance of a conductor at a low temperature would be less than at room temperature because there would be less vibration in the atoms and molecules; note, all atoms and molecules are in motion, even in a solid material, and the amount of this motion depends on the temperature. But Onnes unpredictably discovered that at the freezing temperature of -451.8 °F (-268.8°C), the mercury he was working with, which was a solid at that temperature, suddenly lost all of its resistance. At this temperature it became a superconductor, that is, there was no resistance to the flow of charges.
Because a superconductor has no resistance, once a current is set into motion it will flow forever. Superconductors are especially useful materials since none of the energy of the moving charges is lost.
The aspiration of building electrical circuits with superconductors is not yet achievable because whereas many substances display the property of superconductivity, they do so at exceptionally low temperatures. Above a certain temperature they are normal, resistance-bearing conductors, and below that temperature termed to as the critical temperature, they are superconductors. Cooling a substance is more expensive than the loss of energy due to the resistance of room-temperature conductors, so it is not yet cost effective to employ superconductors in our typical circuits. This is an area that is still under research; therefore anything is possible in the future with regard to superconductors.
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Superconductors are used in a device known as a superconducting quantum interference device (SQUID). SQUIDs are sensitive detectors of magnetic fields, for example, they are employed in detection of tiny magnetic field on a human head. The measurement of these small magnetic fields is called magnetoencephalography. Most of these applications use the lower-temperature superconductors.
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The development of superconductors at room temperatures or higher would allow many more applications for example, electronic circuits could be made smaller and much more efficient. Our electricity utility companies could transport power with no losses; this in return, will reduce the cost of electricity.
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